JP7627898B2 - Positioning method, program and positioning system - Google Patents

Description

The present disclosure relates generally to positioning methods, programs and positioning systems, and more specifically to positioning methods, programs and positioning systems for determining the position of a beacon terminal.

The position detection system (positioning system) described in Patent Document 1 includes multiple fixed communication devices, a mobile communication device, a pattern selection unit, a device selection unit, a correction unit, and a position calculation unit. The pattern selection unit selects a reference pattern. The device selection unit selects three or more fixed communication devices based on a partial area corresponding to the selected reference pattern. The correction unit corrects an index value of radio wave strength wirelessly communicated between the selected three or more fixed communication devices and the mobile communication device using a predetermined exponential function to calculate a corrected radio wave strength value. The position calculation unit calculates the position of the mobile communication device based on the corrected radio wave strength value.

Various means have been devised for improving the accuracy of calculating the position of a mobile communication device (beacon terminal), such as the means described in Patent Document 1.

JP 2020-112521 A

The present disclosure aims to provide a positioning method, program, and positioning system that can improve the accuracy of calculating the position of a beacon terminal.

A positioning method according to one aspect of the present disclosure is a positioning method for determining a position of a beacon terminal. The positioning method includes a main scanner selection process, a transmission instruction process, and a correction process. In the main scanner selection process, a scanner that has a function of transmitting a second beacon signal and whose reception signal strength of the first beacon signal satisfies a predetermined condition is selected as a main scanner from among a plurality of scanners that receive a first beacon signal transmitted from the beacon terminal. In the transmission instruction process, the main scanner selected in the main scanner selection process transmits the second beacon signal. In the correction process, the position of the beacon terminal determined based on the reception signal strength of the first beacon signal in the plurality of scanners is corrected based on the reception signal strength of the second beacon signal in each of a plurality of slave scanners that are a part of the plurality of scanners, and the distance between the main scanner and each of the plurality of slave scanners.
A positioning method according to another aspect of the present disclosure is a positioning method for determining a position of a beacon terminal. The positioning method includes a main scanner selection process and a correction process. In the main scanner selection process, a scanner that has a function of transmitting a second beacon signal and whose reception signal strength of the first beacon signal satisfies a predetermined condition is selected as a main scanner from among a plurality of scanners that receive a first beacon signal transmitted from the beacon terminal. In the correction process, the position of the beacon terminal determined based on the reception signal strength of the first beacon signal in the plurality of scanners is corrected based on the reception signal strength of the second beacon signal in each of a plurality of slave scanners that are a part of the plurality of scanners, and the distance between the main scanner and each of the plurality of slave scanners. The correction process includes an intensity correction process and a position derivation process. In the intensity correction process, the reception signal strength of the first beacon signal in each of the plurality of slave scanners is corrected based on the reception signal strength of the second beacon signal and the distance between the main scanner and each of the plurality of slave scanners. In the position derivation process, the position of the beacon terminal is obtained based on the received signal strength of the first beacon signal in each of the plurality of slave scanners corrected in the intensity correction process. In the intensity correction process, the received signal strength of the first beacon signal in each of the plurality of slave scanners is corrected by the following formula [U1]. Formula [U1] is F = 20 log (d' / d) + F'. F is a corrected value of the received signal strength of the first beacon signal in each of the plurality of slave scanners. F' is a measured value of the received signal strength of the first beacon signal in each of the plurality of slave scanners. d' is a distance between each of the plurality of slave scanners and the primary scanner obtained based on the received signal strength of the second beacon signal. d is a known distance between each of the plurality of slave scanners and the primary scanner.

A program according to one aspect of the present disclosure is a program for causing one or more processors to execute the positioning method.

A positioning system according to an aspect of the present disclosure is a positioning system that determines the position of a beacon terminal. The positioning system includes a primary scanner selection unit and a correction processing unit. The primary scanner selection unit selects a scanner that has a function of transmitting a second beacon signal and whose reception signal strength of the first beacon signal satisfies a predetermined condition among a plurality of scanners that receive a first beacon signal transmitted from the beacon terminal as a primary scanner, and causes the primary scanner to transmit the second beacon signal. The correction processing unit corrects the position of the beacon terminal that is determined based on the reception signal strength of the first beacon signal in the plurality of scanners based on the reception signal strength of the second beacon signal in each of a plurality of secondary scanners that are a part of the plurality of scanners, and the distance between the primary scanner and each of the plurality of secondary scanners.
A positioning system according to another aspect of the present disclosure is a positioning system for determining a position of a beacon terminal. The positioning system includes a main scanner selection unit and a correction processing unit. The main scanner selection unit selects, as a main scanner, a scanner that has a function of transmitting a second beacon signal and whose reception signal strength of the first beacon signal satisfies a predetermined condition among a plurality of scanners that receive a first beacon signal transmitted from the beacon terminal. The correction processing unit corrects the position of the beacon terminal that is determined based on the reception signal strength of the first beacon signal in the plurality of scanners based on the reception signal strength of the second beacon signal in each of a plurality of slave scanners that are a part of the plurality of scanners, and the distance between the main scanner and each of the plurality of slave scanners. The correction processing unit performs intensity correction to correct the reception signal strength of the first beacon signal in each of the plurality of slave scanners based on the reception signal strength of the second beacon signal and the distance between the main scanner and each of the plurality of slave scanners. The correction processing unit obtains the position of the beacon terminal based on the received signal strength of the first beacon signal in each of the plurality of slave scanners corrected by the intensity correction. The correction processing unit corrects the received signal strength of the first beacon signal in each of the plurality of slave scanners by the following formula [U1] in the intensity correction. Formula [U1] is F = 20 log (d' / d) + F'. F is a corrected value of the received signal strength of the first beacon signal in each of the plurality of slave scanners. F' is a measured value of the received signal strength of the first beacon signal in each of the plurality of slave scanners. d' is a distance between each of the plurality of slave scanners and the primary scanner obtained based on the received signal strength of the second beacon signal. d is a known distance between each of the plurality of slave scanners and the primary scanner.

