JP2006329688A - Position detection method, position detection system, position detection program and computer-readable recording medium recorded with the program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology capable of precisely detecting the position of a radio transmitter, even when the radio wave propagation environment for the position detection area wherein the radio-wave transmitter moves, at the time the coefficient used for position detection of the radio transmitter is recalculated for the constitution with high-accuracy detection of the position of the transmitter, corresponding to the environment in which the radio transmitter is moving. <P>SOLUTION: The position detection method is constituted such that the detection area is divided into a plurality of sub-areas, and the calculation of each coefficient used in the position detection of the radio wave transmitter is performed, with each sub-area taken as a unit. Thereby, when the radio wave propagation environment is different in the area of the position detection, the position detection of the radio transmitter can be calculated with errors smaller than those in the conventional technology, in which the position detection is performed by calculating the coefficients of the objective area taken as a unit area. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a position detection method and system for detecting the position of a radio transmitter attached to a product, a position detection program used for realizing the position detection method, and a computer-readable recording medium on which the program is recorded. And about.

  In the patent document 1 shown below, the present applicant obtains an environment-dependent radio wave propagation coefficient based on the received electric field strength of the active wireless tag, and based on this, detects the position of the active wireless tag with high accuracy. Disclosed.

  In the present invention, a plurality of base station receivers that do not move and a plurality of reference transmitters that do not move are arranged in the area where the wireless transmitter to be detected moves.

  Then, before entering the actual detection process, based on the radio wave intensity transmitted by the reference transmitters received by the base station receivers, the propagation coefficient of the radio waves in the environment of the area, The reception correction coefficient of the station receiver is obtained.

Then, when entering the detection process of the position of the detection target wireless transmitter, the propagation coefficient and the reception correction coefficient obtained in this way and the base station receiver received by the detection target wireless transmitter Based on the radio field intensity, the position of the detection target wireless transmitter and the correction coefficient of the wireless transmitter are detected.
JP 2002-236166 A

  In the invention disclosed in Patent Document 1 by the present applicant, the coefficients used for detecting the position of the wireless transmitter (the propagation coefficient of the radio wave and the reception correction coefficient of the base station receiver) are set according to the environment in which the wireless transmitter moves. Recalculation makes it possible to detect the position with high accuracy and less error.

  However, this conventional technique includes a problem that the position detection error may increase when the environment of the position detection target area is not uniform.

  For example, in two areas in the position detection target area, in an environment where there are no obstacles in one area and obstacles are relatively distributed in the other area, In an environment where the height of the ceiling is different, it is considered that the propagation environment of radio waves in each region is greatly different.

  However, in the conventional technique, since the position detection calculation of the entire position detection target area is performed using a single coefficient, there is a possibility that the position detection accuracy may be lowered when the conventional technique is applied to such an environment. .

  In particular, as for the propagation factor of radio waves, it is known from calculation that the position detection result is different by several meters only by the difference of the first decimal place, and the position detection result is very sensitive. It is.

  From this, even if the radio wave propagation environment is a substantially uniform position target detection area, the position detection accuracy may be lowered if the environment in the area differs for each installation area of the base station receiver.

  Also, even in a position detection target area where the radio wave propagation environment is uniform, if the number of base station receivers to be installed becomes very large due to the large area, the calculation is performed to calculate these coefficients. In the calculation of optimization, since the number of unknowns becomes enormous, there is a big problem in terms of convergence of the optimization calculation.

  The present invention has been made in view of such circumstances, and makes it possible to detect the position of the wireless transmitter with high accuracy even when the radio wave propagation environment of the position detection target area to which the wireless transmitter moves is not uniform. In addition, even if the number of base station receivers to be installed for the position detection increases, the calculation of coefficients used for position detection can be easily performed without degrading the convergence of the optimization calculation. Aims to provide new technology.

  In order to achieve this object, the position detection system of the present invention has a function of transmitting its own identification number by radio wave, and a plurality of references whose installation positions for transmitting its own identification number by radio wave are known. A transmitter that moves in an area that includes a transmitter for use and a plurality of base stations whose installation positions for receiving the radio waves are known, and (1) sets a plurality of subareas, Setting means for setting which subarea each base station belongs to, (2) For each of the subareas set by the setting means, the radio wave transmitted by the reference transmitter received by the base station belonging to the subarea Determining means for determining a parameter defining the strength of the radio wave received by the base station using the intensity and the distance between the reference transmitter and (3) the parameter determined by the determining means and the parameter Estimate the distance between the base station and the transmitter to be detected using the strength of the radio wave transmitted by the transmitter to be detected received by the base station belonging to the subarea, and based on the estimated distance And a detecting means for detecting the position of the detection target transmitter.

