JP6742589B2 - Position estimation system - Google Patents

Description

The present invention relates to a position estimation system that estimates the position of an object that is stationary or slightly moves.

In recent years, there has been an increasing social need for a technique for accurately estimating the current position of a human in order to search for an elderly person who has lost their way due to loitering or search for a victim. Further, there is also a demand for a technique for accurately estimating the current position of a wild animal in order to perform ecological exploration of a wild animal or the like with high accuracy without being limited to the case where the measurement target is a human.

In order to improve the certainty of the estimation, a wireless signal transmitted from an object in a stationary state is received by the moving body, and based on the information obtained from the received signal, the position from the moving body to the object is detected. A technique for estimating the position by obtaining a distance or an angle has also been proposed (for example, refer to Patent Document 1). For example, assuming that the oscillation frequency of the radio signal transmitted from the object is known and the velocity of the mobile body is known, by measuring the frequency of the radio signal received at any position of the mobile body, , The angle from the moving body to the object can be estimated based on the Doppler shift amount. The position of the object can also be estimated by performing these processes at a plurality of places.

Japanese Examined Patent Publication No. 7-117580

However, according to the technique disclosed in Patent Document 1, when the moving body tries to estimate the angle to the object of position estimation at an arbitrary position, in addition to the oscillation frequency of the radio signal oscillated from the object, It is necessary to accurately detect the position at which the signal is received, the moving direction of the moving body at the position, and the moving speed at the position. Further, according to the technique disclosed in Patent Document 1, in order to perform such position estimation, it is also necessary to accurately measure the Doppler shift amount.

The oscillating frequency of the radio signal transmitted from the object can be easily detected by receiving the signal when the moving body is stationary, and the position and traveling direction of the moving body can be easily determined by using GPS or the like. Can be obtained. However, it is actually difficult to accurately measure the moving speed of the moving body at the measurement position and the Doppler shift amount of the radio signal.

Therefore, the present invention has been devised in view of the above-mentioned problems, and an object of the present invention is to eliminate the steps of accurately measuring the moving speed of a moving body and the Doppler shift amount of a radio signal. An object of the present invention is to provide a position estimation system that can estimate the position of an object and can significantly improve the estimation accuracy.

The present inventors have invented a position estimation system having the following configuration in order to solve the above-mentioned problems.

A position estimation system according to a first aspect of the present invention is a position estimation system that estimates the position of an object in a stationary state or slightly moving, in the process of flying on a flight trajectory that is controllable from the outside. An aircraft that continuously receives a radio signal transmitted from a signal transmitter attached to the vehicle, three-dimensional position information of each position on the flight trajectory of the aircraft and the flight trajectory at that position. Aircraft body position information detecting means for detecting a dimensional direction vector, observing means for observing the relative change tendency of the data regarding the radio signal received by the aircraft with respect to the position, and the observing means. A condition-satisfying position where the relative change tendency of the data satisfies a preset condition is obtained, and three-dimensional position information and a direction vector at the condition-satisfying position are acquired from the flying object position information detecting means and are used as a plane. And a position estimating means for substituting the equation into the equation, the position estimating means is based on the relative change tendency observed from the observing means three or more times in the process of flying the flight object on different flight trajectories. The condition satisfying position is obtained at three or more places, and the position of the object is estimated based on the three-dimensional position information at each condition satisfying position and the equation of three or more planes into which the direction vector is substituted. It is characterized by

A position estimation system according to a second aspect of the present invention is the position estimation system according to the first aspect, wherein the position estimation means determines a position that is closest to the object from the relative change tendency of the data observed by the observation means. The feature is that the position is a condition satisfying position.

A position estimating system according to a third aspect of the present invention is the position estimating system according to the second aspect, wherein the observing means observes a relative change tendency of the propagation delay amount as the data regarding the radio signal, and the position estimating means uses the observing means. The position where the observed propagation delay amount is the minimum is set as the condition satisfying position.

A position estimating system according to a fourth aspect is the position estimating system according to the second aspect, wherein the observing means observes a relative change tendency of the reception power of the radio signal as data relating to the radio signal, and the position estimating means is the observing means. The position where the received power observed by the means is maximum is set as the position satisfying the above conditions.

