JP2019086506A - Estimation device, estimation method and program - Google Patents

Abstract

To provide an estimation device which can arrange an electric wave transmitter in a proper position adapted to a positioning method.SOLUTION: An estimation device comprises: an acquisition part for acquiring the setting of the number of electric waves of a beacon in which an intensity value in an estimation-objective position reaches a threshold or larger; and an electric field estimation part for estimating the number and a position of a beacon located in an estimation-objective region in order to receive a prescribed number of electric waves in the estimation-objective position on the basis of an evaluation function f(x) which is indicated when setting a ratio of a first region αin which the intensity value of the electric wave of the beacon reaches a value smaller than a threshold with f1 set in the estimation-objective region, a ratio of a second region βin which the intensity value of one electric wave reaches a value not smaller a threshold with f2 set in the estimation-objective region, a ratio of a third region γin which the intensity values of the two waves reach thresholds or larger with f3 set in the estimation-objective region, and a ratio of a fourth region δin which the intensity values of the three or more electric waves reach thresholds or larger with f4 set in the estimation-objective region as weighing coefficients which vary according to positions x, y, and also on the basis of a value which is acquired by the acquisition part.SELECTED DRAWING: Figure 6

Description

  The present disclosure relates to an estimation device, an estimation method, and a program.

  Various services have been developed that use position information obtained by measuring the position of the user using the intensity value of radio waves transmitted from radio wave transmitters such as beacons and WiFi (registered trademark), etc. The importance of information is increasing. As a method of measuring the position of the user, an electric field map representing the strength of radio waves called fingerprint using radio waves of a plurality of radio wave transmitters etc. is used indoors where the radio waves of GPS (Global Positioning System) do not reach. There is a positioning method.

  As a method of constructing an electric field map used for the above-mentioned positioning method, for example, Non-Patent Document 1 constructs an electric field map from training data taking into consideration the influence of obstructions and reflections by obstacles such as buildings and walls outdoors. Methods are disclosed.

"Construction of Radio Wave Map Considering Obstacles in Radio Wave Positioning Method", Masaaki Kuwahara, Nobuhiko Nishio, Multimedia, Distributed, Cooperative and Mobile (DICOMO 2008) Symposium, July 2008

  By the way, in the positioning which used the conventional electric field map, when the position of the radio wave transmitter was not installed in the suitable position, there existed a case where positioning accuracy fell. For example, as positioning methods, there are positioning methods such as geo-fencing, two-point positioning, and multi-point positioning, but there has been a case in which there is a problem that optimal electric field maps differ depending on these positioning methods.

  The present disclosure has been made in consideration of the above problems, and an object thereof is to provide an estimation device, a method, and a program capable of arranging a radio wave transmission device at an optimal position according to a positioning method. .

In order to achieve the above object, an estimation device according to a first aspect of the present disclosure estimates a position at which a radio wave transmission device for transmitting a radio wave used for positioning is installed in an estimation target area to be estimated. An acquisition unit configured to acquire the setting of the number of radio waves transmitted by the radio wave transmission device whose intensity value is equal to or greater than a threshold at an estimation target position in the estimation target region; The ratio of the first region in which the strength value of the radio wave of the radio wave transmission device is less than the threshold, the second one in which the strength value of one of the radio waves in the estimation target area is greater than the threshold The ratio of the area f3, the ratio of the third area where the intensity value of the two radio waves is equal to or more than the threshold in the estimation target area, the intensity of three or more of the waves in the estimation target area f4 The fourth value is greater than or equal to the threshold The ratio of the area, alpha _{x, y,} beta _{x, y,} gamma _{x, y,} and [delta] _x, a _y, the estimated object position x, when the weighting coefficient that varies according to y, the following (1-1) The radio wave installed in the estimation target area to receive a desired number of radio waves at the estimation target position based on the evaluation function f (x) represented by a formula and the number acquired by the acquisition unit An electric field estimating unit that estimates the number and position of transmitting devices.

