JP7243993B2 - A position estimation device, a program to be executed by a computer, and a computer-readable recording medium recording the program - Google Patents

Description

The present invention relates to a position estimation device, a program to be executed by a computer, and a computer-readable recording medium storing the program.

Conventionally, the method described in Non-Patent Document 1 is known as a method for estimating the position of a terminal device that transmits radio waves.

The method described in Non-Patent Document 1 is a method of estimating the position of a terminal device by back-calculating the propagation distance of radio waves from the amount of attenuation of radio waves based on a propagation loss model of radio waves.

Also, a method described in Non-Patent Document 2 is known as a method for estimating the position of a terminal device that transmits radio waves.

The method described in Non-Patent Document 2 is a method of learning a position estimation model using the received signal strength RSSI (Received Signal Strength Indicator) of a plurality of transmitting/receiving stations as a feature quantity, and estimating the position using the learned model. be.

https://ipsj.ixsq.nii.ac.jp/ej/index.php action=pages_view_main&active_action=repository_action_common_download&item_id=105592&item_no=1&attribute_id=1&file_no=1&page_id=13&block_id=8. Yiu, Simon, et al. “Wireless RSSI fingerprinting localization.” Signal Processing 131 (2017): 235-244.

However, the position estimation methods described in Non-Patent Documents 1 and 2 have the problem that pinpoint position estimation requires three or more measurement stations arranged at three or more positions.

Therefore, according to the embodiments of the present invention, there is provided a position estimation device capable of estimating the position of a terminal device that transmits radio waves using less than three measuring instruments.

Further, according to an embodiment of the present invention, there is provided a program for causing a computer to estimate the position of a terminal device that transmits radio waves using less than three measuring instruments.

Further, according to an embodiment of the present invention, there is provided a computer-readable recording medium storing a program for causing a computer to estimate the position of a terminal device that transmits radio waves using less than three measuring instruments. do.

(Configuration 1)
According to an embodiment of the invention, a position estimator comprises first and second measuring instruments, a detector, processing means and estimating means. A first measuring instrument indicates the elapsed time dependence of the first received signal strength when receiving radio waves in a communication environment in which the shielding/non-shielding of radio waves transmitted from a terminal device changes with elapsed time. Measure the received signal strength timing chart. The second measuring instrument is placed at a position different from the first measuring instrument, and receives radio waves in a communication environment in which the shielding/non-shielding of radio waves transmitted from the terminal device changes depending on the elapsed time. A second received signal strength timing chart showing the dependence of the received signal strength on the elapsed time is measured. The detector detects a position timing chart showing elapsed time dependency of the position, which consists of three-dimensional coordinates of a shielding object moving between the terminal device and the first and second measuring devices. The processing means performs a first process of generating, based on the received signal strength timing chart, a shielding timing chart showing elapsed time dependence of a shielding state in which radio waves are shielded by a shielding object. All of the signal strength timing charts are run to generate first and second shielding timing charts. The estimating means performs a second process of obtaining a shielding position, which is a position where radio waves transmitted from the terminal device are shielded, based on the position timing chart and the first and second shielding timing charts, and performs the first measurement. position of the terminal device based on the shielded position using a first Fresnel zone represented by an ellipse having a first focal point where the instrument or a second measuring device is located and a second focal point where the terminal device is located to estimate

(Configuration 2)
In configuration 1, in the second process, the estimating means determines the first position, which is the position of the shielding object at the start time of the shielding state, and the shielding object at the end time of the shielding state, based on the position timing chart and the shielding timing chart. for all of the first and second shielding timing charts, and a second position, which is the position of the shielding timing chart, for all of the plurality of shielding states in the shielding timing chart; a fourth process of obtaining a major axis direction of an ellipse by fitting a plurality of first plane coordinates and a plurality of second plane coordinates representing a plurality of second positions with an ellipse at first and second shielding timings; Executed for all of the charts, and corresponding to the first straight line having an inclination in the first major axis direction and the second shielding timing chart obtained corresponding to the first shielding timing chart in the fourth process A fifth process of estimating the position of the terminal device as the position of the intersection with the obtained second straight line whose inclination is the second major axis direction is executed.

(Composition 3)
In the configuration 2, in the fourth process, the estimating means adds the square of the function obtained by transposing the right side of the elliptic equation representing the ellipse to the left side for N (N is an integer of 2 or more) plane coordinates. A plurality of first plane coordinates representing a plurality of first positions and a plurality of By substituting a plurality of second plane coordinates representing the second positions, the major axis direction when the error evaluation function is minimized is obtained.

(Composition 4)
In configuration 2 or configuration 3, the processing means detects the average time of the time interval in which the received signal strength is attenuated based on the received signal strength timing chart, calculates the cutoff frequency based on the detected average time, and receives A process of obtaining a low-frequency received signal strength timing chart by removing frequency components equal to or higher than the cutoff frequency from the signal strength timing chart is executed for all of the first and second received signal strength timing charts. A low-frequency received signal strength timing chart is generated, and based on the low-frequency received signal strength timing chart, radio waves are classified into a non-shielded state and a shielded state in which radio waves are not blocked by a shielding object, and a blocking timing chart is generated. is performed for all of the first and second low-frequency received signal strength timing charts to generate first and second shielding timing charts.

(Composition 5)
In configuration 4, the processing means calculates twice the reciprocal of the average time as the cutoff frequency.

(Composition 6)
In configuration 4 or configuration 5, the processing means uses a clustering technique, which is a method of dividing the set to be classified into subsets such that internal coupling and external separation are achieved, or the attenuation pattern of the received signal strength in the occlusion state. to classify the non-shielding state and the shielding state by pattern matching using , and generate the first and second shielding timing charts.

(Composition 7)
In any one of configurations 2 to 6, in the third process, the estimating means detects an attenuation start time at which the received signal strength begins to attenuate and an attenuation end time at which the received signal strength finishes attenuating in the shielding timing chart, In the position timing chart, the three-dimensional coordinates at the same time as the attenuation start time are obtained as the first position, and the three-dimensional coordinates at the same time as the attenuation end time are obtained as the second position.

(Composition 8)
In any one of configurations 2 to 7, in the fourth processing, the estimation means moves the plurality of first positions toward the plurality of second positions by a predetermined distance to determine the plurality of third positions. moving the plurality of second positions toward the plurality of first positions by a predetermined distance to generate a plurality of fourth positions; and a plurality of third planes representing the plurality of third positions. A major axis direction of the ellipse is obtained by fitting the coordinates and the plurality of fourth plane coordinates representing the plurality of fourth positions with an ellipse.

(Composition 9)
In configuration 8, in the third process, the estimating means obtains the first and second positions for all of the plurality of shielding states in one shielding timing chart out of the first and second shielding timing charts, and obtains the error A sixth process of substituting a plurality of third plane coordinates and a plurality of fourth plane coordinates into the evaluation function to obtain one major axis direction and one shortest distance when the error evaluation function is minimized is performed as follows: Measure the received signal strength timing chart from which one shielding timing chart is generated based on one major axis direction and one shortest distance obtained in the sixth process, which is executed in place of the process in 4. In place of the fifth process, a seventh process of estimating a position away from the position of the measuring instrument measured by one shortest distance in one long axis direction as the position of the terminal device is executed.

(Configuration 10)
In any of configurations 1 to 9, the position estimation device further comprises a shielding/unshielding device as the shielding object. The shielding/unshielding device shields/unshields the radio wave transmitted from the terminal device while moving. The detector detects as a position timing chart a timing chart showing the elapsed time dependence of the position of the shielded/unshielded device, which consists of three-dimensional coordinates.

(Composition 11)
Further, according to the embodiment of the present invention, a program is provided for causing a computer to estimate the position of a terminal device in a position estimation device that receives radio waves transmitted from the terminal device and estimates the position of the terminal device. a program,
The position estimator is
Measure a first received signal strength timing chart showing the dependence of the first received signal strength on the elapsed time when radio waves are received in a communication environment where the shielding/non-shielding of radio waves transmitted from a terminal device changes over time. a first measuring device that
Elapsed time of the second received signal strength when radio waves are received in a communication environment placed at a position different from the first measuring instrument and in which the shielding/non-shielding of radio waves transmitted from the terminal device changes depending on the elapsed time a second measuring device for measuring a second received signal strength timing chart indicative of the dependence;
a detector that detects a position timing chart showing the elapsed time dependence of the position consisting of the three-dimensional coordinates of the shielding object moving between the terminal device and the first and second measuring devices;
The program
The processing means generates, based on the received signal strength timing chart, a shielding timing chart indicating the dependence of the shielding state, in which radio waves are shielded by a shielding object, over time. a first step of running through all of the signal strength timing charts to generate first and second shielding timing charts;
The estimating means performs a second process of obtaining a shielding position, which is a position where radio waves transmitted from the terminal device are shielded, based on the position timing chart and the first and second shielding timing charts, and performs the first measurement. position of the terminal device based on the shielded position using a first Fresnel zone represented by an ellipse having a first focal point where the instrument or a second measuring device is located and a second focal point where the terminal device is located is a program for causing a computer to execute a second step of estimating .

(Composition 12)
In configuration 11, in the second process of the second step, the estimating means determines the first position, which is the position of the shielding object at the start time of the shielding state, and the shielding state, based on the position timing chart and the shielding timing chart. a second position, which is the position of the shielding object at the end time, for all of the plurality of shielding states in the shielding timing chart; a fourth process of obtaining a major axis direction of the ellipse by fitting a plurality of first plane coordinates representing one position and a plurality of second plane coordinates representing a plurality of second positions with an ellipse; A first straight line having an inclination in the direction of the first major axis and a second shielding timing obtained corresponding to the first shielding timing chart in the fourth process by executing all of the second shielding timing charts. A fifth process of estimating the position of the terminal device at the position of the intersection with the second straight line having the inclination in the second major axis direction obtained corresponding to the chart is executed.

(Composition 13)
In configuration 12, in the fourth process of the second step, the estimating means squares the function obtained by transposing the right side of the elliptic equation representing the ellipse to the left side N (N is an integer of 2 or more) A plurality of first positions representing a plurality of first positions in an error evaluation function consisting of the square root of the addition result obtained by adding about the plane coordinates of and having parameters of the major axis direction of the ellipse and the shortest distance between the two focal points By substituting the plane coordinates and the plurality of second plane coordinates representing the plurality of second positions, the major axis direction when the error evaluation function is minimized is obtained.

(Composition 14)
In configuration 12 or 13, the processing means detects the average time of the time interval in which the received signal strength is attenuated based on the received signal strength timing chart, calculates the cutoff frequency based on the detected average time, and receives A process of obtaining a low-frequency received signal strength timing chart by removing frequency components equal to or higher than the cutoff frequency from the signal strength timing chart is executed for all of the first and second received signal strength timing charts. A low-frequency received signal strength timing chart is generated, and based on the low-frequency received signal strength timing chart, radio waves are classified into a non-shielded state and a shielded state in which radio waves are not blocked by a shielding object, and a blocking timing chart is generated. is performed for all of the first and second low-frequency received signal strength timing charts to generate first and second shielding timing charts.

(Composition 15)
In configuration 14, the processing means calculates twice the reciprocal of the average time as the cutoff frequency.

(Composition 16)
In configuration 14 or 15, the processing means comprises a clustering technique, which is a method of dividing the set to be classified into subsets such that internal coupling and external separation are achieved, or a pattern of attenuation of received signal strength in occluded conditions. to classify the non-shielding state and the shielding state by pattern matching using , and generate the first and second shielding timing charts.

(Composition 17)
In any one of configurations 12 to 16, in the third processing of the second step, the estimating means includes the attenuation start time at which the received signal strength begins to attenuate and the attenuation end time at which the received signal strength finishes attenuating in the shielding timing chart. is detected, and the three-dimensional coordinates at the same time as the attenuation start time in the position timing chart are obtained as the first position, and the three-dimensional coordinates at the same time as the attenuation end time are obtained as the second position.

(Composition 18)
In any one of configurations 12 to 17, in the fourth processing of the second step, the estimating means moves the plurality of first positions toward the plurality of second positions by a predetermined distance to move the plurality of generating a third position; moving the plurality of second positions toward the plurality of first positions by a predetermined distance to generate a plurality of fourth positions; The major axis direction of the ellipse is obtained by fitting the third plane coordinates of and the plurality of fourth plane coordinates representing the plurality of fourth positions with an ellipse.

(Composition 19)
In configuration 18, in the third process of the second step, the estimating means calculates the first and second A position is obtained, a plurality of third plane coordinates and a plurality of fourth plane coordinates are substituted into the error evaluation function, and one major axis direction and one shortest distance are obtained when the error evaluation function is minimized. 6 is executed instead of the 4th process, and the received signal from which one shielding timing chart is generated based on one longitudinal direction and one shortest distance obtained in the sixth process A seventh process of estimating a position away from the position of the measuring instrument that measured the intensity timing chart by one shortest distance in one long axis direction as the position of the terminal device is executed instead of the fifth process.

(Configuration 20)
In any of configurations 11 to 19, the position estimation device further comprises an occluded/unoccluded device as the occluded object. The shielding/unshielding device shields/unshields the radio wave transmitted from the terminal device while moving. The detector detects as a position timing chart a timing chart showing the elapsed time dependence of the position of the shielded/unshielded device, which consists of three-dimensional coordinates.

(Composition 21)
Further, according to the embodiment of the present invention, the recording medium is a computer-readable recording medium recording the program according to any one of structures 11 to 20.

It is possible to estimate the location of a terminal transmitting radio waves using less than three measuring instruments.

1 is a schematic diagram of a position estimation device according to Embodiment 1 of the present invention; FIG. Fig. 2 is a schematic diagram of a room in which the measuring instruments and cameras shown in Fig. 1 are arranged; Figure 2 is another schematic view of the room in which the measuring instrument and camera shown in Figure 1 are arranged; It is a figure which shows the relationship between the received signal strength and elapsed time in an experiment. FIG. 2 is a diagram showing the mutual positional relationship between measuring instruments 1 and 2, camera 3, terminal device 30, and shield 50 in the xz plane. It is a figure for demonstrating the method to calculate a cutoff frequency. FIG. 4 is a diagram showing the relationship between received signal strength and elapsed time; FIG. 10 is a diagram for explaining a method of classifying a shielded state and a non-shielded state; FIG. 10 is a diagram showing the result of classification into a shielded state and a non-shielded state by the k-means method; It is a figure which shows the elapsed time dependence of the position of a shield. It is a figure which shows the position (consisting of x coordinate and z coordinate) of a shielding object, and the elapsed time dependence of received signal strength. 2 is a diagram plotting x-coordinates x _{start — 1} to x _{start — 8} and z coordinates z _{start — 1} to z _{start — 8} of occluders shown in Table 1; FIG. 1 is a conceptual diagram of a first Fresnel zone; FIG. Fig. 10 shows fitting with an ellipse ELL_2; FIG. 10 is a diagram showing the results of fitting the position at the start time of the shielding state and the position at the end time of the shielding state using an elliptic equation; FIG. 10 is a diagram showing a result of estimating the position of the terminal device 30 by estimation method 1; 3 is a diagram showing the result of estimating the position of the terminal device 30 by estimation method 2 using measuring device 1. FIG. 3 is a diagram showing the result of estimating the position of the terminal device 30 by estimation method 2 using measuring device 2. FIG. 2 is a flowchart for explaining the operation of the position estimation device shown in FIG. 1; FIG. 20 is a flowchart for explaining the detailed operation of step S7 in the flowchart shown in FIG. 19; FIG. FIG. 20 is a flowchart for explaining the detailed operation of step S10 in the flowchart shown in FIG. 19; FIG. FIG. 20 is a flowchart for explaining the detailed operation of step S11 shown in FIG. 19; FIG. Fig. 2 is a schematic diagram of a position estimation device according to Embodiment 2; Figure 24 is a schematic diagram of the shielded/unshielded device shown in Figure 23; . 24 is a flowchart for explaining the operation of the position estimation device shown in FIG. 23; Fig. 4 is a schematic diagram of another position estimating device according to Embodiment 2; Figure 27 is a schematic diagram of the shielded/unshielded device shown in Figure 26; FIG. 28 is a plan view of the cover member 76-1 shown in FIG. 27; FIG. 28 is a plan view of a rotating member 76-3 shown in FIG. 27; 27 is a diagram for explaining a method of estimating the position of the terminal device 30 by the position estimation device shown in FIG. 26; FIG. 27 is another diagram for explaining a method of estimating the position of the terminal device 30 by the position estimation device shown in FIG. 26. FIG. 27 is still another diagram for explaining a method of estimating the position of the terminal device 30 by the position estimation device shown in FIG. 26. FIG. FIG. 4 is a diagram showing the relationship between received signal strength and elapsed time; Figure 28 shows the directions of movement of the shielding/unshielding device shown in Figure 27; 27 is a flowchart for explaining the operation of the position estimation device shown in FIG. 26; FIG. 36 is a flow chart for explaining the detailed operation of step S25 shown in FIG. 35; FIG. FIG. 36 is a flowchart for explaining the detailed operation of step S26 shown in FIG. 35; FIG. FIG. 36 is a flowchart for explaining the detailed operation of step S27 shown in FIG. 35; FIG. FIG. 36 is a flowchart for explaining the detailed operation of step S28 shown in FIG. 35; FIG.

An embodiment of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is a schematic diagram of a position estimation device according to Embodiment 1 of the present invention. Referring to FIG. 1, position estimation device 10 according to Embodiment 1 of the present invention comprises measuring instruments 1 and 2, camera 3, processing means 4, and estimation means 5. In FIG.

The measuring device 1 receives radio waves transmitted from a terminal device through a shield and measures a received signal strength timing chart RSSI_CHT_1 that indicates the dependence of the received signal strength RSSI on the elapsed time when the radio waves are received. The measuring device 1 then outputs the received signal strength timing chart RSSI_CHT_1 to the processing means 4 .

Measuring instrument 2 is placed at a position different from that of measuring instrument 1, and receives radio waves transmitted from the terminal device through a shield. Measure the received signal strength timing chart RSSI_CHT_2. The measuring device 1 then outputs the received signal strength timing chart RSSI_CHT_2 to the processing means 4 .

The camera 3 is, for example, a GRB-D camera, detects a position timing chart PS_CHT representing the elapsed time dependence of the position of the shielding object made up of three-dimensional coordinates, and outputs the detected position timing chart PS_CHT to the estimation means 5. do.

The processing means 4 receives the received signal strength timing chart RSSI_CHT_1 from the measuring device 1 and receives the received signal strength timing chart RSSI_CHT_2 from the measuring device 2 .

Then, based on the received signal strength timing chart RSSI_CHT_1, the processing means 4 uses a method to be described later to determine whether the radio wave is blocked by a shielding object or not blocked by a shielding object. Generate a shielding/unshielding timing chart SHL/UNSHL_CHT_1 that indicates the elapsed time dependency with the state.

Further, the processing means 4 generates a shielding/non-shielding timing chart SHL/UNSHL_CHT_2 indicating the elapsed time dependency between the shielding state and the non-shielding state based on the received signal strength timing chart RSSI_CHT_2 by a method described later.

Then, the processing means 4 outputs the shielding/non-shielding timing charts SHL/UNSHL_CHT_1 and SHD/UNSHD_CHT_2 to the estimation means 5 .

The estimating means 5 holds coordinates (x ₁ , z ₁ ) indicating the position of the measuring device 1 and coordinates (x ₂ , z ₂ ) indicating the position of the measuring device 2 in advance. The estimating means 5 receives the position timing chart PS_CHT from the camera 3 and the shielding/unshielding timing charts SHL/UNSHL_CHT_1, SHD/UNSHD_CHT_2 from the processing means 4 .

Based on the position timing chart PS_CHT and the shielding/unshielding timing charts SHL/UNSHL_CHT_1 and SHD/UNSHD_CHT_2, the estimation means 5 estimates the position of the terminal device by a method described later.

FIG. 2 is a schematic diagram of a room in which measuring instruments 1, 2 and camera 3 shown in FIG. 1 are arranged. In FIG. 2, xyz axes are defined. As for the x-axis, the direction from the upper side to the lower side in the plane of FIG. 2 is the positive direction. The y-axis is set along the height direction of the room 20 . As for the y-axis, the positive direction is the direction from the back side to the front side in the plane of FIG. The xz plane is the bottom of room 20 . Therefore, FIG. 2 is a plan view showing the positional relationship of measuring instruments 1 and 2, camera 3, terminal device 30 and base station 40 when room 20 is viewed from above.

