Position estimation device, position estimation system, position estimation method, and program

Abstract

To estimate the position of a wireless terminal with high accuracy.SOLUTION: A management device 30 estimates the position of a user terminal 20b. A correction unit 315 corrects a value based on the reception strength of a wireless signal at the user terminal 20b, using correction information 300 generated on the basis of the reception strength at multiple positions of the wireless signal transmitted from a transmitter 10. A position estimation unit 316 estimates the position of the user terminal 20b on the basis of the value corrected by the correction unit 315 and the position of the transmitter 10.SELECTED DRAWING: Figure 13

Description

[Technical Field]

[0001] The present disclosure relates to a position estimation device, a position estimation system, a position estimation method, and a program. [Background technology]

[0002] There is known a technique for estimating the position of a wireless terminal based on the received strength of a wireless signal. For example, Patent Document 1 discloses a system for estimating the position of a wireless device using a moving object. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-173564 Summary of the Invention [Problem to be solved by the invention]

[0004] In the technology for estimating the position of a wireless terminal based on the reception strength of a wireless signal as described above, there is a problem in that the accuracy of the position estimation decreases due to the influence of obstacles such as walls, furniture, etc., which can impede the propagation of the wireless signal.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a position estimation device and the like that can estimate the position of a wireless terminal with high accuracy. [Means for solving the problem]

[0006] In order to achieve the above object, a position estimation device according to the present disclosure includes: A position estimation device that estimates a position of a wireless terminal, a correction means for correcting a value based on the reception strength of a radio signal transmitted from a transmitter at the wireless terminal using correction information generated based on the reception strength of the radio signal at a plurality of positions; The radio terminal includes a position estimation unit that estimates the position of the radio terminal based on the value corrected by the correction unit and the position of the transmitter. [Effects of the Invention]

[0007] A position estimation device according to the present disclosure corrects a value based on the reception strength of a wireless signal at a wireless terminal using correction information generated based on the reception strength at multiple positions of a wireless signal transmitted from a transmitter, and estimates the position of the wireless terminal based on the corrected value and the position of the transmitter. Thus, according to the present disclosure, the position of the wireless terminal can be estimated with high accuracy. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing the overall configuration of a position estimation system according to a first embodiment. [Figure 2] A side view of a building in which a transmitter according to the first embodiment is installed. [Figure 3] 1 is a top view of a building in which a transmitter according to the first embodiment is installed. [Figure 4] FIG. 1 is a block diagram showing the hardware configuration of a measurement terminal and a user terminal according to a first embodiment. [Figure 5] FIG. 1 is a block diagram showing a hardware configuration of a management device according to a first embodiment. [Figure 6] FIG. 1 is a block diagram showing a functional configuration of a position estimation system in a preliminary phase according to a first embodiment. [Figure 7] FIG. 10 is a diagram showing an example of transmitter information according to the first embodiment; [Figure 8] FIG. 10 is a diagram showing an example of intensity information in a preliminary phase in the first embodiment; [Figure 9] FIG. 10 is a diagram showing an example of intermediate data for generating correction information according to the first embodiment; [Figure 10] FIG. 10 is a diagram showing an example of correction information according to the first embodiment; [Figure 11] 1 is a flowchart showing a flow of a measurement process executed by a measurement terminal according to the first embodiment; [Figure 12]1 is a flowchart showing a flow of a correction information generation process executed by a management device according to the first embodiment; [Figure 13] FIG. 1 is a block diagram showing a functional configuration of a position estimation system in an operation phase according to a first embodiment. [Figure 14] FIG. 10 is a diagram showing an example of strength information in the operation phase in the first embodiment. [Figure 15] FIG. 10 is a diagram showing an example of displaying a position estimated by the position estimation system according to the first embodiment. [Figure 16] 1 is a flowchart showing a flow of strength information transmission processing executed by a user terminal according to the first embodiment; [Figure 17] 1 is a flowchart showing a flow of a position estimation process executed by a management device according to the first embodiment; [Figure 18] FIG. 10 is a block diagram showing a functional configuration of a position estimation system in an operation phase according to a second embodiment. [Figure 19] FIG. 10 is a diagram showing a data flow in a learning process according to the second embodiment. [Figure 20] FIG. 13 is a diagram showing an example in which a new obstacle is installed after the start of the operation phase in the fourth embodiment. [Figure 21] 10 is a flowchart showing the flow of a position estimation process executed by a management device according to a fourth embodiment. [Figure 22] A contour diagram showing the reception strength of a radio signal transmitted from a transmitter according to the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described in detail with reference to the drawings, in which the same or corresponding parts are designated by the same reference numerals.

[0010] (Embodiment 1) 1 shows the overall configuration of a position estimation system 1 according to the first embodiment. The position estimation system 1 is a system that estimates the position of a wireless terminal 20 and the position of a user who carries or operates the wireless terminal 20. The position estimation system 1 includes a plurality of transmitters 10, a measurement terminal 20a, a user terminal 20b, and a management device 30. The plurality of transmitters 10 are installed in a building 5, which is an example of a position estimation range.

[0011] Each of the multiple transmitters 10 is a device that transmits a wireless signal. The wireless signal is a signal for transmitting information between distant devices. As an example, the wireless signal is a Bluetooth (registered trademark) radio wave signal, which is a beacon signal conforming to the BLE (Bluetooth Low Energy (registered trademark)) standard.

[0012] Each transmitter 10 is installed in a building 5 as shown in Figures 2 and 3. The building 5 is a structure such as a detached house, an apartment building, an office building, a commercial facility, or a factory. The building 5 has multiple areas. Each of the multiple areas corresponds to, for example, one room in the building 5. Note that each of the multiple areas is not limited to being a room, but may be a partial range within one room. Each transmitter 10 is installed in an appropriate location, such as a wall, ceiling, or pillar, in one of the multiple areas in the building 5.

[0013] 2 and 3, for ease of understanding, an example is shown in which two transmitters 10 are installed in each of three areas A1 to A3 within building 5. However, there may be areas within building 5 in which no transmitters 10 are installed, or one or three or more transmitters 10 may be installed in one area. Furthermore, the number of areas is not limited to three. Building 5 may have multiple floors, and each floor may have multiple areas.

[0014] An obstacle 7a exists between area A1 and area A2, and an obstacle 7b exists between area A2 and area A3. Obstacles 7a and 7b are objects that obstruct the propagation of the wireless signal transmitted from transmitter 10, such as a wall, furniture, an indoor unit, or a pillar.

[0015] Each transmitter 10 may be any device that transmits a wireless signal. For example, each transmitter 10 may be a device that only has the function of transmitting a Bluetooth (registered trademark) radio signal. Alternatively, devices such as air conditioners, lighting, and environmental sensors installed in the building 5 may have the function of transmitting a wireless signal, and these devices may function as transmitters 10.

[0016] It is not necessary for each transmitter 10 to be completely fixed as long as it is installed. However, since the position of each transmitter 10 is used to estimate the position of the wireless terminal 20, it is desirable to keep it as still as possible.

[0017] Each transmitter 10 repeatedly transmits a radio signal of a predetermined strength periodically at a predetermined time interval or at irregular timing. For example, each transmitter 10 repeatedly transmits a radio signal once per second. The strength of the radio signal transmitted from each transmitter 10 is preset so that the strength is equal among the multiple transmitters 10 installed in the building 5.

[0018] A transmitter ID, which is identification information of the transmitter, is included in the wireless signal transmitted from each transmitter 10. The transmitter ID is, for example, a beacon ID, and is information that is uniquely set for each transmitter 10, which is the transmitter, so that the source of the wireless signal can be identified.

[0019] Returning to FIG. 1 , the measurement terminal 20a and the user terminal 20b are terminal devices such as a smartphone, a PC (Personal Computer), a tablet terminal, etc. The measurement terminal 20a is a terminal for pre-processing used in a pre-phase before the operation phase of the position estimation system 1. The measurement terminal 20a is used to measure the strength of wireless signals in multiple areas within the building 5. A user of the measurement terminal 20a is, for example, an operator that operates the position estimation system 1. In contrast, the user terminal 20b is a terminal that is the target of position estimation in the position estimation system 1. A user of the user terminal 20b is a general user present within the building 5, such as a user or resident of the building 5. The measurement terminal 20a and the user terminal 20b are each a portable terminal that is carried and operated by a user and moves to various locations within the building 5 as the user moves. Hereinafter, when the measurement terminal 20a and the user terminal 20b are referred to without distinction, they will be simply referred to as "wireless terminal 20."

[0020] The measurement terminal 20a and the user terminal 20b have the same hardware configuration. Specifically, as shown in Fig. 4, each of the measurement terminal 20a and the user terminal 20b includes a control unit 21, a storage unit 22, an operation unit 23, a display unit 24, and a communication unit 25.

[0021] The control unit 21 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The CPU is also called a central processing unit, central arithmetic unit, processor, microprocessor, microcomputer, etc., and functions as a central arithmetic processing unit that executes processing and calculations related to the control of the wireless terminal 20. In the control unit 21, the CPU reads programs and data stored in the ROM and uses the RAM as a work area to perform overall control of the wireless terminal 20.

[0022] The storage unit 22 includes a nonvolatile semiconductor memory such as a flash memory, an EPROM (Erasable Programmable ROM), or an EEPROM (Electrically Erasable Programmable ROM), and serves as a so-called secondary storage device or auxiliary storage device. The storage unit 22 stores programs and data used by the control unit 21 to perform various processes. The storage unit 22 also stores data generated or acquired by the control unit 21 as a result of performing various processes.

[0023] The operation unit 23 includes input devices such as a keyboard, a mouse, buttons, a touchpad, and a touch panel, and receives operations from a user. The user can input various instructions to the wireless terminal 20 by operating the operation unit 23. When the operation unit 23 receives an operation instruction input by the user, it transmits the received operation instruction to the control unit 21.

[0024] The display unit 24 includes a display device such as a liquid crystal display, an organic EL (Electro Luminescence) display, etc. The display unit 24 is driven by a display drive circuit (not shown), and displays various images under the control of the control unit 21.

