JP2016217943A - Location estimation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a location estimation system that can estimate a location of a transmitter as suppressing the number of transmitters, in systems estimating the location of the transmitter on the basis of an electric wave of the transmitter received by receivers.SOLUTION: A location estimation system comprises: access points of more than three receivers; and a location estimation device 30 that estimates a location of a portable terminal on the basis of information on intensity of an electric wave of the portable terminal received by the access point. The location estimation device includes a determination unit 35b, and an estimation unit 35c. The determination unit is configured to determine one access point as a maximum intensity electric wave receiver on the basis of electric wave intensity information by the access point and time zone about the intensity of the electric wave of the portable terminal received by each access point in each of plurality of time zones. The estimation unit is configured to estimate the position of the portable terminal in a determination object time zone composed of more than two time zones on the basis of a combination of the maximum intensity electric wave receivers in the time zone included in the determination object time zone.SELECTED DRAWING: Figure 4

Description

  The present invention includes a position estimation system, more specifically, a plurality of radio wave receivers that receive radio waves transmitted from a radio wave transmitter, and estimates the position of the radio wave transmitter based on radio waves received by the radio wave receiver. The present invention relates to a position estimation system.

  Conventionally, a system is known in which a plurality of radio wave receivers are installed, radio waves transmitted by the radio wave transmitters are received by the radio wave receivers, and the position of the radio wave transmitters is estimated based on the received radio waves.

  For example, Patent Document 1 (International Publication No. WO2005 / 111880) includes three or more radio wave receivers that receive radio waves transmitted from radio wave transmitters attached to a shopping cart, and includes three radio wave receivers. A so-called RSSI (Received Signal Strength Indicator) type position estimation system that estimates the position of a radio wave transmitter based on a difference in received radio wave intensity is disclosed. Patent Document 1 (International Publication No. WO2005 / 111880) includes three or more radio wave receivers that receive radio waves transmitted from radio wave transmitters attached to a shopping cart. A so-called TOA (Time of Arrival) method or TDOA (Time Difference of Arrival) method position estimation system for estimating the position of a radio wave transmitter based on a difference in radio wave reception time is disclosed. Patent Document 1 (International Publication No. WO2005 / 111880) includes a plurality of radio wave receivers that communicate with radio wave transmitters attached to a shopping cart or the like, and with which radio wave transmitters communicated. Based on this, a position estimation system that estimates that a radio wave transmitter is present at a position where a radio wave receiver with which communication has been made is disclosed.

  In addition, for example, there are three or more radio receivers that receive radio waves transmitted by a radio transmitter, and three or more radio receivers with relatively strong received radio waves are extracted, and a plurality of extracted radio waves are received. There is also known a radio wave transmitter position estimation system that uses a barycentric method for estimating the barycentric position of the machine as the radio wave transmitter position.

  However, in a position estimation system using the RSSI method, TOA method, TDOA method, center of gravity method, etc., not only information relating to communication of a radio wave receiver that has received the strongest radio wave is used, but a radio wave having a weaker intensity. Since the information regarding the communication of the radio wave receiver that received the signal is also used, the accuracy of position estimation may be reduced.

  In addition, in a position estimation system that estimates that a radio wave transmitter is present at the position where the radio wave receiver with which it communicated is installed depends on which radio wave receiver the radio wave transmitter has communicated with, in order to improve the accuracy of position estimation In addition, it is necessary to install a large number of radio wave receivers, which may increase the installation cost.

  An object of the present invention is a position estimation system that includes a plurality of radio wave receivers that receive radio waves transmitted from a radio wave transmitter, and estimates the position of the radio wave transmitter based on the radio waves received by the radio wave receiver. An object of the present invention is to provide a position estimation system capable of accurately estimating the position of a radio wave transmitter while suppressing the number of installed receivers.

  A position estimation system according to a first aspect of the present invention includes at least three radio wave receivers and a position estimation device. Each radio receiver is installed at a different position. The position estimation device estimates the position of the radio wave transmitter based on the information regarding the strength of the radio wave of the radio wave transmitter received by the radio wave receiver. The position estimation device includes a determination unit and an estimation unit. The deciding unit receives the radio wave for each time zone based on the radio wave strength information for each radio wave receiver and each time zone regarding the strength of the radio wave of the radio wave transmitter received by each radio wave receiver in each of a plurality of time zones. One radio wave receiver that has received the maximum intensity radio wave from the machine is determined as the maximum intensity radio wave receiver. The estimation unit estimates the position of the radio wave transmitter in the determination target time zone composed of two or more time zones based on the combination of the maximum strength radio wave receivers in the time zone included in the determination target time zone.

  In the position estimation system according to the first aspect of the present invention, one radio wave receiver that has received the maximum intensity radio wave for each time zone is determined as the maximum intensity radio wave receiver, and the maximum intensity radio wave receiver for a plurality of time zones is determined. According to the combination, the position of the radio wave transmitter in the determination target time zone is estimated. That is, here, only information related to a radio wave receiver that has received a radio wave having the maximum intensity is used for position estimation, so that the accuracy of position estimation can be kept high. Here, since the position of the radio wave transmitter is estimated based on the combination of the maximum intensity radio wave receivers in a plurality of time zones, it is assumed that the radio wave transmitter exists at the position where the radio wave receiver that has simply communicated is installed. Compared to the estimation, the position of the radio wave transmitter can be accurately estimated with a small number of radio wave receivers.

  A position estimation system according to a second aspect of the present invention is the position estimation system according to the first aspect, wherein the shortest distance between radio wave receivers in a plan view is determined by the estimated maximum moving speed and time zone of the radio wave transmitter. The relationship between the shortest distance and the length of the time zone is set so that the value becomes 2 or more when divided by the product of the length of the time.

  In the position estimation system according to the second aspect of the present invention, since the position of the radio wave transmitter can be estimated while the radio wave transmitters move by the shortest distance between the radio wave receivers, the position of the radio wave transmitter is accurately estimated. Easy to do.

  A position estimation system according to a third aspect of the present invention is the position estimation system according to the second aspect, and the length of the determination target time zone is obtained by dividing the shortest distance between radio wave receivers in plan view by the maximum moving speed. Or less than the calculated length of time.

  In the position estimation system according to the third aspect of the present invention, the position of the radio wave transmitter is estimated at least once while the radio wave transmitters move by the shortest distance between the radio wave receivers. It is easy to estimate the position.

  A position estimation system according to a fourth aspect of the present invention is the position estimation system according to any one of the first aspect to the third aspect, and further includes an information generation unit. The information generator generates radio wave intensity information for each radio receiver and for each time zone. The information generation unit, based on the value related to the strength of the radio wave received from the radio wave transmitter by each of the radio wave receivers at a plurality of time points within each time zone, Is generated.