Referring to FIG. 2, measuring devices 1 and 2 are arranged at different positions in the x-axis direction at positions separated from walls 21 of a room 20 by a predetermined distance in the z-axis direction. Camera 3 is fixed to wall 21 at a predetermined height from the bottom of room 20 .

FIG. 3 is another schematic view of the room in which the measuring instruments 1, 2 and camera 3 shown in FIG. 1 are arranged. Also in FIG. 3, the xyz axes are defined. In FIG. 3 , the x-axis is positive in the direction from the back side to the front side on the paper surface of FIG. 3 .

Referring to FIG. 3 , measuring instruments 1 and 2 , terminal device 30 and base station 40 are arranged at a predetermined height from bottom surface 22 of room 20 . Camera 3 is fixed to wall 21 at a position higher than measuring instruments 1 and 2 . Although the terminal device 30 is not shown in FIG. 3, the terminal device 30 is arranged on the far side of the base station 40 on the page of FIG. Therefore, FIG. 3 is a plan view showing the positional relationship of the measuring instruments 1 and 2, the camera 3, the terminal device 30 and the base station 40 when the room 20 is viewed from the side.

The room 20 is, for example, 7 m long in the z-axis direction, 6 m long in the y-axis direction, and 6 m long in the x-axis direction.

The terminal device 30 transmits radio waves to the base station 40 on the uplink to the base station 40 . A moving shield 50 exists between the measuring instruments 1 , 2 and the terminal device 30 . Shield 50 is, for example, a human.

As a result, the measuring device 1 intercepts the radio wave transmitted from the terminal device 30 to the base station 40 on the uplink through the shield 50, and measures the received signal strength timing chart SHD/UNSHD_CHT_1. In addition, the measuring instrument 2 intercepts the radio wave transmitted by the terminal device 30 to the base station 40 in the uplink through the shield 50 at a position different from that of the measuring instrument 1, and measures the received signal strength timing chart SHD/UNSHD_CHT_2. . Furthermore, the camera 3 photographs the shielding object 50 and acquires the position timing chart PS_CHT.

Received signal strength RSSI in the measuring instruments 1 and 2 is measured using a whiteboard as the shield 50 in the arrangement relationship of the measuring instruments 1 and 2, the camera 3, the terminal device 30 and the base station 40 shown in FIGS. The results of the experiments will be described.

In the experiment, a human moved the whiteboard. A MacBook Pro was used as the measuring instruments 1 and 2 and the terminal device 30, and a ZED Stereo Camera was used as the camera 3. The communication environment has a frequency of 5 GHz and 44 channels.

FIG. 4 is a diagram showing the relationship between received signal strength and elapsed time in an experiment. In FIG. 4, the vertical axis represents received signal strength RSSI, and the horizontal axis represents elapsed time.

A curve k1 shows the relationship between the received signal strength and the elapsed time in the measuring device 1, and a curve k2 shows the relationship between the received signal strength and the elapsed time in the measuring device 2. FIG.

Referring to FIG. 4, the received signal RSSI attenuates in multiple time intervals. The time interval in which the received signal strength RSSI attenuates on the curve k1 is different from the time interval in which the received signal strength RSSI attenuates on the curve k2 (see curves k1 and k2).

The relationship between the received signal strength RSSI and the elapsed time indicated by the curve k1 constitutes the received signal strength timing chart RSSI_CHT_1, and the relationship between the received signal strength RSSI indicated by the curve k2 and the elapsed time constitutes the received signal strength timing chart RSSI_CHT_2. configure.

FIG. 5 is a diagram showing the mutual positional relationship between the measuring instruments 1 and 2, the camera 3, the terminal device 30 and the shield 50 on the xz plane.

In FIG. 5, the vertical axis represents the position in the z-axis direction, and the horizontal axis represents the position in the x-axis direction. Note that the origin of the x-axis is the arrangement position of the camera 3 .

Referring to FIG. 5 , the position of shielding object 50 consists of (x, z) coordinates in the three-dimensional coordinates of shielding object 50 detected by camera 3 . It can be seen that the shield 50 moved in the range of about −2 m to about 1.6 m in the x-axis direction and in the range of about 1.9 m to about 3.7 m in the z-axis direction. Also, the moving range of the shield 50 exists in the area between the terminal device 30 and the measuring instruments 1 and 2 .

Therefore, it can be seen that the measuring instruments 1 and 2 received the radio wave transmitted from the terminal device 30 to the base station 40 through the moving shield 50 and measured the received signal strength RSSI when the radio wave was received. .

FIG. 6 is a diagram for explaining a method of calculating the cutoff frequency. In (a) and (b) of FIG. 6, the vertical axis represents received signal strength RSSI, and the horizontal axis represents elapsed time. A curve k1 shows the relationship between the received signal strength RSSI measured by the measuring device 1 and the elapsed time, and a curve k2 shows the relationship between the received signal strength RSSI measured by the measuring device 2 and the elapsed time.

With reference to (a) of FIG. 6, the processing unit 4 determines times t ₁ , t ₂ , t ₃ , and t ₄ at which the received signal strength RSSI of the radio wave begins to attenuate and the received signal strength of the radio wave based on the curve k1. The times t ₅ , t ₆ , t ₇ and t ₈ at which the RSSI finishes decaying are detected.

Then, the processing means 4 subtracts the time _t1 from the time _t5 to calculate the time interval T _{itv_1} in which the received signal strength RSSI is attenuating. Similarly, the processing means 4 calculates a time interval T itv_2 based on the times t ₂ and t ₆ , calculates a time interval T _{itv_3} based on the times t ₃ and t ₇ , and calculates a time interval T _{itv_3} based on the times t ₄ and t ₈ Based on this, the time interval T _{itv_4} is calculated.

Then, the processing means 4 calculates the average time of the four time intervals T _{itv_1} to T _{itv_4} , and calculates twice the reciprocal of the calculated average time as the cutoff frequency f _{OFF_1} .

Referring to FIG. 6(b), the processing unit 4 calculates the time _t9 , _t10 , _t11 , _t12 at which the received signal strength RSSI of the radio wave begins to attenuate and the received signal strength of the radio wave based on the curve k2. The times t ₁₃ , t ₁₄ , t ₁₅ and t ₁₆ at which the RSSI finishes decaying are detected. Then, the processing means 4 calculates four time intervals T _{itv — 5} to T _{itv — 8} based on the times t ₉ to t ₁₆ by the same method as described in (a) of FIG. Double the reciprocal of the average time of T _{itv_5} to T _{itv_8} is calculated as the cutoff frequency f _{OFF_2} .

Thus, the processing means 4 selects a plurality of time intervals in which the received signal strength RSSI is attenuated based on the received signal strength timing chart RSSI_CHT_1 (=curve k1) or the received signal strength timing chart RSSI_CHT_2 (=curve k2). Then, based on the sampling theorem, twice the reciprocal of the average time of a plurality of time intervals is calculated as the cutoff frequency.

FIG. 7 is a diagram showing the relationship between received signal strength and elapsed time. In FIG. 7, the vertical axis represents received signal strength RSSI, and the horizontal axis represents elapsed time. A curve k1 shows the relationship between the received signal strength RSSI measured by the measuring device 1 and the elapsed time, and a curve k2 shows the relationship between the received signal strength RSSI measured by the measuring device 2 and the elapsed time. Curve k3 shows the relationship between received signal strength RSSI after curve k1 is processed by low-pass filter LPF1 and elapsed time, and curve k4 shows the relationship between received signal strength RSSI and elapsed time after curve k2 is processed by low-pass filter LPF2. indicates a relationship with

Referring to FIG. 7, processing means 4 processes curve k1 with a low-pass filter LPF1 having cutoff frequency _{fOFF_1} to remove frequency components above cutoff frequency _{fOFF_1} from curve k1 to generate curve k3. . The processing means 4 also processes the curve k2 with a low-pass filter LPF2 having a cutoff frequency _{fOFF_2} to remove frequency components equal to or higher than the cutoff frequency _{fOFF_2} from the curve k2, thereby generating a curve k4.

As a result, the curve k3 consists of the elapsed time dependence of the received signal strength RSSI with smaller variations in the received signal strength RSSI than the curve k1, and the curve k4 consists of the received signal strength RSSI with smaller variations in the received signal strength RSSI than the curve k2. It consists of the elapsed time dependence of RSSI.

FIG. 8 is a diagram for explaining a method of classifying the shielded state and the non-shielded state. In FIG. 8, a curve k3 shows the elapsed time dependence of the received signal strength after the frequency components above the cutoff frequency _{fOFF_1} are removed from the curve k1 by the low-pass filter LPF1.

The processing means 4 classifies each point of the curve k3 into the shielded state and the non-shielded state by the k-means method based on the elapsed time dependence of the received signal strength indicated by the curve k3.

More specifically, the processing means 4 detects N points P ₁ to P _N on the curve k3 at regular time intervals in the time interval SEC. Here, N is the number determined to include at least one region in which the received signal strength RSSI is attenuated and at least one region in which the received signal strength RSSI is hardly attenuated.

Each of the points P ₁ to P _N consists of (time t, received signal strength RSSI). By executing the following steps (I) to (IV), the processing means 4 divides the N points P ₁ to P _N into a cluster A consisting of the hidden state and a cluster B consisting of the non-shielded state by the k-means method. and

(I) Allocate N points P ₁ to P _N to clusters A and B at random.

(II) Calculate the center of gravity for the points assigned to each of the clusters A and B.

(III) For each point, calculate the distance from the calculated centroid, and reassign each point to the cluster of the centroid with the closest distance.

(IV) Repeat steps (II) and (III) until the cluster assigned to each point does not change.

FIG. 9 is a diagram showing the result of classification into a shielded state and a non-shielded state by the k-means method. (a) of FIG. 9 shows the result of classifying each point on the curve k3 into the shielded state and the non-shielded state by the k-means method based on the curve k3, and (b) of FIG. Based on this, each point on the curve k4 is classified into the shielded state and the non-shielded state by the k-means method. Here, of the two clusters classified by the k-means method, the cluster with the smaller minimum value or average value of the received signal strength RSSI is the cluster A indicating the shielding states SHL_1, SHL_2, SHL_3, and SHL_4. A cluster with a larger minimum value or average value of signal strength RSSI is cluster B indicating the unshielded states UNSHL_1, UNSHL_2, UNSHL_3, UNSHL_4, and UNSHL_5.

Referring to (a) of FIG. 9, processing means 4 performs shielding based on points classified into cluster A based on curve k3 (consisting of some of points P ₁ to P _N ). Detect states SHL_1, SHL_2, SHL_3, SHL_4, and based on the points classified into cluster B (consisting of the remaining points among points P ₁ to P _N ), unshielded states UNSHL_1, UNSHL_2, UNSHL_3, UNSHL_4, Detect UNSHL_5.

Then, _the processing means 4 detects the time when the shielding state SHL_1 starts as the start time T start_1 of the shielding state SHL_1, and detects the time when the shielding state SHL_1 ends as the end time T _{end_1} of the shielding state SHL_1. Similarly, the processing means 4 detects the start time T _{start_2} of the shielding state SHL_2 and the end time T _{end_2} of the shielding state SHL_2, and detects the start time T _{start_3} of the shielding state SHL_3 and the end time T _{end_3} of the shielding state SHL_3. Detect the start time T _{start_4} of the shielding state SHL_4 and the end time T _{end_4} of the shielding state SHL_4.

Referring to FIG. 9B, processing means 4 performs shielding based on points classified into cluster A based on curve k4 (consisting of some of points P ₁ to P _N ). Detect states SHL_5, SHL_6, SHL_7, and SHL_8, and based on the points classified into cluster B (consisting of the remaining points of points P ₁ to P _N ), unshielded states UNSHL_6, UNSHL_7, UNSHL_8, UNSHL_9, Detect UNSHL_10.

Then, the processing means 4 detects the start time T _{start_5 of} the shielding state SHL_5 and the end time T _{end_5} of the shielding state SHL_5 by the method described in (a) of FIG. The end time T _{end_6} of the shielded state SHL_6 is detected, the start time T _{start_7} of the shielded state SHL_7 and the end time T _{end_7} of the shielded state SHL_7 are detected, the start time T _{start_8} of the shielded state SHL_8 and the end time of the shielded state SHL_8 are detected. Detect T _{end_8} .

The elapsed time dependencies of the shielded states SHL_1, SHL_2, SHL_3, and SHL_4 and the unshielded states UNSHL_1, UNSHL_2, UNSHL_3, UNSHL_4, and UNSHL_5 shown in FIG. The elapsed time dependencies of the shielded states SHL_5, SHL_6, SHL_7, SHL_8 and the unshielded states UNSHL_6, UNSHL_7, UNSHL_8, UNSHL_9, and UNSHL_10 shown in FIG. do.

Therefore, the processing means 4 generates the shielded/unshielded timing chart SHL/UNSHL_CHT_1 based on the received signal strength timing chart (=curve k1 shown in FIG. 4) measured by the measuring device 1, and A shielding/unshielding timing chart SHL/UNSHL_CHT_2 is generated based on the received signal strength timing chart (=curve k2 shown in FIG. 4).

FIG. 10 is a diagram showing the dependence of the position of the shield 50 on elapsed time. In FIG. 10, the vertical axis represents the position of the shield 50, and the horizontal axis represents elapsed time. The position of the shield 50 consists of three-dimensional coordinates (x, y, z).

The camera 3 detects, for example, the dependence of the position of the shield 50 shown in FIG. 10 on elapsed time. The elapsed time dependence of the position of the shield 50 constitutes the position timing chart PS_CHT.

Referring to FIG. 10(a), when estimation means 5 receives from processing means 4 the shielding/unshielding timing chart SHL/UNSHL_CHT_1 (see curve k3) shown in FIG. Detect the start times T _{start_1} to T start_4 of the shielding states SHL_1 to SHL_4 in the timing chart SHL/UNSHL_CHT_1 (see curve k3), and position the positions PS _{start_1 to} PS _{start_4} at the same times as the detected start times T _{start_1} to T _{start_4} . It is detected from the timing chart PS_CHT (see (a) of FIG. 10).

The estimating means 5 also detects the end times T _{end_1} to T _{end_4} of the shielded states SHL_1 to SHL_4 in the shielded/unshielded timing chart SHL/UNSHL_CHT_1 (see curve k3), and the detected end times T _{end_1} to T _{end_4} and Positions PS _{end — 1} to PS _{end — 4} at the same time are detected from the position timing chart PS_CHT (see FIG. 10(a)).

Referring to FIG. 10(b), estimation means 5 receives from processing means 4 the shielding/unshielding timing chart SHL/UNSHL_CHT_2 (see curve k4) shown in FIG. 9(b). Detect the start times T _{start_5} to T start_8 of the shielding states SHL_5 to SHL_8 in the timing _chart SHL/UNSHL_CHT_2 (see curve k4), and position the positions PS _{start_5} to PS _{start_8} at the same times as the detected start times T _{start_5} to T _{start_8} . It is detected from the timing chart PS_CHT (see (b) of FIG. 10).

Further, the estimation means 5 detects end times T _{end_5} to T _{end_8} of the shielded states SHL_5 to SHL_8 in the shielding/non-shielding timing chart SHL/UNSHL_CHT_2 (see curve k4), and the detected end times T _{end_5} to T _{end_8} and Positions PS _{end — 5} to PS _{end — 8} at the same time are detected from the position timing chart PS_CHT (see FIG. 10(b)).

FIG. 11 is a diagram showing the position of the shielding object 50 (consisting of x-coordinates and z-coordinates) and the dependence of received signal strength on elapsed time.

In FIG. 11, the vertical axis represents the received signal strength RSSI and the x- and z-coordinates of the position of the shield 50, and the horizontal axis represents elapsed time. FIG. 11(a) shows the elapsed time dependence of the received signal strength RSSI shown in FIG. (b) of FIG. 11 shows the elapsed time dependence of the received signal strength RSSI shown in FIG. show gender.

With reference to (a) of FIG. 11 , the estimation means 5 calculates the position x The coordinates and the z-coordinates are detected to create the x-coordinate dependence on elapsed time k5 of the position of the shielding object 50, and the z-coordinate dependence on elapsed time k6 of the position of the shielding object 50 is generated. Also, the estimation means 5 sets the elapsed time dependency of the received signal strength RSSI shown in (a) of FIG. 9 as the elapsed time dependency of the received signal strength RSSI shown in (a) of FIG. 11 .

Then, the estimating means 5 calculates the x-coordinate x start_1 at the _start time T _{start_1} of the shielding state SHL_1 and the x-coordinate x _{end_1} at the end time T _{end_1} of the shielding state SHL_1 according to the elapsed time dependency of the x coordinate shown in FIG. Detect from k5. In addition, the estimating means 5 calculates the z-coordinate z start_1 at the start time T _{start_1} of the shielding state _{SHL_1} and the z-coordinate z _{end_1} at the end time T _{end_1} of the shielding state SHL_1 according to the elapsed time dependency of the z coordinate shown in FIG. Detect from k6.

Thereafter, in the same way, the estimating means 5 determines the x-coordinates _{xstart_2} , xstart_3, xstartd_4 at the start times _{Tstart_2} , _{Tstart_3} , and _{Tstart_4} of the shielding states SHL_2, _{SHL_3} , and _{SHL_4} , and the end times of the shielding states SHL_2, SHL_3, and SHL_4. Find the x-coordinates _{xend_2} , _{xend_3} , _{xend_4} at times _{Tend_2} , _{Tend_3} , _{Tend_4} . In addition, the estimating means 5 calculates the start times _{Tstart_2} , _{Tstart_3} , and _{Tstart_4} of the shielding states _{SHL_2} , _{SHL_3} , _and SHL_4, and the end times _{Tend_2} and Detect z-coordinates _{zend_2} , _{zend_3} , and _{zend_4} in Tend_3 _{and Tend_4} .

Referring to FIG. 11(b), estimation means 5 calculates each elapsed time based on the relationship between the position of shielding object 50 and the elapsed time shown in FIG. 10 by the method described in FIG. Detect the x-coordinate and z-coordinate of the position of the shielding object 50 to create the dependence of the x-coordinate on the position of the shielding object 50 over time (curve k7) and the dependence of the z-coordinate on the elapsed time of the position of the shielding object 50 (curve k8). Also, the estimating means 5 sets the elapsed time dependency of the received signal strength RSSI shown in FIG. 9(b) as the elapsed time dependency of the received signal strength RSSI shown in FIG. 11(b).

Then, the estimation means 5 calculates the x-coordinates xstart_5, _{xstart_6} at the start times _{Tstart_5} , Tstart_6, Tstart_7, _{Tstart_8} of the shielding states SHL_5, SHL_6, _{SHL_7} , _{SHL_8} by the method described _in (a) of FIG. , _{xstart_7} , _{xstart_8} and the end times _{Tend_5} , _{Tend_6} , _{Tend_7} , _{Tend_8} of the shielding states _{SHL_5} , _{SHL_6} , _{SHL_7} , _{SHL_8} . In addition, the estimating means 5 calculates the z-coordinates _{zstart_5} and zstart_6 at the start times Tstart_5, _{Tstart_6} , _{Tstart_7} and _{Tstart_8} of the shielding states SHL_5, SHL_6, SHL_7 and _{SHL_8} by the method described _in (a) of FIG. , _{zstart_7} , _{zstart_8} and the end times _{Tend_5} , _{Tend_6} , _{Tend_7} , _{Tend_8} of the shielding states _{SHL_5} , _{SHL_6} , _{SHL_7} , _{SHL_8} .

Measuring instruments 1 and 2, shielding states SHL_1 to SHL_8, start times T _{start_1} to T _{start_8} of shielding states SHL_1 to SHL_8 / end times T _{end_1} to T _{end_8} , and start times T _{start_1} to T _{start_8} of shielding states SHL_1 to SHL_8 position (x _{start — 1} , z _{start — 1 )} to (x _{start — 8} , z _{start — 8 )} of the shielding object 50 at , and positions (x _{end — 1} , z _{end — 1} ) to ( x _{end — 8} , z _{end — 8} ) are shown in Table 1.