  In order to achieve the above object, in the estimation device of the second aspect of the present disclosure, in the estimation device of the first aspect, each of the weighting coefficients corresponds to the number of radio waves acquired by the acquisition unit and the estimation target It is decided according to the position.

  A third aspect of the present disclosure is the estimation device according to the first aspect or the second aspect, wherein the electric field estimation unit increases space as the distance between the radio wave transmission device and the estimation target position decreases. Obtained on the basis of a radio wave propagation model represented by a logarithmic function, in which a coefficient is included, and the frequency with which the space propagation coefficient takes different values increases as the distance between the radio wave transmission device and the estimation target position decreases. It estimates using the intensity | strength in the said estimation object position of the electromagnetic wave emitted from the said electromagnetic wave transmission apparatus in the said estimation object position.

According to a fourth aspect of the present disclosure, in the estimation device according to any one of the first to third aspects, the evaluation function f (x) is a function of к with respect to the equation (1-1). The weighting factor is expressed by the following equation (2) which further adds f5 'which is a term for maximizing the distance between the radio wave transmission devices, and the f5' is the distance emitted by the radio wave transmission device. It functions as a penalty term if it is smaller than the radius of the circle when the range in which positioning by the radio wave is possible is represented by a circle.

  A fifth aspect of the present disclosure relates to the estimation device according to any one of the first to fourth aspects, wherein the electric field estimation unit is the number of radio wave transmission devices installed in the estimation target area. An optimization process is performed to alternately change the number and optimize the evaluation function f (x).

  In addition, the estimation device according to the sixth aspect of the present disclosure is a device for transmitting a wave, which transmits the wave in order to perform positioning using at least one wave of radio wave, sound wave, and light wave in indoor space. And a cover area which is an area in which waves emitted from the first wave transmission device can be used for positioning, and a cover of the second wave transmission device to be overlapped with the cover area. An acquisition unit for acquiring n, which is the number of areas, a cover area of the first wave transmitting device in the indoor space, and an area in which the number of cover areas of the second wave transmitting device is n Estimate the installation positions of the first wave transmitting device and the second wave transmitting device so as to minimize the area not included in the cover area of any wave transmitting device in the indoor space And the estimation unit Equipped with a.

In order to achieve the above object, an estimation apparatus according to a seventh aspect of the present disclosure is an estimation apparatus for estimating a position where a transmission apparatus for transmitting a wave used for positioning is installed in an estimation target area to be estimated. An acquisition unit configured to acquire the setting of the number of waves transmitted by the transmission device whose intensity value is equal to or greater than a threshold at an estimation target position in the estimation target region; f1 among the estimation target region The ratio of the first area in which the intensity value of the wave of the transmission device is less than the threshold, the ratio of the second area in which the intensity value of one of the waves is equal to or greater than the threshold , F3 is the ratio of the third region in which the strength value of two of the waves is equal to or more than the threshold in the estimation target region, f4 is the strength value of three or more of the waves in the estimation target region The ratio of the fourth region which is equal to or greater than the threshold, α _{x, y} , When β _{x, y 1} , γ _{x, y} and δ _{x, y} are weighting coefficients that change according to the estimation target position x, y, an evaluation function f represented by the following equation (1-1) Estimating the number and position of the transmission devices installed in the estimation target area to receive a desired number of waves at the estimation target position based on (x) and the number acquired by the acquisition unit An estimation apparatus, comprising: an estimation unit, wherein the wave is any one of a radio wave, a sound wave, and a light wave.

In order to achieve the above object, according to an estimation method of an eighth aspect of the present disclosure, there is provided an estimation device for estimating a position where a radio wave transmission device for transmitting radio waves used for positioning is installed in an estimation target area to be estimated. Obtaining the setting of the number of the radio waves transmitted by the radio wave transmission device, the intensity value at the estimation target position in the estimation target area being equal to or greater than a threshold, and the electric field estimation unit The ratio of the first area to which the radio wave of the radio wave transmission device does not reach out of the estimation target area, f1, and the radio wave of one of the radio wave transmission devices of the estimation target area reaches f2 The ratio of the second area, f3 to the ratio of the third area to which the radio waves of the two radio wave transmitting devices reach out of the estimation target area, f4 to the three or more of the estimation target areas Radio wave transmitter Weighting coefficient waves of the proportion of the fourth region has been _{reached, α x, y, β x} , y, γ x, y, and [delta] _x, a _y, varies depending on the estimated target position x, y In the above case, a desired number of radio waves are received at the estimation target position based on the evaluation function f (x) represented by the following equation (1-1) and the set number of acquired radio waves: And the step of estimating the number and position of the radio wave transmission devices installed in the estimation target area.