  In the position estimation system according to the fourth aspect of the present invention, the radio wave intensity information for each time zone is generated based on the values related to the radio wave intensity at a plurality of time points within the time zone. It is easy to get information.

  A position estimation system according to a fifth aspect of the present invention is the position estimation system according to any of the first to fourth aspects, wherein the radio wave receiver includes a first radio wave receiver and a second radio wave receiver. . Only the first radio wave receiver and the second radio wave receiver are included in the combination of the maximum intensity radio wave receivers in the time zone included in the determination target time zone, and both the first radio wave receiver and the second radio wave receiver are included. If the radio wave transmitter is present at an intermediate position between the first radio wave receiver and the second radio wave receiver in plan view, the estimation unit estimates the position of the radio wave transmitter.

  In the position estimation system according to the fifth aspect of the present invention, since it is estimated that a radio wave transmitter is present at an intermediate position between the first radio wave receiver and the second radio wave receiver, the position of the first radio wave receiver, Alternatively, the position of the radio wave transmitter can be estimated with higher accuracy than when only the radio wave transmitter is estimated at the position of the second radio wave receiver.

  A position estimation system according to a sixth aspect of the present invention is the position estimation system according to the fifth aspect, and the radio wave receiver further includes a third radio wave receiver. Only the first radio wave receiver, the second radio wave receiver, and the third radio wave receiver are included in the combination of the maximum intensity radio wave receivers in the time zone included in the determination target time zone, and the first radio wave receiver, When all of the second radio wave receiver and the third radio wave receiver are included, the estimation unit is located at the center of gravity of the first radio wave receiver, the second radio wave receiver, and the third radio wave receiver in plan view. If a radio wave transmitter is present, the position of the radio wave transmitter is estimated.

  In the position estimation system according to the sixth aspect of the present invention, since it is estimated that a radio wave transmitter is present at the center of gravity of the first to third radio wave receivers, the radio wave transmitter is located at any radio wave receiver position. The position of the radio wave transmitter can be estimated with higher accuracy than in the case where it is only estimated that the signal exists.

  A position estimation system according to a seventh aspect of the present invention is the position estimation system according to any one of the first aspect to the sixth aspect, and the radio wave transmitter moves with a person.

  In the position estimation system according to the seventh aspect of the present invention, it is possible to grasp the human traffic line by estimating the position of the radio wave transmitter.

  In the position estimation system according to the first aspect of the present invention, only information relating to the radio wave receiver that has received the radio wave having the maximum intensity is used for position estimation, so that the accuracy of position estimation can be kept high. Here, since the position of the radio wave transmitter is estimated based on the combination of the maximum intensity radio wave receivers in a plurality of time zones, it is assumed that the radio wave transmitter exists at the position where the radio wave receiver that has simply communicated is installed. Compared to the estimation, the position of the radio wave transmitter can be accurately estimated with a small number of radio wave receivers.

  In the position estimation system according to the second aspect or the third aspect of the present invention, it is easy to accurately estimate the position of the radio wave transmitter.

  In the position estimation system according to the fourth aspect of the present invention, it is easy to obtain highly reliable radio field intensity information by time period.

  In the position estimation system according to the fifth aspect and the sixth aspect of the present invention, the position of the radio wave transmitter can be accurately estimated.

  In the position estimation system according to the seventh aspect of the present invention, it is possible to grasp the human traffic line by estimating the position of the radio wave transmitter.

1 is an overall schematic diagram of a position estimation system according to an embodiment of the present invention. It is an example of the arrangement | positioning state in planar view of the access point contained in the position estimation system of FIG. It is an example of the installation state of the access point contained in the position estimation system of FIG. The access point is disposed adjacent to the indoor unit of the air conditioner. It is a block diagram of the position estimation apparatus contained in the position estimation system of FIG. It is an example of the arrangement | positioning state in planar view of an access point in case the number of the access points contained in a position estimation system is three. 6 is a table for explaining position estimation when the three access points in FIG. 5 are used. It is an example of the flowchart of the position estimation by the position estimation system of FIG.

  A position estimation system 100 as an embodiment of a position estimation system according to the present invention will be described with reference to the drawings. The position estimation system 100 described below is merely a specific example of the position estimation system according to the present invention, and can be appropriately changed without departing from the spirit of the present invention.

(1) Overall Configuration FIG. 1 is an overall schematic diagram of the position estimation system 100.

  The position estimation system 100 includes a plurality of (more specifically, three or more) wireless LAN access points 20 and a position estimation device 30 (see FIG. 1). The access points 20 are installed at different positions. The access point 20 and the position estimation device 30 are connected by a communication line 40. The position estimation device 30 estimates the position of the radio wave transmitter based on information on the intensity of the radio wave of the radio wave transmitter received by the access point 20.

  The access point 20 is installed in a space R (sale floor etc.) in a commercial facility such as a supermarket (see FIG. 2). Specifically, one access point 20 is attached adjacent to each of the plurality of indoor units 50 of the air conditioner installed on the ceiling of the space R (see FIG. 3). The indoor units 50 are generally installed at substantially equal intervals over the entire space R so that the entire area of the space R is subject to air conditioning. Therefore, the access points 20 attached adjacent to the indoor unit 50 are installed at substantially equal intervals throughout the space R, for example, as shown in FIG. The position estimation device 30 is installed in a commercial facility where the access point 20 is installed, for example, in a backyard of the commercial facility.

  Here, the air-conditioning communication line that connects the control unit (not shown) of the indoor unit 50 of the air conditioner and the control unit (not shown) of the outdoor unit using the data superposition technique is connected to the access point 20 and the position. It is also used as a communication line 40 that connects the estimation device 30. Thereby, the expense and effort which install separately the communication line which connects the access point 20 and the position estimation apparatus 30 can be saved.

  A radio wave transmitter that transmits radio waves to the access point 20 is, for example, a portable terminal 90 such as a smartphone carried by a person. In other words, the mobile terminal 90 moves with the person. By using the position estimation system 100, it is possible to acquire flow line information and the like of the person carrying the mobile terminal 90 in the space R of the commercial facility.

  In FIG. 1, only one portable terminal 90 is drawn, but a plurality of portable terminals 90 may be provided. In other words, two or more people may own the mobile terminal 90 in the space R.

  Each portable terminal 90 has a unique identification code (hereinafter referred to as transmitter ID). The portable terminal 90 transmits a radio wave (radio wave signal) including a transmitter ID as information. Radio waves are transmitted from the portable terminal 90 periodically, for example, at intervals of 0.5 seconds. However, the transmission interval of the radio wave from the portable terminal 90 is an example, and is not limited to this.