In Table 1, the shielding states SHL_1 to SHL_4 are detected based on the elapsed time dependence of the received signal strength RSSI measured by the measuring device 1 (see curve k1 in FIG. 4), so they are associated with the measuring device 1. . Then start time T _{start_1} and end time T _{end_1} are associated with occlusion state SHL_1, position (x _{start_1} , z _{start_1} ) is associated with start time T _{start_1} , and position (x _{end_1} , z _{end_1} ) is: It is associated with the end time T _{end_1} .

Also, the start time T _{start_2} and the end time T _{end_2} are associated with the shielding state SHL_2, the position (x _{start_2} , z _{start_2} ) is associated with the start time T _{start_2} , and the position (x _{end_2} , z _{end_2} ) is It is associated with the end time T _{end_2} .

Furthermore, start time T _{start — 3} and end time T _{end — 3} are associated with occlusion state SHL — 3, position (x _{start — 3} , z _{start — 3} ) is associated with start time T start _{— 3} , and location (x _{end — 3} , z _{end — 3} ) is associated with It is associated with the end time T _{end_3} .

Furthermore, start time T _{start — 4} and end time T _{end — 4} are associated with occlusion state SHL — 4, position (x _{start — 4} , z _{start — 4} ) is associated with start time T _start — 4 and position (x _{end — 4} , z _{end — 4} ) is associated with It is associated with the end time T _{end — 4} .

In addition, in Table 1, the shielding states SHL_5 to SHL_8 are detected based on the elapsed time dependency of the received signal strength RSSI measured by the measuring device 2 (see curve k2 in FIG. 4). Attached. Then start time T _{start — 5} and end time T _{end — 5} are associated with occlusion state SHL — 5, position (x _{start — 5} , z _{start — 5} ) is associated with start time T _start — 5, and location (x _{end — 5} , z _{end — 5} ) is: It is associated with the end time T _{end — 5} .

Also, the start time T _{start — 6} and the end time T _{end — 6} are associated with the shielding state SHL — 6, the position (x _{start — 6} , z _{start — 6} ) is associated with the start time T _{start — 6} , and the position (x _{end — 6} , z _{end — 6} ) is: It is associated with the end time T _{end — 6} .

Furthermore, start time T _{start — 7} and end time T _{end — 7} are associated with occlusion state SHL — 7, position (x _{start — 7} , z _{start — 7} ) is associated with start time T _{start — 7} , and position (x _{end — 7} , z _{end — 7} ) is: It is associated with the end time T _{end_7} .

Furthermore, start time T _{start — 8} and end time T _{end — 8} are associated with occlusion state SHL — 8, position (x _{start — 8} , z _{start — 8} ) is associated with start time T _start — 8 and position (x _{end — 8} , z _{end — 8} ) is associated with It is associated with the end time T _{end — 8} .

Therefore, according to Table 1, the estimating means 5 determines the positions (x _{start — 1} , z _{start — 1} ) to (x _{start — 8} , z start — ₈ ) of the shielding object 50 at the start times T _{start —} 1 to T _{start —} 8 of the shielding states SHL — 1 to SHL — 8 and the end times The positions (x _{end — 1} , z _{end — 1} ) to (x _{end — 8} , z _{end — 8} ) of the shield 50 in T _{end — 1} to T end — 8 are detected.

FIG. 12 is a diagram plotting x coordinates x _{start — 1} to x _{start — 8} and z coordinates z _{start — 1} to z _{start — 8} of the shield 50 shown in Table 1. FIG.

Referring to FIG. 12, _the estimating means 5 calculates the position of the shielding object 50 shown in Table 1 (x _{start — 1 , z start — 1} ), (x end — 1, z _{end —} 1); _{end_2} ); ( _{xstart_3} , _{zstart_3} ), ( _{xend_3} , _{zend_3} ); ( _{xstart_4} , _{zstart_4} ), ( _{xend_4} , _{zend_4} ) are plotted on the xz plane. As a result, the pentagons contained in region REG1 and the pentagons contained in REG2 are plotted on the xz plane. In FIG. 12, only three pentagons exist in the region REG1, but this is because the positions (x coordinates, z coordinates) at the start time of two of the shielding states SHL_1 to SHL_4 are the same. Because it is.

In addition, the estimation means 5 calculates the position of the shield 50 shown in Table 1 (x _{start — 5} , z _{start — 5} ), (x _{end — 5} , z _end — 5); (x _start — 6, z _{start — 6} ), (x _{end — 6} , z _{end — 6} ); Plot _{start — 7} , z _{start — 7} ), (x _{end — 7} , z _{end — 7} ); (x _{start — 8} , z _{start — 8} ), (x _{end — 8} , z _{end — 8} ) on the xz plane. As a result, the circle contained in region REG3 and the circle contained in REG4 are plotted on the xz plane.

Three pentagons included in the region REG1 represent the positions (x _{start — 1} , z _{start — 1} ) to (x _{start — 4} , z start _{— 4} ) of the shielding object 50 at the start times T _{start — 1} to T _{start —} 4 of the shielding states SHL — 1 to SHL — 4.

The four pentagons included in the region REG2 represent the positions (x _{end — 1} , z _{end — 1} ) to (x _{end — 4} , z end — ₄ ) of the shielding object 50 at the end times T _{end — 1} to T _{end —} 4 of the shielding states SHL — 1 to SHL — 4.

Furthermore, the four circles included in the region REG3 represent the positions (x _{start — 5} , z _{start — 5} ) to (x _{start — 8} , z start — ₈ ) of the shield 50 at the start times T _{start — 5} to T _{start —} 8 of the shield states SHL — 5 to SHL — 8.

Further, four circles included in the region REG4 represent the positions (x _{end — 1} , z _{end — 1} ) to (x _{end — 4} , z _{end — 4} ) of the shielding object 50 at the end times T _{end — 5} to T _{end — 8 of the shielding states SHL — 5 to SHL — 8} .

[Estimation method 1]
A method of estimating the position of the terminal device 30 in estimation method 1 will be described.

FIG. 13 is a conceptual diagram of the first Fresnel zone. Referring to FIG. 13(a), the first Fresnel zone is the area inside the ellipse ELL_1. The perimeter of the first Fresnel zone is represented by an ellipse ELL_1, and when the center of the ellipse ELL_1 is at the origin of the xz plane, the ellipse ELL_1 is represented by the following equation.

The coordinates of the focus FCS_1 are (c, 0) and the coordinates of the focus FCS_2 are (-c, 0). As a result, the distance between the origin and focus FCS_1 and the distance between the origin and focus FCS_2 are c. Also, the shortest distance between the focal point FCS_1 and the focal point FCS_2 is d.

When the distance between an arbitrary point A on the ellipse representing the outer circumference of the Fresnel zone and the focal point FCS_1 is _r1 , and the distance between the point A and the focal point FCS_2 is _r2 , the following equation holds.

In Equation (2), λ is the wavelength of radio waves.

Assuming the first Fresnel zone and setting m=1, a, b, and c are expressed by the following equations.

The first Fresnel zone is inside the ellipse ELL_1 where the sum of the distances from the two focal points FCS_1 and FCS_2 (r ₁ +r ₂ ) is longer than the shortest distance d between the two focal points FCS_1 and FCS_2 by half a wavelength (λ/2). is the area of Therefore, the first Fresnel zone is a region in which a curved propagation path exists such that the difference between the radio wave propagation path from the shortest straight path connecting the transmitting station and the receiving station is within half a wavelength.

Referring to FIG. 13(b), in order to generalize the location of the first Fresnel zone, assume an ellipse ELL_2 whose center has been moved from the origin and rotated by an angle θ with respect to the x-axis direction.

_{Let the coordinates of the focal point FCS_2 of the ellipse ELL_2 be (x 0 , z 0 ) and the} coordinates of the center of the ellipse ELL_ 2 be ( _{X 0} , Z ₀ ) _. ) is expressed by the following equation.

Using the relationship between the coordinates (X ₀ , Z ₀ ) and the coordinates (x ₀ , z ₀ ) shown in Equation (4), the ellipse ELL_2 is expressed by the following equation.

FIG. 14 is a diagram showing fitting with an ellipse ELL_2. Referring to FIG. 14, measuring device 1 is placed at one focal point of ellipse ELL_2. As a result, the position of the terminal device 30 can be estimated to be the other focus of the ellipse ELL_2.

As described above, the positions (x _{start — 1} , z _{start — 1} ) to (x start — ₄ , z start _{— 4} ) of the shielding object 50 at the start times T _{start — 1} to T _{start —} 4 of the shielding states SHL — 1 to SHL — 4 exist in the region REG1, and the shielding state SHL — 1 The positions (x _{end — 1} , z _{end — 1) to (x end — 4, z end} — 4) of the shield 50 at the end times T end — 1 to T _{end — 4} of ˜SHL — ₄ exist in the region REG2 (see FIG. 12).

Therefore, as shown in FIG. 14, the estimation means 5 converts the positions (x _{start — 1} , z _{start — 1} ) to (x _{start — 4} , z _{start — 4} ) and the positions (x _end — 1, z _{end — 1} ) to (x _{end — 4} , z _{end — 4} ) into ellipses. Fit with ELL_2.

More specifically, the estimating means 5 calculates positions (x _{start — 1} , z _{start — 1} ) to (x _{start — 4} , z _{start — 4} ) and positions (x _end — 1, z _{end — 1} ) to (x _{end — 4} , z _{end — 4} ) by the following method. Fit with ellipse ELL_2.

Let the coordinates of the i (i is an integer from 1 to N) th data of the N (N is an integer of 2 or more) data groups be (x _i , z _i ), and the error evaluation function E is defined by the following equation.

Then, F(x _i , z _i ; d, θ) in Equation (6) is expressed by the following equation.

In equation (7), x ₀ , z ₀ are coordinates of the position of measuring device 1 or measuring device 2, and λ is the wavelength of the radio wave, so x ₀ , z ₀ , λ are known. In addition, x _i and z _i in equation (7) include N data groups (for example, eight positions (x _{start — 1} , z _{start — 1} ) to (x _{start — 4} , z _{start — 4} ), (x _{end — 1} , z _{end — 1} ) ~(x _{end — 4} , z _{end — 4} )) is substituted. The result is that the error estimation function E is a function with d and θ as parameters. That is, the error evaluation function E is obtained by adding the squares of the function F (x _i , z _i ; d, θ) obtained by transposing the right side of the elliptic equation representing the outer circumference of the first Fresnel zone to the left side for N plane coordinates. It consists of the square root of the result of addition, and consists of a function whose parameters are the major axis direction θ of the ellipse and the shortest distance d between the two focal points.

Then, the estimating means 5 obtains the parameters d and .theta. when the error evaluation function E is minimized while changing the values of d and .theta. at predetermined intervals.

The estimation means 5 fits the positions (x _{start — 1} , z _{start — 1} ) to (x _{start — 4} , z start — ₄ ), (x _{end — 1} , z _{end — 1} ) to (x _{end — 4} , z _{end — 4} ) with the ellipse ELL — 2 by the above method.

The estimating means 5 performs the fitting with the above-described ellipse ELL_2, the position (x _{start — 5} , z _{start — 5} ) to (x _{start — 8} , z _{start — 8} ) of the shielding object 50 at the start times T _start — 5 to T start — 8 of the shielding states SHL — 5 to SHL — 8, and the shielding state The positions (x end _{— 5} , z end — 5 ) to (x _{end — 8} , z _end — 8 ) of the shield 50 at the end times T end — 5 to T _{end — 8} of SHL _{— 5 to SHL — 8} are also executed.

FIG. 15 is a diagram showing the results of fitting the position at the start time of the shielded state and the position at the end time of the shielded state using an elliptic equation.

In FIG. 15, (a) shows the result of fitting the position at the start time and the position at the end time of the shielding state classified based on the received signal strength timing chart RSSI_CHT_1 measured by the measuring device 1 with an ellipse ELL_2. , (b) show the result of fitting the position at the start time and the position at the end time of the shielding state classified based on the received signal strength timing chart RSSI_CHT_2 measured by the measuring device 2 with the ellipse ELL_2.

Table 2 shows the change range and width of the parameters d and θ when using the measuring instrument 1 and the optimum values of the parameters d and θ. Table 3 shows the width of change and the optimum values of the parameters d and θ.

Referring to FIG. 15, the direction .theta. is generally correct, but the distance d is not correct. Therefore, the estimating means 5 obtains a straight line L1 having a slope a _SLP1 in the direction of θ ₁ (consisting of 73.0 degrees in Table 2) from the measuring device 1 and θ ₂ (108.5 in Table 2) from the measuring device 2 _degree .

The straight line L1 is expressed by Equation (8), and the straight line L2 is expressed by Equation (9).

In equation (8), tan(θ ₁ ) is the slope a _SLP1 , and in equation (9) tan(θ ₂ ) is the slope a _SLP2 .

The estimating means 5 substitutes the coordinates (x ₁ , z ₁ ) of the position of the measuring instrument 1 into x and z of the equation (8) to calculate the intercept b ₁ of the equation (8), and calculates the position of the measuring instrument 2. Substitute the coordinates (x ₂ , z ₂ ) into x and z in equation (9) to calculate the intercept b ₂ in equation (9).

FIG. 16 is a diagram showing the estimation result of the position of the terminal device 30 by estimation method 1. As shown in FIG. Referring to FIG. 16, when the straight lines L1 and L2 are obtained, the estimating means 5 calculates the coordinates of the intersection of the straight lines L1 and L2, and calculates the position indicated by the calculated coordinates of the intersection (the position of the intersection). The position of the terminal device 30 is estimated.

In FIG. 16, the true position of the terminal device 30 is (0.0, 4.5) and the estimated position of the terminal device 30 is (-0.02, 4.03). Therefore, the error between the true position of the terminal device 30 and the estimated position is 0.47 m.

Thus, by using two measuring devices 1 and 2, the position of the terminal device 30 can be estimated by obtaining only the parameter θ for the two measuring devices 1 and 2 among the parameters d and θ.

[Estimation method 2]
A method of estimating the position of the terminal device 30 in estimation method 2 will be described.

When the estimation means 5 detects the positions (x _{start — 1} , z _{start — 1} ) to (x _start — 4, z start _{— 4} ), (x _{end — 1} , z _{end — 1} ) to (x _{end — 4} , z _{end — 4} ), the positions (x _start — 1, z _{start — 1} ) to (x _{start_4} , z _{start_4} ) is moved from position (x _{end_1} , z _{end_1} ) to (x _{end_4} , z _{end_4} ) in the direction (x-axis direction) by a predetermined distance to position (x' _{start_1} , z' _{start_1} ) to Generate (x' _{start — 4} , z' _{start — 4} ).

In addition, the estimating means 5 moves the positions (x _{end — 1} , z _{end — 1} ) to (x _{end — 4} , z end _{— 4} ) to the positions (x _{start —} 1, z _{start — 1} ) to (x _{start — 4} , z _{start — 4} ) in a predetermined direction (x-axis direction). Move the distance to generate positions (x' _{end — 1} , z' _{end — 1} ) to (x' _{end — 4} , z' _{end — 4} ).

The predetermined distance is set to approximately half the width of the shield 50 . For example, if the width of the shield 50 is 90 cm, the predetermined distance is 40 cm.

In this way, the estimating means 5 calculates positions (x _{start — 1} , z _{start — 1} ) to (x _{start — 4} , z _{start — 4} ), (x _{end — 1} , z _{end — 1} ) to (x _{end — 4} , z _{end — 4} ) in consideration of the width of the shield 50. are corrected to positions ( _{x'start_1} , _{z'start_1} ) to ( _{x'start_4} , _{z'start_4} ), ( _{x'end_1} , _{z'end_1} ) to ( _{x'end_4} , _{z'end_4} ).

Then, the estimation means 5 calculates the corrected positions (x' _{start — 1} , z' _{start — 1} ) to (x' _start — 4, z' _start — 4), (x' _{end — 1} , z' _end — 1) to (x' _{end — 4} , z' _{end — 4} ) as Obtain θ' ₁ and d' ₁ when fitting with the ellipse ELL_2. That is, the estimation means 5 calculates the corrected positions (x' _{start — 1} , z' _{start — 1} ) to (x' _start — 4, z' _start — 4), (x' _{end — 1} , z' _end — 1) to (x' _{end — 4} , z' _{end — 4} ) as θ' ₁ and d' ₁ are obtained when the error evaluation function E is minimized by substituting it into the error evaluation function E.

Then, the estimating means 5 estimates the position of the terminal device _{30 at a position separated by a distance d′1 in} the direction of θ′1 from the position of the measuring instrument 1 . More specifically, the estimating means 5 uses the coordinates (x ₃₀ , z ₃₀ ) to indicate the position of the terminal device 30 and the coordinates (x ₁ , z ₁ ) to indicate the position of the measuring instrument 1 to form the equation ( Solve the simultaneous equations represented by the two equations (10A) and (10B) in 10) to calculate x ₃₀ and z ₃₀ , and estimate the calculated coordinates (x ₃₀ , z ₃₀ ) as the position of the terminal device 30 do.

Note that the intercept b ₁ of the equation (10A) is calculated by substituting the position (x ₁ , z ₁ ) of the measuring device 1 into the equation z=tan(θ ₁ ')x+b ₁ .

The estimating means 5 converts positions (x _{start — 5} , z _{start — 5} ) to (x _{start — 8} , z _{start — 8} ), (x _{end — 5} , z _{end — 5} ) to (x _{end — 8} , z _{end — 8} ) into positions (x' _{start — 5} , z ' _{start — 5} ) to (x' _{start — 8} , z' _{start — 8} ), (x' _{end — 5} , z' _{end — 5} ) to (x' _{end — 8} , z' _{end — 8} ).

Then, the estimation means 5 calculates the corrected positions (x' _{start — 5} , z' _{start — 5} ) to (x' _start — 8, z' _start — 8), (x' _{end — 5} , z' _end — 5) to (x' _{end — 8} , z' _{end — 8} ) as Obtain θ' ₂ and d' ₂ when fitting with the ellipse ELL_2. That is, the estimation means 5 calculates the corrected positions (x' _{start — 5} , z' _{start — 5} ) to (x' _start — 8, z' _start — 8), (x' _{end — 5} , z' _end — 5) to (x' _{end — 8} , z' _{end — 8} ) as θ' ₂ and d' ₂ are obtained when the error evaluation function E is minimized by substituting it into the error evaluation function E.

Then, the estimating means 5 estimates the position of the terminal device _{30 at a position separated by a distance d′2 in} the direction of θ′2 from the position of the measuring device 2 . More specifically, the estimating means 5 uses the coordinates (x ₃₀ , z ₃₀ ) to indicate the position of the terminal device 30 and the coordinates (x ₂ , z ₂ ) to indicate the position of the measuring instrument 2 to form the equation ( Solve the simultaneous equations represented by the two equations (11A) and (11B) in 11) to calculate x ₃₀ and z ₃₀ , and estimate the calculated coordinates (x ₃₀ , z ₃₀ ) as the position of the terminal device 30 do.

Note that the intercept b ₂ of equation (11A) is calculated by substituting the position (x ₂ , z ₂ ) of the measuring device 2 into the equation z=tan(θ ₂ ′)x+b ₂ .

FIG. 17 is a diagram showing the result of estimating the position of the terminal device 30 by the estimation method 2 using the measurement device 1. As shown in FIG.

(a) of FIG. 17 shows the estimation result of the position of the terminal device 30 using the position before correction, and (b) of FIG. 17 shows the estimation result of the position of the terminal device 30 using the position after correction. show.

Referring to (a) of FIG. 17, measuring device 1 is arranged at one focus of ellipse ELL_2. Another focal point of the ellipse ELL_2 is located farther than the actual position of the terminal device 30 . As a result, when the position of the terminal device 30 is estimated using the position before correction, the direction _θ1 is correct, but the distance _d1 is not correct.

Referring to FIG. 17(b), measuring instrument 1 is placed at one focus of ellipse ELL_2' and estimated position PS _est is placed at another focus of ellipse ELL_2'. As a result, when the position of the terminal device 30 is estimated using the post-correction position, the direction θ′ ₁ and the distance d′ ₁ are greater than the estimation result using the pre-correction position (see (a) of FIG. 17 ). Matching. The error between the actual position of the terminal device 30 and the estimated position PS _est is 69 cm.