  The position detection method of the present invention realized by the operation of each processing means described above can also be realized by a computer program, which is provided by being recorded on a suitable computer-readable recording medium, The present invention is realized by being provided via a network, installed when executing the present invention, and operating on a control means such as a CPU.

  In the position detection system of the present invention configured as described above, a plurality of subareas are set and the subarea to which each base station belongs is set before the detection of the position of the transmitter to be detected is started. To do. Then, for each of the set subareas, the base station using the intensity of the radio wave transmitted by the reference transmitter received by the base station belonging to the subarea and the distance between the reference transmitter The parameter which prescribes | regulates about the intensity | strength of the electromagnetic wave received by is determined.

For example, the intensity of the radio wave transmitted by the reference transmitter i received by the base station j belonging to the sub-area K is e [i, j], and the base station j belonging to the sub-area K and the reference transmitter i Is represented by d [i, j], the propagation coefficient of the subarea K is represented by S [K], and the reception correction coefficient of the base station j belonging to the subarea K is represented by Kr [j]. By calculating S [K] and Kr [j] so that the value of the evaluation function q _K expressed is minimized, the propagation coefficient S [K] of the subarea K and the base station j belonging to the subarea K are determined. A reception correction coefficient Kr [j] is determined.

  Here, the meaning of Equation 1 assumes that the radio wave is attenuated and propagated by the logarithm of distance, and under this assumption, the received radio wave intensity e [i, j] in the entire area is the propagation form. S [K] and Kr [j] that are most suitable for the sub-area K, and the reception correction coefficient Kr [j] of the base station j belonging to the sub-area K Is to decide.

  In this way, when subareas are set and parameters are determined for each of the subareas, the position of the transmitter to be detected can be detected.

  From now on, in the position detection system of the present invention, when the detection of the position of the transmitter to be detected is entered, the detection target transmission received by the base station belonging to the parameter set in subarea and the subarea having the parameter. The distance between the base station and the detection target transmitter is estimated using the intensity of the radio wave transmitted by the machine, and the position of the detection target transmitter is detected based on the estimated distance.

For example, the intensity of the radio wave transmitted by the detection target transmitter l received by the base station j belonging to the subarea K is e [l, j], the propagation coefficient of the subarea K is S [K], and the substation K belongs to the subarea K. The reception correction coefficient of base station j is Kr [j], the correction coefficient of detection target transmitter l is Kt [l], the position coordinates of base station j belonging to subarea K are (x _j, y _j ), and detection target transmission If the position coordinates of the machine l are represented by (x _l, y _l ), the estimated distance m [l, j between the base station j belonging to the subarea K and the detection target transmitter l according to the following equation 2. ] Is calculated.

Subsequently, using these estimated distances m [l, j], for example, (x _l, y _l ) and Kt [l so that the value of the evaluation function h _l represented by the following Expression 3 is minimized. ] Is detected to detect the position coordinates (x _l, y _l ) of the transmitter ₁ to be detected.

Here, Expression 2 is described in Expression 1 except for the correction coefficient Kt [l] of the detection target transmitter l.
Received signal strength ≡ S [K] x log ₁₀ (d [i, j]) + Kr [j]
Is represented in the form of an exponential function, and as can be seen, m [l, j] is a base station j belonging to subarea K estimated using the received radio wave intensity and a transmitter to be detected. This corresponds to the distance between l.

From this point of view, Equation 3 means that the distance m [l, j] estimated using the received radio wave intensity is most consistently realized when viewed from the entire area. _l, by obtaining the y _l), it is to detect the position coordinates of the detection target transmitter l a (x _l, y _l).

  As described above, according to the present invention, the position of the wireless transmitter is detected with high accuracy by recalculating the coefficient used for the position detection of the wireless transmitter according to the environment in which the wireless transmitter moves. When the configuration is adopted, the position detection target area is divided into a plurality of subareas, and the calculation of these coefficients is performed in units of subareas. When there is a difference in the propagation environment, the position of the wireless transmitter can be determined with a smaller error than the conventional technology that employs a configuration in which the position detection target area is a single area and the coefficient is calculated to calculate the position estimation. Can be detected.