(2) Detailed Configuration (2-1) Access Point The access point 20 is an example of a radio wave receiver that receives radio waves emitted from the mobile terminal 90. The access point 20 receives radio waves transmitted from the mobile terminal 90. The access point 20 detects the intensity of the radio wave received from the mobile terminal 90.

  The access point 20 generates information about radio waves for each radio wave received from the mobile terminal 90. For each radio wave, the radio wave information includes the time at which the access point 20 received the radio wave, the transmitter ID included as information in the received radio wave, and information on the radio wave intensity detected by the access point 20 (the radio wave Value of the intensity). The access point 20 transmits information on the generated radio wave to the position estimation device 30 together with an identification code unique to each access point 20 (hereinafter referred to as a receiver ID).

  Here, every time the access point 20 receives a radio wave from the mobile terminal 90, the access point 20 generates information about the radio wave for the received radio wave, and transmits the generated information about the radio wave to the position estimation device 30. However, it is not limited to this. For example, the access point 20 may generate radio wave information for each of the plurality of radio waves after receiving the radio waves a plurality of times, and transmit these to the position estimation device 30. In addition, for example, the access point 20 may generate information about a radio wave every time it receives a radio wave, and transmit the generated information about the radio wave to the position estimation device 30 a plurality of times.

(2-2) Position Estimation Device The position estimation device 30 is a general-purpose computer. The position estimation device 30 estimates the position of the mobile terminal 90 based on information on the strength of the radio waves of the mobile terminal 90 received by the access point 20.

  As illustrated in FIG. 4, the position estimation device 30 mainly includes a communication unit 31, an input unit 32, an output unit 33, a storage unit 34, and a control unit 35.

(2-2-1) Communication Unit The communication unit 31 is a communication interface for enabling communication between the access point 20 and the position estimation device 30 via the communication line 40.

  The position estimation device 30 receives information about the receiver ID and the radio wave from the access point 20. Information related to the receiver ID and the radio wave received from the access point 20 via the communication unit 31 is stored in a reception data storage area 34a of the storage unit 34 to be described later.

(2-2-2) Input unit The input unit 32 is, for example, a keyboard or a mouse. Various information and various commands are input to the input unit 32 by an operator of the position estimation device 30 or the like.

  (2-2-3) Output unit The output unit 33 is, for example, a liquid crystal display. Various kinds of information are output (displayed) to the output unit 33. For example, information based on the position of the mobile terminal 90 estimated by the control unit 35 described later is displayed on the output unit 33. Specifically, on the output unit 33, for example, flow line information of a person (information indicating a movement route of the person carrying the portable terminal 90) based on the position of the portable terminal 90 estimated by the control unit 35 is displayed. Is done.

(2-2-4) Storage Unit The storage unit 34 is mainly configured by a ROM, a RAM, and a hard disk.

  The storage unit 34 stores various programs executed by the control unit 35.

  Various information is stored in the storage unit 34. The storage unit 34 includes a reception data storage area 34a, a radio wave intensity information storage area 34b, a maximum intensity radio wave receiver storage area 34c, and a position estimation result storage area 34d as information storage areas.

(2-2-4-1) Received Data Storage Area The received data storage area 34a stores information on the receiver ID and the radio wave received from the access point 20 via the communication line 40. The radio wave information includes the time when the access point 20 having the receiver ID transmitted together with the radio wave information received a certain radio wave, the transmitter ID included as information in the radio wave, and the intensity of the radio wave. (Information regarding the intensity of the radio wave detected by the access point 20). The reception data storage area 34a stores radio wave reception time and radio wave intensity information in association with each other for each transmitter ID and for each receiver ID.

(2-2-4-2) Radio wave intensity information storage area The radio wave intensity information storage area 34b includes, for each transmitter ID, a receiver ID and a time zone generated by an information generator 35a of the controller 35 described later. Another field strength information is stored. The radio wave intensity information will be described in detail in the description related to the information generation unit 35a.

(2-2-4-3) Maximum intensity radio wave receiver storage area The maximum intensity radio wave receiver storage area 34c is determined by the time zone determined by the determination unit 35b of the control unit 35 described later for each transmitter ID. The maximum strength radio receiver is stored. The maximum intensity radio wave receiver will be described in detail in the description regarding the determination unit 35b.

(2-2-4-4) Position estimation result storage area In the position estimation result storage area 34d, the estimation result of the position of the portable terminal 90 by the estimation unit 35c of the control unit 35 described later is time-series for each transmitter ID. Is stored as information.

(2-2-5) Control unit The control unit 35 mainly includes a CPU. The control unit 35 estimates the position of the mobile terminal 90 by executing various programs stored in the storage unit 34.

  Specifically, the control unit 35 mainly functions as an information generation unit 35a, a determination unit 35b, and an estimation unit 35c by executing various programs for estimating the position of the mobile terminal 90.

(2-2-5-1) Information Generation Unit The information generation unit 35a receives the radio wave reception time and radio wave intensity stored in the reception data storage area 34a in association with each other for each transmitter ID and each receiver ID. For each portable terminal 90 (for each transmitter ID), radio field strength information for each receiver ID (for each access point 20) and for each time zone is generated.

  Here, all the time zones have the same length. The length of the time zone is set so that each time zone includes a predetermined number of times when the access point 20 receives radio waves from the mobile terminal 90. For example, if the time zone length is set so that radio waves are transmitted from the mobile terminal 90 at intervals of 0.5 seconds and each time zone includes three times when the access point 20 receives the radio waves, The length of the time zone is 1.5 seconds.

  The generation of the radio wave intensity information by the information generator 35a will be specifically described. Here, in order to simplify the description, the description will be made assuming that there is only one mobile terminal 90 (only one transmitter ID). When there are a plurality of portable terminals 90, the information generation unit 35a may perform the process described below for each transmitter ID.

  The information generation unit 35a is information regarding the strength of radio waves received from the mobile terminal 90 by each of the access points 20 at a plurality of time points within each time slot (a plurality of radio wave reception times included in each time slot). Based on (value related to strength), radio wave strength information about the access point 20 in the time zone is generated. As will be described later, the determination unit 35b determines the maximum strength receiver for each time zone based on the radio field strength information for each time zone generated by the information generation unit 35a. The maximum intensity receiver will be described later.

  This will be described more specifically with a specific example.