A position estimation system according to a fifth aspect of the present invention is the position estimation system according to the first aspect of the present invention, wherein the observing means observes a relative change tendency of the frequency of the radio signal as data relating to the radio signal. It is characterized in that the frequency f ₀ of the radio signal transmitted from is acquired in advance and the position where the frequency observed by the observing means is closest to the frequency f ₀ is set as the condition satisfying position.

The position estimation system according to a sixth aspect of the present invention is the position estimation system according to the first aspect of the present invention, wherein the observing means continues to acquire data regarding a radio signal until the condition-satisfying position can be detected. After being able to detect the condition satisfaction position, it is characterized by changing to another flight trajectory and continuing to fly.

According to the position estimation system to which the present invention having the above-described configuration is applied, the signal is transmitted in the direction forming 90° from the flight direction only by following the relative change tendency of the data regarding the radio signal observed by the observation unit 33. It is possible to specify the condition satisfy position on the flight trajectory k in which the position U of the aircraft 20 exists. Then, the position of the object is estimated by repeatedly substituting the three-dimensional position information and the direction vector at the position satisfying the condition into the equation of the plane three or more times between different flight trajectories. be able to.

In the actual process, the position of the object can be estimated by simply following the relative change tendency of the data without performing the step of accurately measuring the data regarding the radio signal. Therefore, the position of the object can be estimated without going through the step of accurately measuring the moving speed of the moving body and the Doppler shift amount of the wireless signal as in the conventional technique, and the estimation accuracy is significantly improved. It becomes possible.

It is a figure which shows the whole structure of the position estimation system to which this invention is applied. It is a block block diagram of a signal transmitter and an air vehicle. It is a figure for demonstrating the concept of the position estimation in the position estimation system to which this invention is applied. It is a figure which shows the example at the time of making one flight orbit k fly by a flying body. It is a figure which shows the example which receives the radio signal transmitted from a signal transmitter, while making a flying body fly on the flight orbit set to the linear form. It is a figure which shows each horizontal position of a flight orbit on the horizontal axis toward the flight direction, and shows the relative change tendency of the data regarding a radio signal on the vertical axis.

Hereinafter, embodiments for implementing a position estimation system to which the present invention is applied will be described in detail with reference to the drawings.

The position estimation system 10 to which the present invention is applied includes a signal transmitter 20 and an air vehicle 30 as shown in FIG.

FIG. 2A shows the configuration of the signal transmitter 20. The signal transmitter 20 includes a signal generator 21 that generates a signal having a predetermined frequency, and an antenna 22 connected to the signal generator 21. The signal having a predetermined frequency generated by the signal generation unit 21 is converted into a radio wave by the antenna 22 and transmitted in all directions. Hereinafter, the radio wave transmitted from the antenna 22 will be referred to as a radio signal.

Incidentally, the signal transmitter 20 has the signal generation unit 21 and the antenna 22, and may be embodied in any form as long as it transmits a radio signal having a predetermined frequency. For example, it may be embodied as a beacon transmitter that transmits only a beacon, or can perform wireless communication such as a mobile phone, a smartphone, a wearable terminal, a tablet terminal, and a personal computer (PC). It may be embodied as a communication terminal. This signal transmitter 20 is carried or attached to the object whose position is actually estimated. If the target whose position is to be estimated is a human such as an elderly person or a child, the person is caused to carry the signal transmitter 20. If the target whose position is to be estimated is an animal, the signal transmitter 20 is attached to the animal. Incidentally, the signal transmitter 20 is not limited to being attached to such a freely moving life form, and may be attached to a plant such as a tree. The signal transmitter 20 may be attached to a non-living body such as a building structure, building materials, stones, roads, bridges, tunnels and various infrastructures.

It is premised that the object to which the signal transmitter 20 is attached is stationary at the time of position estimation by the position estimation system 10 to which the present invention is applied, but the present invention is not limited to this and may be slightly moved. It may be.

The position estimation system 10 to which the present invention is applied is a system for accurately estimating the position of the signal transmitter 20 to actually estimate the position, and for grasping the position of an object to which the signal transmitter 20 is attached. Is.

The flying object 30 is any flying object capable of autonomous flight. The flying body 30 is embodied as a fixed-wing aircraft, a rotary-wing aircraft, an airship, a balloon, a drone, an unmanned aerial vehicle (UAV), a helicopter, an airplane, or the like. The flying object 30 may be an unmanned person that is not boarded by a human, or may be a boardable person. However, it is premised that this flight body 30 does not fly randomly but its flight trajectory can be controlled from the outside.