FIG. 1 is a block diagram of a positioning system according to an embodiment. FIG. 2 is a plan view showing a typical example of use of the positioning system. FIG. 3 is a sequence diagram illustrating an example of use of the positioning system. FIG. 4 is a plan view showing a typical example of use of the positioning system.

Below, the positioning method, program, and positioning system according to the embodiments are described with reference to the drawings. However, the embodiment described below is merely one of various embodiments of the present disclosure. The embodiment described below can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. Furthermore, each figure described in the embodiment described below is a schematic diagram, and the ratio of the size and thickness of each component in the figure does not necessarily reflect the actual dimensional ratio.

(Embodiment)
(overview)
As shown in Fig. 1, the positioning system 1 of this embodiment is used as a positioning system (LPS: Local Positioning System) that measures the position of a beacon terminal 5 in a facility. The beacon terminal 5 is carried by a user. Each of the multiple users who use the facility carries a beacon terminal 5. Each beacon terminal 5 is assigned identification information, and the positioning system 1 distinguishes between the multiple beacon terminals 5 based on the identification information.

In this disclosure, a "facility" refers to, for example, an office building, a factory, a commercial complex, a library, an art gallery, a museum, an amusement facility, a theme park, a park, an airport, a train station, a baseball stadium, a hotel, a hospital, a residence, etc. In addition, a "facility" may be, for example, a moving object such as a ship or a railroad car.

In this disclosure, a "beacon terminal" is, for example, a mobile terminal carried by a user who uses a facility, such as a communication terminal such as a smartphone. Furthermore, the "beacon terminal" in this disclosure is not limited to a smartphone, but may be a tablet-type mobile terminal or a terminal dedicated to the positioning system 1, such as a tag. Furthermore, a "beacon terminal" may be owned by a user, or may be borrowed.

The multiple scanners 4 are installed in the facility. The multiple scanners 4 are installed, for example, on the ceiling of a building in the facility. The multiple scanners 4 receive a first beacon signal Sig1 from a beacon terminal 5 and measure the received signal strength (RSSI: Received Signal Strength Indication) of the first beacon signal Sig1. The positioning system 1 determines the distance between each of the multiple scanners 4 and the beacon terminal 5 based on the received signal strength of the first beacon signal Sig1 at each of the multiple scanners 4. The positioning system 1 then determines the position of the beacon terminal 5 based on the distance.

However, the received signal strength of the first beacon signal Sig1 may vary depending on the radio wave environment in the location where the multiple scanners 4 are installed. For example, in a facility, the received signal strength of the first beacon signal Sig1 may vary due to interference with radio waves other than the first beacon signal Sig1 and reflection of the first beacon signal Sig1. If no measures are taken against this, the position of the beacon terminal 5 cannot be determined with high accuracy. The present disclosure has been made in view of such problems, and aims to determine the position of the beacon terminal 5 with high accuracy by correcting the position of the beacon terminal 5 determined based on the received signal strength of the first beacon signal Sig1.

The positioning system 1 of this embodiment is a positioning system 1 that determines the position of a beacon terminal 5. The positioning system 1 includes a main scanner selection unit 21 and a correction processing unit 23. The main scanner selection unit 21 selects, as the main scanner 4M, a scanner 4 that has a function of transmitting a second beacon signal Sig2 and whose reception signal strength of the first beacon signal Sig1 satisfies a predetermined condition among the multiple scanners 4 that receive the first beacon signal Sig1 transmitted from the beacon terminal 5. The correction processing unit 23 corrects the position of the beacon terminal 5 that is determined based on the reception signal strength of the first beacon signal Sig1 in the multiple scanners 4 based on the reception signal strength of the second beacon signal Sig2 in each of the multiple slave scanners 4S that are part of the multiple scanners 4, and the distance between the main scanner 4M and each of the multiple slave scanners 4S.

According to this embodiment, the accuracy of calculating the position of the beacon terminal 5 can be improved by correcting the position of the beacon terminal 5 calculated based on the received signal strength of the first beacon signal Sig1.

(detail)
(1) Overall Configuration Each of the positioning system 1, the scanner 4, and the beacon terminal 5 includes a computer system having one or more processors and memories. At least some of the functions of the positioning system 1, the scanner 4, and the beacon terminal 5 are realized by the processor of the computer system executing a program recorded in the memory of the computer system. The program may be recorded in the memory, may be provided through a telecommunication line such as the Internet, or may be recorded in a non-transitory recording medium such as a memory card and provided.

1, the positioning system 1 includes a processing unit 2, a first communication unit 31, and a memory unit 32. The scanner 4 includes a first communication unit 41, a second communication unit 42, a memory unit 43, and a processing unit 44. The beacon terminal 5 includes a first communication unit 51, a second communication unit 52, and a memory unit 53.