  Here, for example, assume that there are three access points 20A, 20B, and 20C (see FIG. 5). The three access points 20A, 20B, and 20C are access points 20 having receiver IDs of A, B, and C, respectively. The three access points 20A, 20B, and 20C are respectively arranged at the positions of the vertices of the triangle in plan view, for example, as shown in FIG. It is assumed that radio waves are transmitted from the portable terminal 90 to the access point 20 three times in each time zone having a predetermined length. In other words, in the received data storage area 34a, it is assumed that three values of radio wave intensity associated with the reception time of radio waves belonging to a certain time zone are stored for each access point 20 of a certain receiver ID. To do. For example, as shown in Table 1, the received data storage area 34a stores values (units are decibels) related to radio wave intensity (at times t1, t2, t3...) For each access point 20 according to time. Yes. Here, it is assumed that the times t1, t2, and t3 belong to the time zone T1, and the times t4, t5, and t6 belong to the time zone T2 subsequent to the time zone T1 (the same applies to the time after the time t7).

  For each time zone T1, T2,..., The information generation unit 35a is a value related to the strength of the radio wave at a plurality of time points (radio wave reception times) within each time zone T1, T2,. Is stored in the radio wave intensity information storage area 34b as radio wave intensity information for each access point 20 and for each time zone. For example, information shown in Table 2 is stored in the radio wave intensity information storage area 34b.

(2-2-5-2) Determining Unit The determining unit 35b determines the maximum strength radio wave receiver for each portable device 90 with respect to a certain transmitter ID, based on the information stored in the radio wave intensity information storage area 34b. To do. That is, the determination unit 35b relates to the mobile terminal 90 having a certain transmitter ID, and relates to the strength of the radio wave of the mobile terminal 90 received by each access point 20 in each of a plurality of time zones. ) And based on the radio field strength information for each time zone, the maximum strength radio wave receiver is determined for each time zone. Here, the maximum intensity radio wave receiver means one access point 20 that has received the maximum intensity radio wave among the access points 20.

  Specifically, the determination process of the maximum intensity radio wave receiver by the determination unit 35b will be described by taking as an example the case where the information shown in Table 2 is stored in the radio wave intensity information storage area 34b for the portable terminal 90 having a certain transmitter ID. To do. Here, it is assumed that there are three access points 20A, 20B, and 20C as shown in FIG.

  When the information shown in Table 2 is stored in the radio wave intensity information storage area 34b, the determination unit 35b receives the receiver ID indicating the value of the maximum radio wave intensity information for each time zone T1, T2, T3,. Access point 20 is determined to be the maximum intensity radio wave receiver. For example, the determination unit 35b determines the access point 20A with the receiver ID A for the time zones T1 and T2 and the access point 20B with the receiver ID B for the time zone T3 as the maximum strength radio wave receiver (time The same applies to the band T4 and later).

  Information on the maximum strength radio wave receiver for each time zone determined by the determination unit 35b (for example, information as shown in Table 3) is stored in the maximum strength radio wave receiver storage area 34c for each transmitter ID.

(2-2-5-3) Estimating Unit The estimating unit 35c is composed of two or more time zones using information on the maximum strength radio wave receivers for each time zone stored in the maximum strength radio wave receiver storage area 34c. The position of the portable terminal 90 in the determination target time zone is estimated based on the combination of the maximum intensity radio wave receivers in the time zone included in the determination target time zone.

  A specific example will be described.

  Here, there are three access points 20, 20 A, 20 B, and 20 C each having a receiver ID of A, B, and C, and the access points 20 A, 20 B, and 20 C are shown in FIG. As described above, it is assumed that the triangles are respectively arranged at the vertex positions. Here, it is assumed that each determination target time zone is composed of three time zones. For example, when the information of the maximum intensity radio wave receiver for each time zone (time zones T1, T2, T3,...) As shown in Table 3 is used, the determination target time is also combined with the time zones T1, T2, T3. The time zone T1, T5, and T6 are combined as a determination target time zone E2, and the time zones T7, T8, and T9 are combined into a determination target time zone E3 (the same applies to T10 and later).

  The estimation unit 35c determines the position of the mobile terminal 90 in each determination target time zone E1, E2, E3,... Based on the combination of the maximum strength radio wave receivers in the time zone included in each determination target time zone. Decide like this.

(A) When the combination of the maximum strength radio wave receivers in the time zone included in the determination target time zone is composed only of access points with the same receiver ID, the estimation unit 35c determines the maximum time zone included in the determination target time zone. When the combination of the strength radio wave receivers is composed of only the access point 20 having the same receiver ID, it is determined that the mobile terminal 90 is present at the position where the access point 20 is installed in plan view in the determination target time zone. To do. If the maximum intensity radio wave receivers in the time zone included in the determination target time zone are all access points 20A whose receiver ID is A, the estimation unit 35c includes the position (position) of the access point 20A in the determination target time zone. It is determined that the portable terminal 90 exists in P1) (see FIGS. 5 and 6). If the maximum intensity radio wave receivers in the time zone included in the determination target time zone are all access points 20B with the receiver ID B, the estimation unit 35c determines the position (position) of the access point 20B in the determination target time zone. It is determined that the portable terminal 90 exists in P2) (see FIGS. 5 and 6). If the maximum intensity radio wave receivers in the time zone included in the determination target time zone are all access points 20C with the receiver ID C, the estimation unit 35c includes the position (position) of the access point 20C in the determination target time zone. It is determined that the portable terminal 90 exists in P3) (see FIGS. 5 and 6).

  If it demonstrates using the example of Table 3, all the maximum intensity | strength radio wave receivers of the time slot | zones T4, T5, and T6 included in the determination object time slot | zone E2 are the access points 20B whose receiver ID is B. Therefore, the estimation unit 35c determines that the mobile terminal 90 exists at the position P2 in the determination target time zone E2.

(B) When the combination of the maximum strength radio wave receivers in the time zone included in the determination target time zone is composed of two access points having different receiver IDs When the combination includes two access points 20 having different receiver IDs, in other words, two access points 20 having different receiver IDs are included in the combination of the maximum strength radio wave receivers in the time zone included in the determination target time zone. In the case where access points 20 other than those receiver IDs are included, the estimation unit 35c determines that the mobile terminal 90 is present at the intermediate position between the two access points 20 included in the combination in plan view. The position of the terminal 90 is estimated. For example, when the maximum intensity radio wave receiver in the time zone included in the determination target time zone is the access point 20A with the receiver ID A and the access point 20B with the receiver ID B, the estimation unit 35c It is estimated that the mobile terminal 90 is present at an intermediate position (position P4) between the access point 20A and the access point 20B in the determination target time zone (see FIGS. 5 and 6). When the maximum intensity radio wave receiver in the time zone included in the determination target time zone is the access point 20A with the receiver ID A and the access point 20C with the receiver ID C, the estimation unit 35c It is estimated that the portable terminal 90 exists at an intermediate position (position P5) between the access point 20A and the access point 20C during the time period (see FIGS. 5 and 6). When the maximum intensity radio wave receiver in the time zone included in the determination target time zone is the access point 20B with the receiver ID B and the access point 20C with the receiver ID C, the estimation unit 35c It is estimated that the mobile terminal 90 exists at an intermediate position (position P6) between the access point 20B and the access point 20C during the time period (see FIGS. 5 and 6).