  In particular, it is possible to calculate a coefficient used for position detection of a wireless transmitter for each base station receiver by dividing each base station receiver installed in the position detection target area into sub-areas. Thus, even when the environment in the position detection target area is different for each installation area of the base station receiver, the position of the wireless transmitter can be detected with high accuracy.

  And even when the number of base station receivers installed in the position detection target area increases, the number of unknowns can be suppressed by dividing the calculation unit of the coefficient used for the position detection of the wireless transmitter for each sub-area. As a result, calculation of coefficients used for position detection can be easily performed without degrading the convergence of the optimization calculation.

  Hereinafter, the present invention will be described in detail according to embodiments.

  FIG. 1 illustrates a system configuration of a position detection system to which the present invention is applied.

  In the figure, 1 is a position detection target area, 10 to 17 are base station receivers whose installation positions are known in the position detection target area 1, and 20 to 30 are installation positions known in the position detection target area 1. Reference transmitter 40, 40 is a detection target transmitter that moves in the position detection target area 1, 100 is a position detection device of the present invention that performs processing to detect the position of the detection target transmitter 40, and 200 is a base station receiver 10 to 17 and a local area network that connects the position detection apparatus 100.

  The reference transmitters 20 to 30 modulate the identification number of the own device with radio waves of the assigned frequency and transmit the modulated wirelessly.

  The detection target transmitter 40 is a position detection target, and modulates its own identification number with a radio wave of the allocated frequency and transmits it wirelessly. Here, there may be a plurality of detection target transmitters 40, but in this figure, it is assumed that there is only one for convenience of explanation.

  The base station receivers 10 to 17 receive the radio waves transmitted from the reference transmitters 20 to 30 before entering the position detection process of the detection target transmitter 40, and which of the reference transmitters has transmitted the radio waves. Information on the received intensity of the radio wave, the ID of the receiver itself, and the reference transmitter ID as the decoding result (e [i, j shown in the figure) ]). Then, when the position detection process of the detection target transmitter 40 is started, the radio wave transmitted by the detection target transmitter 40 is received, and the detection target transmitter that has transmitted the radio wave is decoded, and the position detection device 100 is notified of information (e [l, j] shown in the figure) regarding the reception intensity of the radio wave, the ID of the receiver itself, and the detection target transmitter ID that is the decoding result.

  Here, the base station receivers 10 to 17 add e [i, j] and e [l, j] to e [i, j] and e [l, j] to be notified in this notification. However, the reception time information may be added on the position detection apparatus 100 side.

  The position detection apparatus 100 of the present invention receives e [i, j] and e [l, j] notified from the base station receivers 10 to 17 as inputs, and in the position detection target area 1 based on the information. The position of the detection target transmitter 40 that moves is detected.

  FIG. 2 illustrates an example of a device configuration of the position detection device 100 of the present invention.

  As shown in this figure, the position detection apparatus 100 of the present invention includes a base station receiver information storage unit 101, a reference transmitter information storage unit 102, a subarea configuration information setting unit 103, and a subarea configuration information storage. Unit 104, radio wave reception information collection unit 105, switching unit 106, preprocessing reception information storage unit 107, detection reception information storage unit 108, propagation coefficient / reception correction coefficient calculation unit 109, propagation coefficient / A reception correction coefficient storage unit 110 and a position detection unit 111 are provided.

As shown in FIG. 3, the base station receiver information storage unit 101 manages the locations of the base station receivers 10 to 17 as shown in FIG. Stores the coordinates (x _j, y _j ) of the installation position.

The reference transmitter information storage unit 102 manages each reference transmitter 20 to 30 as shown in FIG. 4 in order to manage where the reference transmitters 20 to 30 are installed. Stores the coordinates (x _i, y _i ) of the installation position.

  Subarea configuration information setting section 103 sets a plurality of subareas and sets which subarea each base station receiver 10 to 17 belongs to.

  The sub-area configuration information storage unit 104 stores information related to the sub-area set by the sub-area configuration information setting unit 103.