[0025] The communication unit 25 includes a communication interface for the wireless terminal 20 to communicate with external devices. The communication unit 25 communicates with external devices, including the management device 30, via a communication network, which is a wide-area communication network. The protocol used for communication is not particularly limited, but a protocol with a certain degree of versatility, such as the ECHONET Lite (registered trademark) standard, can be adopted. The communication unit 25 also receives wireless signals transmitted from each of the multiple transmitters 10, for example, according to the BLE (registered trademark) communication standard.

[0026] Returning to FIG. 1 , management device 30 is a device that manages position estimation system 1 and is an example of a position estimation device that estimates the position of wireless terminal 20. Management device 30 is an information processing device such as a PC or a server, and is installed under the management of an administrator of position estimation system 1. Management device 30 may be a cloud server such as AWS (Amazon Web Services). As shown in FIG. 5 , management device 30 includes a control unit 31, a storage unit 32, and a communication unit 35.

[0027] The control unit 31 includes a CPU, a ROM, and a RAM. The CPU is also called a central processing unit, a processor, a microprocessor, a microcomputer, etc., and functions as a central processing unit that executes processing and calculations related to the control of the management device 30. In the control unit 31, the CPU reads out programs and data stored in the ROM and uses the RAM as a work area to perform overall control of the management device 30.

[0028] The storage unit 32 includes a nonvolatile semiconductor memory such as a flash memory, an EPROM, or an EEPROM, and serves as a so-called secondary storage device or auxiliary storage device. The storage unit 32 stores programs and data used by the control unit 31 to perform various processes. The storage unit 32 also stores data generated or acquired by the control unit 31 as a result of performing various processes.

[0029] The communication unit 35 includes a communication interface for communication between the management device 30 and external devices. The communication unit 35 communicates with external devices including the measurement terminal 20a and the user terminal 20b via a communication network, which is a wide area communication network.

[0030] The position estimation system 1 operates in two phases: a preliminary phase and an operational phase. The preliminary phase is a first phase in which correction information 300 is generated using the measurement terminal 20a before the operational phase begins. The preliminary phase is implemented, for example, when multiple transmitters 10 are installed in a building 5. In contrast, the operational phase is a second phase in which the correction information 300 generated in the preliminary phase is used to estimate the position of the user terminal 20b that is the estimation target. Below, the functional configuration of the position estimation system 1 will be described, divided into the preliminary phase and the operational phase.

[0031] <Preliminary Phase> 6, the measurement terminal 20a and the management device 30 are operated. The measurement terminal 20a includes, in the control unit 21, functionally a transmitter information acquisition unit 211 which is an example of a transmitter information acquisition means, a position information acquisition unit 212 which is an example of a position information input means, a signal receiving unit 213 which is an example of a signal receiving means, and an intensity information transmission unit 214 which is an example of an intensity information transmission means. The management device 30 includes, in the control unit 31, functionally a transmitter information transmission unit 311 which is an example of a transmitter information transmission means, an intensity information acquisition unit 312 which is an example of an intensity information acquisition means, and a correction information generation unit 313 which is an example of a correction information generation means.

[0032] Each of these functions is realized by software, firmware, or a combination of software and firmware in the control units 21 and 31. The software and firmware are written as programs and stored in the ROM or storage units 22 and 32. Then, in the control units 21 and 31, the CPU executes the programs stored in the ROM or storage units 22 and 32, thereby realizing each of the functions shown in FIG.

[0033] In the management device 30, the storage unit 32 stores transmitter information 321. The transmitter information 321 is information relating to the plurality of transmitters 10 installed in the building 5. Specifically, as shown in FIG. 7 , the transmitter information 321 includes a transmitter ID, which is identification information for each of the plurality of transmitters 10, and location information for each of the plurality of transmitters 10 within the building 5.

[0034] In the transmitter information 321, the transmitter ID is the same as the identification information included in the wireless signal transmitted from each transmitter 10, and is information for uniquely identifying each transmitter 10. The location information is information for specifying the location in the building 5 where each transmitter 10 is installed.

[0035] 7, the location information in the transmitter information 321 indicates the location where each transmitter 10 is installed using three-dimensional coordinates that uniquely indicate the location within the building 5. Alternatively, the location information is not limited to this, and may indicate the location of each transmitter 10 using information that indicates the area in which each transmitter 10 is installed and the detailed location within that area. Such transmitter information 321 is prepared in advance when multiple transmitters 10 are installed in the building 5, which is the location estimation range, and is stored in the storage unit 32 of the management device 30.

[0036] 6 , in the measurement terminal 20a, the transmitter information acquisition unit 211 acquires the transmitter information 321 from the management device 30. Specifically, the transmitter information acquisition unit 211 communicates with the management device 30 via the communication unit 25 and transmits a request for the transmitter information 321 to the management device 30. In the management device 30, when the transmitter information transmission unit 311 receives the request for the transmitter information 321 from the measurement terminal 20a, it reads out the transmitter information 321 stored in the storage unit 32 and transmits it to the measurement terminal 20a that has made the request. The transmitter information acquisition unit 211 acquires the transmitter information 321 transmitted from the management device 30 in this manner and stores it in the storage unit 22.

[0037] Here, the timing at which the transmitter information acquisition unit 211 acquires the transmitter information 321 from the management device 30 is arbitrary. For example, the transmitter information acquisition unit 211 acquires the transmitter information 321 from the management device 30 immediately after the user operates the operation unit 23 of the measurement terminal 20a to start up application software that acquires the location information of the measurement terminal 20a. Alternatively, the transmitter information acquisition unit 211 may acquire the transmitter information 321 from the management device 30 at any timing according to the user's operation.

[0038] In the measurement terminal 20a, the location information acquisition unit 212 acquires location information of the measurement terminal 20a. The location information of the measurement terminal 20a is used as information indicating the measurement location where the reception strength of the wireless signal transmitted from each transmitter 10 is measured.

[0039] Specifically, the location information acquisition unit 212 acquires location information indicating the current location of the measurement terminal 20a within the building 5 based on the user's operation. The user of the measurement terminal 20a operates the operation unit 23 to input coordinate information of the user's current location as location information of the measurement terminal 20a. Note that the user is not limited to detailed location information, and may also input location information with lower accuracy, such as information about the floor and area where the user is currently located. The location information acquisition unit 212 acquires the location information input by the user in this manner.

[0040] In the measurement terminal 20a, the signal receiving unit 213 receives a wireless signal transmitted from each of the multiple transmitters 10. As described above, each transmitter 10 periodically transmits a wireless signal of a predetermined intensity. When a wireless signal is transmitted from a transmitter 10 that is present within a range in which the measurement terminal 20a can receive the wireless signal, the signal receiving unit 213 receives the wireless signal.

[0041] When the signal receiving unit 213 receives a wireless signal transmitted from any of the transmitters 10, it measures the strength of the received wireless signal. The strength of the wireless signal transmitted from each transmitter 10 is constant at the time of transmission, but attenuates according to the propagation distance of the wireless signal. Therefore, the longer the distance from the transmitting transmitter 10 to the measurement terminal 20a, the weaker the strength of the wireless signal received at the measurement terminal 20a. When the signal receiving unit 213 receives a wireless signal, it measures the reception strength, which is the strength of the received wireless signal, and stores the measured reception strength value in the memory unit 22.

[0042] More specifically, when the signal receiving unit 213 receives a wireless signal, it updates the intensity information 221 stored in the storage unit 22. The intensity information 221 is information that indicates, in association with each other, a transmitter ID that is identification information of the transmitter 10, the reception intensity of the wireless signal at the measurement terminal 20a, and location information of the measurement terminal 20a, in the order of reception date and time when the measurement terminal 20a received the wireless signal, as shown in Fig. 8. The location information is the location information of the measurement terminal 20a at the time of receiving the wireless signal, acquired by the location information acquiring unit 212.

[0043] When the signal receiving unit 213 receives a wireless signal, it measures the reception strength of the received wireless signal. Then, the signal receiving unit 213 stores the measured reception strength value in the strength information 221 together with the identification information included in the received wireless signal, the current location information of the measurement terminal 20a, and the current date and time. The signal receiving unit 213 executes a process of updating such strength information 221 every time it receives a wireless signal transmitted from any one of the multiple transmitters 10. In this way, the signal receiving unit 213 accumulates data on the reception strength at the measurement terminal 20a of the wireless signals repeatedly transmitted from each of the multiple transmitters 10.

[0044] The user of the measurement terminal 20a moves between various locations within the building 5 and collects data on the reception strength in each of a plurality of areas within the building 5. As a result, the measurement terminal 20a accumulates data on the strength information 221 in each of the plurality of areas within the building 5.

[0045] 6, in the measurement terminal 20a, the intensity information transmission unit 214 transmits intensity information 221 to the management device 30. Specifically, the intensity information transmission unit 214 communicates with the management device 30 via the communication unit 25 every time a first time period elapses, and transmits the latest intensity information 221 stored in the storage unit 22 to the management device 30. Here, the first time period is a predetermined time period, and is set in advance to, for example, one minute, minutes, etc.

[0046] In the management device 30, the intensity information acquisition unit 312 acquires the intensity information 221 transmitted from the measurement terminal 20a. Specifically, the intensity information acquisition unit 312 communicates with the measurement terminal 20a via the communication unit 35, and receives the intensity information 221 transmitted from the measurement terminal 20a every time the first time period elapses, together with the identification information of the measurement terminal 20a that is the transmission source.

[0047] As described above, the intensity information 221 is information indicating the reception intensity at the measurement terminal 20a of the wireless signals repeatedly transmitted from each of the multiple transmitters 10. When the intensity information acquisition unit 312 acquires the intensity information 221, the intensity information acquisition unit 312 stores the acquired intensity information 221 in the storage unit 32.