  In order to achieve the above object, a program of a ninth aspect of the present disclosure is for causing a computer to function as each part of the estimation device according to any one of the first to seventh aspects. is there.

  According to the present disclosure, it is possible to obtain the effect that the radio wave transmission device can be arranged at the optimum position according to the positioning method.

It is a graph which shows an example of the electromagnetic wave propagation model in 1st Embodiment. It is a graph for demonstrating an example of the electromagnetic wave propagation model in 1st Embodiment. It is a figure for demonstrating the positioning method using geo fencing. It is a figure for demonstrating the positioning method using 2 point positioning. It is a figure for demonstrating the positioning method using multipoint positioning. It is a figure for demonstrating the optimization method of installation of the electromagnetic wave transmitter in 1st Embodiment. It is a figure for demonstrating the optimization method of installation of the electromagnetic wave transmitter in 1st Embodiment. It is a block diagram which shows an example of a structure of the estimation apparatus in 1st Embodiment. It is a flowchart which shows an example of the electromagnetic wave propagation model derivation | leading-out routine which the electric field estimation part in 1st Embodiment performs. It is a flowchart which shows an example of the estimation routine which the field intensity estimation apparatus in 1st Embodiment performs. It is a figure which shows an example of the presumed arrangement | positioning figure with respect to the measuring method using the geo-fencing which was derived | led-out by the field intensity estimation apparatus in 1st Embodiment. It is a block diagram which shows the example of implementation of the field intensity estimation apparatus in 1st Embodiment. It is a graph for demonstrating approximation of the field intensity value by a field propagation model. It is a figure for demonstrating the positioning system using the electromagnetic wave intensity of an electromagnetic wave transmission apparatus. It is a figure for demonstrating the positioning system using delay time, such as an electromagnetic wave, an acoustic wave, and a laser. It is a figure for demonstrating the positioning system using the angle (direction) which an electromagnetic wave, a sound wave, etc. arrive. It is a figure for demonstrating the positioning system which measures the distance from a transmitter to a user directly. It is a figure for demonstrating the optimization method of installation of the transmission device in 2nd Embodiment. It is a graph for demonstrating the relationship between the precision of positioning, and the cost (an initial investment cost, an operation cost, etc.) in connection with the whole system based on the number of transmission apparatuses. It is a graph for demonstrating the relationship between the precision of positioning, and the cost (an initial investment cost, an operation cost, etc.) in connection with the whole system based on the number of transmission apparatuses. It is a figure which shows an example of the presumed object area | region for constructing a positioning system. It is an explanatory view for explaining construction of a positioning system to a presumed object field. It is a figure for demonstrating the optimization method of the transmission device in 2nd Embodiment. It is a figure which shows an example of the installation position of the transmission apparatus suitable for geofencing. It is a figure which shows an example of the installation position of the transmission apparatus suitable for 2 point | piece positioning. It is a figure which shows an example of the installation position of the transmission apparatus suitable for multipoint positioning. It is a block diagram which shows an example of a structure of the display apparatus in 2nd Embodiment. It is a flowchart which shows an example of the routine performed with the display apparatus of 2nd Embodiment.

First Embodiment
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present embodiment does not limit the present invention. Although the case where the radio wave transmission device is a beacon (Beacon) transmitting a beacon signal including a beacon ID (Identification) for identifying the own device will be described as an example below, the radio wave transmission device is limited to the beacon It is not a thing. As such a beacon signal, for example, a WiFi (registered trademark) signal, a BLE (Bluetooth (registered trademark) Low Energy) signal, or the like can be used.