  For example, as shown in FIG. 5 (a), the subarea configuration information setting unit 103 includes subarea 1 composed of base station receivers 10 to 13, and subarea 2 composed of base station receivers 14 to 17. Are set, the sub-area configuration information storage unit 104 has two sub-areas having sub-area number 1 and sub-area number 2 as shown in FIG. Of the base station receivers 10 to 17, information that the base station receivers 10 to 13 belong to the subarea of subarea number 1 and the base station receivers 14 to 17 belong to the subarea of subarea number 2 Store it.

  Also, for example, as shown in FIG. 5B, the subarea configuration information setting unit 103 sets eight subareas 1 to 8 (SA1 to 8 shown in the figure) for each base station receiver 10 to 17. In this case, the sub-area configuration information storage unit 104 has eight sub-areas having sub-area numbers 1 to 8 as shown in FIG. 17, the base station receiver 10 belongs to the subarea of subarea number 1, the base station receiver 11 belongs to the subarea of subarea number 2, and the base station receiver 12 belongs to the subarea of subarea number 3. The base station receiver 13 belongs to the subarea of subarea number 4, the base station receiver 14 belongs to the subarea of subarea number 5, the base station receiver 15 belongs to the subarea of subarea number 6, The base station receiver 16 is Belongs to the sub-area number 7, the base station receiver 17 is to store the information that belongs to a sub-area of the sub-area number 8.

  The radio wave reception information collecting unit 105 collects e [i, j] and e [l, j] notified from the base station receivers 10 to 17.

  In the mode before entering the position detection process of the detection target transmitter 40, the switching unit 106 collects e [i, j] from the base station receivers 10 to 17 because the radio wave reception information collection unit 105 collects e [i, j]. E [i, j] is stored in the preprocessing reception information storage unit 107. In the mode in which the detection target transmitter 40 is in the position detection process, the radio wave reception information collecting unit 105 collects e [l, j] from the base station receivers 10 to 17, and the collected e [ l, j] is stored in the reception information storage unit 108 for detection.

  The propagation coefficient / reception correction coefficient calculation unit 109 stores information stored in the base station receiver information storage unit 101, information stored in the reference transmitter information storage unit 102, and sub-area configuration information storage unit 104. Based on the received information and e [i, j] stored in the preprocessing reception information storage unit 107, the propagation coefficient of the subarea (the propagation coefficient S [K] described above) and the bases belonging to the subarea The reception correction coefficient of the station receiver (the reception correction coefficient Kr [j] described above) is calculated.

  The propagation coefficient / reception correction coefficient storage unit 110 stores the propagation coefficient and the reception correction coefficient calculated by the propagation coefficient / reception correction coefficient calculation unit 109.

  For example, as shown in FIG. 5 (a), the subarea configuration information setting unit 103 includes subarea 1 composed of base station receivers 10 to 13, and subarea 2 composed of base station receivers 14 to 17. Is set, the propagation coefficient / reception correction coefficient storage unit 110, as shown in FIG. 7A, has the propagation coefficient of the subarea of subarea number 1 as S [1], The reception correction coefficients of the base station receivers 10 to 13 to which it belongs are Kr [10], Kr [11], Kr [12] and Kr [13], respectively, and the propagation coefficient of the subarea of subarea number 2 is S [2 ], It is stored that the reception correction coefficients of the base station receivers 14 to 17 belonging to the subarea are Kr [14], Kr [15], Kr [16], and Kr [17], respectively.

  Also, for example, as shown in FIG. 5B, when the sub-area configuration information setting unit 103 sets eight sub-areas 1 to 8 for each base station receiver 10 to 17, the propagation coefficient / reception As shown in FIG. 7B, the correction coefficient storage unit 110 has the propagation coefficient S [1] of the subarea of subarea number 1 and the reception correction coefficient of the base station receiver 10 belonging to the subarea is Kr. [10], the propagation coefficient of the subarea of subarea number 2 is S [2], the reception correction coefficient of the base station receiver 11 belonging to the subarea is Kr [11], and the subarea number 3 The propagation coefficient of the subarea is S [3], the reception correction coefficient of the base station receiver 12 belonging to the subarea is Kr [12], and the propagation coefficient of the subarea of subarea number 4 is S [4]. The reception correction coefficient of the base station receiver 13 belonging to the subarea is Kr [13]. , The propagation coefficient of the subarea of subarea number 5 is S [5], the reception correction coefficient of the base station receiver 14 belonging to the subarea is Kr [14], and the propagation coefficient of the subarea of subarea number 6 is Is S [6], the reception correction coefficient of the base station receiver 15 belonging to the subarea is Kr [15], and the propagation coefficient of the subarea of subarea number 7 is S [7]. The reception correction coefficient of the base station receiver 16 to which it belongs is Kr [16], the propagation coefficient of the subarea of subarea number 8 is S [8], and the reception correction coefficient of the base station receiver 17 belonging to that subarea is The fact that it is Kr [17] is stored.