(1.1) First Communication Unit The positioning system 1, the scanner 4, and the beacon terminal 5 can communicate with each other via the first communication units 31, 41, and 51. That is, the "first communication unit" in this disclosure can communicate with other "first communication units." In this disclosure, "capable of communication" means that signals can be transmitted and received directly or indirectly via a network or a repeater, etc., by an appropriate communication method such as wired communication or wireless communication.

The communication method of the "first communication unit" is, for example, a communication method conforming to the Ethernet (registered trademark) standard, or Wi-Fi (registered trademark), etc.

(1.2) Second Communication Unit The second communication unit 42 of the scanner 4 and the second communication unit 52 of the beacon terminal 5 are used to measure the position of the beacon terminal 5. The second communication units 42 and 52 have a communication function for performing wireless communication using radio waves. The communication method of the second communication units 42 and 52 is, for example, Bluetooth (registered trademark) Low Energy or WiFi (registered trademark).

The second communication unit 52 of the beacon terminal 5 transmits the first beacon signal Sig1, which is a wireless signal. The first beacon signal Sig1 is, for example, a wireless signal called an advertisement packet. The second communication unit 52 wirelessly transmits the first beacon signal Sig1 at a predetermined time interval and with a predetermined transmission power. The second communication unit 42 of the scanner 4 receives the first beacon signal Sig1 transmitted from the second communication unit 52. The first beacon signal Sig1 contains identification information of the beacon terminal 5. The identification information is, for example, a Bluetooth (registered trademark) Device Address.

The second communication unit 42 of the scanner 4 transmits a second beacon signal Sig2, which is a wireless signal. The second beacon signal Sig2 is, for example, a wireless signal called an advertisement packet. The second communication unit 42 wirelessly transmits the second beacon signal Sig2 at a predetermined time interval and with a predetermined transmission power. The second communication unit 42 of the scanner 4 receives the second beacon signal Sig2 transmitted from the second communication unit 42 of another scanner 4. The second beacon signal Sig2 contains identification information of the scanner 4 that sent it. The identification information is, for example, a Bluetooth (registered trademark) Device Address.

That is, each of the multiple scanners 4 receives the first beacon signal Sig1 transmitted from the beacon terminal 5 at the second communication unit 42. Also, each of the multiple scanners 4 has a function of transmitting the second beacon signal Sig2. Furthermore, each of the multiple scanners 4 has a function of receiving the second beacon signal Sig2.

Of the multiple scanners 4, the function of transmitting the second beacon signal Sig2 is enabled in the main scanner 4M, and the function of transmitting the second beacon signal Sig2 is disabled in the other scanners 4 (including the secondary scanner 4S).

(2) Beacon Terminal The storage unit 53 of the beacon terminal 5 stores information about the beacon terminal 5. The storage unit 53 stores identification information of the beacon terminal 5.

(3) Scanner The multiple scanners 4 are arranged in a matrix (see FIG. 2). The multiple scanners 4 are arranged at equal intervals.

The memory unit 43 of the scanner 4 stores information about the scanner 4. The memory unit 43 stores identification information of the scanner 4.

The processing unit 44 of the scanner 4 determines the received signal strength of the first beacon signal Sig1 received by the second communication unit 42 of the scanner 4. The processing unit 44 also determines the received signal strength of the second beacon signal Sig2 received by the second communication unit 42.

(4) Positioning System The positioning system 1 is, for example, a server computer. The positioning system 1 may be installed in a facility where a plurality of scanners 4 are installed, or may be installed outside the facility.

The memory unit 32 of the positioning system 1 stores position information and identification information of the multiple scanners 4. The position information and identification information of the multiple scanners 4 are registered in the positioning system 1 by a facility manager or the like when the multiple scanners 4 are installed in a facility. Alternatively, the position information and identification information of the multiple scanners 4 are transmitted from the multiple scanners 4 to the positioning system 1, for example. The position information of the multiple scanners 4 includes information on the coordinates of each of the multiple scanners 4 and information on the distance between the multiple scanners 4. The distance between the multiple scanners 4 may be determined from the coordinates of each of the multiple scanners 4.

The processing unit 2 of the positioning system 1 has a main scanner selection unit 21, a slave scanner selection unit 22, and a correction processing unit 23. The main scanner selection unit 21, the slave scanner selection unit 22, and the correction processing unit 23 merely indicate functions realized by the positioning system 1, and do not necessarily indicate actual configurations.

The main scanner selection unit 21 selects the main scanner 4M from among the multiple scanners 4.

In the multiple scanners 4, the function of transmitting the second beacon signal Sig2 is disabled by default. The main scanner selection unit 21 transmits a transmission instruction signal to the scanner 4 selected as the main scanner 4M, instructing it to transmit the second beacon signal Sig2. This enables the function of transmitting the second beacon signal Sig2 in the main scanner 4M.

The main scanner selection unit 21 selects a scanner 4 whose received signal strength of the first beacon signal Sig1 satisfies a predetermined condition as the main scanner 4M. In this embodiment, the scanner 4 that satisfies the predetermined condition is the scanner 4 whose received signal strength of the first beacon signal Sig1 is the strongest among the multiple scanners 4. As shown in FIG. 2, typically, among the multiple scanners 4, the scanner 4 closest to the beacon terminal 5 has the strongest received signal strength, and this scanner 4 is selected as the main scanner 4M.

The main scanner selection unit 21 requires that the main scanner 4M has the function of transmitting the second beacon signal Sig2. In this embodiment, all scanners 4 have the function of transmitting the second beacon signal Sig2.