  First, the radio wave propagation model of the present disclosure will be described.

  In general, the signal strength of a beacon signal (RSSI: Received Signal Strength Indicator) at a point away from a beacon is represented by a radio wave propagation model represented by the following equation (1). In the following equation (1), “d” is the distance from the beacon installation position (d> 0), “K” is the maximum radio wave output of the beacon, and “n” is the space propagation coefficient, "C" is a constant term.

RSSI = K− (n × log ₁₀ d−C) (1)

  The above "K" is a known value, and "n" and "C" are model coefficients that change depending on the environment.The combination of n and C that best fits the plot of measured points is the least squares method In the radio wave propagation model of the above equation (1) defined by the derived model coefficients (n, C), the measured value of the radio wave intensity (hereinafter referred to simply as “measured value”) By approximating the radio wave propagation curve obtained by connecting the two), it becomes possible to derive the radio wave intensity at various points other than the measurement point.

  FIG. 11 is a graph showing the relationship between the distance from the beacon and the radio wave intensity. FIG. 11 shows an example of a graph of measured values of radio wave intensities at eight points having different distances from the beacon and an example of a graph of radio wave intensity values derived by the radio wave propagation model of the above equation (1). ing.

  As shown in FIG. 11, the shorter the distance from the beacon, in other words, the closer to the beacon, the greater the divergence between the measured value and the radio wave intensity value derived by the radio wave propagation model. That is, in the case shown in FIG. 11, with respect to a point near the beacon, it is not possible to approximate the actual radio wave intensity appropriately by using one radio wave propagation model.

  In general, when the radio wave propagation model is applied to a positioning device for positioning the position of a user, it is used for a distance (near the beacon) within a certain range from a beacon with a large rate of change in radio wave intensity in the radio wave propagation model. Ru. Therefore, the approximation accuracy of the radio wave propagation model in the vicinity of the beacon greatly affects the positioning accuracy.

  Therefore, in the present disclosure, a section in the vicinity of a beacon where the approximation accuracy of the radio wave propagation model decreases is divided into a plurality of sections, and model coefficients (n, C) derived using actual values are used for each divided section. Apply the radio wave propagation model. For example, as shown in FIG. 1, when the measured value of the radio wave intensity is obtained, first, a section from the beacon having a relatively large change rate of the radio wave intensity value and a distance of d0 to d2 (d0 <d2), It is divided into sections where the rate of change of the radio wave intensity value is relatively small and the distance from the beacon is d2 to d3 (d2 <d3). Furthermore, the distance from the beacon is divided into a plurality of sections (sections d0 to d1 and two sections of sections d1 to d2) for the sections d0 to d2. Then, the model coefficients (n, C) in the equation (1) are derived for each section to define a radio wave propagation model in which the radio wave propagation curve is approximated. Here, assuming that the space propagation coefficient in section d0 to d1 is n1, the space propagation coefficient in section d1 to d2 is n2, and the space propagation coefficient in section d2 to d3 is n3, the space propagation coefficient n1 is higher than the space propagation coefficient n2 The space propagation coefficient n2 is larger than the space propagation coefficient n3 (n1> n2> n3). That is, the value of the space propagation coefficient n becomes larger as the section is closer to the beacon. For example, the following equation (2) holds.

n1 = n3 + 0.2
n2 = n3 + 0.04 (2)

  By defining the radio wave propagation model of the above equation (1) with such space propagation coefficients n1, n2 and n3, as shown in FIG. 1, the radio wave intensity value derived by the radio wave propagation model for each section and the actual measurement Deviation from the value is suppressed, and the approximation accuracy by the radio wave propagation model is improved.

  On the other hand, when radio wave intensity values in all the sections are derived by the radio wave propagation model defined by the space propagation coefficient n3 applied in the sections d2 to d3, as shown in FIG. 2, in the vicinity of the beacon (section d0 to d2) The divergence between the actual measurement value and the radio wave intensity value derived by the radio wave propagation model becomes large.