  If it demonstrates using the example of Table 3, as for the combination of the maximum intensity | strength radio wave receiver of the time slot | zones T1, T2, T3 included in the determination target time slot | zone E1, the access point 20A with receiver ID A and receiver Since the two access points 20B with ID B are included, the estimation unit 35c determines that the mobile terminal 90 is present at the position P4 in the determination target time zone E1.

(C) When the combination of the maximum strength radio wave receivers in the time zone included in the determination target time zone is composed of three access points having different receiver IDs The maximum strength radio wave receiver in the time zone included in the determination target time zone When the combination includes three access points 20 having different receiver IDs, the estimation unit 35c determines the position of the mobile terminal 90 when the mobile terminal 90 exists at the center of gravity of the three access points 20 included in the combination in plan view. Is estimated. That is, the access point 20A with the receiver ID A, the access point 20B with the receiver ID B, and the access with the receiver ID C are combined with the combination of the maximum strength radio wave receivers in the time zone included in the determination target time zone. When the point 20C is included, the estimation unit 35c includes the mobile terminal 90 at the center of gravity (position P7) of the access point 20A, the access point 20B, and the access point 20C in the determination target time zone. Then, it estimates (refer FIG. 5 and FIG. 6).

  If it demonstrates using the example of Table 3, as for the combination of the maximum intensity | strength radio wave receiver of the time slot | zones T7, T8, and T9 included in determination object time slot | zone E3, receiver ID is the access point 20A and receiver A Since the access point 20B with ID B and the access point 20C with receiver ID C are included, the estimation unit 35c determines that the mobile terminal 90 exists at the position P7 in the determination target time zone E3.

  The position of the mobile terminal 90 estimated by the estimation unit 35c by the method as described above is time-series information (information on determination target time zones E1, E2, E3,...) For each transmitter ID. It is stored in the position estimation result storage area 34d. For example, the information shown in Table 4 is stored in the position estimation result storage area 34d for the portable terminal 90 having a certain transmitter ID.

(3) Setting of parameters related to position estimation of portable terminal In order to accurately estimate the position of portable terminal 90, it is preferable that the following Expression 1 holds between parameters related to position estimation of portable terminal 90.

[Formula 1]
D / V ≧ (1 / n) × K × 2

  Here, D is the shortest distance [m] between the access points 20 in plan view. V is the expected maximum moving speed [m / sec] of the mobile terminal 90. In other words, V is the expected maximum moving speed [m / sec] of the person carrying the mobile terminal 90. n is the transmission frequency [times / second] of the mobile terminal 90. K is the number of times radio waves are transmitted by the portable terminal 90 during one time zone, which is a time unit in which the radio wave intensity information is generated by the information generator 35a. (1 / n) × K represents the length [second] of one time zone.

  When the shortest distance D between the access points 20 in plan view is divided by the product of the predicted maximum moving speed V of the mobile terminal 90 and the time zone length (1 / n) × K, It means that the value is 2 or more. Between the shortest distance D and the length (1 / n) × K of the determination target time zone, there is a relationship such as Equation 1, so that the mobile terminal 90 moves by the shortest distance D between the access points 20. In addition, since the position of the portable terminal 90 can be estimated, it is easy to estimate the position of the portable terminal 90 with high accuracy.

  More preferably, it is preferable that the following Expression 2 holds between parameters related to position estimation of the mobile terminal 90.

[Formula 2]
D / V ≧ (1 / n) × K × N

  N is the number of time zones included in the determination target time. N is an integer of 2 or more.

  In other words, the length of the determination target time zone (1 / n) × K × N is calculated by dividing the shortest distance D between the access points 20 in a plan view by the expected maximum moving speed V of the mobile terminal 90. The relationship is that it is less than or equal to the calculated time length. When the relationship of Expression 2 is satisfied, for example, after the estimation unit 35c estimates that the mobile terminal 90 is at the position of one access point 20 in a certain determination target time zone, the next determination target of the estimation unit 35c In the time zone, it is possible to prevent being estimated to be at the position of the access point 20 that is not adjacent to the access point 20.

  By avoiding such a state, there are the following advantages. For example, when the estimation result of the person's position by the estimating unit 35c is used for the person's flow line analysis, it is preferable to grasp the route on which the person carrying the portable terminal 90 has moved. However, after being estimated by the estimating unit 35c to be in the position of one access point 20 in a certain determination target time zone, if in the next determination target time zone, the access point 20 is not adjacent to the access point 20 If it is estimated, even though it is known that the user is at that position as a result, there may be a plurality of routes to that position, and thus there is a possibility that the moving route (human moving route) of the portable terminal 90 cannot be grasped. However, by setting the parameters so as to satisfy the relationship of Expression 2, it is possible to avoid such a situation and grasp the movement route of the mobile terminal 90.

  The shortest distance D between the access points 20 is, for example, in the range of 2 to 200 m. The shortest distance D is determined according to the accuracy of the position of the mobile terminal 90 to be grasped, the installation conditions of the access point 20, and the like. The shortest distance D is preferably 4 m or more in order to suppress the number of installed access points 20. The expected maximum movement speed V of the mobile terminal 90 is appropriately determined according to the assumed human movement.

  A parameter determination method using Equation 2 will be described with a specific example.

  For example, as an example, the shortest distance D is 5 m, the expected maximum moving speed V of the mobile terminal 90 is 1 m / second, the radio wave transmission frequency n of the mobile terminal 90 is 2 times / second, and the time zone included in the determination target time zone In the case where the number N is set to 3 times, the number K of radio wave transmissions by the mobile terminal 90 during the time period 1 can be set to 3.3 times or less, for example, 3 times. preferable.

  In addition, for example, the number K of radio wave transmissions by the mobile terminal 90 during the time period of 1 in which the shortest distance D is 5 m, the expected maximum moving speed V of the mobile terminal 90 is 1 m / second, and 1 is 5 When setting the condition that the number N of time zones included in the time zone is 5 times, it is preferable from Formula 2 that the radio wave transmission frequency n of the mobile terminal 90 is set to 5 times or more.