The slave scanner selection unit 22 selects multiple slave scanners 4S from the multiple scanners 4. The correction processing unit 23 determines the position of the beacon terminal 5 using information acquired from the main scanner 4M and multiple slave scanners 4S among the multiple scanners 4.

The slave scanner selection unit 22 executes a slave scanner selection process. The slave scanner selection process is a process of selecting scanners 4 located around the main scanner 4M from among the multiple scanners 4 as multiple slave scanners 4S. For example, in FIG. 2, multiple scanners 4 are arranged in a matrix. In this case, the slave scanner selection unit 22 selects multiple scanners 4 (eight in FIG. 2) that are arranged in the same row as the main scanner 4M or an adjacent row, and in the same column as the main scanner 4M or an adjacent column, as the slave scanners 4S.

(5) Operation Example Next, an example of a process for determining the position of the beacon terminal 5 using the positioning system 1 will be described with reference to FIG. 3. The sequence diagram in FIG. 3 is merely an example, and the order of the processes may be changed as appropriate, and processes may be added or omitted as appropriate. In FIG. 3, the main scanner 4M and the slave scanner 4S are illustrated separately, but before step ST3, it is not yet determined which of the multiple scanners 4 will be the main scanner 4M. Also, before step ST4, it is not yet determined which of the multiple scanners 4 will be the slave scanner 4S.

The beacon terminal 5 transmits a first beacon signal Sig1 at a predetermined time interval (step ST1). The first beacon signal Sig1 includes identification information of the beacon terminal 5. The multiple scanners 4 receive the first beacon signal Sig1 and measure the received signal strength indicator (RSSI).

The multiple scanners 4 transmit a first notification signal including information on the received signal strength of the first beacon signal Sig1 to the positioning system 1 (step ST2). The first notification signal includes identification information of the beacon terminal 5 and identification information of the scanner 4 that transmitted the first notification signal.

The correction processing unit 23 of the positioning system 1 reads the first notification signals received from the multiple scanners 4 and obtains the received signal strength values of the first beacon signal Sig1 at each of the multiple scanners 4.

The primary scanner selection unit 21 of the positioning system 1 selects, from among the multiple scanners 4, the scanner 4 having the strongest received signal strength of the first beacon signal Sig1 as the primary scanner 4M (step ST3). Furthermore, the secondary scanner selection unit 22 selects scanners 4 located around the primary scanner 4M as multiple secondary scanners 4S (step ST4).

The positioning system 1 transmits a transmission instruction signal to the main scanner 4M to instruct the main scanner 4M to transmit the second beacon signal Sig2 (step ST5). As a result, the main scanner 4M starts transmitting the second beacon signal Sig2 (step ST6). The second beacon signal Sig2 includes identification information of the main scanner 4M. The multiple slave scanners 4S receive the second beacon signal Sig2 and measure the received signal strength.

The multiple slave scanners 4S transmit second notification signals including information on the received signal strength of the second beacon signal Sig2 to the positioning system 1 (step ST7). The second notification signal includes identification information of the slave scanner 4S that transmitted the second notification signal.

The correction processing unit 23 of the positioning system 1 reads the second notification signals received from the multiple slave scanners 4S and obtains the value of the received signal strength f' of the second beacon signal Sig2 in each of the multiple slave scanners 4S.

The correction processing unit 23 calculates f based on d using [Equation 1]. d is the distance between the main scanner 4M and the secondary scanner 4S. d is pre-stored in the memory unit 32 as position information of multiple scanners 4. f is defined as follows. In an ideal environment without radio wave interference and reflection, when the distance between the main scanner 4M and the secondary scanner 4S is d, the received signal strength of the second beacon signal Sig2 transmitted from the main scanner 4M at the secondary scanner 4S is f. In other words, f is the theoretical value of the received signal strength corresponding to the distance d. In [Equation 1], T is the received signal strength measured at a location 1 m away from the main scanner 4M. T is pre-stored in the memory unit 32.

From [Equation 1], [Equation 2] holds true.

d' and f' are defined as follows: In an ideal environment without radio wave interference or reflection, when the distance between the primary scanner 4M and the secondary scanner 4S is d', the received signal strength at the secondary scanner 4S of the second beacon signal Sig2 transmitted from the primary scanner 4M is f'. In other words, f' is the theoretical value of the received signal strength corresponding to the distance d'.

Transforming [Equation 2] gives [Equation 3].

The correction processing unit 23 calculates d' using [Equation 3]. Here, in [Equation 3], the received signal strength f' (measured value) of the second beacon signal Sig2 in each of the multiple slave scanners 4S is substituted for f'.

From [Equation 1], f is known. Also, as mentioned above, d and f' are known. Therefore, d' can be found from [Equation 3]. In other words, d' can be found based on f, d, and f'.

The correction processing unit 23 uses 20 log(d'/d) as a correction value for the received signal strength of the first beacon signal Sig1 transmitted from the beacon terminal 5. In other words, as described above, the correction processing unit 23 can obtain a correction value for the received signal strength of the first beacon signal Sig1. The correction processing unit 23 corrects the received signal strength F' (measured value) of the first beacon signal Sig1 using 20 log(d'/d), which is the correction value for the received signal strength of the first beacon signal Sig1, and obtains the position of the beacon terminal 5 based on the corrected received signal strength F.

The received signal strength F (corrected received signal strength) of the first beacon signal Sig1 when there is no influence from the radio wave environment can be approximately expressed by [Equation 4] using F', which is the measured value of the received signal strength of the first beacon signal Sig1, and the above correction value.