FIG. 2B shows the configuration of the flying object 30. The flying body 30 includes an airframe controller 31, a radio signal receiver 32 connected to the antenna 29, an observation unit 33 connected to the radio signal receiver 32, an information detector 34, an observation unit 33, and information. A position estimation unit 35 connected to the detection unit 34, an operation unit 36 and a control signal reception unit 37 connected to the machine body control unit 31, an information storage unit 38 and an estimated information transmission unit connected to the position estimation unit 35. And 39.

The machine body control unit 31 controls the propulsion system and the steering system (neither is shown) of the flying body 30 based on the flight trajectory and the flight control command defined in the flight plan input in advance. The machine body control unit 31 acquires these flight plans and flight control commands via the operation unit 36 or the control signal reception unit 37. The aircraft control unit 31 specifies the flight altitude and the flight direction based on the flight plan and the flight control command, thereby specifying the flight trajectory and enabling the flight at the specified altitude and coordinates. .. Further, the airframe control unit 31 also specifies the flight speed based on these flight plans and flight control commands.

The operation unit 36 is a user interface for the user to actually input a flight plan and flight control commands. The operation unit 36 is specifically composed of a keyboard, buttons, a touch panel, a mouse, a switch, and the like. However, if the flying body 30 is not an unmanned person but a human being, a control stick is provided. And the cockpit fall under this category. The flight plan and flight control commands input via the operation unit 36 are sent to the airframe control unit 31, and the flight trajectory and the like of the air vehicle 30 are determined along with this.

The control signal receiving unit 37 is a device for receiving a flight plan and flight control commands transmitted via a controller (not shown) or a base station (not shown) that is remotely operated. These flight plans and flight control commands are transmitted from the outside by wire communication or wireless communication. If these flight control commands and the like are transmitted by wireless communication, the control signal receiving section 37 will be configured as an antenna for receiving this. The control signal receiving unit 37 transmits a flight plan and flight control commands to the machine body control unit 31. Upon receiving the flight plan and the flight control command, the machine body control unit 31 determines the flight trajectory and the like of the flying body 30 according to the flight plan and the flight control command.

That is, since the flight altitude and flight direction of the flying object 30 are controlled based on the flight control command or the like input based on the user's intention, the flying object 30 does not fly on an arbitrary flight trajectory, but only to the user. It will fly in the flight trajectory according to the intention. That is, it is premised that the flight trajectory of the flying object 30 is controlled externally.

The wireless signal receiver 32 receives the wireless signal transmitted from the signal transmitter 20 via the antenna 29. The wireless signal reception unit 32 outputs the received wireless signal to the observation unit 33.

The observation unit 33 observes the data regarding the radio signal transmitted from the radio signal reception unit 32 based on various observation standards. The data relating to the radio signal may be any data as long as it relates to the radio signal, and is, for example, the propagation delay amount (propagation delay time) of the radio signal, the received power, the frequency, or the like. The observing unit 33, after acquiring the data regarding the wireless signal, continues observing the change tendency in time series. The observation unit 33 notifies the position estimation unit 35 of the observation result of the data regarding the wireless signal.

The information detection unit 34 is a part for detecting various information in the flying object 30. The information detection unit 34 is composed of one or a plurality of measuring instruments and the like. For example, a device for determining the engine speed, an attitude sensor, an altimeter, an acceleration sensor, an airspeed indicator, a magnetic compass or a gyro compass. It is composed of a compass, etc. Further, the information detecting unit 34 may be a person having a GPS (Global Positioning System) device in order to detect the position information of the flying body 30 at the present time. This GPS device acquires the latitude, longitude, altitude, and time information of the flying body 30 at the present time. Incidentally, as a means for detecting such position information, a satellite positioning system other than the GPS device may be used. Further, when acquiring the time information, a radio clock other than the GPS device may be used. The information detection unit 34 including these measuring instruments and devices can acquire at least three-dimensional position information of each position on the flight trajectory of the flying object 30. Further, it is possible to detect the three-dimensional direction vector of the flight trajectory at the position. The information detection unit 34 detects this direction vector by, for example, GPS or a geomagnetic sensor. The information detection unit 34 transmits at least the acquired three-dimensional position information of each position on the flight trajectory of the flying body 30 and the three-dimensional direction vector of the flight trajectory at the position to the position estimation unit 35.