(4) Flow of position estimation processing The flow of position estimation processing of the mobile terminal 90 by the position estimation system 100 will be described based on the flowchart of FIG.

  Here, it is assumed that the position estimation of the mobile terminal 90 is not performed in real time, but is performed after all the time information for which the position estimation of the mobile terminal 90 is to be performed is stored in the reception data storage area 34a. ing. However, the present invention is not limited to this, and the position of the mobile terminal 90 may be estimated one after another as information is written to the reception data storage area 34a.

  First, in step S1, the information generation unit 35a is based on the radio wave reception time and radio wave intensity information associated with each other for each transmitter ID and each receiver ID stored in the reception data storage area 34a. The radio wave intensity information for each access point 20 (for each receiver ID) and for each time zone is generated. More specifically, the information generation unit 35a determines the value related to the strength of the radio wave received from the mobile terminal 90 (the mobile terminal 90 having a certain transmitter ID) by each of the access points 20 at a plurality of points in time. By calculating the average value, the radio wave intensity information for each access point 20 and for each time zone is generated for the mobile terminal 90. The radio wave intensity information generated by the information generation unit 35a for each access point 20 and for each time zone is stored in the radio wave intensity information storage area 34b for each transmitter ID of the mobile terminal 90. Thereafter, the process proceeds to step S2.

  Next, in step S2, the determination unit 35b determines the maximum intensity radio wave receiver for each portable device 90 with respect to a certain transmitter ID, based on the information stored in the radio wave intensity information storage area 34b. The information on the maximum intensity radio wave receiver for each time zone determined by the determination unit 35b is stored in the maximum intensity radio wave receiver storage area 34c for each transmitter ID. Thereafter, the process proceeds to step S3.

  Next, in step S3, the estimation unit 35c uses the information of the maximum intensity radio wave receiver for each time zone stored in the maximum intensity radio wave receiver storage area 34c, and the mobile terminal 90 in the earliest determination target time zone. Is estimated based on the combination of the maximum intensity radio wave receivers in the time zone included in the determination target time zone. Since the method for estimating the position of the mobile terminal 90 has already been described, the description thereof is omitted here. The position of the mobile terminal 90 estimated by the estimation unit 35c is stored in the position estimation result storage area 34d in association with the determination target time zone for each transmitter ID. Thereafter, the process proceeds to step S4.

  In step S4, it is determined whether or not the estimation of the position of the mobile terminal 90 by the estimation unit 35c has been completed for all information stored in the maximum strength radio wave receiver storage area 34c, in other words, for all determination target time zones. Is done.

  If it is determined in step S4 that there is still a determination target time zone in which position estimation has not been estimated, the process returns to step S3, and the next determination target time of the determination target time zone in which position estimation was performed in the previous step S3 For the band, the position of the mobile terminal 90 is estimated by the estimation unit 35c.

  On the other hand, in step S4, it is determined that the estimation of the position of the mobile terminal 90 by the estimation unit 35c has been completed for all information stored in the maximum strength radio wave receiver storage area 34c, in other words, for all determination target time zones. Then, the position estimation process for the mobile terminal 90 ends. As a result of a series of processing, the time estimation information of the position of the mobile terminal 90 estimated by the estimation unit 35c is stored in the position estimation result storage area 34d.

(5) Features (5-1)
The position estimation system 100 according to the present embodiment includes at least three access points 20 (three access points 20A, 20B, and 20C in the specific example of FIG. 5) and a position estimation device 30. The access point 20 is an example of a radio wave receiver. The access points 20 are installed at different positions. The position estimation device 30 estimates the position of the mobile terminal 90 based on information on the strength of the radio waves of the mobile terminal 90 received by the access point 20. The portable terminal 90 is an example of a radio wave transmitter. The position estimation device 30 includes a determination unit 35b and an estimation unit 35c. The determination unit 35b performs access for each time zone based on the radio field strength information for each access point 20 and each time zone regarding the strength of the radio waves of the mobile terminal 90 received by each access point 20 in each of a plurality of time zones. One access point 20 that has received the maximum strength radio wave from the points 20 is determined as the maximum strength radio wave receiver. The estimation unit 35c determines the position of the mobile terminal 90 in the determination target time zone composed of two or more time zones (three time zones in the example described with reference to Table 1) as the maximum time zone included in the determination target time zone. Estimate based on the combination of strength radio receivers.

  Here, one access point 20 that has received the maximum strength radio wave for each time zone is determined as the maximum strength radio wave receiver, and in the determination target time zone according to the combination of the maximum strength radio wave receivers of a plurality of time zones. The position of the mobile terminal 90 is estimated. In other words, here, only information related to the access point 20 that has received the radio wave with the maximum intensity is used for position estimation. Therefore, compared with a position estimation system using a so-called RSSI method, TOA method, TDOA method, centroid method, etc. The accuracy can be kept high. Here, since the position of the portable terminal 90 is estimated based on the combination of the maximum intensity radio wave receivers in a plurality of time zones, if the portable terminal 90 exists at the position where the access point 20 that has simply communicated is installed. Compared to the estimation, the position of the portable terminal 90 can be estimated with a small number of access points 20 with high accuracy.

(5-2)
In the position estimation system 100 according to the present embodiment, the shortest distance D between the access points 20 in a plan view is obtained by calculating the predicted maximum movement speed V of the mobile terminal 90 and the time zone length (1 / n) × K. When divided by the product, the relationship between the shortest distance D and the length of the determination target time zone (1 / n) × K is set so that the value becomes 2 or more.

  Here, since the position of the mobile terminal 90 can be estimated while the mobile terminal 90 moves by the shortest distance D between the access points 20, it is easy to accurately estimate the position of the mobile terminal 90.

(5-3)
In the position estimation system 100 according to the present embodiment, the length (1 / n) × K × N of the determination target time zone is calculated by dividing the shortest distance D between the access points 20 in plan view by the maximum moving speed V. Is less than the length of time to be played.

  Here, since the position estimation of the mobile terminal 90 is performed at least once while the mobile terminal 90 moves by the shortest distance D between the access points 20, it is easy to accurately estimate the position of the mobile terminal 90. .

(5-4)
The position estimation system 100 according to the present embodiment includes an information generation unit 35a. The information generation unit 35a generates radio wave intensity information for each access point 20 and for each time zone. Based on the values related to the strength of the radio waves received from the mobile terminal 90 by each of the access points 20 at a plurality of time points within each time zone, the information generating unit 35a Generate information.

  Here, the radio wave intensity information for each time zone is generated based on the values related to the radio wave intensity at a plurality of time points within the time zone, so that it is easy to obtain radio wave intensity information with high reliability.