[Math 4] is based on the following idea. Since the main scanner 4M is the scanner 4 that is located relatively close to the beacon terminal 5 among the multiple scanners 4, the radio wave environment in which the main scanner 4M is located can be considered to be approximately the same as the radio wave environment in which the beacon terminal 5 is located. Therefore, 20 log(d'/d), which is a correction value for calibrating the influence of the radio wave environment in the main scanner 4M, can be used as the correction value for calibrating the influence of the radio wave environment in the beacon terminal 5.

[Equation 4] makes it possible to obtain the corrected value F of the received signal strength F' of the first beacon signal Sig1. The correction processing unit 23 obtains the corrected value F of the received signal strength F' of the first beacon signal Sig1 for each of the multiple slave scanners 4S.

Similar to [Equation 1], the distance D between each of the multiple slave scanners 4S and the beacon terminal 5 is calculated using [Equation 5].

The correction processing unit 23 determines the position of the beacon terminal 5 based on the distance D. The following description will be given with reference to Figure 4. In Figure 4, the number of slave scanners 4S is two.

A number of reference points p are set in the space in which the multiple scanners 4 are installed. The coordinates of each reference point p are stored in the memory unit 32 of the positioning system 1. Each reference point p is a virtual point set so that the coordinate information thereof can be used in the processing of the correction processing unit 23, and no specific configuration is provided for the coordinates of each reference point p.

In order to distinguish the multiple reference points p, the multiple reference points p are referred to as p ₁ , p ₂ , p ₃ , .... Furthermore, a specific reference point p among the multiple reference points p is referred to as p _i .

The distance between each of the multiple reference points p and each of the multiple scanners 4 is pre-stored in the storage unit 32. For example, in Fig. 4, the distances between the reference point p _i and the three scanners 4 (the two slave scanners 4S and the one main scanner 4M) are _ri1 , _ri2 , and _ri3 , respectively.

Furthermore, the distance D between each of the multiple slave scanners 4S and the beacon terminal 5 can be calculated using [Equation 5]. The distance D between the main scanner 4M and the beacon terminal 5 can be calculated using [Equation 6], using the received signal strength F' (measured value) of the first beacon signal Sig1 in the main scanner 4M. In other words, the distance D between the main scanner 4M and the beacon terminal 5 is the distance that serves as the basis for correction, so no correction is required.

In FIG. 4, the distances between each of the three scanners 4 and the beacon terminal 5 are D ₁ , D ₂ , and D ₃ , respectively.

In addition, when three scanners 4 (two slave scanners 4S and one main scanner 4M) are used to calculate the degree of approximation W _i between the coordinates of the beacon terminal 5 and the reference point p _i , the degree of approximation W _i can be calculated by [Equation 7].

The equation for finding the degree of approximation W _i using n scanners 4 is expressed by [Equation 8]: The number of main scanners 4M is 1, and the number of multiple slave scanners 4S is n-1.

The correction processing unit 23 obtains the approximation _W1 , _W2 , _W3 , ... for each of the multiple reference points _p1 , _p2 , _p3 , ... by [Equation 8]. Furthermore, the correction processing unit 23 obtains the position of the beacon terminal 5 based on the approximation _W1 , _W2 , _W3 , .... For example, the correction processing unit 23 weights the coordinates of the multiple reference points _p1 , _p2 , _p3 , ... by the respective approximations _W1 , _W2 , _W3 , ..., and sets the sum of the weighted coordinates as the coordinates of the beacon terminal 5.

From the above, the correction processing unit 23 can determine the coordinates (position) of the beacon terminal 5.

In addition, the correction processing unit 23 may determine the position of the beacon terminal 5 by performing three-point positioning using the position information of the multiple scanners 4 and the distance D between each of the multiple scanners 4 and the beacon terminal 5.

As described above, the correction processing unit 23 of this embodiment calculates the distance D from F obtained by correcting F', rather than the distance D' calculated directly from F', which is the measured value of the received signal strength, and calculates the position of the beacon terminal 5 based on the distance D. Therefore, the position of the beacon terminal 5 calculated in this embodiment differs from the position of the beacon terminal 5 calculated based on the distance D' (the measured value F' of the received signal strength). In other words, the correction processing unit 23 corrects the position of the beacon terminal 5.

In this way, the correction processing unit 23 performs a correction process to correct the position of the beacon terminal 5 determined based on the received signal strength F' of the first beacon signal Sig1 in the multiple scanners 4. In the correction process, the position of the beacon terminal 5 is corrected based on the received signal strength f' of the second beacon signal Sig2 in each of the multiple slave scanners 4S and the distance d between the main scanner 4M and each of the multiple slave scanners 4S.

More specifically, the correction process includes an intensity correction process and a position derivation process. In the intensity correction process, the received signal strength F' of the first beacon signal Sig1 in each of the multiple slave scanners 4S is corrected based on the received signal strength f' of the second beacon signal Sig2 and the distance d between the main scanner 4M and each of the multiple slave scanners 4S. This allows the corrected received signal strength F to be obtained. In the position derivation process, the position of the beacon terminal 5 is obtained based on the received signal strength F of the first beacon signal Sig1 in each of the multiple slave scanners 4S corrected in the intensity correction process. More specifically, first, the distance D is obtained based on the received signal strength F, and the position of the beacon terminal 5 is obtained based on the distance D.

In addition, in the intensity correction process, the received signal strength F' of the first beacon signal Sig1 in each of the multiple slave scanners 4S is corrected using [Equation 4]. [Equation 4] is shown again below.