  The position detection unit 111 includes information stored in the base station receiver information storage unit 101, information stored in the subarea configuration information storage unit 104, and information stored in the propagation coefficient / reception correction coefficient storage unit 110. Based on e [l, j] stored in the detection reception information storage unit 108, the position of the detection target transmitter 40 and the correction coefficient of the detection target transmitter 40 (the correction coefficient Kt [l] described above) ) Is detected to detect the position of the detection target transmitter 40.

  FIG. 8 illustrates an example of a processing flow executed by the propagation coefficient / reception correction coefficient calculation unit 109, and FIG. 9 illustrates an example of a processing flow executed by the position detection unit 111.

  Next, according to these processing flows, processing executed by the position detection device 100 of the present invention configured as described above will be described in detail.

  First, processing executed by the propagation coefficient / reception correction coefficient calculation unit 109 will be described according to the processing flow of FIG. Here, although not described below, the propagation coefficient / reception correction coefficient calculation unit 109 performs processing using the received radio wave intensity e [i, j] received by the base station receivers 10 to 17 at approximately the same time. Will do.

  When the propagation coefficient / reception correction coefficient calculation unit 109 is activated by a request for calculating the propagation coefficient and the reception correction coefficient before entering the position detection process of the detection target transmitter 40, the process flow shown in FIG. As described above, first, in step 10, the initial value “1” is set to the variable K indicating the subarea number.

  Subsequently, in step 11, when it is determined whether or not the value of the variable K exceeds the maximum value Kmax of the subarea number, and when it is determined that the value of the variable K does not exceed the maximum value Kmax, step 12 Then, the base station receiver j belonging to the subarea indicated by the subarea number K (hereinafter referred to as subarea K) is specified by referring to the subarea configuration information storage unit 104.

Subsequently, in step 13, for the subarea K, the distance d [i, j] between each base station receiver j belonging to the subarea K and each reference transmitter i.
d [i, j] = ((x _i -x _j ) ² + (y _i -y _j ) ² ) ^1/2
Is calculated.

That is, by referring to the base station receiver information storage unit 101, the installation positions (x _j, y _j ) of each base station receiver j identified in step 12 are acquired, and their installation positions (x _j, y _j ) and the installation position (x _i, y _i ) of each reference transmitter i read from the reference transmitter information storage unit 102 and each base station receiver j belonging to the subarea K and each reference The distance d [i, j] with the transmitter i is calculated.

  Subsequently, in step 14, for the subarea K, reception of radio waves transmitted by the reference transmitters i received by the base station receivers j belonging to the subarea K from the preprocessing reception information storage unit 107. Read the intensity e [i, j].

Subsequently, in step 15, using the distance d [i, j] calculated in step 13 and the received radio wave intensity e [i, j] read in step 14 for subarea K, the quasi-Newton method or the steepest descent The propagation coefficient S [K] of the subarea K is obtained by obtaining S [K] and Kr [j] so that the value of the evaluation function q _K represented by Equation 1 is minimized according to a known algorithm such as the method. And the reception correction coefficient Kr [j] of each base station receiver j belonging to the subarea K is calculated.

  Subsequently, in step 16, the calculated propagation coefficient S [K] and reception correction coefficient Kr [j] are stored in the propagation coefficient / reception correction coefficient storage unit 110, and in step 17, one value of the variable K is set. After incrementing, the process returns to step 11.

  Then, when it is determined in step 11 that the value of the variable K has exceeded the maximum value Kmax by repeating the processing in steps 11 to 17, the processing is terminated.

  In this way, the propagation coefficient / reception correction coefficient calculation unit 109 calculates the propagation coefficient S [K] of the subarea K and the subarea for each subarea K before entering the position detection process of the detection target transmitter 40. The reception correction coefficient Kr [j] of the base station receiver j belonging to K is calculated and processed so as to be stored in the propagation coefficient / reception correction coefficient storage unit 110.