(5-5)
In the position estimation system 100 according to the present embodiment, the access point 20 includes a first access point 20 and a second access point 20. Only the first access point 20 and the second access point 20 are included in the combination of the maximum intensity radio wave receivers in the time zone included in the determination target time zone, and the first access point 20 and the second access point are included. When both of the points 20 are included, the estimation unit 35c estimates the position of the mobile terminal 90 when the mobile terminal 90 is present at an intermediate position between the first access point 20 and the second access point 20 in plan view. To do.

  To explain with a specific example, in the position estimation system 100 according to the present embodiment, as shown in FIG. 5, for example, the access point 20 includes an access point 20A (access point 20 with a receiver ID of A) and an access point 20B ( The access point 20) whose receiver ID is B is included. When the combination of the maximum intensity radio wave receivers in the time zone included in the determination target time zone includes only the access point 20A and the access point 20B and includes both the access point 20A and the access point 20B, the estimation unit 35c estimates the position of the mobile terminal 90 when the mobile terminal 90 is present at an intermediate position between the access point 20A and the access point 20B (position P4 in FIG. 5) in plan view.

  Here, since it is estimated that the mobile terminal 90 exists at an intermediate position between the first access point 20 and the second access point 20, the position of the first access point 20 or the second access point The position of the mobile terminal 90 can be estimated with higher accuracy than when the mobile terminal 90 is estimated only at the position 20.

(5-6)
Furthermore, in the position estimation system 100 according to the present embodiment, the access point 20 includes a third access point 20. Only the first access point 20, the second access point 20, and the third access point 20 are included in the combination of the maximum intensity radio wave receivers in the time zone included in the determination target time zone, and the first access point 20 In a case where all of the access point 20, the second access point 20, and the third access point 20 are included, the estimation unit 35c has the first access point 20, the second access point 20, and When the mobile terminal 90 is present at the center of gravity of the third access point 20, the position of the mobile terminal 90 is estimated.

  To explain with a specific example, in the position estimation system 100 according to the present embodiment, as shown in FIG. 5, for example, the access point 20 includes an access point 20C (receiver ID is C) in addition to the access point 20A and the access point 20B. Access point 20). Only the access point 20A, the access point 20B, and the access point 20C are included in the combination of the maximum strength radio wave receivers in the time zone included in the determination target time zone, and the access point 20A, the access point 20B, and the access point 20C are included. When the mobile terminal 90 is present at the center of gravity (position P7 in FIG. 5) of the access point 20A, the access point 20B, and the access point 20C in plan view, the estimation unit 35c Is estimated.

  Here, since it is estimated that the mobile terminal 90 exists at the center of gravity of the first to third access points 20, as compared with the case where only the mobile terminal 90 is estimated at the position of any access point 20. The position of the portable terminal 90 can be estimated with high accuracy.

(5-7)
In the position estimation system 100 according to the present embodiment, the mobile terminal 90 moves with a person.

  Here, by estimating the position of the mobile terminal 90, it is possible to grasp the flow line of the person.

(6) Modification Examples of the present embodiment are shown below. A plurality of modified examples may be combined within a consistent range.

(6-1) Modification A
In the above embodiment, the position estimation method by the estimation unit 35c has been described using FIG. 5 and FIG. 6 as an example when there are three access points 20 and three time zones included in the determination target time zone. However, the present invention is not limited to this.

  For example, even when there are four or more access points 20, if there are three time zones included in the determination target time zone, the estimation unit 35c determines the position of the mobile terminal 90 in the same manner as in the above embodiment. An estimation may be performed.

  Further, for example, when there are four or more access points 20 and there are four or more time zones included in one determination target time zone, the maximum intensity radio wave receiver in the time zone included in a certain determination target time zone If the combination includes only three or less access points 20 having different receiver IDs, the estimation unit 35c may estimate the position of the mobile terminal 90 in the same manner as in the above embodiment. On the other hand, when the combination of the maximum strength radio wave receivers in the time zone included in a certain determination target time zone includes four or more access points 20 having different receiver IDs, the estimation unit 35c receives the reception included in the combination. If the mobile terminal 90 exists at the center of gravity of the access point 20 having the machine ID, the position of the mobile terminal 90 may be estimated. However, in order to accurately estimate the position of the portable terminal 90, there are many access points 20 having different receiver IDs (for example, 5) in combination with the maximum intensity radio wave receivers in the time zone included in one determination target time zone. It is preferable that it is not included. The number N of time zones included in the determination target time zone is such that the combination of the maximum strength radio wave receivers in the time zone included in one determination target time zone does not include many access points 20 having different receiver IDs. The value is preferably determined.

  Further, for example, there are two time zones included in the determination target time zone, and there is only one access point 20 having a different receiver ID in the combination of the maximum strength radio wave receivers in the time zone included in a certain determination target time zone. If not included, the estimation unit 35c may estimate the position of the mobile terminal 90 when the mobile terminal 90 is present at the position of the access point 20 of the receiver ID in plan view. On the other hand, when the access point 20 having a different receiver ID is included in the combination of the maximum strength radio wave receivers in the time zone included in a certain determination target time zone, the estimation unit 35c displays the receivers in plan view. If the mobile terminal 90 exists at an intermediate position between the access points 20 having different IDs, the position of the mobile terminal 90 may be estimated.

(6-2) Modification B
In the above embodiment, the radio wave transmitter that is the position estimation target is the mobile terminal 90 such as a smartphone carried by a person, but is not limited to this. The radio wave transmitter may be, for example, a wireless tag carried by a person.

  Further, the radio wave transmitter does not have to be carried by a person, and may be, for example, a wireless tag attached to a cart or the like used by the person (moves with the person).

(6-3) Modification C
In the said embodiment, although the position estimation system 100 is installed in a commercial facility, it is not limited to this.

  For example, the position estimation system 100 may be a system that is installed in an office building, a hospital, a factory, a warehouse, or the like and estimates the position of a radio wave transmitter that is carried by a person acting in the facility. Moreover, the access point 20 does not need to be installed indoors, and may be installed outdoors.

(6-4) Modification D
In the above embodiment, the radio wave transmitter that is the position estimation target is the mobile terminal 90 such as a smartphone carried by a person, but is not limited to this. For example, the position estimation system 100 is installed in a commercial facility, office building, hospital, factory, warehouse, etc., and is a radio wave transmitter attached to an object that moves within the facility (for example, a container that moves within the facility). It may be a system for estimating the position.

(6-5) Modification E
In the above embodiment, the information generation unit 35a calculates the average value of the values related to the strength of the radio waves at a plurality of time points (reception times of radio waves) in each time zone for each time zone for each access point 20, and calculates this. Although stored in the radio wave intensity information storage area 34b as radio wave intensity information for each access point 20 and for each time zone, the present invention is not limited to this.