The position estimation unit 35 receives the observation result of the data regarding the wireless signal from the observation unit 33. The position estimating unit 35 also receives from the information detecting unit 34 three-dimensional position information of each position on the flight trajectory of the flying object 30 and a three-dimensional direction vector of the flight trajectory at the position. The position estimation unit 35 estimates the position of the signal transmitter 20 while referring to the position information and the direction vector based on the observation result of the data. Details of this position estimation will be described later. The position estimation unit 35 outputs the estimated position of the signal transmitter 20 to the information storage unit 38 and/or the estimated information transmission unit 39.

The information storage unit 38 is configured by a semiconductor memory device such as (Flash Memory), a storage device such as a hard disk, an optical disk, or the like. The information storage unit 38 stores information about the estimated position of the signal transmitter 20 transmitted from the position estimation unit 35. The information storage unit 38 also stores the observation result of the data regarding the wireless signal transmitted from the observation unit 33, the position information and the direction vector transmitted from the information detection unit 34, as necessary. The information regarding the estimated position of the signal transmitter 20, the observation result of the data regarding the radio signal, the position information, and the direction vector stored in the information storage unit 38 are read out as necessary under the control of the position estimation unit 35 and the like.

The estimated information transmission unit 39 transmits the information regarding the estimated position of the signal transmitter 20 transmitted from the position estimation unit 35 to an external base station, controller, or the like (not shown) through wireless communication or wired communication.

Next, the concept of position estimation in the position estimation system 10 to which the present invention is applied will be described.

According to the position estimation system 10 to which the present invention is applied, as shown in FIG. 3, the flying object 30 is spread over the flight trajectories 1, 2, 3,... K,... N (here, N≧3), To fly. The flying body 30 continues to receive the radio signal of the frequency f ₀ [Hz] transmitted from the signal transmitter 20 in the process of flying each flight trajectory k. Then, the flying object 30 estimates the position of the signal transmitter 20 located in the 90° direction with respect to the direction of the flight trajectory by observing the data regarding the received wireless signal. In the flight trajectory 1 referred to in FIG. 3, the coordinate U of the signal transmitter 20 is located at 90° with respect to the direction of the flight trajectory at Q ₁ . Similarly, in the flight trajectory 2, the U of the signal transmitter 20 is located at 90° with respect to the direction of the flight trajectory at Q ₂ . Further, in the flight trajectory k, the U of the signal transmitter 20 is located in the direction of 90° with respect to the direction of the flight trajectory in Q _k . Hereinafter, it is assumed that the three-dimensional coordinates of the signal transmitter 20 as the estimation target are given by U=[X, Y, Z].

FIG. 4 shows an example in which one flight trajectory k is flown by the flying body 30. The direction vector in the flight direction of the flying body 30 on the flight trajectory k is given by d _k =[a _k , b _k , c _k ]. Further, the position vector of the position Q _k on the flight trajectory k in which the position U of the signal transmitter 20 exists in the direction forming 90° from the flight direction is given by Q _k =[x _k , y _k , y _k ]. To be That is, the direction vector d _k =[a _k , b _k , c _k ] indicates the flight direction of the flying object 30 at the position Q _k on the flight trajectory k, and the direction forming 90° from this position Q _k. Therefore, the position U of the signal transmitter 20 is present at.

According to the position estimation system 10 to which the present invention is applied, while the flying body 30 is flying on the flight trajectory k, a signal is generated in a direction forming 90° from the flight direction d _k =[a _k , b _k , c _k ]. The operation for searching the position Q _k on the flight trajectory k where the position U of the transmitter 20 exists will be performed.