  Next, processing executed by the position detection unit 111 will be described according to the processing flow of FIG. Here, although not described below, the position detection unit 111 performs processing using the received radio wave intensity e [l, j] received by the base station receivers 10 to 17 at substantially the same time. .

  When there is a request for detecting the position of the detection target transmitter l by designating the transmitter number l of the detection target transmitter, the position detection unit 111 first starts at step 20 as shown in the processing flow of FIG. The transmitter number l is received.

  Subsequently, in step 21, an initial value “1” is set in a variable K indicating a subarea number.

  Subsequently, at step 22, when it is determined whether or not the value of the variable K exceeds the maximum value Kmax of the subarea number, and when it is determined that the value of the variable K does not exceed the maximum value Kmax, step 23 Then, the sub-area configuration information storage unit 104 is referred to, and the base station receiver j belonging to the sub-area (sub-area K) indicated by the sub-area number K is specified.

  Subsequently, in step 24, for the subarea K, the propagation coefficient S [K] of the subarea K and the reception of each base station receiver j belonging to the subarea K are received from the propagation coefficient / reception correction coefficient storage unit 110. Read out the correction coefficient Kr [j].

  Subsequently, in step 25, for the subarea K, the reception intensity e of the radio wave transmitted by the detection target transmitter l received by each base station receiver j belonging to the subarea K from the detection reception information storage unit 108. Read [l, j].

  Subsequently, in step 26, the propagation coefficient S [K] and the reception correction coefficient Kr [j] read in step 24 and the received radio wave intensity e [l, j] read in step 25 are used for the subarea K. After calculating the estimated distance m [l, j] (estimated distance between each base station receiver j belonging to the subarea K and the detection target transmitter l) expressed by Equation 2, the process returns to step 22. .

  Here, since the estimated distance m [l, j] includes the correction coefficient Kt [l] of the detection target transmitter l which is an unknown number, the calculation process performed in step 26 is specifically performed by the equation The process of substituting the propagation coefficient S [K] / reception correction coefficient Kr [j] / reception radio wave intensity e [l, j] for the estimated distance m [l, j] expressed in FIG. Become.

In this way, when it is determined in step 22 that the value of the variable K has exceeded the maximum value Kmax by repeating the processing of step 22 to step 26, the process proceeds to step 27 where the base station receiver By referring to the information storage unit 101, the installation position (x _j, y _j ) of each base station receiver j identified in step 23 is acquired, and the installation position (x _j, y _j ) and step 26 are obtained. Using the estimated distance m [l, j] calculated in step (1), the value of the evaluation function h ₁ represented by Equation 3 is minimized (x _l according to a known algorithm such as the quasi-Newton method or the steepest descent method). _, y _l ) and Kt [l], the position coordinates (x _l, y _l ) of the detection target transmitter l and the correction coefficient Kt [l] of the detection target transmitter l are calculated and detected thereby. The position coordinate (x _l, y _l ) of the target transmitter l is detected.

Subsequently, in step 28, the detected position coordinates (x _l, y _l ) of the detection target transmitter _l are output, and the process is terminated.

In this way, the position detection unit 111 designates the transmitter number l of the detection target transmitter and when there is a detection request for the position of the detection target transmitter, the propagation coefficient S [K] calculated for each subarea K. Then, using the reception correction coefficient Kr [j], processing is performed so as to detect the position coordinates (x _l, y _l ) of the detection target transmitter l.

According to this configuration, according to the position detection apparatus 100 of the present invention, when there is a difference in the radio wave propagation environment in the position detection target area 1, the position detection target area 1 is used as a single area to calculate a coefficient and estimate the position. Compared with the prior art that employs a configuration in which the calculation of is performed, the position coordinates (x _l, y _l ) of the detection target transmitter l can be detected with a smaller error.

  Next, as shown in FIG. 5A, the sub-area configuration information setting unit 103 includes a sub-area 1 composed of base station receivers 10 to 13 and a sub-area composed of base station receivers 14 to 17. A specific process when two subareas called area 2 are set will be described.