  For example, the information generation unit 35a replaces the average value of the radio wave intensity at a plurality of time points within each time zone with the maximum value and the mode value of the radio wave intensity at a plurality of time points within each time zone. Alternatively, an intermediate value, a weighted average value, and the like may be calculated and stored in the radio wave intensity information storage area 34b as radio wave intensity information for each time zone.

  When calculating the weighted average value, the information generation unit 35a may calculate the weighted average value by increasing the weight, for example, as the value related to the radio wave intensity at a later time in the time zone. For example, when calculating the weighted average value, the information generating unit 35a may calculate the weighted average value by increasing the weight as the value related to the intensity of the radio wave at the intermediate time point in the time zone.

  In addition, the information generation unit 35a calculates a moving average value of values related to the strength of radio waves at a plurality of times (including values related to the strength of radio waves at a plurality of times within the time zone) as the radio wave strength information for a certain time zone. However, this may be stored in the radio wave intensity information storage area 34b.

(6-6) Modification F
In the above embodiment, the position estimation device 30 includes the information generation unit 35a, but is not limited to this. For example, each access point 20 may have a functional unit corresponding to the information generating unit 35a. Then, each access point 20 calculates an average value of values related to radio wave intensity at a plurality of time points in each time zone by using this functional unit, and the position estimation device 30 uses the calculation result as radio wave intensity information. May be configured to transmit to.

(6-7) Modification G
In the said embodiment, although one access point 20 is attached adjacent to each of the some indoor unit 50 of the air conditioner installed in the ceiling of the space R of a commercial facility, it is limited to this. is not. The access point 20 may be installed independently of the indoor unit 50. In addition, the access point 20 may not be installed on the ceiling, but may be attached to a wall of the space R or equipment installed in the space R.

  In the above embodiment, the air conditioning communication line is also used as the communication line 40. However, the present invention is not limited to this, and a wired or wireless communication line 40 different from the air conditioning communication line is used. Also good.

(6-8) Modification H
In the above embodiment, the position estimation device 30 is installed in a facility where the access point 20 is installed, but is not limited to this. For example, the position estimation device 30 may be installed in a place different from the facility where the access point 20 is installed. Further, the position estimation device 30 may be a device that estimates the position of the mobile terminal 90 for a plurality of facilities where the access point 20 is installed.

(6-9) Modification I
In the embodiment described above, the mobile terminal 90 transmits radio waves a plurality of times within each time period, but is not limited to this. The portable terminal 90 may transmit radio waves only once within each time slot. In this case, the information generation unit 35a uses the value related to the strength of the radio wave received from the portable terminal 90 by each of the access points 20 for each time slot as the radio wave intensity information for the access point 20 for that time slot. do it.

(6-10) Modification J
In the above embodiment, all the mobile terminals 90 transmit radio waves the same number of times within each time period, but the present invention is not limited to this. The mobile terminal 90 may be configured to transmit radio waves a different number of times within each time period. In this case, it is preferable to set parameters relating to the position estimation of the mobile terminal 90 so that the relations of Expressions 1 and 2 are satisfied even if the radio wave transmission frequency of the mobile terminal 90 is different.

  The position estimation system according to the present invention is a system for estimating the position of a radio wave transmitter based on the radio wave of the radio wave transmitter received by the radio wave receiver, wherein the number of radio wave receivers is suppressed, This is useful as a position estimation system that can accurately estimate the position.

20 Access point (radio wave receiver)
20A access point (first radio receiver)
20B access point (second radio receiver)
20C access point (third radio receiver)
30 position estimation device 35a information generation unit 35b determination unit 35c estimation unit 90 portable terminal (radio wave transmitter)
100 Position estimation system

International Publication Number WO2005 / 111880

Claims (7)

At least three radio wave receivers (20) each installed at a different position;
A position estimation device (30) for estimating the position of the radio wave transmitter based on information on the intensity of the radio wave of the radio wave transmitter (90) received by the radio wave receiver;
A position estimation system comprising:
The position estimation device includes:
Based on the radio wave intensity information for each radio wave receiver and for each time zone regarding the strength of the radio wave of the radio wave transmitter received by each radio wave receiver in each of a plurality of time zones, for each time zone, A determination unit (35b) that determines one of the radio wave receivers that has received a radio wave of the maximum intensity from the radio wave receivers as the maximum intensity radio wave receiver;
An estimation unit (35c) that estimates a position of the radio wave transmitter in a determination target time zone including two or more time zones based on a combination of the maximum strength radio wave receivers in the time zone included in the determination target time zone. ) And
Position estimation system (100). When the shortest distance between the radio wave receivers in a plan view is divided by the product of the predicted maximum moving speed of the radio wave transmitter and the length of the time zone, the value is 2 or more. A relationship between the shortest distance and the length of the time zone is set.
The position estimation system according to claim 1. The length of the determination target time zone is equal to or less than the length of time calculated by dividing the shortest distance by the maximum moving speed.
The position estimation system according to claim 2. An information generator (35a) for generating the radio wave intensity information for each radio wave receiver and for each time zone;
Further comprising
The information generating unit is configured to detect the radio wave receiver in the time zone based on values related to the strength of radio waves received from the radio wave transmitter by the radio wave receivers at a plurality of time points in the time zones. Generating the signal strength information of
The position estimation system according to any one of claims 1 to 3. The radio wave receiver includes a first radio wave receiver (20A) and a second radio wave receiver (20B),
Only the first radio wave receiver and the second radio wave receiver are included in the combination of the maximum intensity radio wave receivers in the time zone included in the determination target time zone, and the first radio wave receiver and the If both of the second radio receivers are included,
The estimation unit estimates a position of the radio wave transmitter when the radio wave transmitter is present at an intermediate position between the first radio wave receiver and the second radio wave receiver in a plan view.
The position estimation system according to any one of claims 1 to 4. The radio wave receiver further includes a third radio wave receiver (20C),
Only the first radio wave receiver, the second radio wave receiver, and the third radio wave receiver are included in the combination of the maximum intensity radio wave receivers in the time zone included in the determination target time zone, and When all of the first radio wave receiver, the second radio wave receiver, and the third radio wave receiver are included,
The estimation unit estimates the position of the radio wave transmitter when the radio wave transmitter is present at the center of gravity of the first radio wave receiver, the second radio wave receiver, and the third radio wave receiver in plan view. To
The position estimation system according to claim 5. The radio wave transmitter moves with a person.
The position estimation system according to any one of claims 1 to 6.

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