In the example of FIG. 5, an example is shown in which a radio signal transmitted from the signal transmitter 20 is received while flying the flying body 30 on the flight trajectory k set in a straight line. In the flight trajectory k, the flying body 30 passes through the positions Q _k-1 ,... Q _k-2, ... Q _k-3 , and is a straight line in the direction of the direction vector d _k =[a _k , b _k , c _k ]. In the case of flying like a plane, the position closest to the position U is the position Q _k-2 . Then, the position U of the signal transmitter 20 moves in a direction forming an angle of 90° with respect to the direction vector d _k =[a _k , b _k , c _k ] from the position Q _{k-2 which} is the closest to the position U. Exists. In FIG. 5, the position closest to the position U is the position Q _k-2 , and the perpendicular line drawn from the position U toward the flight trajectory of this direction vector d _k =[a _k , b _k , c _k ]. The position becomes the position Q _k-2 .

Therefore, the position Q _k-2 on the flight trajectory k, which is the closest to the position U, is analyzed via the radio signal transmitted from the signal transmitter 20. For example, when the received power of the radio signal is analyzed, the flying body 30 passes through the positions Q _k-1 ,... Q _k-2, ... Q _k-3 , and the direction vector d _k =[ _ak , b _k , c _In the process of flying in a straight line in the direction [ _k ], the distance from the position U gradually becomes closer from the position Q _k-1 to the position Q _k-2 , and accordingly the received power gradually increases. growing. On the other hand, since the distance from the position U gradually increases from the position Q _k-2 to the position Q _k-3 of the flying object 30, the received power gradually decreases accordingly. As a result, the peak of the received power will appear at the position Q _k-2 .

Therefore, the flying object 30 flies linearly in the direction of the direction vector d _k =[a _k , b _k , c _k ] via the positions Q _k-1 ,... Q _k-2, ... Q _k-3. By following the relative change tendency of the received power in the process of specifying, the position of the peak can be specified to obtain the position information of the position Q _k-2 . As a result, the flight trajectory in which the position U of the signal transmitter 20 exists in a direction forming 90° from the flight direction d _k =[a _k , b _k , c _k ] only by following the relative change tendency of the received power. It is possible to specify a position Q k on _k (hereinafter, a position Q _k that satisfies such a condition is referred to as a condition satisfying position).

In FIG. 6, the horizontal axis represents each position of a linear flight trajectory k directed to the flight direction d _k =[a _k , b _k , c _k ], and the vertical axis represents the relative change tendency of data relating to radio signals. Showing. FIG. 6A shows the propagation delay amount as the data regarding the wireless signal forming the vertical axis, and FIG. 6B shows the above-mentioned received power as the data regarding the wireless signal forming the vertical axis. Each assigns a reception frequency as data relating to a radio signal forming the vertical axis.

In the example of FIG. 6A, the propagation delay amount (propagation delay time) of the radio signal is measured along a straight flight trajectory directed in the flight direction d _k =[ _ak , b _k , c _k ]. Go. Then, the position Q _{k at} which this propagation delay amount is the minimum is the condition satisfying position.

In the example of FIG. 6B, the position Q _{k at} which the received power is maximum is the condition satisfying position as in the above case.

In the example of FIG. 6C, when the fact that the amount of Doppler shift received by the received wireless signal is 0 is used, the frequency of the wireless signal is observed, and that frequency is the frequency f ₀ transmitted from the signal transmitter 20. The position closest to is the condition satisfaction position.

In any of the cases of FIG. 6, it is not necessary to measure an absolute accurate value on the vertical axis in any case, but the change tendency relative to the position on the horizontal axis is identified, and the maximum and minimum values are determined. The condition-satisfying position can be obtained by specifying the value or the position closest to the frequency f ₀ . Therefore, it is possible to prevent the observation unit 33 from observing data regarding a radio signal in detail when the condition-satisfying position is obtained, and prevent the observation from becoming complicated.

Note that the method for obtaining the condition satisfaction position is not limited to these, and may be obtained based on any other method. That is, any method can be used as long as other data capable of identifying the distance from the position U can be observed from the wireless signal and the condition satisfying position where the distance is closest can be specified from the relative change tendency. It may be one. Alternatively, a condition satisfying a preset condition, such as a condition that the frequency f ₀ is closest to the frequency f ₀ shown in FIG. 6C, is specified as the condition satisfaction position by following the relative change tendency of the observed data. Any other method may be applied as long as it is one.