[0048] The correction information generation unit 313 generates correction information 300 based on the strength information 221 acquired by the strength information acquisition unit 312. The correction information 300 is information used to estimate the position of the user terminal 20b in the operation phase. In other words, the correction information 300 is used to correct a value based on the reception strength of a wireless signal at the user terminal 20b, in order to improve the accuracy of estimating the position of the user terminal 20b.

[0049] As an example, as shown in FIGS. 2 and 3, a case will be described in which a user carrying a wireless terminal 20 is located in area A2 sandwiched between obstacles 7a and 7b. Here, the obstacles 7a and 7b are made of different materials and therefore have different radio wave attenuation characteristics. Specifically, it is assumed that the radio wave attenuation characteristic of obstacle 7a is greater than that of obstacle 7b. In this case, the reception strength in area A2 of a wireless signal transmitted from a transmitter 10 in area A1 is relatively weak, and the reception strength in area A2 of a wireless signal transmitted from a transmitter 10 in area A3 is relatively strong. Therefore, if the location of the wireless terminal 20 is estimated using the reception strength without correction, the location of the wireless terminal 20 will be estimated to be closer to area A3 than its actual location.

[0050] In this way, if the position of the wireless terminal 20 is estimated without taking into account the materials of the obstacles 7a and 7b, the estimated position will vary depending on the materials of the obstacles 7a and 7b. Therefore, to improve the accuracy of the position estimation, a correction that takes into account the materials of the obstacles 7a and 7b is necessary. To perform such a correction, the correction information generator 313 generates correction information 300 based on the reception strengths of wireless signals transmitted from multiple transmitters 10 measured at multiple positions within the building 5.

[0051] 9 from the intensity information 221 acquired by the intensity information acquisition unit 312, in order to generate the correction information 300. First, the correction information generation unit 313 converts the reception intensity indicated in the intensity information 221 acquired by the intensity information acquisition unit 312 into an intensity distance, which is a distance corresponding to the reception intensity. Generally, the reception intensity of a wireless signal at the wireless terminal 20 attenuates depending on the distance between the transmitter 10 and the wireless terminal 20. Therefore, the correction information generation unit 313 calculates, as the intensity distance, a distance that decreases as the reception intensity increases.

[0052] As an example, the correction information generator 313 substitutes the value of the reception intensity into an ideal attenuation curve that represents the relationship between distance and reception intensity. Then, the correction information generator 313 calculates the distance corresponding to the reception intensity in the attenuation curve as the intensity distance. The correction information generator 313 calculates the intensity distance from the reception intensity for each piece of data included in the intensity information 221. As a result, the correction information generator 313 generates the intensity distance data in the intermediate data shown in FIG. 9.

[0053] Second, the correction information generation unit 313 calculates a distance error, which is the difference between the intensity distance and the actual distance. Specifically, the correction information generation unit 313 refers to the transmitter information 321 and reads out the position information of the transmitter 10 corresponding to the transmitter ID for each data included in the intensity information 221. Then, the correction information generation unit 313 calculates the actual distance between the transmitter 10 and the measurement terminal 20a from the read-out position information of the transmitter 10 and the position information of the measurement terminal 20a associated with the transmitter ID in the intensity information 221.

[0054] The correction information generation unit 313 calculates the actual distance for each data included in the intensity information 221, and further calculates the distance error, which is the difference between the calculated intensity distance and the actual distance. As a result, the correction information generation unit 313 generates data on the distance error in the intermediate data shown in FIG.

[0055] Third, the correction information generator 313 generates correction information 300 shown in Fig. 10 based on the calculated distance error. The correction information 300 is information that indicates, for each transmitter 10, the amount of correction to the value based on the reception strength when a wireless terminal 20 is present in each of a plurality of areas.

[0056] Here, the correction amount is a value indicating the degree to which a value based on reception intensity is corrected during the operation phase. If there are no obstacles 7a, 7b between the transmitter 10 and the measurement terminal 20a, the intensity distance and the actual distance ideally match, and the distance error is zero. On the other hand, if there are obstacles 7a, 7b between the transmitter 10 and the measurement terminal 20a, the intensity distance will be greater than the actual distance, resulting in a larger distance error. The correction information generator 313 converts the distance error into a corresponding correction amount so that the larger the distance error, the larger the correction amount. The correspondence between the distance error and the correction amount is preset and stored in the storage unit 32.

[0057] More specifically, the correction information generation unit 313 aggregates the distance errors calculated in the intermediate data for each area and each transmitter 10, and sets a correction amount for each area and each transmitter 10. Specifically, the correction information generation unit 313 identifies the receiving area in the building 5 where the measurement terminal 20a received the wireless signal, from the location information of the measurement terminal 20a included in each data of the intensity information 221. The correction information generation unit 313 then classifies the distance errors calculated for each data of the intensity information 221 by the receiving area where the measurement terminal 20a received the wireless signal, and further classifies them by transmitter 10. The correction information generation unit 313 calculates a representative value, such as the average, median, or mode, of the distance errors classified for each receiving area and each transmitter 10, and converts the calculated representative value into a corresponding correction amount.

[0058] When specifying the reception area from the position information of the measurement terminal 20a, the correction information generation unit 313 refers to the property information 322 stored in the storage unit 32. The property information 322 includes information on the floors and areas of the building 5. Specifically, the property information 322 includes information such as the number of floors of the building 5 and a floor map showing the layout of areas on each floor.

[0059] The correction information generation unit 313 stores the correction amount calculated in this manner in the correction information 300 in association with the combination of the corresponding area and transmitter 10. In this way, the correction information generation unit 313 generates correction information 300 that determines the correction amount for each combination of transmitter 10 and area. In this way, the correction information generation unit 313 generates correction information 300 based on the reception strength of the wireless signal measured by the measurement terminal 20a at multiple positions across multiple different areas within the building 5. The correction information generation unit 313 saves the generated correction information 300 in the storage unit 32.

[0060] Next, the flow of the process executed by the measurement terminal 20a and the management device 30 in the preliminary phase will be described with reference to FIGS.

[0061] 11 is started when application software for measuring the reception strength of a wireless signal is started in the measurement terminal 20a. When the measurement process starts, the control unit 21 acquires the transmitter information 321 from the management device 30 and stores it in the storage unit 22 (step S11).

[0062] Upon acquiring the transmitter information 321, the control unit 21 acquires the location information of the measurement terminal 20a based on the user's operation (step S12). In the measurement process, the user carrying the measurement terminal 20a moves to various locations within the building 5 to collect data on the reception strength of wireless signals on each of multiple floors. In step S12, the user inputs location information such as the floor and area where the user is currently located into the measurement terminal 20a.

[0063] When the location information is acquired, the control unit 21 determines whether or not a wireless signal has been received from any of the transmitters 10 (step S13). If a wireless signal has been received (step S13; YES), the control unit 21 measures the reception strength of the received wireless signal (step S14).

[0064] When the reception strength is measured, the control unit 21 updates the strength information 221 (step S15). Specifically, the control unit 21 associates the measured reception strength value with the identification information of the transmitter 10 that is the sender and is included in the received wireless signal, the location information of the measurement terminal 20a acquired in step S12, and the current date and time, and stores the value in the strength information 221 stored in the storage unit 22. On the other hand, if a wireless signal is not received (step S13; NO), the control unit 21 skips the processes of steps S14 to S15.

[0065] Next, the control unit 21 determines whether or not a first time has elapsed since the most recent transmission of the strength information 221 (step S16). If the first time has elapsed (step S16; YES), the control unit 21 transmits the strength information 221 to the management device 30 (step S17). On the other hand, if the first time has not elapsed since the most recent transmission of the strength information 221 (step S16; NO), the control unit 21 skips step S17.

[0066] Thereafter, control unit 21 returns the process to step S12 and executes the processes of steps S12 to S17 again, thereby causing control unit 21 to repeat the process of acquiring location information, the process of updating intensity information 221 every time a wireless signal is received from any of transmitters 10, and the process of transmitting intensity information 221 to management device 30 every time the first time period elapses.

[0067] In step S12, the control unit 21 does not need to acquire the location information every time. For example, if the user moves and the location of the measurement terminal 20a changes significantly, the user only needs to input the current location information to the measurement terminal 20a, and if the location of the measurement terminal 20a has not changed much, the control unit 21 does not need to repeatedly input the current location information.

[0068] Secondly, the correction information generation process shown in FIG. 12 is executed by the management device 30 in a state where the intensity information 221 transmitted from the measurement terminal 20a by the process shown in FIG. 11 is stored in the storage unit 32.

[0069] When the correction information generation process is executed, the control unit 31 calculates the intensity distance by converting the value of the reception intensity of each piece of data included in the intensity information 221 into an intensity distance (step S21). After calculating the intensity distance, the control unit 31 calculates the actual distance between the transmitter 10 and the measurement terminal 20a based on the location information of the measurement terminal 20a included in the intensity information 221 and the location information of each transmitter 10 included in the transmitter information 321 (step S22). After calculating the actual distance, the control unit 31 calculates the distance error, which is the difference between the calculated intensity distance and the actual distance (step S23). As a result, the control unit 31 generates the intermediate data shown in FIG. 9.

[0070] After calculating the distance error, the control unit 31 aggregates the calculated distance error for each area and each transmitter 10, and sets a correction amount corresponding to the aggregated value (step S24). After setting the correction amount, the control unit 31 generates correction information 300 indicating the calculated correction amount for each area and each transmitter 10, and stores it in the storage unit 32 (step S25). This completes the correction information generation process shown in FIG.

[0071] <Operation phase> Next, the operation phase will be described. In the operation phase, as shown in Fig. 13, the user terminal 20b and the management device 30 are operated. In the control unit 21, the user terminal 20b functionally comprises a transmitter information acquisition unit 211, a signal receiving unit 213, a strength information transmission unit 214, and a notification unit 215 which is an example of a notification means. In the control unit 31, the management device 30 functionally comprises a transmitter information transmission unit 311, a strength information acquisition unit 312, an area estimation unit 314 which is an example of an area estimation means, a correction unit 315 which is an example of a correction means, a position estimation unit 316 which is an example of a position estimation means, and an output unit 317 which is an example of an output means.