The propagation coefficient / reception correction coefficient calculation unit 109 executes the processing flow of FIG. 8 so that the value of the evaluation function q ₁ represented by the following expression 4 is minimized for the subarea 1 S [ 1] and Kr [j], the propagation coefficient S [1] of the subarea 1, the reception correction coefficient Kr [10] of the base station receiver 10 belonging to the subarea 1, and the bases belonging to the subarea 1 are obtained. The reception correction coefficient Kr [11] of the station receiver 11, the reception correction coefficient Kr [12] of the base station receiver 12 belonging to subarea 1, and the reception correction coefficient Kr [of the base station receiver 13 belonging to subarea 1 13] is calculated.

Then, for subarea 2, S [2] and Kr [j] are obtained so that the value of the evaluation function q ₂ represented by the following expression 5 is minimized, so that the propagation coefficient S [ 2], the reception correction coefficient Kr [14] of the base station receiver 14 belonging to the subarea 2, the reception correction coefficient Kr [15] of the base station receiver 15 belonging to the subarea 2, and the bases belonging to the subarea 2 The reception correction coefficient Kr [16] of the station receiver 16 and the reception correction coefficient Kr [17] of the base station receiver 17 belonging to the subarea 2 are calculated.

  In response to S [K] and Kr [j] calculated in this way, the position detection unit 111 first executes the processing flow of FIG. 6, the estimated distance m [40,10] between the base station receiver 10 belonging to the subarea 1 and the detection target transmitter 40 is calculated, and the base station receiver 11 belonging to the subarea 1 and the detection target transmitter are calculated. 40, an estimated distance m [40,11] between the base station receiver 12 belonging to the subarea 1 and the detection target transmitter 40 is calculated, The estimated distance m [40,13] between the base station receiver 13 belonging to area 1 and the detection target transmitter 40 is calculated.

  Then, the estimated distance m [40,14] between the base station receiver 14 belonging to the subarea 2 and the detection target transmitter 40 is calculated for the subarea 2 according to the following equation (7). An estimated distance m [40,15] between the base station receiver 15 and the detection target transmitter 40 belonging to the substation 2 is calculated, and the estimated distance between the base station receiver 16 belonging to the subarea 2 and the detection target transmitter 40 is calculated. m [40,16] is calculated, and an estimated distance m [40,17] between the base station receiver 17 belonging to the sub-area 2 and the detection target transmitter 40 is calculated.

Next, the position detection unit 111 and the position coordinates (x ₄₀ , y ₄₀ ) of the detection target transmitter ₄₀ and the detection target transmission so that the value of the evaluation function h ₄₀ expressed by the following Expression 8 is minimized. By calculating the correction coefficient Kt [40] of the machine 40, the position coordinates (x ₄₀ , y ₄₀ ) of the detection target transmitter ₄₀ are detected.

  Next, a specific process when the subarea configuration information setting unit 103 sets eight subareas 1 to 8 for each base station receiver 10 to 17 as shown in FIG. 5B will be described. To do. Hereinafter, the base station receiver belonging to the sub-area K is represented by the base station receiver K.

The propagation coefficient / reception correction coefficient calculation unit 109 executes the processing flow of FIG. 8, and thereby evaluates the evaluation function q represented by the following Expression 9 for each of the eight subareas K (K = 1 to 8). _By obtaining S [K] and Kr [K] so that the value of _K is minimized, the propagation coefficient S [K] of each subarea K and the reception correction of the base station receiver K belonging to each subarea K are obtained. The coefficient Kr [K] is calculated.

  In response to S [K] and Kr [K] calculated in this way, the position detection unit 111 first executes the processing flow of FIG. 9 to first start with eight subareas K (K = 1). For each of ˜8), the estimated distance m [40, K] between the base station receiver K and the detection target transmitter 40 is calculated according to the following equation 10.

Subsequently, the position detection unit 111 and the position coordinates (x ₄₀ , y ₄₀ ) of the detection target transmitter ₄₀ and the detection target transmission so that the value of the evaluation function h ₄₀ represented by the following expression 11 is minimized. By calculating the correction coefficient Kt [40] of the machine 40, the position coordinates (x ₄₀ , y ₄₀ ) of the detection target transmitter ₄₀ are detected.