F is the corrected value of the received signal strength F' of the first beacon signal Sig1 in each of the multiple slave scanners 4S. F' is the measured value of the received signal strength of the first beacon signal Sig1 in each of the multiple slave scanners 4S. d' is the distance between each of the multiple slave scanners 4S and the primary scanner 4M determined based on the received signal strength f' of the second beacon signal Sig2. d is the known distance between each of the multiple slave scanners 4S and the primary scanner 4M.

(Modification of the embodiment)
Modifications of the embodiment will be listed below. The following modifications may be implemented in appropriate combination.

The multiple scanners 4 do not have to be arranged at equal intervals.

The multiple scanners 4 do not have to be arranged in a matrix. For example, the multiple scanners 4 may be arranged in a staggered pattern or may be arranged irregularly.

The positioning system 1 may further include multiple scanners 4.

The correction processing unit 23 may determine the position of the beacon terminal 5 by using the corrected values of the distances between each of the multiple slave scanners 4S and the beacon terminal 5, without using the distance between the main scanner 4M and the beacon terminal 5. In this case, n in [Equation 8] is the number of multiple slave scanners 4S.

The main scanner selection unit 21 selects a scanner 4 whose received signal strength of the first beacon signal Sig1 satisfies a predetermined condition as the main scanner 4M. In the embodiment, the scanner 4 that satisfies the predetermined condition is a scanner 4 whose received signal strength of the first beacon signal Sig1 is the largest among the multiple scanners 4. In contrast, the scanner 4 that satisfies the predetermined condition may be a scanner 4 whose received signal strength of the first beacon signal Sig1 is greater than a threshold among the multiple scanners 4. Alternatively, the scanner 4 that satisfies the predetermined condition may be a scanner 4 that is within the Nth (N is a predetermined natural number equal to or greater than 2) of the multiple scanners 4 in order of the received signal strength of the first beacon signal Sig1. When there are multiple scanners 4 that satisfy the predetermined condition, any one of them may be the main scanner 4M.

The multiple scanners 4 may include a scanner 4 that has the capability of receiving the first beacon signal Sig1 but does not have the capability of transmitting the second beacon signal Sig2. Such a scanner 4 may be selected as a slave scanner 4S but is not selected as a main scanner 4M.

Functions similar to those of positioning system 1 may be embodied in a positioning method, a (computer) program, or a non-transitory recording medium on which a program is recorded, etc.

A positioning method according to one embodiment is a positioning method for determining the position of a beacon terminal 5. The positioning method includes a main scanner selection process and a correction process. In the main scanner selection process, a scanner 4 that has a function of transmitting a second beacon signal Sig2 and whose reception signal strength of the first beacon signal Sig1 satisfies a predetermined condition is selected as the main scanner 4M from among a plurality of scanners 4 that receive a first beacon signal Sig1 transmitted from the beacon terminal 5. In the correction process, the position of the beacon terminal 5 determined based on the reception signal strength of the first beacon signal Sig1 in the plurality of scanners 4 is corrected based on the reception signal strength of the second beacon signal Sig2 in each of a plurality of slave scanners 4S that are a part of the plurality of scanners 4, and the distance between the main scanner 4M and each of the plurality of slave scanners 4S.

In one embodiment, the program is a program for causing one or more processors to execute the positioning method described above. The program may be recorded on a non-transitory recording medium readable by a computer.

The positioning system 1 in the present disclosure includes a computer system. The computer system is mainly composed of a processor and a memory as hardware. At least a part of the functions of the positioning system 1 in the present disclosure is realized by the processor executing a program recorded in the memory of the computer system. The program may be pre-recorded in the memory of the computer system, may be provided through an electric communication line, or may be recorded and provided in a non-transitory recording medium such as a memory card, an optical disk, or a hard disk drive that can be read by the computer system. The processor of the computer system is composed of one or more electronic circuits including a semiconductor integrated circuit (IC) or a large-scale integrated circuit (LSI). The integrated circuits such as IC or LSI referred to here are called different names depending on the degree of integration, and include integrated circuits called system LSI, VLSI (Very Large Scale Integration), or ULSI (Ultra Large Scale Integration). Furthermore, a field-programmable gate array (FPGA) that is programmed after the manufacture of the LSI, or a logic device that can reconfigure the connection relationship inside the LSI or reconfigure the circuit partition inside the LSI, can also be used as a processor. The electronic circuits may be integrated in one chip or distributed among multiple chips. The chips may be integrated in one device or distributed among multiple devices. The computer system referred to here includes a microcontroller having one or more processors and one or more memories. Thus, the microcontroller is also composed of one or more electronic circuits including a semiconductor integrated circuit or a large-scale integrated circuit.

In addition, it is not essential for the positioning system 1 that multiple functions in the positioning system 1 are concentrated in one device, and the components of the positioning system 1 may be distributed across multiple devices. Furthermore, at least some of the functions of the positioning system 1, for example, some of the functions of the processing unit 2, may be realized by the cloud (cloud computing) or the like.

(summary)
The above-described embodiments and the like disclose the following aspects.