[0072] Each of these functions is realized by software, firmware, or a combination of software and firmware in the control units 21 and 31. The software and firmware are written as programs and stored in the ROM or storage units 22 and 32. Then, in the control units 21 and 31, the CPU executes the programs stored in the ROM or storage units 22 and 32, thereby realizing each of the functions shown in FIG.

[0073] The functions of the transmitter information acquisition unit 211, signal receiving unit 213, and intensity information transmission unit 214 in the user terminal 20b are similar to the functions of the respective units in the measurement terminal 20a. Specifically, in the user terminal 20b, the transmitter information acquisition unit 211 acquires transmitter information 321 from the management device 30. The signal receiving unit 213 receives wireless signals transmitted from each of the multiple transmitters 10, and updates the intensity information 222. The intensity information transmission unit 214 transmits the intensity information 222 to the management device 30.

[0074] Here, the user terminal 20b is the target of location estimation, and the current location of the user terminal 20b is unknown. Therefore, unlike the strength information 221 in the measurement terminal 20a, the strength information 222 in the user terminal 20b does not include location information of the measurement terminal 20a. Specifically, as shown in Fig. 14, the strength information 222 in the user terminal 20b is information that indicates, in association with each other, a transmitter ID, which is identification information of the transmitter 10, and the reception strength of the wireless signal in the user terminal 20b, in order of the reception date and time when the wireless signal was received by the user terminal 20b. The strength information transmission unit 214 transmits such strength information 222 to the management device 30 every time a first time period elapses.

[0075] 13, in the management device 30, the strength information acquisition unit 312 acquires the strength information 222 transmitted from the user terminal 20b. Specifically, the strength information acquisition unit 312 communicates with the user terminal 20b via the communication unit 35, and receives the strength information 222 transmitted from the user terminal 20b every time the first time period elapses, together with the identification information of the user terminal 20b that is the transmission source.

[0076] The area estimation unit 314 estimates the area in which the user terminal 20b is located from among the multiple areas, based on the reception strength indicated in the strength information 222 acquired by the strength information acquisition unit 312 and the positions of the multiple transmitters 10. The area estimation unit 314 references the transmitter information 321 to acquire position information for the multiple transmitters 10. Then, the area estimation unit 314 references the property information 322 to acquire information on the multiple areas that the building 5 has, and estimates the area in which the user terminal 20b is located from among the multiple areas.

[0077] Specifically, the area estimation unit 314 estimates the area where the user terminal 20b is located using the following estimation methods (1), (2), or other estimation methods. The estimation method to be adopted may be set in advance by, for example, an operator of the management device 30, or may be selectable by the user of the user terminal 20b.

[0078] (1) As a first estimation method, the area estimation unit 314 estimates that the user terminal 20b is located in an area where the transmitter 10 with the strongest reception strength is located among the multiple transmitters 10 installed in the building 5. For example, if the transmitter 10 with the strongest reception strength is installed in area A2, the area estimation unit 314 estimates that the user terminal 20b is located in area A2.

[0079] (2) As a second estimation method, the area estimation unit 314 estimates the area in which the user terminal 20b is located using the principles of so-called triangulation or triangulation. Specifically, the area estimation unit 314 sets a range for each of the multiple transmitters 10 based on the position of one transmitter 10 and the received strength of the wireless signal transmitted from that single transmitter 10. The area estimation unit 314 then estimates that the user terminal 20b is located in an area where the ranges set for each of the multiple transmitters 10 overlap. Here, the range based on the received strength is represented by a circle that becomes larger as the received strength value decreases, based on an attenuation curve of the wireless signal according to the distance. The area estimation unit 314 sets such a circle for each transmitter 10 and estimates that the user terminal 20b is located in an area where the multiple circles overlap.

[0080] In this way, the area estimation unit 314 estimates the position of the user terminal 20b on an area-by-area basis. In other words, the area estimation unit 314 uses the reception strength before correction by the correction unit 315, and therefore has lower position estimation accuracy than the position estimation unit 316, which will be described later. Therefore, the area estimation unit 314 estimates the position of the user terminal 20b with coarse accuracy on an area-by-area basis. The area estimation unit 314 functions as a first estimation unit that estimates the position of the user terminal 20b with coarse accuracy, and the position estimation unit 316 functions as a second estimation unit that estimates the position of the user terminal 20b with high accuracy.

[0081] In the management device 30, the correction unit 315 corrects values ​​based on the reception strength at the user terminal 20b of the wireless signals transmitted from each of the multiple transmitters 10, using the correction information 300 generated by the correction information generation unit 313. As described above, the correction information 300 is information that indicates, for each transmitter 10, the amount of correction when a wireless terminal 20 is present in each of the multiple areas.

[0082] The correction unit 315 corrects the reception strength using a correction amount determined for an area in the correction information 300 that is estimated by the area estimation unit 314 to be where the user terminal 20b is located, among the multiple areas. For example, if the area estimation unit 314 estimates that the user terminal 20b is located in area A2, the correction unit 315 reads out the correction amount for each transmitter 10 associated with area A2 in the correction information 300. Then, the correction unit 315 corrects the reception strength indicated in the strength information 222 for each transmitter 10 using the read correction amount for each transmitter 10.

[0083] Specifically, the correction unit 315 corrects the reception strength of the wireless signal transmitted from the transmitter 10 with ID "X" by the correction amount associated with area A2 and the transmitter 10 with ID "X" in the correction information 300. Note that X=0001, 0002, 0003, .... The correction unit 315 performs such correction processing on the reception strength of the wireless signal transmitted from each of the multiple transmitters 10.

[0084] More specifically, the correction unit 315 increases the value of the reception strength by the correction amount. For example, if the correction amount is 10%, the correction unit 315 increases the value of the reception strength by 10%. Here, the larger the correction amount, the greater the attenuation of the wireless signal due to the obstacles 7a and 7b. The correction unit 315 increases the value of the reception strength by a larger amount as the correction amount increases, correcting the value to the reception strength that would have been obtained if the signal had not been attenuated by the obstacles 7a and 7b.

[0085] In the management device 30, the location estimation unit 316 estimates the location of the user terminal 20b based on the value of the reception strength corrected by the correction unit 315 and the locations of the multiple transmitters 10. In order to estimate the location of the user terminal 20b, the location estimation unit 316 uses the above-mentioned (1), (2) or other estimation method, similar to the area estimation unit 314.

[0086] (1) As a first estimation method, the location estimation unit 316 estimates that the user terminal 20b is located at the location of the transmitter 10 that has the strongest reception strength after correction by the correction unit 315 among the multiple transmitters 10 installed in the building 5.

[0087] (2) As a second estimation method, the position estimation unit 316 estimates the position of the user terminal 20b using the principles of so-called triangulation or triangulation. Specifically, the position estimation unit 316 sets, for each of the multiple transmitters 10, a range based on the reception strength of the wireless signal transmitted from that single transmitter 10 after correction by the correction unit 315, using the position of that single transmitter 10 as a reference. The position estimation unit 316 then estimates that the user terminal 20b is located at a position where the ranges set for each of the multiple transmitters 10 overlap. Here, the range based on the reception strength is represented by a circle that becomes larger as the reception strength value decreases, based on an attenuation curve of the wireless signal according to the distance. The position estimation unit 316 sets such a circle for each transmitter 10 and estimates that the user terminal 20b is located at a position where the multiple circles overlap.

[0088] The position estimation unit 316 may estimate the position of the user terminal 20b using a method other than the above methods (1) and (2). For example, the position estimation unit 316 may set multiple candidate positions and estimate the position where the user terminal 20b is located from among the multiple candidate positions.

[0089] Specifically, the position estimation unit 316 sets multiple candidate positions within a predetermined range based on the previous position, which is the most recently estimated position. Then, the position estimation unit 316 compares a distance order, in which the distance between one of the multiple candidate positions and each of the multiple transmitters 10 is arranged in ascending order, with an intensity order, in which the threshold intensities identified for each of the multiple transmitters 10 are arranged in descending order. The position estimation unit 316 performs a comparison process of comparing the distance order with the intensity order for each of the multiple candidate positions. Then, the position estimation unit 316 estimates that the user terminal 20b is located at the candidate position among the multiple candidate positions whose distance order and intensity order most closely match.

[0090] Regardless of which of the above estimation methods is used, the location estimation unit 316 estimates the location based on the reception strength after correction by the correction unit 315, so that the location estimation unit 316 can estimate the location of the user terminal 20b with higher accuracy than the area estimation unit 314.

[0091] 13, the output unit 317 outputs output information based on the position of the user terminal 20b estimated by the position estimation unit 316. Specifically, when the position estimation unit 316 estimates the position of the user terminal 20b, the output unit 317 communicates with the user terminal 20b via the communication unit 35 and transmits output information indicating the estimated position to the user terminal 20b. As a result, the output unit 317 causes the position of the user terminal 20b estimated by the position estimation unit 316 to be displayed on the display unit 24 of the user terminal 20b.

[0092] In the user terminal 20b, the notification unit 215 notifies the user of the position of the user terminal 20b estimated by the position estimation unit 316. When the output information is transmitted from the management device 30, the notification unit 215 receives the transmitted output information and displays the received output information on the display unit 24 of the user terminal 20b.

[0093] 15 on the display unit 24. Specifically, the notification unit 215 displays a floor map centered on the area to be estimated on the floor to be estimated in the building 5. The notification unit 215 then displays a mark indicating the current location of the user terminal 20b on the floor map at a position indicated in the output information received from the management device 30. This allows the user of the user terminal 20b to easily confirm their own current location within the building 5.

[0094] Next, a flow of processing executed by the user terminal 20b and the management device 30 in the operation phase will be described with reference to Figures 16 and 17. The processing shown in Figures 16 and 17 is an example of a position estimation method.

[0095] 16 is started when application software for acquiring location information of the user terminal 20b is started. When the strength information transmission process is started, the control unit 21 acquires the transmitter information 321 from the management device 30 and stores it in the storage unit 22 (step S31).