  Therefore, in the present disclosure, as described above, the section according to the distance from the beacon is divided into a section in which the rate of change in the field strength value is relatively large and a section in which the rate of change in the field strength value is relatively small. A section in which the rate of change of the radio wave intensity value is relatively small is divided into a plurality of sections, and the value (n1 to n3 in FIG. 1) of the space propagation coefficient n applied to the radio wave propagation model is switched for each section.

  That is, in the present disclosure, the optimized radio wave propagation model represented by one equation is used while switching the space propagation coefficient, which is the coefficient, according to the distance between the estimation target point for estimating the radio wave intensity and the beacon. And estimate the electric field by each beacon.

  In addition, it is preferable to make the area for switching a space propagation coefficient into a short area, so that it is close to a beacon. As the rate of change of the radio wave intensity value (curvature of the radio wave propagation curve) becomes larger as it gets closer to the beacon, the approximation accuracy of the radio wave propagation curve becomes higher by shortening the section in which the space propagation coefficient is switched.

  In addition, as a method of section division for switching the space propagation coefficient, for example, the number of section divisions is changed according to a standard that the sum of squares of approximation errors with the radio wave propagation curve is minimized, and the error is minimized. There is a method of automatically determining the number of divisions into the minimum number of divisions. Also, for example, as a method of section division, a method of focusing on a change in curvature of the radio wave propagation curve and dividing at a point where the rate of change is equal to or more than a threshold value can be mentioned. In this method, a threshold used when dividing into a section in which the rate of change in the field strength value is relatively large and a section in which the rate of change in the field strength value is relatively small, and a section in which the rate of change in the field strength value is relatively small It is preferable to make the threshold different from that used when dividing the section for switching the space propagation coefficient in the inside.

  Next, the estimation method regarding installation of the beacon in this embodiment is demonstrated. In the present embodiment, the appropriate number of beacons and the installation position are estimated according to the positioning method. Examples of the positioning method include methods using geo-fencing, two-point positioning, and multi-point positioning.

  In the positioning method using geofencing, the area where the intensity value of the radio wave from the beacon is equal to or more than the threshold (hereinafter, referred to as "electric field area") is provided so as to reduce the overlapping area. Positioning can be performed. For example, as in the example shown in FIG. 3A, the beacons are installed so that the electric field regions of the beacons do not overlap. On the other hand, in the positioning method using two-point positioning, as shown in FIG. 3B, by placing the beacon in a state in which the electric field regions of two beacons are superimposed, any position on the line segment connecting the beacon positions The position can be measured. On the other hand, in the positioning method using multipoint positioning, as shown in FIG. 3C, the beacon is placed in a state in which the electric field area of three or more beacons is overlapped, thereby arbitrary position in the overlapped area Positioning can be performed.

  So, in this embodiment, the installation position of a beacon is optimized by optimizing the area of the field according to the overlapping state of the electric field field of each beacon, and an electric field field according to a positioning method. Therefore, in this embodiment, according to the positioning method, the evaluation function f (x) having the area (ratio) of the four types of areas (areas 92 to 98) shown in FIG. Is used to estimate the optimum number of beacons installed and their installation positions (hereinafter simply referred to as "beacon installation"). The point is that, in the present embodiment, the number of radio waves of beacons at a point to be measured is optimized according to the positioning method. That is, according to the positioning method, the installation number and installation position of beacons are estimated such that the number of radio waves at the position to be measured becomes optimum.

  In all the positioning methods, the area of the area 92 which is the area outside the electric field area of all the beacons, that is, the area where the radio wave intensity value is less than the threshold value is minimized for all the beacons. Moreover, in the positioning method using geofencing, the electric field area by one beacon, ie, the area of the area 94 where a plurality of electric field areas do not overlap, is maximized. Moreover, in the two-point positioning method, the area 96 where the electric field area by two beacons overlaps is maximized. Furthermore, in the multipoint positioning method, the region 98 where the electric field regions of three or more beacons overlap is maximized.