FIG. 18 is a diagram showing the result of estimating the position of the terminal device 30 by the estimation method 2 using the measurement device 2. As shown in FIG.

(a) of FIG. 18 shows the result of estimating the position of the terminal device 30 using the position before correction, and (b) of FIG. 18 shows the result of estimating the position of the terminal device 30 using the position after correction. show. Note that since there are outliers in (a) of FIG. 18 , in (b) of FIG. 18 , the outliers are removed and the positions after correction are fitted with an ellipse ELL_2′.

18A, when the position of the terminal device 30 is estimated using the position before correction, the direction _θ2 is correct, but the distance d ₂ do not match.

Referring to FIG. 18(b), measuring instrument 2 is placed at one focus of ellipse ELL_2' and estimated position PS _est is placed at another focus of ellipse ELL_2'. As a result, when the position of the terminal device 30 is estimated using the position after correction, the direction _θ′2 and the distance d′ ₂ are larger than the estimation result using the position before correction (see (a) of FIG. 18). Matching. The error between the actual position of the terminal device 30 and the estimated position PS _est is 62 cm.

Thus, in the estimation method 2, the estimation means 5 uses the received signal strength timing chart RSSI_CHT (one of the received signal strength timing charts RSSI_CHT_1 and RSSI_CHT_2) measured by one of the measuring devices 1 and 2. The position PS_start of the shielding object 50 at the start time and the position PS_end of the shielding object 50 at the end time of the shielding state SHL detected based on is corrected according to the width of the shielding object 50, and the corrected position PS'_start and position The position of the terminal device 30 is estimated using PS'_end.

Therefore, according to the estimation method 2, the position of the terminal device 30 can be estimated using one measuring device.

[Estimation method 3]
A method of estimating the position of the terminal device 30 in estimation method 3 will be described.

The estimating means 5 converts the positions (x _{start — 1} , z _{start — 1} ) to (x _{start — 4} , z _{start — 4} ), (x _{end — 1} , z _{end — 1} ) to (x _{end — 4} , z _{end — 4} ) to the position (x ' _{start_1} , _{z'start_1} ) to ( _{x'start_4} , _{z'start_4} ), ( _{x'end_1} , _{z'end_1} ) to ( _{x'end_4} , _{z'end_4} ).

Then, the estimation means 5 determines positions (x' _{start — 1} , z' _{start — 1} ) to (x' _{start — 4} , z' start — ₄ ), (x' _{end — 1} , z' _end — 1) to (x' _end — 4, z' _{end_4} ) is fitted with an ellipse ELL_2' to obtain _θ'1 when the error evaluation function E is minimized, and the obtained _θ'1 is used to obtain a straight line L1'. The straight line L1' is represented by an equation obtained by substituting _θ'1 for _θ1 in Equation (8).

In addition, the estimation means 5 calculates the positions (x _{start — 5} , z _{start — 5} ) to (x _start — 8, z _{start — 8} ), (x _end — 5, z _{end — 5} ) to (x _{end — 8} , z _{end — 8} ) by the method described in the estimation method 2. (x' _{start — 5} , z' _{start — 5} ) to (x' _{start — 8} , z' _{start — 8} ), (x' _{end — 5} , z' _end — 5) to (x' _{end — 8} , z' _end — 8), and the corrected position (x' _{start — 5} , z' _{start — 5} ) to (x' _{start —} 8, z' _start — 8), (x' _end — 5, z' _end — 5) to (x' _{end — 8} , z' end — ₈ ) are fitted with an ellipse ELL — 2', and the error evaluation function E is minimized. _θ′2 is obtained when θ′2 is obtained, and the straight line L2 _′ is obtained using the obtained θ′2. The straight line L2' is expressed by an equation obtained by substituting _θ'2 for _θ2 in equation (9).

Then, the estimation means 5 calculates the position of the intersection of the straight lines L1' and L2', and estimates the calculated position of the intersection as the position of the terminal device 30. FIG.

Thus, in estimation method 3, corrected positions (x' _{start — 1} , z' _{start — 1} ) to (x' _{start — 4} , z' start — ₄ ), (x' _{end — 1} , z' _{end — 1} ) to (x' _{end — 4} , z' _{end_4} ) is fitted with an ellipse ELL_2' to find the direction _θ'1 , and the corrected positions ( _{x'start_5} , _{z'start_5} ) ~ ( _{x'start_8} , _{z'start_8} ), ( _{x'end_5} , _{z'end_5} ) ~ Find the direction _θ′2 by fitting (x′ _{end — 8} , z′ _{end — 8} ) with the ellipse ELL_2′, and the intersection point of two straight lines L1 _′ and _L2 ′ whose slopes are the directions θ′1 and θ′2 thus obtained. is estimated to be the position of the terminal device 30 .

FIG. 19 is a flow chart for explaining the operation of the position estimation device 10 shown in FIG.

Referring to FIG. 19, when the operation of position estimation device 10 is started, camera 3 detects position timing chart PS_CHT of shielding object 50 (step S1). Output to The estimation means 5 then receives the position timing chart PS_CHT from the camera 3 .

Then, the measuring devices M_1 and M_2 measure the received signal strength timing charts RSSI_CHT_1 and RSSI_CHT_2, respectively, through the moving shield 50 in a communication environment where the terminal device 30 transmits radio waves to the base station 40 (step S2 ). Then, the measuring devices M_1 and M_2 output received signal strength timing charts RSSI_CHT_1 and RSSI_CHT_2 to the processing means 4, respectively. The processing means 4 receives received signal strength timing charts RSSI_CHT_1 and RSSI_CHT_2 from the measuring devices M_1 and M_2, respectively.

Subsequently, the estimation means 5 sets i=1 (step S3). Then, the processing means 4 calculates the cutoff frequency _{fOFF_i} by the above-described method according to the sampling theorem based on the received signal strength timing chart RSSI_CHT_i (step S4).

After that, the processing means 4 removes frequency components equal to or higher than the cutoff frequency _{fOFF_i} of the received signal strength timing chart RSSI_CHT_i by the low-pass filter LPF_i having the cutoff frequency _{fOFF_i} (step S5).

Subsequently, based on the received signal strength timing chart RSSI_CHT_i after being processed by the low-pass filter LPF_i, the processing means 4 converts each point on the received signal strength timing chart RSSI_CHT_i into two states, the shielded state and the non-shielded state, by the k-means method. clustering into one (step S6) to generate a shielded/unshielded timing chart SHL/UNSHL_CHT_i. Then, the processing means 4 outputs the shielding/non-shielding timing chart SHL/UNSHL_CHT_i to the estimation means 5 .

The estimation means 5 receives the shielding/unshielding timing chart SHL/UNSHL_CHT_i from the processing means 4 . Then, using the position timing chart PS_CHT, the estimating means 5 determines the shielding state SHL_j for each of the J (J is an integer equal to or greater than 1) shielding states 1 to J of the shielding/non-shielding timing chart SHL/UNSHL_CHT_i. The position PS _{start_j_i} of the shielding object 50 at the start time and the position PS _{end_j_i} of the shielding object 50 at the end time of the shielding state SHL_j are detected (step S7).

After that, the estimation means 5 determines whether or not i=2 (step S8). When it is determined in step S8 that i is not 2, the estimation means 5 sets i=i+1 (step S9). After that, the series of operations proceeds to step S4, and steps S4 to S9 are repeatedly executed until it is determined that i=2 in step S8.

Then, in step S8, when it is determined that i=2, the estimation means 5 generates N (N=2×J) positions PS _{start — 1} — PS _start — J — 1 , PS _{end — 1 —} 1 — PS _{end — J — 1} and N positions PS Based on _{start_1_2} to PS _{start_J_2} and PS _{end_1_2} to PS _{end_J_2} , a data group DG used for estimating the position of the terminal device 30 is acquired (step S10).

After that, the estimation means 5 estimates the position of the terminal device 30 by fitting an ellipse to a plurality of positions included in the data group DG (step S11). This completes the operation of the position estimation device 10 .

FIG. 20 is a flow chart for explaining the detailed operation of step S7 in the flow chart shown in FIG.

Referring to FIG. 20, estimation means 5 sets j=1 after step S6 in FIG. 19 (step S71). Here, j represents one of the arguments 1, 2, 3, and 4 of the shielding states SHL_1 to SHL_4, and the arguments 5, 6, 7, and 8 of the shielding states SHL_5 to SHL_8 are the arguments 1, 2, 3, and 4, respectively. , and represents any of the arguments 1, 2, 3, and 4 that have been replaced.

After step S71, the estimation means 5 detects the start time T _{start_j_i} and the end time T _{end_j_i} in the shielded state SHL_j of the shielded/unshielded timing chart SHL/UNSHL_CHT_i (step S72).

Then, the estimation means 5 detects the position PS start_j_i of the shield 50 at the same time as the start time T _{start_j_i} and the position PS _{end_j_i} of the shield ₅₀ at the same time as the end time T _{end_j_i} in the position timing chart PS_CHT ( step S73).

After that, the estimation means 5 determines whether or not j=J (step S74). Here, J is, for example, J=4.

When it is determined in step S74 that j is not J, the estimation means 5 sets j=j+1 (step S75). After that, the series of operations proceeds to step S72, and steps S72 to S75 are repeatedly executed until it is determined that j=J in step S74.

Then, when it is determined that j=J in step S74, the series of operations proceeds to step S8 in FIG.

In the flowchart shown in FIG. 20, after step S3 in FIG. 19 is executed, steps S72 to S75 are repeatedly executed until it is determined that j=J (=4) in step S74. The start times T _{start_1} to T start_4 and the end times T _{end_1} to T _{end_4} in the four shielding states SHL_1 to _{SHL_4} of the signal strength timing chart RSSI_CHT_1 (see curve k3 shown in (a) of FIG. 9) are detected (see step S72). ), in the position timing chart PS_CHT, the positions PS _{start_1} to PS _{start_4} of the shield 50 at the same times as the start times T _{start_1} to T _{start_4} (see FIG. 10(a)), and the same times as the end times T _{end_1} to T _{end_4} , are detected (see step _S73 ) _.

In the flowchart shown in FIG. 20, after step S9 in FIG. 19 is executed, steps S72 to S75 are repeatedly executed until it is determined that j=J (=4) in step S74. , the start times T _{start_5} to T start_8 and the end times T _{end_5} to T _{end_8} in the four shielding states SHL_5 to _{SHL_8} of the received signal strength timing chart RSSI_CHT_2 (see curve k4 shown in (b) of FIG. 9) are detected (step S72), in the position timing chart PS_CHT, the positions PS _{start_5} to PS _{start_8} of the shielding object 50 at the same times as the start times T _{start_5} to T _{start_8} (see FIG. 10(b)), and the end times T _{end_5} to T _{end_8} . The positions PS _{end — 5} to PS _{end — 8} of the shield 50 at the same time (see (b) of FIG. 10) are detected (see step S73).

FIG. 21 is a flow chart for explaining the detailed operation of step S10 in the flow chart shown in FIG.

Referring to FIG. 21, when it is determined that i=2 in step S8 of FIG. Determine (step S101). In this case, the estimating means 5 prestores estimation methods for estimating the position of the terminal device 30. When the prestored estimation method is one of the estimation methods 1 and 3, the position of the terminal device 30 is not the estimation method 2 and the pre-stored estimation method is the estimation method 2, it is determined that the estimation method for estimating the position of the terminal device 30 is the estimation method 2.

In step S101, when it is determined that the estimation method for estimating the position of the terminal device 30 is the estimation method 2, the estimation means 5 selects N positions PS _{start — 1} — PS _{start — J — 1} , PS _{end — 1 — 1} — PS _{end — J — 1} and N positions A data group DG1 consisting of positions PS _{start — 1 — 2} to PS _{start — J — 2} and PS _{end — 1 —} 2 to PS _{end — J —} 2 is selected (step S102).

On the other hand, when it is determined in step S101 that the estimation method for estimating the position of the terminal device 30 is not the estimation method 2, the estimation means 5 selects N positions PS _{start_1_1} to PS _{start_J_1} , PS _{end_1_1} to PS _{end_J_1} and N positions position PS _{start_1_2} to PS _{start_J_2} and PS _{end_1_2} to PS _{end_J_2} are selected (step S103).

After step S102 or step S103, the series of operations proceeds to step S11 in FIG.

In the flowchart shown in FIG. 21, when it is determined in step S101 that the estimation method for estimating the position of the terminal device 30 is the estimation method 2, in step S102, positions (x _{start — 1} , z _{start — 1} ) to (x _{start — 4} ) , z _{start_4} ), (x _{end_1} , z _{end_1} ) to (x _{end_4} , z _{end_4} ) and positions (x _{start_5} , z _{start_5} ) to (x _{start_8} , z _{start_8} ), (x _{end_5} , z _{end_5} ) to (x _{end_8} , z _{end — 8} ) is selected. This is because in the estimation method 2, the position of the terminal device 30 is estimated using either one of the measuring instruments 1 and 2 (that is, one measuring instrument).

Further, in the flowchart shown in FIG. 21, when it is determined in step S101 that the estimation method for estimating the position of the terminal device 30 is not the estimation method 2, in step S103, positions (x _{start — 1} , z _{start — 1} ) to (x _{start_4} , z _{start_4} ), (x _{end_1} , z _{end_1} ) to (x _{end_4} , z _{end_4} ) and positions (x _{start_5} , z _{start_5} ) to (x _{start_8} , z _{start_8} ), (x _{end_5} , z _{end_5} ) to (x _{end_8} , z _{end — 8} ) is selected. This is because in estimation methods 1 and 3, the position of the terminal device 30 is estimated using two measuring instruments 1 and 2 .

FIG. 22 is a flow chart for explaining the detailed operation of step S11 shown in FIG.

Referring to FIG. 22, after step S10 in FIG. 19, estimation means 5 determines whether or not data group DG1 is selected (step S111). In this case, the estimation means 5 determines that the data group DG1 is selected when the data group DG selected in step S10 of FIG. 19 includes N positions, and the data group DG selected in step S10 of FIG. When DG contains (2×N) positions, it is determined that data group DG1 has not been selected.

When it is determined in step S111 that the data group DG1 has been selected, the estimating means 5 converts the N positions P 1 to P N included in the data group DG1 into the N positions P _{' 1} to P' ₁ to P _N by the method described above. It is corrected to _P'N (step S112).

Then, the estimating means 5 obtains the direction θ and the shortest distance d by fitting an ellipse to the N positions P′ ₁ to P′ _N (step S113).

Then, the estimating means 5 measures the received signal strength timing chart RSSI_CHT (one of the received signal strength timing charts RSSI_CHT_1, RSSI_CHT_2) on which the N positions P ₁ to P _N are based (measuring device 1 , 2) is estimated to be the position of the terminal device 30 (step S114).

On the other hand, when it is determined in step S111 that the data group DG1 has not been selected, the estimation means 5 determines whether the estimation method for estimating the position of the terminal device 30 is estimation method 1 (step S115). In step S115, the method for determining whether the estimation method for estimating the position of the terminal device 30 is estimation method 1 is the estimation method 2 for estimating the position of the terminal device 30 in step S101 of FIG. This is the same as the method for determining whether or not

When it is determined in step S115 that the estimation method for estimating the position of the terminal device 30 is the estimation method 1, the estimation means 5 sets i=1 (step S116).

Then, the estimating means 5 obtains the direction θ _i by fitting the N positions P ₁ — i to P _{N — i} included in the data group DG2 with an ellipse (step S117).

After that, the estimating means 5 determines whether or not i=2 (step S118).

When it is determined in step S118 that i is not 2, the estimation means 5 sets i=i+1 (step S119). After that, the series of operations proceeds to step S117, and steps S117 to S119 are repeatedly executed until it is determined that i=2 in step S118.

Then, in step S118, when it is determined that i=2, the estimation means 5 sets the position of the intersection of the straight line with the slope of tan(θ ₁ ) and the straight line with the slope of tan(θ ₂ ) to the terminal. The position of the device 30 is estimated (step S120).

On the other hand, when it is determined in step S115 that the estimation method for estimating the position of the terminal device 30 is not estimation method 1, the estimation means 5 sets i=1 (step S121).

Then, the estimation means 5 corrects the N positions P _{1 — i} to P _{N — i} included in the data group DG2 to N positions P′ _{1 —} i to P′ _{N — i} by the method described above (step S122).

Then, the estimation means 5 obtains the direction θ' _i by fitting the N positions P′ ₁ — i to P′ _{N — i} with an ellipse (step S123).

After that, the estimating means 5 determines whether or not i=2 (step S124).

When it is determined in step S124 that i is not 2, the estimation means 5 sets i=i+1 (step S125). After that, the series of operations proceeds to step S122, and steps S122 to S125 are repeatedly executed until it is determined that i=2 in step S124.

Then, when it is determined that i=2 in step S124, the estimation means 5 determines the position of the intersection of the straight line with the slope of tan(θ′ ₁ ) and the straight line with the slope of tan(θ′ ₂ ). is estimated as the position of the terminal device 30 (step S126).

Then, after one of step S114, step S120 and step S126, the series of operations proceeds to "end" in FIG.

In the flowchart shown in FIG. 22, steps S112 to S114 are steps for estimating the position of the terminal device 30 by the estimation method 2 described above, and steps S116 to S120 are steps for estimating the position of the terminal device 30 by the estimation method 1 described above. Steps S122 to S126 are steps for estimating the position, and steps S122 to S126 are steps for estimating the position of the terminal device 30 by the estimation method 3 described above.

In the flowchart shown in FIG. 22, the estimation method 2 is executed when the data group DG1 is selected in step S111 because the data group DG1 includes N positions P ₁ to P _N. (See step S102 in FIG. 21).

Furthermore, in the flowchart shown in FIG. 22, it is determined in step S115 whether or not the estimation method for estimating the position of the terminal device 30 is the estimation method 1 because the data group DG1 is selected in step S111. Therefore, the data group DG2 is selected, and the data group DG2 consists of N positions P _{1 — 1} to P _{N — 1} (=N positions PS _{start — 1} — PS _{start — J — 1} , PS _{end — 1} — PS _{end — J — 1} ). and N positions P _{1 — 2} to P _{N — 2} (=N positions PS _{start — 1} — PS _{start — J — 2} , PS _{end — 1 — 2} to PS _{end — J — 2} ) (see step S103 in FIG. 21), and N positions P _{1 — 1} to P _{N — 1} and This is because the estimation methods 1 and 3 are estimation methods for estimating the position of the terminal device 30 using the N positions P _{1 — 2} to P _{N — 2} , and therefore it is necessary to distinguish between the estimation method 1 and the estimation method 3. .

Step S6 in the flow chart shown in FIG. 19 (including the flow charts shown in FIGS. 20 to 22) is a step of determining the occluded state, and a step of clustering by unsupervised learning.

Further, in step S8 of the flowchart shown in 19 (including the flowcharts shown in FIGS. 20 to 22), it is determined whether or not i=2 because steps S4 to S7 are performed by two measuring instruments M_1. , M_2 based on each of the two received signal strength timing charts RSSI_CHT_1 and RSSI_CHT_2 measured by M_2.

Furthermore, in the flow chart shown in FIG. 19 (including the flow charts shown in FIGS. 20 to 22), shielding signals clustered based on the received signal strength timing chart RSSI_CHT_1 after removing frequency components equal to or higher than the cutoff frequency _{fOFF_1} . It is assumed that the number of states is J, which is the same as the number of blocked states clustered based on the received signal strength timing chart RSSI_CHT_2 after removing the frequency components equal to or higher than the cutoff frequency _{fOFF_2} (see step S7). In the embodiment of the present invention, the number J of shielded states clustered based on the received signal strength timing chart RSSI_CHT_1 after removing the frequency components equal to or higher than the cutoff frequency _{fOFF_1} is determined by the cutoff frequency fOFF_1. It may be different from the number J' of shielding states clustered based on the received signal strength timing chart RSSI_CHT_2 after removing frequency components of f _{OFF_2} or higher. In this case, the number of positions PS _{start_1_1} to PS _{start_J_1} and PS _{end_1_1} to PS _{end_J_1} in step S10 differs from the number of positions PS _{start_1_2} to PS _{start_J'_2} and PS _{end_1_2} to PS _{end_J'_2} .