[0096] Upon acquiring the transmitter information 321, the control unit 21 executes the processes of steps S32 to S36. Here, steps S32 to S36 are the same as steps S13 to S17 described in the pre-phase with reference to FIG. 11, except that the "measurement terminal 20a" is replaced with the "user terminal 20b." However, in the operation phase, there is no process of acquiring location information in step S12. Therefore, the intensity information 222 updated in step S34 and transmitted to the management device 30 in step S36 does not include location information, as shown in FIG. 14.

[0097] By repeating the processing of steps S32 to S36, the control unit 21 repeats the processing of updating the intensity information 222 every time a wireless signal is received from any of the transmitters 10, and the processing of transmitting the intensity information 222 to the management device 30 every time the first time period elapses.

[0098] Second, the position estimation process shown in Fig. 17 is executed when the strength information 222 is transmitted from the user terminal 20b by the process shown in Fig. 16. When the position estimation process starts, the control unit 31 in the management device 30 determines whether or not the strength information 222 transmitted from the wireless terminal 20 has been acquired (step S41). If the strength information 222 has not been acquired (step S41; NO), the control unit 31 does not execute the processes from step S42 onwards and ends the position estimation process shown in Fig. 17.

[0099] When the strength information 222 is acquired (step S41; YES), the control unit 31 estimates the area where the user terminal 20b is located (step S42) based on the reception strength indicated in the acquired strength information 222 and the positions of the multiple transmitters 10. After estimating the area where the user terminal 20b is located, the control unit 31 reads out the correction amount corresponding to the estimated area from the correction information 300 generated in the preliminary phase (step S43).

[0100] After reading out the correction amount, the control unit 31 uses the read out correction amount to correct the reception strength indicated in the strength information 222 acquired in step S41 (step S44). After correcting the reception strength, the control unit 31 estimates the position of the user terminal 20b based on the corrected reception strength and the positions of the multiple transmitters 10 (step S45).

[0101] After estimating the position of the user terminal 20b, the control unit 31 outputs the estimation result (step S46). For example, the control unit 31 transmits output information indicating the position of the user terminal 20b estimated in step S45 to the user terminal 20b, and causes the display unit 24 of the user terminal 20b to display the output information. This completes the position estimation process shown in FIG. 17.

[0102] As described above, the position estimation system 1 according to the first embodiment generates correction information 300 based on the reception strength at multiple positions of wireless signals transmitted from multiple transmitters 10. The position estimation system 1 according to the first embodiment then corrects the reception strength of the wireless signals at the wireless terminal 20 using the correction information 300, and estimates the position of the wireless terminal 20 based on the corrected reception strength and the positions of the multiple transmitters 10. In this way, the position estimation system 1 according to the first embodiment corrects the reception strength used for estimating the position of the wireless terminal 20 using the correction information 300 generated based on the reception strength of the wireless signals at multiple positions. Therefore, even if obstacles 7a and 7b that attenuate wireless signals are present between the transmitter 10 and the wireless terminal 20, it is possible to estimate the position of the wireless terminal 20 with high accuracy.

[0103] Here, the physical positions of obstacles 7a, 7b such as walls, fixtures, indoor units, pillars, etc. can be determined from the design drawings of the building 5, which are usually available. However, it is difficult to determine from the design drawings whether the obstacles 7a, 7b are made of glass or metal, in other words, whether they have an electromagnetic shielding effect. In contrast, the position estimation system 1 according to the first embodiment generates correction information 300 based on reception intensities actually measured at multiple positions. Therefore, regardless of the material of the obstacles 7a, 7b, which is difficult to determine from the design drawings alone, it is possible to accurately correct the reception intensities.

[0104] (Embodiment 2) Next, a description will be given of embodiment 2. Descriptions of the same configurations and functions as embodiment 1 will be omitted where appropriate.

[0105] In the first embodiment, the correction information 300 is information indicating the amount of correction to the reception strength of a wireless signal for each transmitter 10 when a wireless terminal 20 is present in each of a plurality of areas. In contrast, in the second embodiment, a trained model 301 generated by machine learning is used as the correction information.

[0106] 18 shows a functional configuration of the operation phase of the position estimation system 1 according to the second embodiment. The management device 30 according to the second embodiment functionally includes, in a control unit 31, a transmitter information transmission unit 311, an intensity information acquisition unit 312, a correction unit 315, a position estimation unit 316, an output unit 317, and a learning unit 318 which is an example of a learning means. Each of these functions is realized in the control unit 31 by software, firmware, or a combination of software and firmware.

[0107] The correction unit 315 infers the amount of correction for a value based on the reception strength using the trained model 301. The trained model 301 is a model for inferring the amount of correction from the reception strength of wireless signals transmitted from multiple transmitters 10 and the positions of the multiple transmitters 10. The trained model 301 is configured by, for example, a neural network, a Q table, etc.

[0108] 19 , the correction unit 315 inputs the reception strength indicated in the strength information 222 acquired by the strength information acquisition unit 312 and the positions of the multiple transmitters 10 to the trained model 301. The trained model 301 receives the reception strength of the wireless signals transmitted from the multiple transmitters 10 and the positions of the multiple transmitters 10 as input, and outputs correction amounts for the reception strength of the wireless signals transmitted from the multiple transmitters 10. The correction unit 315 infers the correction amounts output from the trained model 301 as correction amounts for the reception strength of the wireless signals transmitted from the multiple transmitters 10.

[0109] Having deduced the correction amount, the correction unit 315 uses the deduced correction amount to correct the reception strength indicated in the strength information 222 acquired by the strength information acquisition unit 312. The correction method is the same as in embodiment 1. The position estimation unit 316 estimates the position of the user terminal 20b based on the value of the reception strength corrected by the correction unit 315 and the positions of the multiple transmitters 10. The output unit 317 outputs output information based on the position of the user terminal 20b estimated by the position estimation unit 316. The processing of the position estimation unit 316 and the output unit 317 is the same as in embodiment 1.

[0110] The learning unit 318 uses machine learning to generate the trained model 301. As an example, the learning unit 318 uses a reinforcement learning technique to generate the trained model 301.

[0111] The learning unit 318 acquires location information of the user terminal 20b to be used as a correct location in learning. Specifically, the learning unit 318 communicates with the user terminal 20b via the communication unit 35 and requests current location information from the user terminal 20b. Upon receiving the request for location information, the user of the user terminal 20b operates the operation unit 23 to input the user's current location information to the user terminal 20b. Although not shown in the figure, the user terminal 20b has the function of the location information acquisition unit 212, similar to the measurement terminal 20a. The location information acquisition unit 212 acquires the location information input by the user and transmits it to the management device 30.

[0112] When the learning unit 318 acquires the location information of the user terminal 20b, it compares the estimated location estimated by the location estimation unit 316 based on the reception strength corrected by the correction unit 315 with the correct location, which is the location of the user terminal 20b indicated in the acquired location information. Then, the learning unit 318 performs reinforcement learning in which the smaller the distance between the estimated location and the correct location, the higher the reward value.

[0113] Specifically, the learning unit 318 updates the trained model 301 according to the distance between the estimated position and the correct position. Here, updating the trained model 301 means updating the weight coefficients of the neural network in the trained model 301, the Q value of the Q table, and the like. After updating the trained model 301, the learning unit 318 estimates the position of the user terminal 20b using the correction amount inferred by the updated trained model 301. Then, the learning unit 318 increases the reward value when the distance between the estimated position and the correct position decreases, and decreases the reward value when the distance between the estimated position and the correct position increases. The learning unit 318 repeatedly updates the trained model 301 so as to increase the reward value. The learning unit 318 ends learning when the distance between the estimated position and the correct position becomes equal to or less than a threshold.

[0114] In this way, the learning unit 318 generates the trained model 301 by repeatedly updating the trained model 301 based on the reception strength of wireless signals measured when the user terminal 20b moves to various positions within the building 5. Therefore, the trained model 301 corresponds to correction information generated based on the reception strength at multiple positions of wireless signals transmitted from multiple transmitters 10.

[0115] As described above, the location estimation system 1 according to the second embodiment infers a correction amount for the reception strength using the trained model 301 generated by machine learning, and corrects the reception strength using the inferred correction amount. When the number of learning rounds is small, the accuracy of the location estimation is low, but as the learning progresses, the accuracy of the trained model 301 gradually improves, and the location of the wireless terminal 20 can be estimated with high accuracy. In this way, the location estimation system 1 according to the second embodiment improves the accuracy of the location estimation while updating the trained model 301 in the operation phase, eliminating the need for a pre-operation phase. This makes it easy to introduce the location estimation system 1.

[0116] In the second embodiment, the learning unit 318 generates the trained model 301 by reinforcement learning. However, the learning unit 318 may generate the trained model 301 by supervised learning or unsupervised learning, not limited to reinforcement learning. When performing supervised learning, location information acquired from the user terminal 20b may be used as training data. In the second embodiment, the trained model 301 is generated in the operation phase, so no pre-phase is required. However, the learning unit 318 may generate the trained model 301 in the pre-phase.

[0117] Furthermore, in the above-described second embodiment, the management device 30 has the functionality of the learning unit 318. However, the management device 30 does not need to have the functionality of the learning unit 318. In this case, a device external to the management device 30 performs machine learning to generate the trained model 301, and the management device 30 acquires the generated trained model 301 via the communication unit 35. The position estimation unit 316 estimates the position of the user terminal 20b using the trained model 301 acquired from the external device.

[0118] (Embodiment 3) Next, a description will be given of embodiment 3. Descriptions of the same configurations and functions as those of embodiments 1 and 2 will be omitted where appropriate.

[0119] In the above-described first embodiment, when generating the correction information 300, the correction information generation unit 313 sets the amount of correction for each combination of area and transmitter 10 such that the larger the distance error, which is the difference between the intensity distance and the actual distance, the larger the amount of correction. In contrast, in the third embodiment, when the distance error in the combination of any one of the multiple areas and any one of the multiple transmitters 10 is equal to or greater than the first threshold, the correction information generation unit 313 excludes that transmitter 10 from the transmitters 10 to be used in estimation by the position estimation unit 316 when the user terminal 20b is located in that area.