The evaluation function f (x) is expressed by the following equation (3). In addition, "I" in the following equation (3) is the total number of lattice points when an area (hereinafter referred to as "estimate target area") which is a target for estimating the number of installed beacons and the installation position is divided into arbitrary grids. It is. Also, “j” is the number of lattice points included in region 92, “k” is the number of lattice points included in region 94, and “l” is the number of lattice points included in region 96. And “n” is the number of lattice points included in the area 98. Also, “P _j (x)” is 1 (region 92 including lattice point j) / I, “P _k (x)” is 1 (region 94 including lattice point k) / I, “P _l ( “x)” is 1 (region 96 including lattice point l) / I, “P _n (x)” is 1 (region 98 including lattice point n) / I. Further, “α”, “β”, “γ”, and “δ” are weighting coefficients, and “κ” is a penalty coefficient. Accordingly, “f1” is the proportion of the area 92, “f2” is the proportion of the area 94, “f3” is the proportion of the area 94, and “f4” is the proportion of the area 96, “F5 ′” is a penalty term related to the arrangement of beacons to maximize the distance between beacons.
Also, in the case where the function F (·) needs to minimize the area of the corresponding term according to the positioning method, the function in (·) is used as it is to minimize the area of the corresponding term On the other hand, in the case of a term that needs to maximize the area of the relevant term, the function in (·) is set as an inverse to set so as to maximize the area of the relevant term.

  In the case of the positioning method using geofencing, the estimation of the installation of the beacon is the optimization term that maximizes the area, where the second term for the area 94 where the electric field area does not overlap is the optimization term for the equation (3). It is estimated by the following equation (4) as a penalty term which minimizes the third and fourth terms.

  On the other hand, in the case of a positioning method using two-point positioning, the estimation of the installation of beacons is an optimum for maximizing the third term concerning the area 96 where the electric field areas by two beacons overlap in the above equation (3). It is estimated by the following equation (5), where the second term relating to the area 94 is a dependent term to be quasi-maximized, and the first and fourth terms are penalty terms to be minimized. However, in the following equation (5), the coefficient α is smaller than the coefficient γ (α <γ).

In the above equation (5), as shown in FIG. 5, the penalty term of the fifth term is such that the distance between the beacons AP (AP _{1 to} AP _N ) is maximized (dispersed), When the distance between the installation positions of the beacons AP (center position of the electric field area) becomes equal to or less than the radius d of the electric field area, it acts as a penalty term. Therefore, the penalty term of the fifth term is

It works when the condition of

  On the other hand, in the case of the positioning method using multipoint positioning, estimation of the installation of the beacon maximizes the area of the fourth term regarding the area 98 where the electric field area by three or more beacons overlaps in the above equation (3) The optimization term is estimated, and the second and third terms of the area 94 and the area 96 are estimated by the following equation (6) as dependent terms for quasi-maximizing and the penalty term for minimizing the first term. However, in the following equation (6), the coefficient α and the coefficient γ are smaller than the coefficient δ (α <δ, γ <δ).

  Next, the estimation apparatus of the present embodiment, which is an apparatus for performing estimation regarding the above-described estimation of the beacon, will be described.

  In FIG. 6, the block diagram of an example of the estimation apparatus of this embodiment is shown. As shown in FIG. 6, the estimation device 10 of the present embodiment includes a simulation condition setting unit 20, an acquisition unit 21, a derivation unit 22, an output unit 24, and a measured value DB (Data Base) 26. Specifically, the estimation device 10 of the present embodiment is a computer program, and includes a read only memory (ROM) storing the program, a central processing unit (CPU), a random access memory (RAM), and the like. In the computer, a CPU that executes the program functions as the simulation condition setting unit 20, the acquisition unit 21, the derivation unit 22, and the output unit 24 illustrated in FIG.

  The startup unit 12 is a batch file, and specifies a setting file to be used for a simulation for estimating a beacon installation position from simulation condition 2 including a plurality of setting files in which different simulation conditions are set. , And has a function of activating the estimation device 10.

  The simulation condition 2 includes a plurality of setting files in which simulation conditions for each derivation target area are set.