The positioning method according to the first aspect is a positioning method for determining the position of a beacon terminal (5). The positioning method includes a main scanner selection process and a correction process. In the main scanner selection process, a scanner (4) that has a function of transmitting a second beacon signal (Sig2) and whose reception signal strength of the first beacon signal (Sig1) satisfies a predetermined condition among a plurality of scanners (4) that receive a first beacon signal (Sig1) transmitted from the beacon terminal (5) is selected as the main scanner (4M). In the correction process, the position of the beacon terminal (5) determined based on the reception signal strength of the first beacon signal (Sig1) in the plurality of scanners (4) is corrected based on the reception signal strength of the second beacon signal (Sig2) in each of a plurality of slave scanners (4S) that are a part of the plurality of scanners (4) and the distance between the main scanner (4M) and each of the plurality of slave scanners (4S).

According to the above configuration, the accuracy of calculating the position of the beacon terminal (5) can be improved by correcting the position of the beacon terminal (5) calculated based on the received signal strength of the first beacon signal (Sig1).

In addition, in the positioning method according to the second aspect, in the first aspect, the scanner (4) that satisfies the specified condition is the scanner (4) among the multiple scanners (4) that has the greatest received signal strength of the first beacon signal (Sig1).

According to the above configuration, compared to the case where another scanner (4) is used as the primary scanner (4M), the radio interference received by the primary scanner (4M) is considered to be close to the radio interference received by the beacon terminal (5). Therefore, it is considered that the difference between the received signal strength of the second beacon signal (Sig2) transmitted from the primary scanner (4M) to the secondary scanner (4S) and the received signal strength of the first beacon signal (Sig1) transmitted from the beacon terminal (5) to the secondary scanner (4S) is small. Therefore, when performing the above correction process using the received signal strength of the second beacon signal (Sig2) transmitted from the primary scanner (4M), the accuracy of the correction can be improved.

In addition, the positioning method according to the third aspect is the first or second aspect, and further includes a slave scanner selection process. In the slave scanner selection process, scanners (4) located around the main scanner (4M) among the multiple scanners (4) are selected as multiple slave scanners (4S).

According to the above configuration, the degree of radio interference experienced by the first beacon signal (Sig1) and the second beacon signal (Sig2) can be reduced compared to the case where another scanner (4) is used as the slave scanner (4S).

In addition, in the positioning method according to the fourth aspect, in any one of the first to third aspects, the correction process includes an intensity correction process and a position derivation process. In the intensity correction process, the received signal strength of the first beacon signal (Sig1) in each of the multiple slave scanners (4S) is corrected based on the received signal strength of the second beacon signal (Sig2) and the distance between the main scanner (4M) and each of the multiple slave scanners (4S). In the position derivation process, the position of the beacon terminal (5) is found based on the received signal strength of the first beacon signal (Sig1) in each of the multiple slave scanners (4S) corrected in the intensity correction process.

According to the above configuration, the accuracy of calculating the position of the beacon terminal (5) can be improved by correcting the received signal strength.

In addition, in the positioning method of the fifth aspect, in the fourth aspect, the intensity correction process corrects the received signal strength of the first beacon signal (Sig1) in each of the multiple slave scanners (4S) using the following formula [U1].

F=20log(d'/d)+F'...[U1]
F is a corrected value of the received signal strength of the first beacon signal (Sig1) in each of the slave scanners (4S),
F' is a measured received signal strength of the first beacon signal (Sig1) at each of the slave scanners (4S);
d' is the distance between each of the multiple slave scanners (4S) and the main scanner (4M) calculated based on the received signal strength of the second beacon signal (Sig2);
d is a known distance between each of the multiple slave scanners (4S) and the master scanner (4M).

According to the above configuration, the accuracy of calculating the position of the beacon terminal (5) can be improved by correcting the received signal strength.

Configurations other than the first aspect are not essential to the positioning method and can be omitted as appropriate.

In addition, the program relating to the sixth aspect is a program for causing one or more processors to execute a positioning method relating to any one of the first to fifth aspects.

According to the above configuration, the accuracy of calculating the position of the beacon terminal (5) can be improved by correcting the position of the beacon terminal (5) calculated based on the received signal strength of the first beacon signal (Sig1).

The positioning system (1) according to the seventh aspect is a positioning system (1) that determines the position of a beacon terminal (5). The positioning system (1) includes a main scanner selection unit (21) and a correction processing unit (23). The main scanner selection unit (21) selects, as a main scanner (4M), a scanner (4) that has a function of transmitting a second beacon signal (Sig2) and whose received signal strength of the first beacon signal (Sig1) satisfies a predetermined condition, from among a plurality of scanners (4) that receive a first beacon signal (Sig1) transmitted from a beacon terminal (5). The correction processing unit (23) corrects the position of the beacon terminal (5) determined based on the received signal strength of the first beacon signal (Sig1) in the multiple scanners (4), based on the received signal strength of the second beacon signal (Sig2) in each of the multiple slave scanners (4S) that are a part of the multiple scanners (4), and the distance between the main scanner (4M) and each of the multiple slave scanners (4S).

According to the above configuration, the accuracy of calculating the position of the beacon terminal (5) can be improved by correcting the position of the beacon terminal (5) calculated based on the received signal strength of the first beacon signal (Sig1).

In addition, the positioning system (1) of the eighth aspect is the positioning system (1) of the seventh aspect, further comprising a plurality of scanners (4).

According to the above configuration, the accuracy of calculating the position of the beacon terminal (5) can be improved by correcting the position of the beacon terminal (5) calculated based on the received signal strength of the first beacon signal (Sig1).

Not limited to the above aspects, various configurations (including modified examples) of the positioning system (1) of the embodiment can be embodied in a positioning method and a program.