[0120] Specifically, if the distance error is excessively large for any combination of area and transmitter 10, there is a high possibility that the area and the transmitter 10 are far apart, or that an obstacle that significantly attenuates the wireless signal exists between them. Alternatively, there is a possibility that the transmitter 10 is malfunctioning, has a dead battery, or has other abnormalities. In such a case, using that transmitter 10 for position estimation may lead to a decrease in the accuracy of the position estimation.

[0121] Therefore, when the distance error is equal to or greater than the first threshold for any combination of area and transmitter 10, the correction information generator 313 sets a correction amount corresponding to that combination in the correction information 300 so that the reception strength is equal to or less than a specific value. In this way, the correction information generator 313 generates the correction information 300 so that excessively attenuated reception strength is not used for position estimation. The first threshold is set to an appropriate value, such as -15 dBm.

[0122] In the operation phase, the correction unit 315 and the position estimation unit 316 use the correction information 300 generated in this way to execute the processing described in the first embodiment. Specifically, when the distance error is equal to or greater than a threshold value for any combination of an area and a transmitter 10, and the area estimation unit 314 estimates that the user terminal 20b is located in that area, the correction unit 315 corrects the reception strength of the wireless signal transmitted from that transmitter 10 to a specific value or less, for example, −999.

[0123] When the correction unit 315 corrects the reception strength to −999, the position estimation unit 316 estimates the position of the user terminal 20b without using that reception strength. Specifically, the position estimation unit 316 estimates the position of the user terminal 20b based on the reception strength corrected by the correction unit 315, which is the reception strength of a wireless signal transmitted from at least one transmitter 10 other than the transmitter 10 whose reception strength has been corrected to −999, among the multiple transmitters 10 installed in the building 5, and the position of that at least one transmitter 10. Details of the estimation method are the same as those in the first embodiment.

[0124] As described above, in the third embodiment, if the attenuation of the reception strength is excessively large for any combination of area and transmitter 10, that transmitter 10 is excluded, and the position of the user terminal 20b is estimated based on the reception strength of the radio signals transmitted from the other transmitters 10. This is expected to further improve the accuracy of the position estimation.

[0125] (Fourth embodiment) Next, a description will be given of embodiment 4. Descriptions of the same configurations and functions as those of embodiments 1 to 3 will be omitted where appropriate.

[0126] The position estimation system 1 according to the fourth embodiment updates the estimation process so that the position of the user terminal 20b can be estimated with high accuracy even if the situation changes after the start of the operation phase. Specifically, in the fourth embodiment, the position estimation unit 316 estimates the position of the user terminal 20b based on the reception strength of radio signals transmitted from the multiple transmitters 10 and the positions of the multiple transmitters 10, and then calculates a distance error from the estimated position for each of the multiple transmitters 10. Then, if there is at least one transmitter 10 among the multiple transmitters 10 whose calculated distance error is greater than a second threshold, the position estimation unit 316 re-estimates the position of the user terminal 20b.

[0127] As explained in the first embodiment, the position estimation unit 316 estimates the position of the user terminal 20b based on the reception strength corrected by the correction unit 315, and therefore the distance error between the estimated position estimated by the position estimation unit 316 and the position of each transmitter 10 should be close to zero if there is no change in the situation. Therefore, if there is at least one transmitter 10 whose distance error is larger than the second threshold, there is a high possibility that some situation related to that at least one transmitter 10 has changed. Note that the second threshold may be the same value as the first threshold in the third embodiment, or may be a different value.

[0128] First, if there is a group of transmitters among the multiple transmitters 10 whose distance error from the estimated position is greater than a second threshold, the position estimation unit 316 estimates that a new obstacle has been installed between the group of transmitters and the estimated position. Here, the case where a new obstacle has been installed corresponds to the case where an object that affects the propagation of wireless signals, such as a monitor, metal furniture, or metal shelf, has been newly installed after the start of the operation phase.

[0129] Specifically, as shown in Fig. 20, if a new obstacle 7c is installed inside the building 5 after the start of the operation phase, the reception strength at the estimated position of wireless signals transmitted from a group of transmitters located on the opposite side of the new obstacle 7c from the estimated position is attenuated by the new obstacle 7c. This results in a large distance error. In contrast, the distance error between the group of transmitters located on the same side of the new obstacle 7c as the estimated position is not affected by the new obstacle 7c.

[0130] In this way, the distance error of the group of transmitters that exist in the direction of the new obstacle 7c from the estimated position as the reference becomes larger, while the distance errors of the group of transmitters that exist in other directions do not change. Therefore, when two or more transmitters 10 with distance errors greater than the second threshold are concentrated within a limited range of directions from the estimated position as the reference, the position estimation unit 316 identifies those two or more transmitters 10 as targets for re-correcting the reception strength.

[0131] In this case, the correction unit 315 re-corrects the reception strength of the wireless signal transmitted from each transmitter 10 of the identified transmitter group based on the distance error. Specifically, the correction unit 315 sets a correction amount for each transmitter 10 of the identified transmitter group so that the correction amount increases as the distance error increases. Then, the correction unit 315 corrects the reception strength of each transmitter 10 of the transmitter group indicated in the intensity information 222 using the set correction amount. Here, the method of setting the correction amount and correcting the reception strength is the same as the process executed by the correction information generation unit 313 in the first embodiment.

[0132] The position estimation unit 316 re-estimates the position of the user terminal 20b based on the reception strength re-corrected by the correction unit 315. Specifically, the position estimation unit 316 re-estimates the position of the user terminal 20b based on the reception strength re-corrected by the correction unit 315 of the radio signal transmitted from each transmitter 10 of the transmitter group, the reception strength that has not been re-corrected of the radio signal transmitted from at least one transmitter other than the transmitter group, and the positions of the multiple transmitters 10. The method of estimating the position of the user terminal 20b from the reception strength and position of each transmitter 10 is the same as in the first embodiment.

[0133] Second, if there is at least one transmitter 10 among the multiple transmitters 10 for which the distance error is greater than the second threshold in all cases where the user terminal 20b is located in multiple different areas, the position estimation unit 316 estimates that some kind of abnormality has occurred in that at least one transmitter 10. In this case, the position estimation unit 316 estimates the position of the user terminal 20b based on the reception strength of radio signals transmitted from transmitters 10 other than that at least one transmitter 10 among the multiple transmitters 10.

[0134] More specifically, after the start of the operation phase, the position estimation unit 316 executes a position estimation process when the user terminal 20b is present in each of a plurality of different areas within the building 5. In this case, if there is at least one transmitter 10 for which the distance error is greater than the second threshold value regardless of the area in which the user terminal 20b is located, there is a high possibility that an abnormality such as a breakdown, a dead battery, or the like has occurred in that at least one transmitter 10.

[0135] In this case, using at least one transmitter 10 in which an abnormality has occurred for position estimation may lead to a decrease in the accuracy of the position estimation. Therefore, the position estimation unit 316 estimates the position of the user terminal 20b without using the reception strength of the radio signals transmitted from the at least one relevant transmitter 10. Specifically, the position estimation unit 316 estimates the position of the user terminal 20b based on the reception strength of the radio signals transmitted from transmitters 10 other than the at least one relevant transmitter 10 among the multiple transmitters 10 and the position of that transmitter 10.

[0136] Furthermore, the output unit 317 notifies the administrator that an abnormality has occurred in at least one of the relevant transmitters 10 by displaying the information on the display unit of the management device 30. This allows the administrator to understand that an abnormality has occurred.

[0137] Hereinafter, the operation phase processing executed by the management device 30 according to the fourth embodiment will be described with reference to Fig. 21. In the management device 30, the control unit 31 executes the processing of steps S41 to S45 described in the first embodiment with reference to Fig. 17, and estimates the position of the user terminal 20b.

[0138] After estimating the position of user terminal 20b, control unit 31 calculates, for each transmitter 10, a distance error relative to the estimated position estimated in step S45 (step S51). Specifically, control unit 31 calculates an intensity distance for each of the multiple transmitters 10 installed in building 5 from the reception intensity indicated in the intensity information 222 acquired in step S41. The method for calculating the intensity distance is the same as in embodiment 1. Furthermore, control unit 31 calculates the actual distance between each of the multiple transmitters 10 and the estimated position of user terminal 20b. Then, control unit 31 calculates a distance error, which is the difference between the intensity distance and the actual distance, for each of the multiple transmitters 10.

[0139] After calculating the distance error, the control unit 31 determines whether or not there is a group of transmitters 10 installed in the building 5 whose distance error is equal to or greater than a second threshold (step S52). If there is a group of transmitters whose distance error is equal to or greater than the second threshold (step S52; YES), the control unit 31 re-corrects the reception strength of the wireless signals transmitted from each transmitter 10 of that group based on the distance error (step S53). On the other hand, if there is not a group of transmitters whose distance error is equal to or greater than the second threshold (step S52; NO), the control unit 31 skips step S53.

[0140] Next, the control unit 31 determines whether or not there is at least one transmitter 10 whose distance error is equal to or greater than the second threshold value in all cases where the user terminal 20b is located in a plurality of different areas (step S54). If there is at least one such transmitter 10 (step S54; YES), the control unit 31 excludes the at least one such transmitter 10 from the transmitters 10 to be used for re-estimating the position (step S55). Then, the control unit 31 notifies that an abnormality has occurred in the at least one such transmitter 10 (step S56). On the other hand, if there is not at least one such transmitter 10 (step S54; NO), the control unit 31 skips steps S55 to S56.

[0141] Next, the control unit 31 re-estimates the position of the user terminal 20b (step S57). Specifically, the control unit 31 re-estimates the position of the user terminal 20b based on the reception strength of radio signals transmitted from transmitters 10 other than the at least one transmitter 10 excluded in step S55. At this time, part of the reception strength used for the re-estimate has been re-corrected in step S53.