Furthermore, in the flowchart shown in FIG. 19 (including the flowcharts shown in FIGS. 20 to 22), J is an integer of 1 or more because the received signal strength timing chart RSSI_CHT_1 measured by one measuring device M_1 If at least one shielding state SHL is detected based on , the number of positions to be fitted with an ellipse becomes two or more, and fitting with an ellipse is possible.

19 (including the flowcharts shown in FIGS. 20 to 22), the position error of the terminal device 30 is 0.47 m to 0.69 m. 20 to 22), the position of the terminal device 30 can be estimated with high accuracy.

According to the flowchart shown in FIG. 19 (including the flowcharts shown in FIGS. 20 to 22), the position of the terminal device 30 is estimated based on the received signal strength timing chart RSSI_CHT measured by one or two measuring instruments. Therefore, the position of the terminal device 30 can be estimated using less than three measuring instruments.

In addition, in the embodiment of the present invention, the operations of the processing means 4 and the estimation means 5 may be executed by software. In this case, the position estimation device 10 includes measuring instruments 1 and 2, a camera 3, and a personal computer PC. The personal computer PC includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory).

The ROM stores a program Prog_A including steps S3 to S11 of the flowchart shown in FIG. 19 (including the flowcharts shown in FIGS. 20 to 22). The RAM stores cutoff frequencies _{fOFF_1} and _{fOFF_2} , a received signal strength timing chart RSSI_CHT_1 after removing frequency components above cutoff frequency _{fOFF_1} , and a received signal strength after removing frequency components above cutoff frequency _{fOFF_2} . Timing chart RSSI_CHT_2 and straight lines L1 and L2 are temporarily stored.

Then, the CPU receives received signal strength timing charts RSSI_CHT_1 and RSSI_CHT_2 from measuring instruments 1 and 2, respectively, and receives position timing chart PS_CHT from camera 3. FIG. Then, the CPU reads out the program Prog_A from the ROM and executes it, and executes the program Prog_A of the terminal device 30 based on the received signal strength timing charts RSSI_CHT_1 and RSSI_CHT_2 respectively measured by the measuring instruments 1 and 2 and the position timing chart PS_CHT detected by the camera 3. Estimate location.

Also, the program Prog_A may be recorded on a recording medium such as a CD or DVD and distributed. When the recording medium recording the program Prog_A is loaded into the computer, the computer reads out the program Prog_A from the recording medium and executes it to obtain received signal strength timing charts RSSI_CHT_1 and RSSI_CHT_2 measured by the measuring instruments 1 and 2, respectively, and the camera 3. estimates the position of the terminal device 30 based on the detected position timing chart PS_CHT.

Therefore, the recording medium recording the program Prog_A is a computer-readable recording medium.

In the above description, the k-means method is used to classify the shielding state SHL and the non-shielding state UNSHL. The shielded state SHL and the unshielded state UNSHL may be classified using a clustering technique, which is a method of dividing the set to be classified into subsets such that (external isolation) is achieved, and the shielded received signal The shielded state SHL and the unshielded state UNSHL may be classified by pattern matching using the attenuation pattern of the intensity RSSI.

In addition to the above-mentioned k-means method, clustering methods include the nearest neighbor method, furthest neighbor method, group average method, Ward's method, and the like. be.

Further, when classifying the shielded state SHL and the non-shielded state UNSHL by pattern matching, the attenuation pattern of the received signal strength RSSI in the shielded state is detected in advance, and detected in advance in the received signal strength timing charts RSSI_CHT_1 and RSSI_CHT_2 described above. The shielded state SHL and the non-shielded state SHL are detected by detecting an attenuation pattern of the received signal strength that matches the attenuation pattern of the received signal strength RSSI obtained and an attenuation pattern of the received signal strength that does not match the previously detected attenuation pattern of the received signal strength RSSI. state UNSHL.

[Embodiment 2]
23 is a schematic diagram of a position estimation device according to Embodiment 2. FIG. Referring to FIG. 23, position estimation device 10A according to Embodiment 2 is obtained by adding shielding/unshielding device 6 to position estimation device 10 shown in FIG. 1 and replacing estimation means 5 with estimation means 5A. , and others are the same as those of the position estimation device 10 .

The estimating means 5 A drives the shielding/unshielding device 6 . The estimating means 5A performs the same functions as the estimating means 5 otherwise.

When driven by the estimating means 5A, the shielding/unshielding device 6 shields and transmits (unshields) radio waves transmitted from the terminal device 30 while moving between the terminal device 30 and the measuring instruments 1 and 2. .

FIG. 24 is a schematic diagram of the shielding/unshielding device 6 shown in FIG. Referring to FIG. 24, shielding/non-shielding device 6 includes main body 61, support member 62, control device 63, power supply 64, motor 65, driving device 66, wheels 67 and 68, shielding a member 69;

A control device 63 , a power source 64 , a motor 65 and a drive device 66 are housed in the body portion 61 . The shielding member 69 is fixed to the body portion 61 by the support member 62 .

The control device 63 controls the power source 64 to supply power to the motor 65 upon receiving the drive signal from the estimation means 5A. The control device 63 also controls the motor 65 to rotate the drive wheels (wheels 67) at a predetermined number of revolutions. That is, the control device 63 controls the moving speed of the shielding/unshielding device 6 . Further, the control device 63 controls the motor 65 to switch the direction of rotation so that the shielding/unshielding device 6 moves forward or backward. Further, the control device 63 outputs a control signal to the drive device 66 for changing the direction of the drive wheels (wheels 67) so that the shielding/unshielding device 6 moves rightward or leftward with respect to the traveling direction. .

The power supply 64 consists of a rechargeable battery and supplies power to the motor 65 under the control of the control device 63 .

The motor 65 receives power from the power source 64 and supplies power to the drive device 66 to rotate the drive wheels (wheels 67 ) under the control of the control device 63 .

The driving device 66 receives power from the motor 65 and rotates the drive wheels (wheels 67) so that the shielding/unshielding device 6 moves forward or backward by the received power. Further, the drive device 66 changes the direction of the drive wheels (wheels 67 ) according to the control signal from the control device 63 .

In FIG. 24, a plan view of the shielding member 69 seen from direction A is illustrated. The shielding member 69 has a circular planar shape and includes a shielding portion 691 and a shaft member 692 . The shielding part 691 is arranged on the outer peripheral side of the shaft member 692 . The shielding unit 691 shields radio waves transmitted from the terminal device 30 . The shielding part 691 may be made of any material, such as metal, as long as it can shield radio waves. The shaft member 692 is connected to one end of the support member 62 .

The driving device 66 has a preset range of movement of the shielding/unshielding device 6 . That is, the driving device 66 is preset with a movable range in the x-axis direction and a movable range in the z-axis direction on the xz plane.

The driving device 66 senses the rotational speed and orientation of the drive wheels (wheels 67), and based on the sensed rotational speed and orientation, determines the x-axis distance and the z-axis distance traveled by the shielding/unshielding device 6. Calculate Then, the driving device 66 is such that the calculated distance in the x-axis direction is within a preset range of movement in the x-axis direction, and the calculated distance in the z-axis direction is within a preset range of movement in the z-axis direction. The driving wheels (wheels 67) are driven so as to be within the range.

In the position estimation device 10A, the measuring devices 1 and 2 receive the radio waves transmitted from the terminal device 30 via the shielding member 69 of the shielding/unshielding device 6, and obtain received signal strength timing charts RSSI_CHT_1 and RSSI_CHT_2, respectively. Measure.

In the position estimating device 10A, the camera 3 detects a position timing chart PS_CHT representing elapsed time dependency of the position of the shielded/unshielded device 6 made up of three-dimensional coordinates.

FIG. 25 is a flow chart for explaining the operation of the position estimation device 10A shown in FIG.

The flowchart shown in FIG. 25 is the same as the flowchart shown in FIG. 19 except that step S20 is added to the flowchart shown in FIG. 19 and step S2 is changed to step S2A. As a result, the detailed operation of step S7 of the flowchart shown in FIG. 25 is executed according to the flowchart shown in FIG. 20, and the detailed operation of step S10 of the flowchart shown in FIG. 25 is executed according to the flowchart shown in FIG. Detailed operation of step S11 in the flowchart shown in 25 is executed by the flowchart shown in FIG. Accordingly, the flowchart shown in FIG. 25 includes the flowcharts shown in FIGS. 20-22.

Referring to FIG. 25, when position estimation device 10A starts operating, estimation means 5A outputs a drive signal for driving shielding/unshielding device 6 to control device 63 of shielding/unshielding device 6. Then, the control device 63 of the shielding/unshielding device 6 drives the shielding/unshielding device 6 upon receiving the drive signal from the estimation means 5A. Then, the driving device 66 drives the driving wheels (wheels 67) so as to move within a preset range. As a result, the shielding/unshielding device 6 moves within a preset range (step S20).

Thereafter, after step S1 described above is executed, in a communication environment in which the terminal device 30 transmits radio waves to the base station 40, the measuring instruments M_1 and M_2 receive signals via the moving shielded/unshielded device 6, respectively. Signal strength timing charts RSSI_CHT_1 and RSSI_CHT_2 are measured (step S2A).

After step S2A, steps S3 to S11 described above are sequentially executed, and the estimation means 5A estimates the position of the terminal device 30 by the method described above. This completes the operation of the position estimation device 10A.

According to the flow chart shown in FIG. 25 (including the flow charts shown in FIGS. 20 to 22), since the moving speed of the shielding/unshielding device 6 can be controlled, the shielding when shielding the radio waves transmitted from the terminal device 30 can be controlled. / Receiving by controlling the moving speed of the non-shielding device 6 in the x-axis direction to be lower than the moving speed of the shielding/non-shielding device 6 in the x-axis direction when the radio waves transmitted from the terminal device 30 are not shielded In the signal strength timing charts RSSI_CHT_1 and RSSI_CHT_2, the elapsed time in the region where the received signal strength RSSI is attenuated becomes longer, and the number of points in the region where the received signal strength RSSI is attenuated (each point is calculated from the elapsed time and the received signal strength RSSI). ) can be classified into the shielded state SHL by the k-menas method. As a result, the start time T _start and the end time T _end of the shielding state SHL can be determined more accurately, and finally the position of the terminal device 30 can be estimated more accurately.

In addition, in the embodiment of the present invention, the operations of the processing means 4 and the estimation means 5A may be executed by software. In this case, the position estimation device 10A comprises measuring instruments 1 and 2, a camera 3, a shielding/unshielding device 6, and a personal computer PC. A personal computer PC includes a CPU, a ROM, and a RAM.

The ROM stores a program Prog_A including steps S3 to S11 of the flowchart shown in FIG. 25 (including the flowcharts shown in FIGS. 20 to 22). The RAM stores cutoff frequencies _{fOFF_1} and _{fOFF_2} , a received signal strength timing chart RSSI_CHT_1 after removing frequency components above cutoff frequency _{fOFF_1} , and a received signal strength after removing frequency components above cutoff frequency _{fOFF_2} . Timing chart RSSI_CHT_2 and straight lines L1 and L2 are temporarily stored.

Then, the CPU receives received signal strength timing charts RSSI_CHT_1 and RSSI_CHT_2 from measuring instruments 1 and 2, respectively, and receives position timing chart PS_CHT from camera 3. FIG. Then, the CPU reads out the program Prog_A from the ROM and executes it, and executes the program Prog_A of the terminal device 30 based on the received signal strength timing charts RSSI_CHT_1 and RSSI_CHT_2 respectively measured by the measuring instruments 1 and 2 and the position timing chart PS_CHT detected by the camera 3. Estimate location.

Also, the program Prog_A may be recorded on a recording medium such as a CD or DVD and distributed. When the recording medium recording the program Prog_A is loaded into the computer, the computer reads out the program Prog_A from the recording medium and executes it to obtain received signal strength timing charts RSSI_CHT_1 and RSSI_CHT_2 measured by the measuring instruments 1 and 2, respectively, and the camera 3. estimates the position of the terminal device 30 based on the detected position timing chart PS_CHT.

Therefore, the recording medium recording the program Prog_A is a computer-readable recording medium.

26 is a schematic diagram of another position estimation device according to Embodiment 2. FIG. The position estimation device according to Embodiment 2 may be position estimation device 10B shown in FIG.

Referring to FIG. 26, position estimation device 10B is obtained by replacing estimation means 5A of position estimation device 10A shown in FIG. , and the rest is the same as the position estimation device 10A shown in FIG.

The estimation means 5B drives the shielding/unshielding device 6A. The estimating means 5B receives from the processing means 4 the received signal strength timing chart RSSI_CHT_1 from which the frequency components above the cutoff frequency _{fOFF_1} have been removed and the received signal strength timing chart RSSI_CHT_2 from which the frequency components above the cutoff frequency _{fOFF_2} have been removed. The estimating means 5B also receives the position timing chart PS_CHT from the camera 3 .

Then, the estimating means 5B estimates the position of the terminal device 30 by a method described later based on the received signal strength timing charts RSSI_CHT_1 and RSSI_CHT_2 from which frequency components above the cutoff frequency are removed and the position timing chart PS_CHT.

The estimation means 5B holds the position (x ₁ , z ₁ ) of the measuring device 1 and the position (x ₂ , z ₂ ) of the measuring device 2 in advance.

When the shielding/non-shielding device 6A is driven by the estimating means 5B, it reciprocates in the z-axis direction while moving in the x-axis direction between the terminal device 30 and the measuring instruments 1 and 2. It shields and transmits (unshields) transmitted radio waves.

FIG. 27 is a schematic diagram of the shielding/unshielding device 6A shown in FIG. Referring to FIG. 27, shielding/unshielding device 6A has motor 75 added to shielding/unshielding device 6 shown in FIG. , the shielding member 69 is replaced with the shielding/non-shielding member 76, and the support member 62 is replaced with the support member 72. Others are the same as the shielding/non-shielding device 6.

The support member 72 fixes the motor 75 to the body portion 61 . The shielding/unshielding member 76 is connected to one end of the shaft 751 of the motor 75 .

The controller 63A controls the power supply 64 so as to supply power to the motor 75 as well. Further, the control device 63A controls the motor 75 to rotate the shaft 751 at a predetermined number of revolutions. Further, the control device 63A controls the driving device 66 so that the shielding/unshielding device 6A is moved in the x-axis direction and reciprocated in the z-axis direction. The control device 63A performs the same functions as the control device 63 otherwise.

The motor 75 rotates the shaft 751 at a predetermined number of revolutions under the control of the control device 63A.

The shielding/non-shielding member 76 comprises a cover member 76-1 and a rotating member 76-3. The cover member 76-1 is fixed to the body portion 61 by a support member (not shown). The rotating member 76-3 is arranged inside the cover member 76-1.

The rotating member 76-3 includes a shaft member 781, a shielding member 782, and a shielding/non-shielding member 783.

The shaft member 781 is connected to one end of the shaft 751 of the motor 75 . The shielding member 782 is arranged on the outer peripheral side of the shaft member 781 . The shielding/non-shielding member 783 is arranged on the outer peripheral side of the shielding member 782 .

28 is a plan view of the cover member 76-1 shown in FIG. 27. FIG. 28(a) is a plan view of the cover member 76-1 seen from direction A shown in FIG. 27, and FIG. 28(b) is a plan view of the cover member 76-1 seen from the motor 75 side shown in FIG. 1 shows a plan view of FIG.

Referring to (a) of FIG. 28, cover member 76-1 has a circular planar shape, and has opening 762 and shielding portion 763. Cover member 76-1 has a flat shape. Each of the two openings 762 and the two shields 763 has a fan-shaped planar shape. The two openings 762 are arranged along the horizontal direction, and the two shielding portions 763 are arranged along the vertical direction. The two openings 762 are alternately arranged with the two shielding portions 763 in the circumferential direction of the cover member 76-1.

Referring to FIG. 28(b), the cover member 76-1 has an opening 764 and a support 765 on the motor 75 side. Each of the four openings 764 has a fan-shaped planar shape. Of the four openings 764, two openings 764 are arranged along the horizontal direction and the remaining two openings 764 are arranged along the vertical direction.

Each support portion 765 is arranged between two openings 764 adjacent in the circumferential direction of the cover member 76-1.

29 is a plan view of the rotating member 76-3 shown in FIG. 27. FIG. Referring to FIG. 29, shielding/non-shielding member 783 of rotating member 76-3 includes shielding portions 783-1 to 783-4 and non-shielding portions 783-5 to 783-8.

Each of the shielding portions 783-1 to 783-4 and the non-shielding portions 783-5 to 783-8 has a fan-shaped planar shape. The shielded portions 783-1 to 783-4 and the non-shielded portions 783-5 to 783-8 have the same arc length. Each of the shielding portions 783-1 to 783-4 and the non-shielding portions 783-5 to 783-8 has an arc length of the opening 762 (see FIG. 28(a)) of the cover member 76-1. shorter than the arc length.

The shielded portions 783-1 to 783-4 are alternately arranged with the non-shielded portions 783-5 to 783-8 in the circumferential direction of the rotating member 76-3.

Each of the shielding parts 783-1 to 783-4 is made of metal, for example. Each of the non-shielding portions 783-5 to 783-8 consists of a through hole.

The diameter of the rotating member 76-3 has a diameter (for example, 2.5 m) that is larger than the distance between the positions of the measuring instruments 1 and 2 in the x-axis direction. Then, the rotating member 76-3 rotates clockwise ARW1 or counterclockwise ARW2.

When the rotating member 76-3 rotates clockwise ARW1 or counterclockwise ARW2, the shielding member 782, the shielding portions 783-1 to 783-4, and the non-shielding portions 783-5 to 783-8 move toward the cover member 76-1. It passes through the opening 762 (see FIG. 28(a)).

As a result, the shielding member 782 shields the radio wave transmitted from the terminal device 30, the shielding/non-shielding member 783 shields the radio wave transmitted from the terminal device 30 by the shielding units 783-1 to 783-4, Radio waves transmitted from the terminal device 30 are transmitted by the non-shielding portions 783-5 to 783-8.

In this way, the rotating member 76-3 includes a shielding member 782 that always shields radio waves transmitted from the terminal device 30, and a shielding/non-shielding member that shields and transmits (non-shields) radio waves transmitted from the terminal device 30. 783.

FIG. 30 is a diagram for explaining a method of estimating the position of the terminal device 30 by the position estimation device 10B shown in FIG.

FIG. 30 describes a method of estimating the position of the terminal device 30 when the position of the terminal device 30 in the x-axis direction is the middle point between the positions of the measuring devices 1 and 2. FIG.

Referring to FIG. 30, the rotating member 76-3 of the shielding/unshielding device 6A is rotated so that the center of the shaft member 781 passes through the midpoint between the positions of the measuring instruments 1 and 2 in the x-axis direction. placed in The shielding/unshielding device 6A then moves in the z-axis direction. Also, the distance between the measuring instruments 1 and 2 in the x-axis direction is v, and the radius of the shielding member 782 of the rotating member 76-3 is a. The distance v is known since it can be calculated based on the position of the measuring device 1 and the position of the measuring device 2 . Also, the radius a of the shielding member 782 is set to, for example, 0.5 m and is known.

When the rotating member 76-3 is at the position _zr1 , radio waves transmitted from the terminal device 30 are transmitted from the non-shielding portions of the shielding/non-shielding member 783 of the rotating member 76-3 (non-shielding portions 783-5 to 783- 8) and directly enter measuring instruments 1 and 2, respectively.

Also, when the rotating member 76-3 is at the position _zr2 , the shielding member 782 begins to shield radio waves directly incident on the measuring instruments 1 and 2 from the terminal device 30. FIG.

Further, when the rotating member 76-3 is at the position _zr3 , radio waves directly incident on the measuring devices 1 and 2 from the terminal device 30 are shielded by the shielding member 782. FIG.

As a result, the received signal strength RSSI when radio waves are received by the measuring devices 1 and 2 decreases as the rotary member 76-3 moves from the position _zr1 toward the terminal device 30 side.

When the rotating member 76-3 is at the position _zr2 , the terminal device 30, the point A of the rotating member 76-3, and the measuring device 1 (point C) are on one straight line, and the terminal device 30, the rotating member Point D of 76-3 and measuring device 2 (point E) lie on one straight line.