・・・・・・・・・（１） Coordinates Q _k =[x _k , y _k , y _k ] at the condition satisfying position Q _k thus obtained are included, and the direction vector d _k =[a _k , b _k of the flight trajectory k of the flying object 30 is included. , C _k ] is perpendicular to the plane P _{k, and} includes the three-dimensional coordinates U=[X, Y, Z] of the signal transmitter 20. The coordinates Q _k =[x _k , y _k , y _k ] at the condition-satisfying position Q _k can be obtained from the information detection unit 34, and the direction vector d _k =[a _k , Since b _k , c _k ] is known, if an arbitrary point on P _k is P=[x, y, z], the equation of the plane is d _k ·(P−Q _k )=0. It can be expressed by equation (1).

・・・・・・・(1)

・・・・・・・・・（２） Further, when P=[x, y, z] is U=[X, Y, Z] at any point on P _k , x=X is substituted in this equation (1), and y By substituting =Y and substituting z=Z, it can be expressed by the following equation (2).

・・・・・・・(2)

However, since there are three variables X, Y, and Z in this equation (2), the solution of these variables X, Y, and Z cannot be obtained unless there are at least three such plane equations in total. It will be.

In FIG. 3, three planes P _k perpendicular to the direction vector d _k =[a _k , b _k , c _k ] of the flight trajectory k are drawn over the planes P ₁ , P ₂ , P _k . It is a thing. These planes P ₁ , P ₂ and P _k are oriented in directions in which the direction vector d _{1 of} the flight trajectory ₁ , the direction vector d _{2 of} the flight trajectory ₂ and the direction vector d _k of the flight trajectory k which are perpendicular to each other are different from each other. It has been extended. If there is no estimation error, the three different planes P ₁ , P ₂ , and P _k intersect at one point, and that point becomes the estimated value of U. Actually, the three-dimensional coordinate U=[X, Y, Z] of this U is based on the above-mentioned method, and the equation of the plane of the equation (2) is made for each plane P ₁ , P ₂ , P _k , and the simultaneous equations are formed. It can be obtained by solving the equation.

Next, an actual position estimation operation in the position estimation system 10 to which the present invention is applied will be described.

Before operating the position estimation system 10, the signal transmitter 20 is attached in advance to the object of position estimation. The signal generator 21 of the signal transmitter 20 constantly or intermittently generates a signal of frequency f ₀ . The generated signal is constantly or intermittently transmitted as a wireless signal via the antenna 22.

The user of the position estimation system 10 inputs a flight plan or flight control command by operating the operation unit 36 or via a base station or controller (not shown). As a result, the flight path of the flying object 30 can be controlled by the user. Upon receiving the flight control command and the like, the machine body control unit 31 causes the flying body 30 to fly toward the flight trajectory k based on this.

In the process of flying the flying object 30 toward the flight trajectory k, the information detecting unit 34 at least three-dimensional position information of the position of the flying object 30 on the flight trajectory and the three-dimensional direction of the flight trajectory at the position. The vector is continuously acquired and is output to the position estimation unit 35. Further, in the process of flying the flying object 30 toward the flight trajectory k, the wireless signal transmitted from the antenna 22 of the signal transmitter 20 is received by the wireless signal receiving section 32 via the antenna 29 of the flying object 30, and It is sent to the observation unit 33. The observation unit 33 observes any data including the received voltage, the propagation delay time, the frequency, etc. from the radio signal as described above.

These operations are repeatedly performed in the process of flying the flying body 30 toward the flight trajectory k. As a result, for each position on the flight trajectory k, the three-dimensional position information and the three-dimensional direction vector of the flight trajectory at that position can be sequentially acquired. Further, by sequentially observing the data regarding the radio signal such as the received voltage at each position on the flight trajectory k in the observation unit 33, the relative change tendency with the horizontal axis as the position as shown in FIG. 6 is acquired. can do.

The relative change tendency of the data regarding the radio signal observed by the observation unit 33 is sequentially input to the position estimation unit 35. At the same time, the position estimating unit 35 is supplied with three-dimensional position information of each position on the flight trajectory k and the three-dimensional direction vector of the flight trajectory k at the position from the information detecting unit 34. The position estimating unit 35 performs the work of identifying the condition satisfying position Q _k based on the relative change tendency of the data regarding the wireless signal. Further, when the condition satisfying position Q _k can be specified, the coordinates Q _k =[x _k , y _k , y _k of the condition satisfying position Q _k in the three-dimensional position information input from the information detecting unit 34. ] And the three-dimensional direction vector d _k =[a _k , b _k , c _k ] of the three flight trajectories k input from the information detection unit 34 is acquired. The position estimating unit 35 calculates the coordinates Q _k =[x _k , y _k , y _k ] of the acquired condition-satisfying position Q _k and the three-dimensional direction vector d _k =[a _k , b _k , c _k ]. By substituting in the equation (2), a plane equation can be obtained.