  The simulation condition setting unit 20 of the present embodiment has a function of reading a setting file corresponding to the derivation target area from the simulation condition 2 and setting the setting file to be available in the derivation unit 22. Therefore, the simulation condition setting unit 20 outputs simulation conditions set according to the setting file.

  Further, the simulation condition setting unit 20 of the present embodiment is used when the optimization unit 30 described in detail later optimizes the model coefficients (n, C) (minimizes the evaluation function f (n, C)). It has a function to set an initial value etc. of the model coefficient (n, C). Therefore, from the simulation condition setting unit 20, the model coefficients (n, C) used for the derivation of the optimization are output according to the instruction of the optimization unit 30.

  The acquisition unit 21 of the present embodiment has a function of acquiring the setting of the positioning method 3 set by the user using a user interface (not shown) or the like. In the present embodiment, the acquisition unit 21 acquires the setting of whether to perform positioning using any of geofencing, two-point positioning, and multipoint positioning.

  As described above, the derivation unit 22 of the present embodiment has a function of deriving a radio wave propagation model. Data of measured values of the radio wave intensity in the derivation target area is stored in the measured value DB 26 in association with each beacon. Moreover, the derivation | leading-out part 22 of this embodiment has a function which estimates the optimal number of installation of the beacon installed in a derivation | leading-out object area | region, and an installation position.

  As shown in FIG. 6, the derivation unit 22 of the present embodiment includes an optimization unit 30, an evaluation function derivation unit 32, an electric field estimation unit 34, and a radio wave propagation model unit 36. The radio wave propagation model unit 36 has a function of deriving a radio wave intensity value by the radio wave propagation model of the present disclosure described above. In addition, the information regarding the installation position of the beacon optimized by the optimization part 30 which mentions a detail later is input into the electromagnetic wave propagation model part 36 of this embodiment. When the radio wave propagation model unit 36 of the present embodiment receives information on the installation position of the beacon from the optimization unit 30, the radio wave propagation model unit 36 beacons at the installation position of the beacon that is input according to the instruction input from the electric field estimation unit 34. The radio wave intensity value in the case where is installed is derived, and the derived radio wave intensity value is output.

  The electric field estimation unit 34 of the present embodiment has a function of setting a radio wave propagation model in the radio wave propagation model unit 36 and deriving a radio wave intensity value by the set radio wave propagation model. Further, the electric field estimation unit 34 of the present embodiment derives the electric field area of each beacon based on the radio wave intensity value input from the radio wave propagation model unit 36 and the simulation conditions acquired from the simulation condition setting unit 20. .

  The evaluation function deriving unit 32 of the present embodiment described above based on the actual measurement value acquired from the actual measurement value DB 26 based on the instruction of the optimization unit 30, and the radio wave intensity value derived by the radio wave propagation model unit 36. It has a function of deriving and outputting an evaluation function f (x).

  The optimization unit 30 of the present embodiment is a function of outputting the estimation result 7 in which the number of installed beacons and the installation position in the estimation target area are optimized by minimizing the evaluation function f (x) according to the measurement method. Have. Therefore, information representing the setting of the measurement method is input from the acquisition unit 21 to the optimization unit 30. Further, the evaluation function f (x) is input from the evaluation function derivation unit 32 to the optimization unit 30. In addition, the optimization unit 30 of this embodiment is a diagram showing the setting position of the beacon in the estimation target region and the electric field region of each beacon as the estimation result 7 (hereinafter referred to as “estimated layout diagram”, see FIG. Output information representing Further, the optimization unit 30 outputs a calculation result in the middle of derivation of optimization, for example, values of each of f1 to f5.

  Further, the optimization unit 30 of the present embodiment also performs optimization of the model coefficients (n, C) of the radio wave propagation model (minimization of the evaluation function f (n, C)). The method of optimization of the radio wave propagation model is not particularly limited.

  The above-mentioned progress is output from the optimization unit 30 to the output unit 24 of the present embodiment, and the progress is input to the outside as a progress record 4. Further, the estimation result 7 is input from the electric field estimation unit 34 to the output unit 24 of the present embodiment, and the input estimation result 7 is output. The output unit 24 is, for example, a monitor that displays the estimation result 7.