Then, if point B is set to have the same x-coordinate as that of point A, ΔABC becomes a right-angled triangle. Similarly, setting a point F with the same x-coordinate as the x-coordinate of point D makes ΔDEF a right-angled triangle.

Then the distance between points B and C and the distance between points E and F are represented by v/2-a. The distance between points A and B is d _S1 , and the distance between points D and F is d _S2 (=d _S1 ). d _S1 and d _S2 are detected based on the received signal strength timing charts RSSI_CHT_1 and RSSI_CHT_2, respectively, and the position timing chart PS_CHT indicating the dependence of the position of the rotary member 76-3 detected by the camera 3 on elapsed time. be done.

Therefore, ∠CAB is the same as θ _S1 , and if the position of the terminal device 30 is represented by point S, tan(θ _S1 ) represents the reciprocal of the slope of the straight line connecting point S and point C, and point S Since the slope of the straight line connecting C and point C has a negative value, the following equation holds.

∠EDF is the same as θ _S2 , tan(θ _S2 ) represents the reciprocal of the slope of the straight line connecting point S and point E, and the slope of the straight line connecting point S and point E is positive. , the following equation holds.

θ _S1 represents the angle formed by the z-axis direction when the radio wave _from the terminal device 30 is directly incident on the measuring instrument 1 and the incident direction of the radio wave, It represents the angle between the z-axis direction and the incident direction of radio waves when directly incident.

v in Equation (12) is the distance between the position of measuring device 1 and the position of measuring device 2 in the x-axis direction and is known. Also, a is the radius of the shielding member 782 and is known. Furthermore, since the position of point A and the position of point D can be determined from the position timing chart PS_CHT detected by camera 3, d _S1 and d _S2 are known. Therefore, the estimating means 5B can calculate θ _S1 and θ _S2 by equations (12) and (13), respectively.

[Estimation method 4]
After calculating θ _S1 and θ _S2 , the estimation means 5B estimates the position of the terminal device 30 by the following method.

The estimation means 5B uses d _S1 , which is the distance between points A and B, and (v/2−a), which is the distance between points B and C, to estimate the distance d _AC1 is calculated by the following equation.

Then, the estimation means 5B assumes that the distance between the points S and C is d _SC1 . Then, the distance d _SC1 is represented by the following equation.

In formula (15), formula (15B) is obtained from formula (15A), and formula (15C) is obtained from formula (15B) and formula (14).

Since v, d _S1 , a on the right side of Equation (15C) are already known, the estimation means 5B substitutes v, d _S1 , a into Equation (15C) to calculate the distance d _SC1 . Since a=0.5m and v=approximately 2m, the denominator (=v-2a) of equation (15C) is positive.

According to the Fresnel zone, the transmitting station and the receiving station are located at the two focal points of an ellipse (see equation (5)) defining the perimeter of the first Fresnel zone.

Therefore, the estimation means 15 estimates the position of the terminal device 30 using the first Fresnel zone as follows. Since θ _S1 has a negative value as shown in equation (12), the angle (π/2−θ _S1 ) essentially consists of the absolute value of θ _S1 added to π/2. As a result, the direction (π/2-θ _S1 ) is the direction (π/2+|θ _{S1 |} )become. Therefore, the estimating means 5B estimates the position of the terminal device 30 at a position separated by a distance d _SC1 in the direction (π/2+|θ _S1 |) from the position of the measuring instrument 1 .

More specifically, the estimating means 5B assumes that the coordinates of the position of the terminal device 30 are (x ₃₀ , z ₃₀ ), and solves the simultaneous equations (16A) and (16B) to obtain coordinates (x ₃₀ , z ₃₀ ). Calculate

Note that the estimation unit 5B converts tan(π/2+|θ _S1 |) in Equation (16A) to tan(π/2+|θ _S1 |)=1/tan(|θ _S1 |)=d _S1 /(v/ 2-a).

Further, the estimation means 5B uses _dS2 , which is the distance between the point D and the point F, and (v/2-a), which is the distance between the point E and the point F, to determine the distance between the point D and the point E. The distance d _DE1 is calculated by the following equation.

Then, the estimation means 5B assumes that the distance between the points S and E is d _SE1 . Then, the distance d _SE1 is represented by the following equation.

In formula (18), formula (18B) is obtained from formula (18A), and formula (18C) is obtained from formula (18B) and formula (17).

Since v, d _S2 , a on the right side of Equation (18C) are already known, the estimation means 5B substitutes v, d _S2 , a into Equation (18C) to calculate the distance d _SE1 . Note that the denominator (=v-2a) is also positive in equation (18).

As described above, the transmitting station and the receiving station are located at the two focal points of the ellipse (see equation (5)) that defines the outer circumference of the first Fresnel zone. The position of the terminal device 30 is estimated to be a position separated by a distance d _SE1 in the direction (π/2−θ _S2 ) from .

More specifically, the estimating means 5B assumes that the coordinates of the position of the terminal device 30 are (x' ₃₀ , z' ₃₀ ), and solves the simultaneous equations (19A) and (19B) to obtain the coordinates (x' 30 , z' ₃₀ ). z' ₃₀ ) is calculated.

The estimating means 5B calculates tan(π/2−θ _S2 ) in Equation (19A) by tan(π/2−θ _S2 )=d _S2 /(v/2−a).

Then, the estimation means 5B calculates the distance Δd between the coordinates (x ₃₀ , z ₃₀ ) and the coordinates (x′ ₃₀ , z′ ₃₀ ), and when the calculated distance Δd is equal to or less than the threshold value Δd_th, the coordinates Either (x ₃₀ , z ₃₀ ) or coordinates (x′ ₃₀ , z′ ₃₀ ) is estimated as the position of the terminal device 30 .

On the other hand, when the distance Δd is greater than the threshold Δd_th, the estimator 5B re-estimates the position of the terminal device 30 .

Note that the threshold value Δd_th is set to 0.5 m, for example.

FIG. 31 is another diagram for explaining the method of estimating the position of the terminal device 30 by the position estimation device 10B shown in FIG.

FIG. 31 shows the position of the terminal device 30 when the x-coordinate of the position of the terminal device 30 is between the midpoint between the position of the measuring device 1 and the position of the measuring device 2 in the x-axis direction and the measuring device 1. A method for estimating is explained. 31, it is assumed that the x-coordinates of the terminal device 30 and the measuring device 1 are not the same when estimating the position of the terminal device 30 by the method described below.

When the rotating member 76-3 is at the position _zr1 , radio waves transmitted from the terminal device 30 are transmitted from the non-shielding portions of the shielding/non-shielding member 783 of the rotating member 76-3 (non-shielding portions 783-5 to 783- 8) and directly enter measuring instruments 1 and 2, respectively.

Further, when the rotating member 76-3 is at the position _zr4 , the radio waves transmitted from the terminal device 30 are transmitted from the non-shielding portions (non-shielding portions 783-5 to 783-5) of the shielding/non-shielding member 783 of the rotating member 76-3. 783 - 8 ) and directly enter the measuring device 1 , but the radio waves that directly enter the measuring device 2 begin to be shielded by the shielding member 782 .

Further, when the rotating member 76-3 is at the position _zr5 , radio waves directly incident on the measuring device 1 from the terminal device 30 begin to be shielded by the shielding member 782, and radio waves directly incident on the measuring device 2 from the terminal device 30 is shielded by the shielding member 782 .

Furthermore, when the rotating member 76-3 is at the position _zr6 , radio waves directly incident on the measuring devices 1 and 2 from the terminal device 30 are shielded by the shielding member 782. FIG.

As a result, the position of the rotary member 76-3 when the shielding member 782 starts to shield the radio waves directly incident on the measuring instruments 1 and 2 from the terminal device 30 differs between the measuring instruments 1 and 2. FIG. The received signal strength RSSI when radio waves are received by the measuring devices 1 and 2 decreases as the rotating member 76-3 moves from the position _z1 toward the terminal device 30 side.

When the rotating member 76-3 is at the position _zr4 , the terminal device 30, the point D of the rotating member 76-3, and the measuring instrument 2 (point E) are on one straight line, and the rotating member 76-3 is When present at position _zr5 , terminal device 30, point A of rotating member 76-3 and measuring instrument 1 (point C) are present on one straight line.

Then, if we set a point B having the same x-coordinate as that of point A, ΔABC is a right triangle, and if we set a point F that has the same x-coordinate as that of point D, ΔDEF is a right angle become a triangle.

Then the distance between points B and C and the distance between points E and F are represented by v/2-a. The distance between points A and B is _dS1 , and the distance between points D and F is _dS2 . And the distance d _S2 is smaller than the distance d _S1 (d _S1 >d _S2 ).

Also in the case shown in FIG. 31, ∠CAB is the same as θ _S1 , tan(θ _S1 ) is represented by Equation (12), ∠EDF is the same as θ _S2 , and tan(θ _S2 ) is represented by equation (13).

Therefore, the estimating means 5B can calculate θ _S1 and θ _S2 by equations (12) and (13), respectively.

[Estimation method 5]
The estimation means 5B estimates the position of the terminal device 30 by the following method.

In FIG. 31, the x-coordinate of the position of the terminal device 30 is unknown, but since d ₁ >d ₂ , the estimation means 5B assumes that the x-coordinate of the position of the terminal device 30 is the position of the measuring instrument 1 in the x-axis direction. and the position of the measuring instrument 2 and the measuring instrument 1.

Therefore, the estimating means 5B sets points H and I between the midpoint G and the measuring instrument 1, assumes that the distance between the points C and H is _dx1 , and calculates the distance between the points E and I as Assume d _x2 .

Then, the estimation means 5B sets a point S indicating the position of the terminal device 30, assumes that ΔSHC and ΔSEI are right-angled triangles, and assumes that the distance between the points H and S in ΔSHC is _dz1 . and the distance between points I and S on ΔSEI is assumed to be _dz2 .

As a result, the following equation is obtained.

Equation (20A) is obtained by assuming that ΔABC and ΔSHC are similar, and equation (20B) is obtained by assuming that ΔDEF and ΔSEI are similar.

When d _z1 and d _z2 are calculated from equations (20A) and (20B) respectively, d _z1 and d _z2 are expressed by the following equations.

Assuming that a point K has the same x-coordinate as the position of the terminal device 30, ΔABC and ΔSKC are similar, and ΔDEF and ΔSEK are similar. In this case, d _z1 in Equation (21A) and d _z2 in Equation (21B) match, so the right side of Equation (21A) and the right side of Equation (21B) are equal, and d _x2 is obtained using d _x1 . is expressed by the following equation.

Then, when d _x1 and d _x2 are determined by equations (20C) and (22), d _x1 and d _x2 are expressed by the following equations.

The estimating means 5B substitutes d _x1 represented by equation (23A) into equation (21A) to calculate d _z1 , and substitutes d _x2 represented by equation (23B) into equation (21B) to calculate d Calculate _z2 . As a result, d _z1 and d _z2 are represented by the following equations.

As shown in equation (24), d _z1 matches d _z2 . When the estimating means 5B calculates d _z1 and d _z2 , it confirms that d _z1 matches d _z2 .

d _x1 represents the distance between points K and C, and d _x2 represents the distance between points E and K when d _z1 matches d _z2 .

Therefore, the estimation means 5B calculates the distance d _SC2 between the point S and the point C using the distances d _x1 and d _z1 by the following equation.

Then, in the same manner as in estimation method 4, estimating means 5B estimates the position of terminal device 30 at a distance d _SC2 in the direction (π/2+|θ _S1 |) from the position of measuring instrument 1 .

More specifically, the estimating means 5B assumes that the coordinates of the position of the terminal device 30 are (x ₃₀ , z ₃₀ ), and solves the simultaneous equations (26A) and (26B) to obtain coordinates (x ₃₀ , z ₃₀ ). Calculate

Note that the estimating means 5B converts tan(π/2+|θ _S1 |) in Equation (26A) to tan(π/2+|θ _S1 |)=1/tan(|θ _S1 |)=−d _S1 /(v /2-a).

Similarly, the estimation means 5B uses the distance d _S2 , the direction θ _S2 and the position (x ₂ , z ₂ ) of the measuring device 2 to calculate the distance d _SE2 between the point S and the point E by the following equation. do.

Then, in the same manner as in estimation method 4, the estimation means 5B estimates the position of the terminal device 30 at a distance d _SE2 in the direction (π/2−θ _S2 ) from the position of the measuring instrument 2 .

More specifically, the estimating means 5B assumes that the coordinates of the position of the terminal device 30 are (x' ₃₀ , z' ₃₀ ), and solves the simultaneous equations (28A) and (28B) to obtain coordinates (x' 30 , z' ₃₀ ). z' ₃₀ ) is calculated.

The estimating means 5B calculates tan(π/2−θ _S2 ) in Equation (28A) by tan(π/2−θ _S2 )=d _S2 /(v/2−a).

Then, the estimation means 5B calculates the distance Δd between the coordinates (x ₃₀ , z ₃₀ ) and the coordinates (x′ ₃₀ , z′ ₃₀ ), and when the calculated distance Δd is equal to or less than the threshold value Δd_th, the coordinates Either (x ₃₀ , z ₃₀ ) or coordinates (x′ ₃₀ , z′ ₃₀ ) is estimated as the position of the terminal device 30 .

On the other hand, when the distance Δd is greater than the threshold Δd_th, the estimator 5B re-estimates the position of the terminal device 30 .

Note that FIG. 31 shows a case where the x-coordinate of the position of the terminal device 30 exists between the midpoint between the position of the measuring device 1 and the position of the measuring device 2 in the x-axis direction and the measuring device 1. Even if the x-coordinate of the position of the device 30 is between the midpoint of the position of the measuring device 1 and the position of the measuring device 2 in the x-axis direction and the measuring device 2, the estimating means 5B uses the method described above to The position of device 30 can be estimated.

In this case, points H and I are set between points F and G in the x-axis direction, and point K is set between points I and H in the x-axis direction. Also, d _S1 <d _S2 .

FIG. 32 is yet another diagram for explaining a method of estimating the position of the terminal device 30 by the position estimation device 10B shown in FIG.

FIG. 32 shows the position of terminal device 30 when the x-coordinate of the position of terminal device 30 is farther than the position of measuring device 1 as viewed from measuring device 2 in the direction from measuring device 2 to measuring device 1. Explain how to estimate.

When the rotating member 76-3 is at the position _zr7 , radio waves transmitted from the terminal device 30 can directly enter the measuring device 1 without being blocked by the shielding member 782 of the rotating member 76-3.

Also, when the rotating member 76-3 is at the position _zr8 , radio waves directly incident on the measuring device 1 from the terminal device 30 begin to be shielded by the shielding member 782 of the rotating member 76-3.

Furthermore, when the rotating member 76-3 is at the position _zr10 , radio waves transmitted from the terminal device 30 can directly enter the measuring device 2 without being blocked by the rotating member 76-3.

Furthermore, when the rotating member 76-3 is at the position _zr9 , radio waves directly incident on the measuring device 2 from the terminal device 30 begin to be shielded by the shielding member 782 of the rotating member 76-3.

As a result, the received signal strength RSSI1 when the radio wave is directly received by the measuring instrument 1 decreases as the rotating member 76-3 moves from the position _zr7 toward the measuring instruments 1 and 2, and the radio wave The received signal strength RSSI2 when directly receiving is increased as the rotary member 76-3 moves from the position _zr9 toward the measuring instrument 2 side.

When the rotating member 76-3 is at the position _zr8 , the terminal device 30, the point A of the rotating member 76-3 and the measuring device 1 (point C) are on one straight line.

Further, when the rotating member 76-3 is at the position _zr9 , the terminal device 30, the point D of the rotating member 76-3, and the measuring instrument 2 (point E) are on one straight line.

Then, if we set a point B having the same x-coordinate as that of point A, ΔABC is a right triangle, and if we set a point F that has the same x-coordinate as that of point D, ΔDEF is a right angle become a triangle.

Then, the distance between point B and point C is the distance (x _A −x ₁ ) obtained by subtracting the x coordinate x ₁ of point C from the x coordinate x _A of point A, and the distance between point E and point F is , is the distance obtained by subtracting the x-coordinate x ₂ of point E from the x-coordinate x _D of point D (x _D −x ₂ ). The positions of points A and D are determined based on the position timing chart PS_CHT detected by camera 3 .

Therefore, ∠CAB is the same as θ _S1 , tan(θ _S1 ) represents the reciprocal of the slope of the straight line connecting points S and C, and the slope of the straight line connecting points S and C is (π/ 2−θ _S1 ), which is a positive value, so the following equation holds. Since x _A >x ₁ in FIG. 32, the right side of equation (29) has a positive value.

Also, ∠EDF is the same as θ _S2 and tan(θ _S2 ) is expressed by the following equation.

Therefore, the estimating means 5B can calculate θ _S1 and θ _S2 using equations (29) and (30), respectively.

[Estimation method 6]
After calculating θ _S1 and θ _S2 , the estimation means 5B estimates the position of the terminal device 30 by the following method.

In FIG. 32, although the x-coordinate of the position of the terminal device 30 is unknown, d _S1 >d _S2 , and as the rotating member 76-3 moves from the position z _r8 toward the measuring instruments 1 and 2, the measuring instruments Since the received signal strength RSSI1 measured in 1 is maintained in a lowered state, the estimating means 5B detects that the x-coordinate of the position of the terminal device 30 exists at a position farther than the position of the measuring device 1 in the x-axis direction. do.

Therefore, the estimating means 5B sets points M and N at which the distance from the measuring instrument 1 is longer than the point B, sets the distance between the point C and the point M to _dx3 , and sets the distance between the point E and the point N to d _x4 .

Then, the estimation means 5B sets a point S indicating the position of the terminal device 30, assumes that ΔSCM and ΔSEN are right-angled triangles, and assumes that the distance between points M and S in ΔSCM is _dz3 . and the distance between points N and S in ΔSEN is assumed to be _dz4 .

As a result, the following equation is obtained.

Equation (31A) is obtained by assuming that ΔACB and ΔSCM are similar, and equation (31B) is obtained by assuming that ΔDEF and ΔSEN are similar.

When d _z3 and d _z4 are calculated from equations (31A) and (31B) respectively, d _z3 and d _z4 are expressed by the following equations.

Assuming a point P having the same x-coordinate as the x-coordinate of the position of the terminal device 30, ΔACB and ΔSCP are similar, and ΔDEF and ΔSEP are similar. In this case, d _z3 in equation (32A) and d _z4 in equation (32B) match, so the right side of equation (32A) and the right side of equation (32B) are equal, and d _x4 is obtained using d _x3 . is expressed by the following equation.

In equation (33), _xA is the x-coordinate of point A and _xD is the x-coordinate of point D.

When d _x3 and d _x4 are obtained by the equations (31C) and (33), d _x3 and d _x4 are expressed by the following equations.

The estimating means 5B substitutes d _x3 represented by equation (34A) into equation (32A) to calculate d _z3 , and substitutes d _x4 represented by equation (34B) into equation (32B) to calculate d Calculate _z4 . As a result, d _z3 and d _z4 are represented by the following equations.

As shown in equation (35), d _z3 matches d _z4 . When the estimating means 5B calculates d _z3 and d _z4 , it confirms that d _z3 matches d _z4 .

d _x3 represents the distance between points P and C, and d _x4 represents the distance between points E and P when d _z3 matches d _z4 .

Therefore, the estimation means 5B calculates the distance d _SC3 between the point S and the point C using the distances d _x3 and d _z3 according to the following equation.

Then, similarly to estimation method 4, estimation means 5B estimates the position of terminal device 30 at a distance d _SC3 in the direction (π/2−θ _S1 ) from the position of measuring instrument 1 .

More specifically, the estimating means 5B assumes that the coordinates of the position of the terminal device 30 are (x ₃₀ , z ₃₀ ), and solves the simultaneous equations (37A) and (37B) to obtain coordinates (x ₃₀ , z ₃₀ ). Calculate

The estimating means 5B calculates tan(π/2−θ _S1 ) in equation (37A) by tan(π/2−θ _S1 )=d _S1 /(x _A −x ₁ ).

Similarly, the estimation means 5B uses the distance d _S2 , the direction θ _S2 and the position (x ₂ , z ₂ ) of the measuring device 2 to calculate the distance d _SE3 between the point S and the point E by the following equation. do.