[0142] After re-estimating the position of the user terminal 20b, the control unit 31 outputs the estimation result (step S58). For example, the control unit 31 transmits output information indicating the position of the user terminal 20b re-estimated in step S56 to the user terminal 20b, and causes the display unit 24 of the user terminal 20b to display it. This completes the position estimation process shown in FIG. 20.

[0143] As described above, the position estimation system 1 according to the fourth embodiment estimates the position of the user terminal 20b once, then calculates the distance error between the estimated position and each of the multiple transmitters 10, and re-estimates the position of the user terminal 20b if there is at least one transmitter 10 for which the calculated distance error is greater than the second threshold. This makes it possible to prevent a decrease in the accuracy of the position estimation even if a new obstacle 7c is installed or one of the transmitters 10 stops operating after the operation phase has started.

[0144] (Embodiment 5) Next, a description will be given of embodiment 5. Descriptions of the same configurations and functions as those of embodiments 1 to 4 will be omitted where appropriate.

[0145] In the first embodiment, the correction information generating unit 313 generates the correction information 300 based on the intensity information 221 indicating the reception intensity of the wireless signal at a plurality of positions. In contrast, in the fifth embodiment, the correction information generating unit 313 generates a contour diagram indicating the distribution of the reception intensity of the wireless signal based on the intensity information 221.

[0146] In the fifth embodiment, when the intensity information acquisition unit 312 acquires the intensity information 221 transmitted from the measurement terminal 20a, the correction information generation unit 313 generates a contour diagram from the reception intensity at multiple positions indicated by the acquired intensity information 221. The contour diagram is a diagram showing the distribution of the reception intensity of the wireless signal transmitted from the transmitter 10.

[0147] As an example, the contour diagram shown in Fig. 22 shows the distribution of the reception strength of a wireless signal transmitted from one transmitter 10 in the presence of an obstacle 7a. In this contour diagram, the reception strength between the transmitter 10 and the obstacle 7a smoothly attenuates according to the distance from the transmitter 10. On the other hand, it can be seen that the reception strength rapidly attenuates on the opposite side of the obstacle 7a from the transmitter 10.

[0148] The correction information generation unit 313 generates a contour diagram as shown in Fig. 22 for each of the multiple transmitters 10 installed in the building 5. Then, the correction information generation unit 313 displays the generated contour diagram on the display unit of the management device 30. By checking the displayed contour diagram, the manager can grasp the position of obstacles 7a present in the building 5 before starting the operation phase.

[0149] (Variation) Although the embodiments have been described above, it is possible to combine the embodiments, or to modify or omit the embodiments as appropriate.

[0150] For example, in the first embodiment, the management device 30 includes the functionality of the area estimation unit 314 and estimates the area where the user terminal 20b is located based on the reception strength before correction by the correction unit 315. However, the management device 30 does not need to include the functionality of the area estimation unit 314 if it can acquire information about the area where the user terminal 20b is located by another method. For example, the user of the user terminal 20b may input information about the area where the user is currently located to the user terminal 20b. In this case, the user terminal 20b includes the functionality of the location information acquisition unit 212 and acquires the area information input by the user. Then, the strength information transmission unit 214 transmits the area information acquired by the location information acquisition unit 212 to the management device 30 together with the strength information 222. In the management device 30, the strength information acquisition unit 312 receives the area information transmitted from the user terminal 20b together with the strength information 222. The management device 30 may acquire information about the area where the user terminal 20b is located in this manner.

[0151] In the above embodiment, the correction information generator 313 calculates the intensity distance from the reception intensity using an ideal attenuation curve that represents the relationship between distance and reception intensity. However, the correction information generator 313 may calculate the intensity distance from the reception intensity using a method other than the attenuation curve.

[0152] In the above embodiment, the correction unit 315 corrects the value of the reception strength of the wireless signal at the user terminal 20b using the correction information 300, and the position estimation unit 316 estimates the position of the user terminal 20b based on the value of the reception strength after correction by the correction unit 315. However, the object of correction by the correction unit 315 is not limited to the value of the reception strength itself, as long as it is a value based on the reception strength. For example, the correction unit 315 may correct the value of the intensity distance converted from the reception strength. In this case, the position estimation unit 316 estimates the position of the user terminal 20b based on the value of the intensity distance after correction by the correction unit 315.

[0153] In the above embodiment, the position estimation system 1 includes multiple transmitters 10. However, the position estimation system 1 may include only one transmitter 10. When the number of transmitters 10 is one, the area estimation unit 314 and the position estimation unit 316 estimate that the wireless terminal 20 is located in a range based on the position of the single transmitter 10, with the smaller the threshold strength, the larger the range. In this way, the accuracy of position estimation can be improved by using multiple transmitters 10, but even when the number of transmitters 10 is only one, the position of the wireless terminal 20 can be estimated with a minimum level of accuracy.

[0154] In the above embodiment, there is one wireless terminal 20 whose position is to be estimated in the position estimation system 1. However, there may be a plurality of wireless terminals 20 in the building 5. The management device 30 may then execute the process described in the above embodiment for each of the plurality of wireless terminals 20 to estimate the position of each of the plurality of wireless terminals 20.

[0155] In the above embodiment, the output unit 317 transmits output information indicating the position of the wireless terminal 20 estimated by the position estimation unit 316 to the wireless terminal 20, and causes the output information to be displayed on the display unit 24 of the wireless terminal 20. However, the output unit 317 is not limited to displaying the output information on the display unit 24, and may be used for other purposes. For example, the output unit 317 may control equipment such as air conditioners and lighting installed in the building 5, based on the position of the wireless terminal 20 estimated by the position estimation unit 316.

[0156] Specifically, the output unit 317 may transmit, as output information, a control command to the air conditioner or lighting to turn on the air conditioner or lighting at the position of the wireless terminal 20 estimated by the position estimation unit 316. Alternatively, the position estimation unit 316 may estimate the positions of multiple wireless terminals 20 and estimate areas in the building 5 where people are present and areas where no people are present based on the estimated positions of the multiple wireless terminals 20. Then, the output unit 317 may transmit, as output information, a control command to the air conditioner or lighting to turn on the air conditioner or lighting in areas in the building 5 where people are present and to turn off the air conditioner or lighting in areas in the building 5 where no people are present.

[0157] In the above embodiment, the wireless terminal 20 is an operation terminal that includes the operation unit 23 and the display unit 24 and is operated by a user. However, the wireless terminal 20 does not need to include the operation unit 23 or the display unit 24 as long as it has the function of receiving a wireless signal transmitted from the transmitter 10 and transmitting information related to the reception to the management device 30. For example, the wireless terminal 20 may be a device such as an IC (Integrated Circuit) tag that has only the function of transmitting and receiving radio waves, or may be a mobile object such as a drone. If the wireless terminal 20 does not include the display unit 24, the wireless terminal 20 may transmit information transmitted from the management device 30 to an external device such as a PC or digital signage, and display the information.

[0158] In the above-described embodiment, the wireless terminal 20 and the management device 30 have the functional configurations shown in FIG. 6, FIG. 13, or FIG. 18. However, these configurations are merely examples, and the functions of each unit may be provided in any device in the position estimation system 1. For example, the correction information generation unit 313 may be provided in an external device other than the management device 30. In this case, the management device 30 acquires correction information 300 generated by the external device from the external device and stores it in the storage unit 32. In other words, the pre-phase may be performed not only by the management device 30 but also by an external device. Furthermore, not only by the correction information generation unit 313, but also by multiple devices, the functions of the management device 30 may be distributed.

[0159] In the above-described embodiments, the CPU in the control units 21 and 31 executes a program stored in the ROM or the storage units 22 and 32, thereby functioning as each unit shown in FIG. 6, 13, or 18. However, the control units 21 and 31 may be dedicated hardware. Dedicated hardware is, for example, a single circuit, a composite circuit, a programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof. When the control units 21 and 31 are dedicated hardware, the functions of each unit may be realized by individual hardware, or the functions of each unit may be realized together by a single piece of hardware.

[0160] In addition, some of the functions of each unit may be realized by dedicated hardware, and other parts may be realized by software or firmware. In this way, the control units 21 and 31 can realize each of the above-mentioned functions by hardware, software, firmware, or a combination of these.

[0161] By applying a program that defines the operation of the control units 21 and 31 to an existing computer such as a personal computer or an information terminal device, it is possible to make the computer function as an air conditioning control device.

[0162] Furthermore, the method of distribution of such a program is arbitrary, and for example, it may be stored on a computer-readable recording medium such as a CD-ROM (Compact Disk ROM), a DVD (Digital Versatile Disk), an MO (Magneto Optical Disk), or a memory card and distributed, or it may be distributed via a communication network such as the Internet.

[0163] The present disclosure allows various embodiments and modifications without departing from the broad spirit and scope of the present disclosure. Furthermore, the above-described embodiments are intended to illustrate the present disclosure and do not limit the scope of the present disclosure. That is, the scope of the present disclosure is defined by the claims, not the embodiments. Various modifications made within the scope of the claims and the meaning of equivalent disclosures are considered to be within the scope of the present disclosure.

[0164] Various aspects of the present disclosure are summarized below as appendices.