1 Positioning system 4 Scanner 4M Main scanner 4S Slave scanner 5 Beacon terminal 21 Main scanner selection unit 23 Correction processing unit Sig1 First beacon signal Sig2 Second beacon signal

Claims (9)

A positioning method for determining a position of a beacon terminal, comprising:
A main scanner selection process for selecting, as a main scanner, a scanner having a function of transmitting a second beacon signal and a reception signal strength of the first beacon signal that satisfies a predetermined condition among a plurality of scanners that receive the first beacon signal transmitted from the beacon terminal;
a transmission instruction process for causing the main scanner selected in the main scanner selection process to transmit the second beacon signal;
A correction process is provided for correcting the position of the beacon terminal, which is determined based on the received signal strength of the first beacon signal in the plurality of scanners, based on the received signal strength of the second beacon signal in each of a plurality of slave scanners that are a part of the plurality of scanners, and the distance between the main scanner and each of the plurality of slave scanners.
Positioning method. The scanner that satisfies the predetermined condition is a scanner that receives the first beacon signal with the strongest received signal strength among the plurality of scanners.
The positioning method according to claim 1 . a slave scanner selection process for selecting scanners located around the main scanner from among the plurality of scanners as the plurality of slave scanners;
The positioning method according to claim 1 or 2. The correction process includes:
an intensity correction process for correcting a received signal strength of the first beacon signal at each of the plurality of slave scanners based on a received signal strength of the second beacon signal and a distance between the primary scanner and each of the plurality of slave scanners;
A position derivation process for determining a position of the beacon terminal based on the received signal strength of the first beacon signal in each of the plurality of slave scanners corrected by the intensity correction process.
The positioning method according to any one of claims 1 to 3. A positioning method for determining a position of a beacon terminal, comprising:
A main scanner selection process for selecting, as a main scanner, a scanner having a function of transmitting a second beacon signal and a reception signal strength of the first beacon signal that satisfies a predetermined condition among a plurality of scanners that receive the first beacon signal transmitted from the beacon terminal;
A correction process is provided to correct the position of the beacon terminal, which is determined based on the reception signal strength of the first beacon signal in the plurality of scanners, based on the reception signal strength of the second beacon signal in each of a plurality of slave scanners that are a part of the plurality of scanners, and the distance between the main scanner and each of the plurality of slave scanners;
The correction process includes:
an intensity correction process for correcting a received signal strength of the first beacon signal at each of the plurality of slave scanners based on a received signal strength of the second beacon signal and a distance between the primary scanner and each of the plurality of slave scanners;
A position derivation process for determining a position of the beacon terminal based on the received signal strength of the first beacon signal in each of the plurality of slave scanners corrected by the intensity correction process,
In the intensity correction process, the received signal strength of the first beacon signal in each of the slave scanners is corrected by the following formula [U1]:
Positioning method.
F=20log(d'/d)+F'...[U1]
F is a corrected value of the received signal strength of the first beacon signal in each of the slave scanners,
F' is a measured received signal strength of the first beacon signal at each of the plurality of slave scanners;
d′ is a distance between each of the plurality of slave scanners and the primary scanner, the distance being determined based on the received signal strength of the second beacon signal;
d is the known distance between each of the slave scanners and the primary scanner. A method for causing one or more processors to execute the positioning method according to any one of claims 1 to 5,
program. A positioning system for determining a position of a beacon terminal,
A main scanner selection unit that selects a scanner having a function of transmitting a second beacon signal and a reception signal strength of the first beacon signal that satisfies a predetermined condition among a plurality of scanners that receive the first beacon signal transmitted from the beacon terminal as a main scanner and causes the main scanner to transmit the second beacon signal ;
A correction processing unit corrects the position of the beacon terminal obtained based on the reception signal strength of the first beacon signal in the plurality of scanners based on the reception signal strength of the second beacon signal in each of a plurality of slave scanners that are a part of the plurality of scanners, and the distance between the main scanner and each of the plurality of slave scanners.
Positioning system. A positioning system for determining a position of a beacon terminal,
A main scanner selection unit that selects, as a main scanner, a scanner having a function of transmitting a second beacon signal and a reception signal strength of the first beacon signal that satisfies a predetermined condition among a plurality of scanners that receive the first beacon signal transmitted from the beacon terminal;
A correction processing unit that corrects the position of the beacon terminal obtained based on the reception signal strength of the first beacon signal in the plurality of scanners based on the reception signal strength of the second beacon signal in each of a plurality of slave scanners that are a part of the plurality of scanners, and the distance between the main scanner and each of the plurality of slave scanners,
The correction processing unit
performing intensity correction for correcting the received signal strength of the first beacon signal at each of the plurality of slave scanners based on the received signal strength of the second beacon signal and the distance between the primary scanner and each of the plurality of slave scanners;
determining a position of the beacon terminal based on the received signal strength of the first beacon signal in each of the plurality of slave scanners corrected by the intensity correction;
In the intensity correction, the received signal strength of the first beacon signal in each of the plurality of slave scanners is corrected by the following formula [U1]:
Positioning system.
F=20log(d'/d)+F'...[U1]
F is a corrected value of the received signal strength of the first beacon signal in each of the slave scanners,
F' is a measured received signal strength of the first beacon signal at each of the plurality of slave scanners;
d' is a distance between each of the plurality of slave scanners and the primary scanner, the distance being determined based on the received signal strength of the second beacon signal;
d is the known distance between each of the slave scanners and the primary scanner. further comprising the plurality of scanners;
A positioning system according to claim 7 or 8.

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