Then, the estimation means 5B estimates the position of the terminal device 30 at a distance d _SE3 in the direction (π/2−θ _S2 ) from the position of the measuring instrument 2 in the same manner as in the estimation method 4 .

More specifically, the estimating means 5B assumes that the coordinates of the position of the terminal device 30 are (x' ₃₀ , z' ₃₀ ), and solves the simultaneous equations (39A) and (39B) to obtain coordinates (x' 30 , z' ₃₀ ). z' ₃₀ ) is calculated.

The estimating means 5B calculates tan(π/2−θ _S2 ) in equation (39A) by tan(π/2−θ _S2 )=d _S2 /(x _D −x ₂ ).

Then, the estimation means 5B calculates the distance Δd between the coordinates (x ₃₀ , z ₃₀ ) and the coordinates (x′ ₃₀ , z′ ₃₀ ), and when the calculated distance Δd is equal to or less than the threshold value Δd_th, the coordinates Either (x ₃₀ , z ₃₀ ) or coordinates (x′ ₃₀ , z′ ₃₀ ) is estimated as the position of the terminal device 30 .

On the other hand, when the distance Δd is greater than the threshold Δd_th, the estimator 5B re-estimates the position of the terminal device 30 .

Note that FIG. 32 shows a case where the x-coordinate of the position of the terminal device 30 exists at a position farther than the position of the measuring device 1 when viewed from the measuring device 2 in the direction from the measuring device 2 to the measuring device 1. Even if the x-coordinate of the position of 30 exists at a position farther than the position of the measuring device 2 as seen from the measuring device 1 in the direction from the measuring device 1 to the measuring device 2, the estimation means 5B determines the position of the terminal device 30 by the method described above. position can be estimated.

In this case, the point M is set at a position farther from the point E as seen from the measuring device 1 in the direction from the measuring device 1 to the measuring device 2, and the point N is set at a position farther than the point M in the x-axis direction. be done. Also, d _S2 >d _S1 . Furthermore, the slopes of the two straight lines from point C and point E to point S in FIG. 32 have negative values.

As shown in FIGS. 30 to 32, radio waves transmitted from the terminal device 30 are directly incident on the measuring devices 1 and 2 due to the relationship between the position of the terminal device 30 and the positions of the measuring devices 1 and 2 in the x-axis direction. The relationship between the angles θ _S1 and θ _S2 of the incident direction with respect to the z-axis direction is different.

In the x-axis direction, when the position of the terminal device 30 exists between the position of the measuring device 1 and the position of the measuring device 2, the angles θ _S1 and θ _S2 are mutually independent angles (Figs. 31), when the terminal device 30 is positioned farther from the measuring instrument 1 than the measuring instrument 2 in the x-axis direction, θ _S1 is part of θ _S2 and is included in θ _S2 . (See Figure 32).

Therefore, the relationship between the position of the terminal device 30 and the positions of the measuring instruments 1 and _{2 in the x-axis direction can be determined from the relationship between the angles θ S1 and θ S2 .}

More specifically, if the two angles θ _S1 and θ _S2 are independent of each other, the position of the terminal device 30 in the x-axis direction is the position of the measuring device 1 and the position of the measuring device 2 in the x-axis direction. between, and one of the two angles θ _S1 and θ _S2 includes the other, the position of the terminal device 30 in the x-axis direction is from one of the measuring instruments 1 and 2 in the x-axis direction. It is determined that the position is farther than the other when viewed. Here, the description of "a position farther than the other when viewed from one of measuring instruments 1 and 2" is because, unlike the case shown in FIG. This is because the position may be farther than the measuring instrument 2 when viewed.

FIG. 33 is a diagram showing the relationship between received signal strength and elapsed time. In FIG. 33, the vertical axis represents received signal strength RSSI, and the horizontal axis represents elapsed time. Curve k9 shows the relationship between received signal strength RSSI and elapsed time. Note that the relationship between the received signal strength and the elapsed time shown in FIG. 33 indicates the relationship between the received signal strength and the elapsed time after removing frequency components equal to or higher than the cutoff frequency.

Referring to FIG. 33, when rotating member 76-3 reaches position z _r2 shown in _{FIG .} When moving to the device 30 side, the shielding member 782 further shields the radio waves directly incident on the measuring instrument 1, so that the received signal strength RSSI is further reduced and the radio waves are shielded and transmitted by the shielding/non-shielding member 783. The signal strength RSSI fluctuates (see curve k9).

Therefore, by referring to the position timing chart PS_CHT detected by the camera 3 and detecting the three-dimensional coordinates at the time T _{start — 9} , the coordinates indicating the position of the point A of the rotating member 76-3 can be obtained.

The position of point D shown in FIG. 31, the positions of points A and D shown in FIG. 32, and the positions of points A and D shown in FIG. 33 can also be obtained in the same manner.

FIG. 34 is a diagram showing the direction of movement of the shielding/unshielding device 6A shown in FIG. Referring to FIG. 34, the shielding/unshielding device 6A reciprocates in the z-axis direction while moving in the x-axis direction in the xz plane, as indicated by the arrows.

By moving the shielding/unshielding device 6A as shown in FIG. 34, the positions of points A and D shown in FIGS. 30 to 32 can be detected, and the terminal device 30 shown in FIGS. The difference between the position and the position of the terminal device 30 shown in FIG. 32 can be identified.

The driving device 66 of the shielding/unshielding device 6A in the position estimation device 10B holds in advance the range in which the shielding/unshielding device 6A moves in the x-axis direction and the range in which the shielding/unshielding device 6A moves in the z-axis direction. The driving wheels (wheels 67) are driven so that the shielding/unshielding device 6A reciprocates in the z-axis direction while moving in the x-axis direction on the xz plane. In this case, the driving device 66 is arranged such that the shielding/unshielding device 6A moves in the x-axis direction or The distance moved in the z-axis direction is detected, the movement distance in the x-axis direction falls within the preset range of movement in the x-axis direction, and the movement distance in the z-axis direction moves in the preset z-axis direction. The driving wheels (wheels 67) are driven so as to be within the range.

FIG. 35 is a flow chart for explaining the operation of the position estimation device 10B shown in FIG.

The flowchart shown in FIG. 35 is obtained by replacing steps S6 and S7 of the flowchart shown in FIG. 25 with steps S21 and S22, and replacing steps S10 and S11 of the flowchart shown in FIG. , is the same as the flow chart shown in FIG.

Referring to FIG. 35, when the operation of position estimation device 10B is started, steps S20, S1, S2A, and S3 to S5 described above are sequentially executed.

After step S5, the estimating means 5B determines whether the radio wave directly incident on the measuring device M_i is shielded by the shielding member 782 based on the position timing chart PS_CHT and the received signal strength timing chart RSSI_CHT_i after being processed by the low-pass filter LPF_i. A distance d _Si between the position of the outermost circumference of the shielding member 782 and the position of the measuring device M_i in the z-axis direction at the start is detected (step S21).

After that, the estimating means 5B calculates the incident direction θ _Si of the radio wave with respect to the z-axis direction when the radio wave directly enters the measuring device M_i using the distance d _Si (step S22).

After step S22, step S8 described above is executed, and when it is determined in step S8 that i is not 2, step S9 described above is executed, and the series of operations proceeds to step S4.

Thereafter, steps S4, S5, S21, S22, S8, and S9 are repeatedly executed until it is determined in step S8 that i=2.

Then, when it is determined in step S8 that i=2, the estimator 5B determines whether one of θ _S1 and θ _S2 includes the other (step S23).

When it is determined in step S23 that one of θ _S1 and θ _S2 does not include the other, the estimator 5B determines whether d _S1 =d _S2 (step S24).

When it is determined in step S24 that d _S1 =d _S2 , the estimating means 5B calculates the ellipse 2 The shortest distances d _{SD — 1} and d _{SD — 2} between the two focal points are calculated (step S25).

On the other hand, when it is determined in step S24 that d _S1 is not d _S2 , the estimation means 5B uses equations (20) to (25) and (27) to determine the distance between the two focal points of the ellipse representing the first Fresnel zone. , the shortest distances d _{SD — 1} and d _{SD — 2} are calculated (step S26).

Further, when it is determined in step S23 that one of θ _S1 and θ _S2 includes the other, the estimating means 5B uses equations (29) to (36) and (38) to calculate the ellipse , the shortest distances d _{SD — 1} and d _{SD — 2} between the two focal points are calculated (step S27).

Then, after any of steps S25, S26, and S27, the estimating means 5B determines the terminal position based on the shortest distance d _{SD — 1} and the direction (π/2+|θ _S1 |) (or direction (π/2−θ _S1 )). The position of the device 30 is estimated, and the position of the terminal device 30 is estimated based on the shortest distance d _{SD — 2} and the direction (π/2−θ _S2 ) (step S28). This completes the operation of the position estimation device 10B.

In the flowchart shown in FIG. 35, when steps S4, S5, S21, and S22 are executed for the first time, the distance d _S1 (distance between point A and point B) and the incident direction θ _S1 of radio waves are obtained.

Then, when steps S4, S5, S21, and S22 are executed for the second time, the distance d _S2 (distance between point D and point F) and the incident direction θ _S2 of radio waves are obtained.

Then, depending on the mutual relationship between the two incident directions θ _S1 and θ _S2 of the radio waves and the mutual relationship between the distances d _S1 and d _S2 , the shortest distances d _{SD — 1} and d between the two focal points of the ellipse are calculated using different formulas. _{SD_2} is calculated, and the position of the terminal device 30 is estimated using the calculated shortest distances d _{SD_1} and d _{SD_2} (see steps S25 to S28).

Therefore, the position of the terminal device 30 can be estimated using the two measuring devices 1 and 2. FIG.

FIG. 36 is a flow chart for explaining the detailed operation of step S25 shown in FIG.

Referring to FIG. 36, when it is determined in step S24 of FIG. 35 that d ₁ =d ₂ , estimating means 5B sets i=1 (step S251). Then, the estimating means 5B calculates the distance d _{HYP_i} between the position P _{SOUT_i} of the outermost periphery of the shielding member 782 and the position of the measuring device M_i when the shielding member 782 starts to shield the radio wave directly incident on the measuring device M_i ( step S252).

Then, the estimation unit 5B calculates the distance v/2 between the midpoint MP of the two measuring instruments in the x-axis direction and the position of the measuring instrument M_i (step S253).

After that, the estimating means 5B calculates the distance v/2-a between the position P _{SOUT_i} of the outermost circumference in the x-axis direction and the position of the measuring device M_i (step S254).

Then, the estimating means 5B uses the fact that the ratio of the shortest distance d _{SD_i} between the two foci of the ellipse to the distance d _{HYP_i} is equal to the ratio of the distance v/2 and the distance v/2-a to determine the shortest distance d _{SD_i} is calculated (step S255).

Then, the estimation means 5B determines whether or not i=2 (step S256).

When it is determined in step S256 that i is not 2, the estimation means 5B sets i=i+1 (step S257). Thereafter, the series of operations proceeds to step S252, and steps S252 to S257 are repeatedly executed until it is determined that i=2 in step S256.

Then, when it is determined in step S256 that i=2, the series of operations proceeds to step S28 in FIG.

36, the position P _{SOUT_i} is the position of point A or point D shown in FIG. 30, the distance d _{HYP_i} is the distance d _S1 or the distance d _S2 shown in FIG. 30, and the shortest distance d _{SD_i} is , d _SC1 shown in equation (15C) or d _SE1 shown in equation (18C).

FIG. 37 is a flow chart for explaining the detailed operation of step S26 shown in FIG.

37, when it is determined in step S24 of FIG. 35 that d ₁ =d ₂ is not satisfied, estimating means 5B calculates the midpoint between the position of measuring device 1 and the position of measuring device 2 in the x-axis direction. A first point Point_1 and a second point Point_2 are set on the measuring instrument 1 side or the measuring instrument 2 side of MP (step S261).

Then, the estimating means 5B assumes that the distance between the position of the measuring device 1 and the first point Point_1 is _dx1 in the x-axis direction, and the distance between the position of the measuring device 2 and the second point Point_2 is _dx2 . (step S262).

After that, the estimating means 5B sets i=1 (step S263). A distance d _{Down_i} from M_i is calculated using the radius a of the shielding member 782 (step S264).

Then, the estimating means 5B assumes that a right triangle is formed by the position of the measuring device M_i, the point Point_i, and the assumed position of the terminal device 30, and the assumed position of the terminal device 30 and Assume that the distance to the point Point_i is d _zi (step S265).

Then, the estimation unit 5B determines whether i=2 (step S266).

When it is determined in step S266 that i is not 2, the estimation means 5B sets i=i+1 (step S267). After that, the series of operations proceeds to step S264, and steps S264 to S267 are repeatedly executed until it is determined that i=2 in step S266.

Then, when it is determined in step S266 that i=2, the estimation unit 5B determines that the ratio of the distance d _{Down_1} and the distance d _x1 is equal to the ratio of the distance d _S1 and the distance d _z1 , and the distance d _{Down_2} and Compute the distances _dx1 , _dx2 , _dz1 , _dz2 using the ratio of the distance _dx2 equal to the ratio of the distance dS2 and the distance _{dz2 and the distance dz1 equal} to the distance _dz2 (step S268). In this case, the estimation means 5B substitutes the right side of the equation (22) into d _x2 of the equation (20C) to calculate d _x1 , substitutes the calculated d _x1 into d _x1 of the equation (22), and d _x2 is calculated, the calculated d _x1 is substituted for d _x1 in formula (21A) to calculate d _z1 , and the calculated d _x2 is substituted for d _x2 in formula (21B) to calculate d _z2 .

After that, the estimating means 5B calculates the distance d _SC2 between the assumed position of the terminal device 30 and the position of the measuring device 1 as the shortest distance d _{SD — 1} using the distances d _x1 and d _z1 (step S269).

Then, the estimation means 5B calculates the distance d _SE2 between the assumed position of the terminal device 30 and the position of the measuring device 2 as the shortest distance d _{SD_2} using the distances d _x2 and d _z2 (step S270).

After step S270, the series of operations proceeds to step S28 in FIG.

In the flowchart shown in FIG. 37, the distance d _{Down_i} consists of the distance v/2-a between point A and point C or the distance v/2-a between point D and point E in the x-axis direction shown in FIG. .

FIG. 38 is a flow chart for explaining the detailed operation of step S27 shown in FIG.

The flowchart shown in FIG. 38 is obtained by replacing steps S261 and S264 of the flowchart shown in FIG. 37 with steps S261A and S264A, respectively, and the rest is the same as the flowchart shown in FIG.

38, when it is determined in step S23 of the flowchart shown in FIG. 35 that one of θ _S1 , θ _S2 includes the other, estimation means 5B moves measuring instruments 1 and 2 A first point Point_1 and a second point Point_2 are set at positions farther than the other when viewed from one of (step S261A).

Then, after step S261A, when steps S262 to S263 described above are sequentially executed, the estimating means 5B calculates the x-axis direction when the shielding member 782 starts shielding the radio waves directly incident on the measuring instrument M_i from the terminal device 30. A distance d _{Down_i} between the shielding member 782 and the measuring device M_i at is calculated using the position of the outermost circumference of the shielding member 782 (step S264A).

Thereafter, steps S265 to S270 described above are sequentially executed, and after step S270, the series of operations proceeds to step S28 in FIG.

In the flowchart shown in FIG. 38, the distance d _{Down_i} is the distance x A −x ₁ between points _A and C or the distance x D _{−x 2} between points D and E in the x-axis direction shown in FIG. .

FIG. 39 is a flow chart for explaining the detailed operation of step S28 shown in FIG.

Referring to FIG. 39, after any one of steps S25, S26 and S27 in FIG. 35, estimating means 5B determines whether or not step S25 or step S26 in FIG. 35 has been executed (step S281). .

When it is determined in step S281 that step S25 or step S26 of FIG. 35 has been executed, the estimation means 5B moves the position of the measuring instrument 1 in the direction (π/2+|θ _S1 |) by the shortest distance d _{SD — 1.} Coordinates (x ₃₀ , z ₃₀ ) indicating the distant position are calculated (step S282). In this case, when the process proceeds _from step S25 to step S28, the estimating means _5B calculates the coordinate (x ₃₀ , z ₃₀ ) and moving from step S26 to step S28, the estimating means 5B solves the simultaneous equations of the equation (26A) and the equation (26B) obtained by substituting the shortest distance d _{SD_1} into d _SC2 . Calculate the coordinates (x ₃₀ , z ₃₀ ) by

On the other hand, when it is determined in step S281 that step S25 or step _S26 in _FIG . Coordinates (x ₃₀ , z ₃₀ ) indicating the distant position are calculated (step S283). In this case, the estimating means 5B calculates the coordinates (x ₃₀ , z ₃₀ ) by solving the simultaneous equations of the equation (37A) and the equation (37B) obtained by substituting the shortest distance d _{SD — 1} into d _SC3 .

After step S282 or step S283, the estimating means 5B calculates the coordinates (x' ₃₀ , z' ₃₀ ) indicating the position away from the position of the measuring instrument 2 by the shortest distance d _{SD_2} in the direction (π/2-θ _S2 ). Calculate (step S284). In this case, when the process proceeds from step S25 to step S28, the estimating means 5B solves the simultaneous equations of the equation (19A) and the equation (19B) obtained by substituting the shortest distance _{d_SD_2} into _{d_SE1} . ₃₀ , z' ₃₀ ), and when the process moves from step S26 to step S28, the estimating means 5B calculates the simultaneous equations of the equation (28A) and the equation (28B) obtained by substituting the shortest distance d _{SD_2} into d _SE2 . When the coordinates (x' ₃₀ , z' ₃₀ ) are calculated by solving and the process moves from step S27 to step _S28 , the estimating means 5B calculates the formula (39A) and the _formula ( 39B) to calculate the coordinates (x' ₃₀ , z' ₃₀ ).

Then, the estimation means 5B calculates the distance Δd between the coordinates (x ₃₀ , z ₃₀ ) and the coordinates (x′ ₃₀ , z′ ₃₀ ) (step S285), and determines whether the distance Δd is equal to or less than the threshold value Δd_th. is determined (step S286).

When it is determined in step S286 that the distance Δd is not equal to or less than the threshold value Δd_th, the series of operations proceeds to step S20 in FIG.

On the other hand, when it is determined in step S286 that the distance Δd is equal to or less than the threshold value Δd_th, the estimation means 5B converts either the coordinates (x ₃₀ , z ₃₀ ) or the coordinates (x' ₃₀ , z' ₃₀ ) to The position of the terminal device 30 is estimated (step S287). After that, the series of operations shifts to "END" in FIG.

In the flowchart shown in FIG. 39, according to the first Fresnel zone, the transmitting station and the receiving station are located at the two focal points of the ellipse representing the first Fresnel zone, so that the measuring device 1 is located at one of the two focal points. The terminal device 30 is placed on one side, and the terminal device 30 is placed on the other focal point away from the position of the measuring instrument 1 by the shortest distance d _{SD_1} in the direction (π/2+|θ _S1 |) or in the direction (π/2−θ _S1 ). Therefore, the measuring device 2 is placed at one of the two focal points, and the terminal device 30 is at the other focus, which is separated from the position of the measuring device 2 by the shortest distance d _{SD_2} in the direction (π/2−θ _S2 ). will be placed. Therefore, coordinates (x ₃₀ , z ₃₀ ) and coordinates (x′ ₃₀ , z′ ₃₀ ) indicate the position of terminal device 30 .

The coordinates (x ₃₀ , z ₃₀ ) and (x' ₃₀ , z' ₃₀ ) should match each other, but the distances d _S1 and d _S2 shown in FIGS. 30 to 32 were not detected accurately. Then, assuming that the directions θ _S1 , θ _S2 and the shortest distances d _{SD_1} , d _{SD_2} are different from each other, after confirming that the distance Δd is equal to or less than the threshold value Δd_th, coordinates (x ₃₀ , z ₃₀ ) and coordinates (x' ₃₀ , z' ₃₀ ) are assumed to be the position of the terminal device 30 .