[0165] (Appendix 1) A position estimation device that estimates a position of a wireless terminal, a correction means for correcting a value based on the reception strength of a radio signal transmitted from a transmitter at the wireless terminal using correction information generated based on the reception strength of the radio signal at a plurality of positions; a position estimation means for estimating the position of the wireless terminal based on the value corrected by the correction means and the position of the transmitter, Location estimation device. (Appendix 2) the correction information is information indicating a correction amount of a value based on the reception strength when the wireless terminal is present in each of a plurality of areas, the correction means corrects the value based on the reception strength using a correction amount determined in the correction information for an area in which the wireless terminal is located, among the plurality of areas. 2. The location estimation device of claim 1. (Appendix 3) Further, a correction information generating unit is provided for generating the correction information, the correction information generating means sets the correction amount for each of the plurality of areas based on a difference between an intensity distance based on a reception strength of the wireless signal at the measurement terminal and an actual distance between the measurement terminal and the transmitter. 3. The location estimation device of claim 2. (Appendix 4) the correction information generating means increases the correction amount as the difference between the intensity distance and the actual distance increases; 4. The location estimation device of claim 3. (Appendix 5) the correction information generating means generates correction information such that, for a combination of any one area of ​​the plurality of areas and any one transmitter of the plurality of transmitters, when a difference between the intensity distance and the actual distance is greater than a first threshold, the reception strength of the wireless signal transmitted from the one transmitter in the one area becomes equal to or less than a specific value; the correction means uses the correction information to correct a value based on the reception strength at the wireless terminal of wireless signals transmitted from a plurality of transmitters; the position estimation means estimates the position of the wireless terminal based on the value of transmitters other than those for which the value corrected by the correction means is equal to or less than a specific value, and the positions of the transmitters other than those for which the value is equal to or less than the specific value. 5. The location estimation device according to claim 3 or 4. (Appendix 6) further comprising an area estimation means for estimating an area in which the wireless terminal is present among the plurality of areas based on the reception strength at the wireless terminal and the position of the transmitter; the correction means corrects the value based on the reception intensity using a correction amount determined for the area estimated by the area estimation means among the plurality of areas in the correction information. 6. A position estimation device according to any one of appendices 2 to 5. (Appendix 7) The correction information is a trained model generated by machine learning, The correction means uses the trained model to infer a correction amount for a value based on the reception strength from the reception strength at the wireless terminal of wireless signals transmitted from a plurality of transmitters and the positions of the plurality of transmitters, and corrects the value based on the reception strength using the inferred correction amount. 2. The location estimation device of claim 1. (Appendix 8) Further comprising a learning means for generating the trained model using the machine learning. 8. The location estimation device of claim 7. (Appendix 9) the correction means uses the correction information to correct a value based on the reception strength at the wireless terminal of wireless signals transmitted from a plurality of transmitters; the position estimation means estimates the position of the wireless terminal based on the value corrected by the correction means and the positions of the plurality of transmitters; The position estimation means calculating a distance error, which is a difference between an actual distance between each of the plurality of transmitters and the estimated position of the wireless terminal and an intensity distance based on the reception intensity at the wireless terminal; re-estimating the position of the wireless terminal when there is at least one transmitter among the plurality of transmitters whose distance error is greater than a second threshold; 7. A position estimation device according to any one of appendices 1 to 6. (Appendix 10) when a group of transmitters whose distance error is greater than the second threshold exists among the plurality of transmitters, the correction means re-corrects the reception strength of the wireless signals transmitted from the group of transmitters based on the distance error; the position estimation means re-estimates the position of the wireless terminal based on the reception strength re-corrected by the correction means. 10. The location estimation device of claim 9. (Appendix 11) when there is at least one transmitter among the plurality of transmitters for which the distance error is greater than the second threshold value in all cases where the wireless terminal is located in a plurality of different areas, the location estimation means re-estimates the location of the wireless terminal based on the reception strength of wireless signals transmitted from transmitters among the plurality of transmitters other than the at least one transmitter; 11. The position estimation device according to claim 9 or 10. (Appendix 12) A position estimation system for estimating a position of a wireless terminal, comprising: a transmitter that emits a radio signal; a correction means for correcting a value based on the reception strength of the radio signal at the wireless terminal using correction information generated based on the reception strength of the radio signal at a plurality of positions, the radio signal being transmitted from the transmitter; a position estimation means for estimating the position of the wireless terminal based on the value corrected by the correction means and the position of the transmitter, Location estimation system. (Appendix 13) A location estimation method for estimating a location of a wireless terminal, comprising: generating correction information based on the reception strength at a plurality of positions of a wireless signal transmitted from a transmitter; correcting a value based on the reception strength of the wireless signal at the wireless terminal using the generated correction information; estimating the position of the wireless terminal based on the corrected value and the position of the transmitter; Location estimation method. (Appendix 14) Computer, a correction means for correcting a value based on the reception strength of a radio signal at a wireless terminal, using correction information generated based on the reception strength of the radio signal at a plurality of positions, the radio signal being transmitted from a transmitter; and causing the device to function as a position estimation means for estimating the position of the wireless terminal based on the value corrected by the correction means and the position of the transmitter. program. [Explanation of symbols]

[0166] 1 Position estimation system, 5 Building, 7a, 7b, 7c Obstacle, 10 Transmitter, 20 Wireless terminal 20a Measurement terminal, 20b User terminal, 21 Control unit, 22 Memory unit, 23 Operation unit, 24 Display unit, 25 Communication unit, 30 Management device, 31 Control unit, 32 Memory unit, 35 Communication unit, 211 Transmitter information acquisition unit, 212 Position information acquisition unit, 213 Signal receiving unit, 214 Intensity information transmission unit, 215 Notification unit, 221, 222 Intensity information, 311 Transmitter information transmission unit, 312 Intensity information acquisition unit, 313 Correction information generation unit, 314 Area estimation unit, 315 Correction unit, 316 Position estimation unit, 317 Output unit, 318 Learning unit, 300 Correction information, 301 Trained model, 321 Transmitter information, 322 Property Information

Claims

1. A position estimation device that estimates a position of a wireless terminal, a correction means for correcting a value based on the reception strength of a radio signal transmitted from a transmitter at the wireless terminal using correction information generated based on the reception strength of the radio signal at a plurality of positions; a position estimation means for estimating the position of the wireless terminal based on the value corrected by the correction means and the position of the transmitter, Location estimation device.

2. the correction information is information indicating a correction amount of a value based on the reception strength when the wireless terminal is present in each of a plurality of areas, the correction means corrects the value based on the reception strength using a correction amount determined in the correction information for an area in which the wireless terminal is located, among the plurality of areas. The position estimation device according to claim 1 .

3. Further, a correction information generating unit is provided for generating the correction information, the correction information generating means sets the correction amount for each of the plurality of areas based on a difference between an intensity distance based on a reception strength of the wireless signal at the measurement terminal and an actual distance between the measurement terminal and the transmitter. The position estimation device according to claim 2 .

4. the correction information generating means increases the correction amount as the difference between the intensity distance and the actual distance increases; The position estimation device according to claim 3 .

5. the correction information generating means generates correction information for making the reception strength of the wireless signal transmitted from the one transmitter in the one area equal to or less than a specific value when a difference between the intensity distance and the actual distance is greater than a first threshold value for a combination of any one area of ​​the plurality of areas and any one transmitter of the plurality of transmitters; the correction means uses the correction information to correct a value based on the reception strength at the wireless terminal of wireless signals transmitted from a plurality of transmitters; the position estimation means estimates the position of the wireless terminal based on the value of transmitters other than those for which the value corrected by the correction means is equal to or less than a specific value, and the positions of the transmitters other than those for which the value is equal to or less than the specific value. The position estimation device according to claim 3 .

6. further comprising an area estimation means for estimating an area in which the wireless terminal is present among the plurality of areas based on the reception strength at the wireless terminal and the position of the transmitter; the correction means corrects the value based on the reception intensity using a correction amount determined for the area estimated by the area estimation means among the plurality of areas in the correction information. The position estimation device according to any one of claims 2 to 5.

7. The correction information is a trained model generated by machine learning, The correction means uses the trained model to infer a correction amount for a value based on the reception strength from the reception strength at the wireless terminal of wireless signals transmitted from a plurality of transmitters and the positions of the plurality of transmitters, and corrects the value based on the reception strength using the inferred correction amount. The position estimation device according to claim 1 .

8. Further comprising a learning means for generating the trained model using the machine learning. The position estimation device according to claim 7 .

9. the correction means uses the correction information to correct a value based on the reception strength at the wireless terminal of wireless signals transmitted from a plurality of transmitters; the position estimation means estimates the position of the wireless terminal based on the value corrected by the correction means and the positions of the plurality of transmitters; The position estimation means calculating a distance error, which is a difference between an actual distance between each of the plurality of transmitters and the estimated position of the wireless terminal and an intensity distance based on the reception intensity at the wireless terminal; re-estimating the position of the wireless terminal when there is at least one transmitter among the plurality of transmitters whose distance error is greater than a second threshold; The position estimation device according to claim 1 .

10. when a group of transmitters whose distance error is greater than the second threshold exists among the plurality of transmitters, the correction means re-corrects the reception strength of the radio signals transmitted from the group of transmitters based on the distance error; the position estimation means re-estimates the position of the wireless terminal based on the reception strength re-corrected by the correction means. The position estimation device according to claim 9 .

11. when there is at least one transmitter among the plurality of transmitters for which the distance error is greater than the second threshold value in all cases where the wireless terminal is located in a plurality of different areas, the location estimation means re-estimates the location of the wireless terminal based on the reception strength of wireless signals transmitted from transmitters among the plurality of transmitters other than the at least one transmitter; The position estimation device according to claim 9 .

12. A position estimation system for estimating a position of a wireless terminal, comprising: a transmitter that transmits a radio signal; a correction means for correcting a value based on the reception strength of the radio signal at the wireless terminal using correction information generated based on the reception strength of the radio signal at a plurality of positions, the radio signal being transmitted from the transmitter; a position estimation means for estimating the position of the wireless terminal based on the value corrected by the correction means and the position of the transmitter, Location estimation system.

13. A location estimation method for estimating a location of a wireless terminal, comprising: generating correction information based on the reception strength at a plurality of positions of a wireless signal transmitted from a transmitter; correcting a value based on the reception strength of the wireless signal at the wireless terminal using the generated correction information; estimating the position of the wireless terminal based on the corrected value and the position of the transmitter; Location estimation method.

14. Computer, a correction means for correcting a value based on the reception strength of a radio signal at a wireless terminal, using correction information generated based on the reception strength of the radio signal at a plurality of positions, the radio signal being transmitted from a transmitter; and causing the device to function as a position estimation means for estimating the position of the wireless terminal based on the value corrected by the correction means and the position of the transmitter. program.

Images