It is a system configuration diagram of a position detection system to which the present invention is applied. It is a figure which shows an example of an apparatus structure of the position detection apparatus of this invention. It is explanatory drawing of the information which a base station receiver information storage part stores. It is explanatory drawing of the information which the transmitter information storage part for a reference stores. It is explanatory drawing of the information which a subarea structure information setting part sets. It is explanatory drawing of the information which a subarea structure information storage part stores. It is explanatory drawing of the information which a propagation coefficient and reception correction coefficient storage part stores. It is a processing flow which a propagation coefficient and reception correction coefficient calculation part performs. It is a processing flow which a position detection part performs.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Position detection apparatus 101 Base station receiver information storage part 102 Reference transmitter information storage part 103 Subarea configuration information setting part 104 Subarea configuration information storage part 105 Radio wave reception information collecting part 106 Switching part 107 Preprocessing reception information storage Unit 108 reception information storage unit for detection 109 propagation coefficient / reception correction coefficient calculation unit 110 propagation coefficient / reception correction coefficient storage unit 111 position detection unit

Claims (7)

A plurality of reference transmitters having a function of transmitting their own identification numbers by radio waves and having known installation positions for transmitting their own identification numbers by radio waves, and a plurality of known installation positions for receiving the radio waves. A position detection method for detecting a transmitter that moves in an area including a base station,
Configuring multiple subareas and setting which subarea each base station belongs to;
For each of the sub-areas, it is received by the base station using the strength of the radio wave transmitted by the reference transmitter received by the base station belonging to the sub-area and the distance between the reference transmitters. The process of determining the parameters governing the strength of
The distance between the base station and the detection target transmitter is estimated using the parameter and the intensity of the radio wave transmitted by the detection target transmitter received by the base station belonging to the subarea having the parameter. And a step of detecting the position of the transmitter to be detected based on the estimated distance,
A characteristic position detection method. The position detection method according to claim 1,
In the determining process, as the parameters, determining a propagation coefficient specific to the subarea and a reception correction coefficient specific to a base station belonging to the subarea,
A characteristic position detection method. The position detection method according to claim 2,
In the determining process, the intensity of the radio wave transmitted by the reference transmitter i received by the base station j belonging to the subarea K is e [i, j], and the base station j belonging to the subarea K and the reference transmitter are transmitted. If the distance to i is represented by d [i, j], the propagation coefficient of subarea K is represented by S [K], and the reception correction coefficient of base station j belonging to subarea K is represented by Kr [j],

By calculating S [K] and Kr [j] so that the value of the evaluation function q _K expressed by the following formula is minimized, the propagation coefficient S [K] of the subarea K and the base stations belonging to the subarea K determining the reception correction coefficient Kr [j] for j,
A characteristic position detection method. The position detection method according to claim 2,
In the detecting process, the intensity of the radio wave transmitted by the detection target transmitter l received by the base station j belonging to the subarea K is e [l, j], the propagation coefficient of the subarea K is S [K], The reception correction coefficient of the base station j belonging to the area K is Kr [j], the correction coefficient of the detection target transmitter l is Kt [l], and the position coordinates of the base station j belonging to the subarea K are (x _j, y _j ). If the position coordinates of the transmitter 1 to be detected are represented by (x _l, y _l ),

To calculate the estimated distance m [l, j] between the base station j belonging to the sub-area K and the detection target transmitter l,

(X _l, y _l ) and Kt [l] are calculated so that the value of the evaluation function h _l expressed by the following _formula is minimized, thereby obtaining the position coordinates (x _l, y _l ) of the detection target transmitter l. To detect,
A characteristic position detection method. A plurality of reference transmitters having a function of transmitting their own identification numbers by radio waves and having known installation positions for transmitting their own identification numbers by radio waves, and a plurality of known installation positions for receiving the radio waves. A position detection system for detecting a transmitter that moves in an area including a base station,
Setting means for setting a plurality of subareas and setting which subarea each base station belongs to;
For each of the sub-areas, it is received by the base station using the strength of the radio wave transmitted by the reference transmitter received by the base station belonging to the sub-area and the distance between the reference transmitters. A determination means for determining a parameter that regulates the strength of the radio wave;
The distance between the base station and the detection target transmitter is estimated using the parameter and the intensity of the radio wave transmitted by the detection target transmitter received by the base station belonging to the subarea having the parameter. And a detecting means for detecting the position of the transmitter to be detected based on the estimated distance,
Feature position detection system.   The position detection program for making a computer perform the process used for implementation | achievement of the position detection method of any one of Claim 1 thru | or 4.   A computer-readable recording medium having recorded thereon a position detection program for causing a computer to execute processing used to realize the position detection method according to claim 1.

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