The coordinates (x ₃₀ , z ₃₀ ) indicating the position away from the position of the measuring instrument 1 by the shortest distance d _{SD_1} in the direction (π/2+|θ _S1 |) or in the direction (π/2−θ _S1 ) are calculated. That is, the direction (π/2+|θ _S1 |) or the direction (π/2−θ _S1 ) and the shortest distance d _{SD — 1} are fitted with an ellipse representing the first Fresnel zone and coordinates (x ₃₀ , z ₃₀ ) Calculating the coordinates (x′ ₃₀ , z′ ₃₀ ) indicating the position away from the position of the measuring instrument 2 by the shortest distance d _{SD_2} in the direction (π/2−θ _S2 ) is This corresponds to calculating the coordinates (x' ₃₀ , z' ₃₀ ) by fitting the direction (π/2-θ _S2 ) and the shortest distance d _{SD — 2} with an ellipse representing the first Fresnel zone. As described above, measuring device 1 and terminal device 30 (or measuring device 2 and terminal device 30) are placed at the two focal points of an ellipse representing the first Fresnel zone, with coordinates (x ₃₀ , z ₃₀ ) (or coordinates (x' ₃₀ , z' ₃₀ )).

In the flowchart shown in FIG. 39, step S287 may be executed after step S284 without executing steps S285 and S286.

Furthermore, in the flowchart shown in FIG. 39, only one of steps S282, S283 and step S284 is executed, and then in step S287, coordinates (x ₃₀ , z ₃₀ ) (or coordinates (x' ₃₀ , z' ₃₀ )) may be estimated as the position of the terminal device 30 .

In embodiments of the invention, the operations of the processing means 4 and the estimation means 5B may be performed by software. In this case, the position estimation device 10B includes measuring instruments 1 and 2, a camera 3, a shielding/unshielding device 6A, and a personal computer PC. A personal computer PC includes a CPU, a ROM, and a RAM.

The ROM stores a program Prog_B comprising steps S3 to S5, S8, S9, S21 to S28 of the flowchart shown in FIG. 35 (including the flowcharts shown in FIGS. 36 to 39). The RAM stores cutoff frequencies _{fOFF_1} and _{fOFF_2} , a received signal strength timing chart RSSI_CHT_1 after removing frequency components above cutoff frequency _{fOFF_1} , and a received signal strength after removing frequency components above cutoff frequency _{fOFF_2} . Temporarily store the timing chart RSSI_CHT_2.

Then, the CPU receives received signal strength timing charts RSSI_CHT_1 and RSSI_CHT_2 from measuring instruments 1 and 2, respectively, and receives position timing chart PS_CHT from camera 3. FIG. Then, the CPU reads out the program Prog_B from the ROM and executes it, and executes the program Prog_B of the terminal device 30 based on the received signal strength timing charts RSSI_CHT_1 and RSSI_CHT_2 respectively measured by the measuring instruments 1 and 2 and the position timing chart PS_CHT detected by the camera 3. Estimate location.

Also, the program Prog_B may be recorded on a recording medium such as a CD or DVD and distributed. When the recording medium recording the program Prog_B is loaded into the computer, the computer reads out the program Prog_B from the recording medium and executes it to obtain received signal strength timing charts RSSI_CHT_1 and RSSI_CHT_2 measured by the measuring instruments 1 and 2, respectively, and the camera 3. estimates the position of the terminal device 30 based on the detected position timing chart PS_CHT.

Therefore, the recording medium recording the program Prog_B is a computer-readable recording medium.

Other descriptions of the second embodiment are the same as those of the first embodiment.

In the first embodiment described above, the shielding state SHL is determined based on the reception signal strength timing charts RSSI_CHT_1 and RSSI_CHT_2 measured by the measuring instruments 1 and 2 while the shield 50 is moving and the position timing chart PS_CHT of the shield 50. The starting position PS _start and the position PS _end at which the shielding state SHL ends are obtained, and the position PS _start and the position PS _end detected based on the received signal strength timing chart RSSI_CHT_1 are fitted with an ellipse representing the first Fresnel zone. The direction θ ₁ is obtained, the position PS _start and the position PS _end detected based on the received signal strength timing chart RSSI_CHT_2 are fitted with an ellipse representing the first Fresnel zone to obtain the direction θ ₂ , 1/tan(θ ₁ ) It has been explained that the position of the terminal device 30 is estimated to be the position of the intersection of a straight line with a slope of 1) (consisting of positive or negative values) and a straight line with a slope of 1/tan(θ ₂ ).

In the second embodiment described above, the position of the terminal device 30 is estimated by the same method as in the first embodiment, the direction (π/2+|θ _S1 |) and the shortest distance d _{SD — 1} (or the direction (π /2−θ _S1 ) and the shortest distance d _{SD_1} , or the direction θ _S2 and the shortest distance d _{SD_2} ), and the obtained direction (π/2+|θ _S1 |) and the shortest distance d _{SD_1} (or the direction (π/2 −θ _S1 ) and the shortest distance d _{SD_1} , or the direction θ _S2 and the shortest distance d _{SD_2} ) are respectively applied to the major axis direction of the ellipse representing the first Fresnel zone and the shortest distance between the two focal points, and the position of the terminal device 30 ( We have discussed estimating coordinates (x ₃₀ ,z ₃₀ ) or coordinates (x′ ₃₀ ,z′ ₃₀ )).

Therefore, the position estimating apparatus according to the embodiment of the present invention uses received signal strength timing charts RSSI_CHT_1, RSSI_CHT_2 and Based on the position timing chart PS_CHT of the shielding object 50 (or the shielding/non-shielding devices 6, 6A), the shielding position where the radio wave transmitted from the terminal device 30 is shielded is obtained, and the measuring instrument 1 or the measuring instrument 2 is placed. The position of the terminal device 30 can be estimated based on the shielded position using the first Fresnel zone represented by an ellipse having a first focal point where the terminal device 30 is located and a second focal point where the terminal device 30 is located. .

Here, the shielding positions are the positions PS _{start — 1} to PS _{start — 8} and PS _{end — 1} to PS _{end — 8} shielded by the shield 50 according to the first embodiment, and the position PS _start — 1 shielded by the shielding/unshielding device 6 according to the second embodiment. _{. _ _}

In the embodiment of the present invention, measuring instrument 1 constitutes a "first measuring instrument", measuring instrument 2 constitutes a "second measuring instrument", and camera 3 constitutes a "detector". Configure.

Further, in the embodiment of the present invention, the received signal strength timing chart RSSI_CHT_1 after removing frequency components equal to or higher than the cutoff frequency f _{OFF_1} constitutes a "first low-frequency received signal strength timing chart" and cuts off. The received signal strength timing chart RSSI_CHT_2 after removing the frequency components equal to or higher than the off-frequency f _{OFF_2} constitutes the "second low-frequency received signal strength timing chart".

Furthermore, in the embodiment of the present invention, the elapsed time dependencies of the shielding states SHL_1 to SHL_4 constitute a "first shielding timing chart", and the elapsed time dependencies of the shielding states SHL_5 to SHL_8 constitute a "second timing chart". Shielding Timing Chart”.

Further, in the embodiment of the present invention, the shielding states SHL_1-SHL_4 or the shielding states SHL_5-SHL_8 constitute "a plurality of shielding states".

Furthermore, in the embodiment of the present invention, positions (x _{start — 1} , z start _{— 1} ) to (x _{start — 4 ,} z _{start — 4 )} ; The positions (x _{end — 1} , z _{end — 1} ) to (x _{end — 4} , z end — 4); (x _{end — 5} , z _{end — 5 )} to (x _{end — 8} , z _{end — 8} ) constitute “a plurality of second plane coordinates ” constitutes.

Further, in the embodiment of the present invention, positions ( _{x'start_1} , _{z'start_1} ) to ( _{x'start_4} , _{z'start_4} ); ( _{x'start_5} , _{z'start_5} ) to ( _{x'start_8} , _{z'start_8} ) constitutes "a plurality of third plane coordinates", and positions ( _{x'end_1} , _{z'end_1} ) to ( _{x'end_4} , _{z'end_4} ); ( _{x'end_5} , _{z'end_5} ) to (x' _{end — 8} , z′ _{end — 8} ) constitute “a plurality of fourth plane coordinates”.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the description of the above-described embodiments, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

The present invention is applied to a position estimation device, a program to be executed by a computer, and a computer-readable recording medium recording the program.

1, 2 Measuring device 3 Camera 4 Processing means 5, 5A Estimation means 6, 6A Shielding/non-shielding device 10, 10A, 10B Position estimation device 30 Terminal device 40 Base station 50 Shielding object 61 Main body 62, 72 Supporting member 63, 63A Control device 64 Power source 65, 75 Motor 66 Driving device 67, 68 Wheel 69, 782 Shielding member 76, 783 Shielding/non-shielding member 76-1 Cover member, 76-3 Rotating member, 691, 763, 783-1 to 783-4 Shielding part, 692, 761 Shaft member, 762, 764 Opening, 765 Supporting part, 770 to 773, 783-5 to 783-8 Non-shielded part.

Claims (21)

A first received signal strength timing chart showing the dependence of the first received signal strength on the elapsed time when the radio wave is received in a communication environment in which the shielding/unshielding of the radio wave transmitted from the terminal device changes depending on the elapsed time. a first measuring instrument to measure;
Measure a second received signal strength timing chart showing the elapsed time dependence of the second received signal strength when the radio wave is received in the communication environment while being placed at a position different from the first measuring instrument. a second measuring device that
a detector for detecting a position timing chart showing the elapsed time dependency of a position consisting of three-dimensional coordinates of a shielding object moving between the terminal device and the first and second measuring devices;
a first process for generating a shielding timing chart showing the elapsed time dependence of a shielding state in which the radio wave is shielded by the shielding object based on the received signal strength timing chart; processing means for executing on all of the received signal strength timing charts to generate first and second shielding timing charts;
performing a second process of obtaining a shielding position, which is a position where radio waves transmitted from the terminal device are shielded, based on the position timing chart and the first and second shielding timing charts, and performing the first measurement; based on the shielded position using a first Fresnel zone represented by an ellipse having a first focal point at which the instrument or the second measuring instrument is located and a second focal point at which the terminal device is located; and an estimating means for estimating the position of the terminal device. In the second process, the estimating means calculates a first position, which is the position of the shielding object at the start time of the shielding state, and the end time of the shielding state, based on the position timing chart and the shielding timing chart. performing a third process of obtaining a second position, which is the position of the shielding object in the shielding timing chart, for all of the plurality of shielding states in the shielding timing chart for all of the first and second shielding timing charts; fitting a plurality of first plane coordinates representing the plurality of first positions and a plurality of second plane coordinates representing the plurality of second positions with the ellipse to obtain a major axis direction of the ellipse; is performed for all of the first and second shielding timing charts, and the first major axis direction obtained corresponding to the first shielding timing chart in the fourth process is set as the inclination Fifth, estimating the position of the terminal device at the position of the intersection of the first straight line and the second straight line obtained corresponding to the second shielding timing chart and having an inclination in the longitudinal direction. The position estimating device according to claim 1, wherein the processing of: In the fourth process, the estimating means added the square of the function obtained by transposing the right side of the elliptic equation representing the ellipse to the left side for N (N is an integer equal to or greater than 2) plane coordinates. The plurality of first plane coordinates representing the plurality of first positions and the 3. The position estimating device according to claim 2, wherein said long axis direction when said error evaluation function is minimized is obtained by substituting a plurality of second plane coordinates representing a plurality of second positions. The processing means detects an average time of a time interval in which the received signal strength is attenuated based on the received signal strength timing chart, calculates a cutoff frequency based on the detected average time, and calculates the received signal strength timing. A process of obtaining a low-frequency received signal strength timing chart by removing frequency components equal to or higher than the cutoff frequency from the chart is executed for all of the first and second received signal strength timing charts to obtain the first and second low-frequency received signal strength timing charts. generating a frequency received signal strength timing chart, and classifying the shielding timing into a non-shielding state in which the radio waves are not blocked by the shielding object and a shielded state based on the low-frequency received signal strength timing chart. 4. The method according to claim 2 or 3, wherein generating a chart is performed for all of said first and second low-frequency received signal strength timing charts to generate said first and second shielding timing charts. Position estimator. 5. The position estimation device according to claim 4, wherein said processing means calculates twice the reciprocal of said average time as said cutoff frequency. The processing means is a clustering method, which is a method of dividing the set to be classified into subsets such that internal coupling and external separation are achieved, or pattern matching using the attenuation pattern of the received signal strength in the shielding state. 6. The position estimation device according to claim 4, wherein the first and second shielding timing charts are generated by classifying the non-shielding state and the shielding state by . In the third processing, the estimating means detects an attenuation start time at which the received signal strength begins to attenuate and an attenuation end time at which the received signal strength finishes attenuating in the shielding timing chart, and detects in the position timing chart The three-dimensional coordinates at the same time as the attenuation start time are obtained as the first position, and the three-dimensional coordinates at the same time as the attenuation end time are obtained as the second position. A position estimating device according to any one of the preceding items. In the fourth process, the estimating means generates a plurality of third positions by moving the plurality of first positions toward the plurality of second positions by a predetermined distance; moving a second position toward the plurality of first positions by the predetermined distance to generate a plurality of fourth positions; and a plurality of third planar coordinates representing the plurality of third positions; 8. The position estimation according to any one of claims 2 to 7, wherein a major axis direction of the ellipse is obtained by fitting a plurality of fourth plane coordinates representing the plurality of fourth positions with the ellipse. Device. the estimating means, in the third processing, obtains the first and second positions for all of the plurality of shielding states in one shielding timing chart out of the first and second shielding timing charts; Substituting the plurality of third plane coordinates and the plurality of fourth plane coordinates into the error evaluation function, and determining one of the major axis directions and one of the shortest distances when the error evaluation function is minimized A sixth process for obtaining is executed instead of the fourth process, and the one shielding timing chart is generated based on the one longitudinal direction and the one shortest distance obtained in the sixth process. The seventh process of estimating the position of the terminal device at a position separated by the one shortest distance in the one major axis direction from the position of the measuring device that measured the received signal strength timing chart that is the basis of the The position estimation device according to claim 8, which is executed instead of the fifth process. further comprising a shielding/non-shielding device as the shielding object that shields/non-shields the radio waves transmitted from the terminal device while moving;
10. The detector according to any one of claims 1 to 9, wherein the detector detects, as the position timing chart, a timing chart indicating the elapsed time dependence of the position of the shielded/unshielded device, which consists of the three-dimensional coordinates. The position estimating device according to . A program for causing a computer to execute estimation of the position of the terminal device in a position estimation device that receives radio waves transmitted from the terminal device and estimates the position of the terminal device,
The position estimation device,
A first received signal strength timing chart showing the elapsed time dependence of the first received signal strength when the radio waves are received in a communication environment in which the shielding/non-shielding of the radio waves transmitted from the terminal device changes depending on the elapsed time. a first measuring device that measures
Measure a second received signal strength timing chart showing the elapsed time dependence of the second received signal strength when the radio wave is received in the communication environment while being placed at a position different from the first measuring instrument. a second measuring device that
a detector that detects a position timing chart showing the elapsed time dependence of the position consisting of three-dimensional coordinates of a shielding object moving between the terminal device and the first and second measuring devices;
Said program
The processing means generates a shielding timing chart showing the elapsed time dependency of the shielding state in which the radio waves are shielded by the shielding object based on the received signal strength timing chart. and a first step of performing for all of the received signal strength timing charts to generate first and second shielding timing charts;
estimating means performs a second process of obtaining a shielding position, which is a position where radio waves transmitted from the terminal device are shielded, based on the position timing chart and the first and second shielding timing charts; said shielding position with a first Fresnel zone represented by an ellipse having a first focal point in which said first measuring device or said second measuring device is placed and a second focal point in which said terminal device is placed; and a second step of estimating the position of the terminal device based on. In the second processing of the second step, the estimating means calculates a first position, which is the position of the shielding object at the start time of the shielding state, based on the position timing chart and the shielding timing chart. a second position, which is the position of the shielding object at the end time of the shielding state, for all of the plurality of shielding states in the shielding timing chart; fitting a plurality of first planar coordinates representing the plurality of first positions and a plurality of second planar coordinates representing the plurality of second positions with the ellipse to determine the length of the ellipse A fourth process for determining the axial direction is performed for all of the first and second shielding timing charts, and the first length obtained corresponding to the first shielding timing chart in the fourth process. The position of the intersection of the first straight line slanted in the axial direction and the second straight line slanted in the longitudinal direction obtained corresponding to the second shielding timing chart is determined on the terminal device. 12. The program to be executed by the computer according to claim 11, which executes a fifth process of estimating a position. In the fourth process of the second step, the estimating means squares the function obtained by transposing the right side of the elliptic equation representing the ellipse to the left side N (N is an integer of 2 or more). A plurality of first positions representing the plurality of first positions in an error evaluation function consisting of the square root of the addition result obtained by adding about the plane coordinates of the ellipse and having parameters of the major axis direction of the ellipse and the shortest distance between the two focal points 13. The computer according to claim 12, wherein one plane coordinate and a plurality of second plane coordinates representing said plurality of second positions are substituted to obtain said longitudinal direction when said error evaluation function is minimized. program to run. The processing means detects an average time of a time interval in which the received signal strength is attenuated based on the received signal strength timing chart, calculates a cutoff frequency based on the detected average time, and calculates the received signal strength timing. A process of obtaining a low-frequency received signal strength timing chart by removing frequency components equal to or higher than the cutoff frequency from the chart is executed for all of the first and second received signal strength timing charts to obtain the first and second low-frequency received signal strength timing charts. generating a frequency received signal strength timing chart, and classifying the shielding timing into a non-shielding state in which the radio waves are not blocked by the shielding object and a shielded state based on the low-frequency received signal strength timing chart. 14. The method of claim 12 or claim 13, wherein generating a chart is performed for all of the first and second low frequency received signal strength timing charts to generate the first and second shielding timing charts. A program that makes a computer run. 15. The program to be executed by a computer according to claim 14, wherein said processing means calculates twice the reciprocal of said average time as said cutoff frequency. The processing means is a clustering method, which is a method of dividing the set to be classified into subsets such that internal coupling and external separation are achieved, or pattern matching using the attenuation pattern of the received signal strength in the shielding state. 16. The program according to claim 14 or 15, which classifies said non-shielding state and said shielding state by to generate said first and second shielding timing charts. In the third processing of the second step, the estimating means detects an attenuation start time at which the received signal strength begins to attenuate and an attenuation end time at which the received signal strength finishes attenuating in the shielding timing chart. wherein the three-dimensional coordinates at the same time as the attenuation start time in the position timing chart are obtained as the first position, and the three-dimensional coordinates at the same time as the attenuation end time are obtained as the second position. A program to be executed by the computer according to any one of claims 12 to 16. In the fourth processing of the second step, the estimating means moves the plurality of first positions by a predetermined distance in the direction of the plurality of second positions to determine the plurality of third positions. moving the plurality of second positions toward the plurality of first positions by the predetermined distance to generate a plurality of fourth positions; and generating a plurality of fourth positions representing the plurality of third positions. 18. Any one of claims 12 to 17, wherein the major axis direction of the ellipse is obtained by fitting the third plane coordinates and the plurality of fourth plane coordinates representing the plurality of fourth positions with the ellipse. A program to be executed by the computer according to the item. In the third processing of the second step, the estimating means performs the first and second shielding states for all of the plurality of shielding states in one shielding timing chart out of the first and second shielding timing charts. 2, and substituting the plurality of third plane coordinates and the plurality of fourth plane coordinates into the error evaluation function to obtain the one longitudinal direction and the A sixth process for obtaining one of the shortest distances is executed instead of the fourth process, and the one long axis direction and the one shortest distance obtained in the sixth process are used to determine the one shortest distance. The position of the terminal device is estimated to be the position separated by the one shortest distance in the one major axis direction from the position of the measuring device that measured the received signal strength timing chart from which the shielding timing chart was generated. 19. The program to be executed by a computer according to claim 18, which executes a seventh process instead of said fifth process. The position estimation device further includes, as the shielding object, a shielding/non-shielding device that shields/unshields the radio waves transmitted from the terminal device while moving,
20. The detector according to any one of claims 11 to 19, wherein said detector detects, as said position timing chart, a timing chart indicating said elapsed time dependence of the position of said shielded/unshielded device consisting of said three-dimensional coordinates. A program for executing the computer described in . A computer-readable recording medium recording the program according to any one of claims 11 to 20.

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