Next, the user of the position estimation system 10 operates the operation unit 36 or sets a flight trajectory different from the above-described flight trajectory k through a base station or a controller (not shown). , The flying body 30 is caused to fly, and the same operation as described above is executed. By performing this three times or more, the change tendency of the data regarding the relative radio signal is acquired from the observation unit 33 three times or more via the flying body 30 that has been made to fly on the flight trajectory k different from each other. It is possible to obtain the condition satisfying position at three or more positions. Further, it is possible to obtain three-dimensional position information at each position satisfying each condition and equations of three or more planes into which the direction vector is substituted, and by solving this, the position U of the object can be estimated. Become.

In this way, according to the position estimation system 10 to which the present invention is applied, the signal in the direction forming 90° from the flight direction can be obtained only by following the relative change tendency of the data regarding the radio signal observed by the observation unit 33. It is possible to specify the condition satisfy position on the flight trajectory k in which the position U of the transmitter 20 exists. Then, the position of the object is estimated by repeatedly substituting the three-dimensional position information and the direction vector at the position satisfying the condition into the equation of the plane three or more times between different flight trajectories. be able to.

In the actual process, the position of the object can be estimated by simply following the relative change tendency of the data without performing the step of accurately measuring the data regarding the radio signal. Therefore, the position of the object can be estimated without going through the step of accurately measuring the moving speed of the moving body and the Doppler shift amount of the wireless signal as in the conventional technique, and the estimation accuracy is significantly improved. It becomes possible.

After estimating the position U of the target object, the position estimation unit 35 may store the position U in the information storage unit 38, or may display it on a display screen (not shown). Alternatively, the position estimating unit 35 may transmit the estimated position U of the object to the external base station, controller, or the like (not shown) via the estimation information transmitting unit 39 via wireless communication or wired communication.

In the embodiment described above, the three-dimensional direction vector d _k =[a _k , b _k , c _k ] of the flight trajectory k is detected by the information detection unit 34, and this is detected by the position estimation unit 35. The description has been given by taking the case of sending as an example, but the present invention is not limited to this. When such a direction vector d _k can be specified based on the flight plan or flight control command input by the user from the operation unit 36 or the like, it may be obtained by providing it to the position estimation unit 35. ..

Further, in the above-described embodiment, the case where there is no estimation error has been described as an example, but if there is an estimation error, the following estimation may be performed.

・・・・・・・・・・・（３） Generally, when there is such an estimation error, the planes do not intersect at one point. The distance from the true position U=[X, Y, Z] of U to the plane P _k is given by the following equation (3).

・・・・・・・・・・・ (3)

・・・・・・・・・・・（４） Therefore, if this distance is considered as an error and U is estimated by the least squares estimation method, it can be obtained by the following equation (4).

・・・・・・・・・・・ (4)

Further, according to the present invention, the moving speed of the flying object 30 is measured by the information detecting section 34, or the moving speed of the object is measured by a measuring means (not shown), and the measured value is stored in the information storing section 38. The number of flight trajectories k may be determined based on one or more of the moving speed of 30 and the moving speed of the object.

Further, any one or more of the observation unit 33 and the position estimation unit 35 may be installed in an external base station or controller (not shown) instead of being provided inside the flying object 30. In such a case, when the wireless signal reception unit 32 receives a wireless signal, the wireless signal reception unit 32 transmits the wireless signal to the base station or controller (not shown) via the estimation information transmission unit 39, and the observation unit mounted therein. The position estimation is performed via the 33 and the position estimation unit 35.

According to the present invention, it is premised that the flight trajectory k of the flying body 30 is linear, but when the flight trajectory k is switched to another flight trajectory k+1, The takeoff and landing may be performed each time, but the flight trajectory of the flying object 30 may be changed by changing the flight trajectory on the way.

In such a case, when the condition-satisfying position is tracked at the position of the received power as shown in FIG. 6B, if the received power is measured and as a result the flying body 30 continues to decrease, the aircraft 30 It means that the position is gradually separated from the condition satisfying position. In such a case, even if the flying object 30 continues to fly on the flight trajectory, it cannot reach the condition satisfying position where the received power is maximum, so the flight of the flying object 30 on the flight trajectory is stopped.

On the other hand, as a result of measuring the received power, if the received power continues to rise as the flight vehicle 30 advances, it means that the flight vehicle 30 is gradually approaching the condition satisfaction position. In such a case, the flying body 3 will continue to fly on its flight path. During the flight, the flying body 3 continued to detect the received power, and as a result, when the received power that had been kept rising as the flying body 30 started to decrease until now, the peak just as shown in FIG. It means that the position has appeared. Such a peak position corresponds to the above-mentioned condition-satisfying position, but when the condition-satisfying position can be specified, the flying body 30 can be changed to another flight trajectory and the same observation can be performed. The above-described example has been described by exemplifying the case where the received power is observed as the data regarding the radio signal, but the same applies to the other examples, and the aircraft 30 until the position where the propagation delay amount becomes the minimum appears. The flight may be continued, or the flight may be continued until the position where the observed frequency is closest to the frequency f ₀ can be specified.

That is, according to the present invention, data regarding a radio signal is continuously obtained in real time, and it is determined whether or not a condition-satisfying position appears while flying the flying object 30, and the flight trajectory is maintained until the condition-satisfying position can be confirmed. You may make it fly in a straight line. Then, after the observation unit 33 can confirm the condition-satisfying position, the flying body 30 may change to another flight trajectory and continue flying as it is. That is, whether or not the condition-satisfying position is specified may be used for determining the flight trajectory change.

10 Position Estimation System 20 Signal Transmitter 21 Signal Generator 22, 29 Antenna 30 Aircraft 31 Aircraft Controller 32 Radio Signal Receiver 33 Observing 34 Information Detecting 35 Position Estimating 36 Operation 37 Control Signal Receiving 38 Information Storage Part 39 Estimated information transmitter

Claims (6)

In a position estimation system that estimates the position of an object that is stationary or moves slightly,
An aircraft that continuously receives a radio signal transmitted from a signal transmitter attached to the object in the process of flying on a flight trajectory that can be controlled from the outside,
Flight body position information detecting means for detecting three-dimensional position information of each position on the flight trajectory of the flight vehicle and three-dimensional direction vector of the flight trajectory at the position,
Observing means for observing a relative change tendency of the data regarding the radio signal received by the flying object with respect to the position,
The condition-satisfying position where the relative change tendency of the data observed by the observing means satisfies a preset condition is obtained, and the three-dimensional position information and the direction vector at the condition-satisfying position are detected by the aircraft position information detecting means. And position estimation means for substituting this into the equation of the plane,
The position estimating means obtains the condition satisfying positions at three or more locations from the relative change tendency observed three times or more from the observing means in the process of flying the flight object on different flight trajectories, A position estimation system which estimates the position of the object based on three-dimensional position information at each of the condition-satisfying positions and equations of three or more planes into which direction vectors are substituted. 2. The position estimating means sets the position closest to the object to the condition satisfying position based on the relative change tendency of the data observed by the observing means. Position estimation system. The observing means observes a relative change tendency of the propagation delay amount as data relating to the radio signal,
The position estimating system according to claim 2, wherein the position estimating means sets a position where the amount of propagation delay observed by the observing means is minimum as the condition satisfying position. The observing means observes a relative change tendency of the reception power of the radio signal as data relating to the radio signal,
The position estimating system according to claim 2, wherein the position estimating unit sets a position where the received power observed by the observing unit is maximum as the condition satisfying position. The observing means observes a relative change tendency of the frequency of the radio signal as data relating to the radio signal,
The position estimating means acquires the frequency f ₀ of the radio signal transmitted from the object in advance, and sets the position where the frequency observed by the observing means is closest to the frequency f ₀ as the condition satisfying position. The position estimation system according to claim 1, wherein: The observing means continues to acquire the data regarding the radio signal until the condition satisfying position can be detected,
The position estimating system according to claim 1, wherein the flying body changes to another flight trajectory and continues to fly after the position satisfying the condition can be detected by the observation means.

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