  Next, the operation of the estimation device 10 of the present embodiment will be described.

  When activated by the activation unit 12, first, the estimation device 10 selects one beacon from a plurality of beacons provided in the derivation target region according to the simulation conditions, and a radio wave propagation model, an example of which is shown in FIG. Execute the derivation routine.

  In step S10 shown in FIG. 7, the electric field estimation unit 34 acquires the actual measurement value of the selected beacon from the actual measurement value DB 26, and the radio wave arrival section of the selected beacon is calculated based on the radio wave intensity value. Are divided into a first section in which the rate of change is relatively large and a second section in which the rate of change in the radio wave intensity value is relatively small. For example, in the example illustrated in FIG. 1, division is performed such that the first section is section d0 to d2 and the second section is section d2 to d3. When the section used for positioning is determined in advance according to the distance from the beacon, the section may be divided as a first section, and the outside of the section may be divided as a second section.

  In the next step S12, the electric field estimating unit 34 further divides the first section into a plurality of sections as described above. In the example shown in FIG. 1, the first section is divided into two sections of sections d0 to d1 and sections d1 to d2.

  In the next step S14, the electric field estimation unit 34 derives the radio wave propagation model by approximating the radio wave propagation curve by deriving the model coefficients (n, C) as described above for each section, and then performs the radio wave propagation model derivation routine. finish. In the example shown in FIG. 1, space propagation coefficients n1, n2, and n3 are derived, and a derivation target region is defined by each.

  The electric field estimation unit 34 sets the radio wave propagation model for each beacon in the radio wave propagation model unit 36 by executing the radio wave propagation model derivation routine for each of the plurality of beacons provided in the derivation target region. . Needless to say, when the radio wave propagation model of each beacon is obtained in advance, the execution of the radio wave propagation model deriving routine can be omitted.

  Next, the estimation device 10 executes an estimation routine, an example of which is illustrated in FIG.

  As shown in FIG. 8, in step S100, the estimation apparatus 10 causes the acquisition unit 21 to acquire the set measurement method.

  In the next step S102, the estimation device 10 performs the evaluation function f (x (x) according to the measurement method as described above by the optimization unit 30, the evaluation function derivation unit 32, the electric field estimation unit 34, and the radio wave propagation model unit 36. Minimize). Thereby, in the estimation device 10 of the present embodiment, the number of installed beacons and the optimum installation position are derived according to the derivation target area condition. Specifically, the optimization unit 30 derives an evaluation function for the number and location of temporary beacons, and the number and location of beacons when the evaluation function f (x) is minimized are optimum. The number of beacons installed and their locations.

  In the next step S104, the estimation apparatus 10 causes the electric field estimation unit 34 to generate an estimated layout diagram based on the derivation result of the optimization unit 30, and the output unit 24 outputs the generated estimated layout diagram as the estimation result 7 After that, the estimation routine is ended. FIG. 9 shows an example of the estimated layout for the measurement method using geofencing. FIG. 9 shows an example of an estimated layout diagram 11 represented by superposing the arrangement of beacons and the electric field range of each beacon on a plan view of the inside of a building. It goes without saying that the display method and the like of the estimated layout drawing 11 are not limited to those illustrated in FIG. For example, the electric field area of each beacon may not be displayed.

Further, the weights α _{x, y} , β _{x, y} , γ _{x, which} are given to the evaluation function f (x) so as to change the weights α, β, γ, δ in accordance with the arbitrary position (x, y) _It may be _y , δ _{x, y} . In such a case, the equation (3) can be modified as the following equation (3-1).

For example, in the case of an area where stores are densely packed and detailed navigation is required, the weight by position requires high-accuracy three-point positioning, and the weighting coefficient δ _x of the fourth term of the above equation (3-1) _{, Y} is set to a large value, while in the case of an area that only walks as a walkway, two-point positioning in which only the route along the walkway is sufficient is sufficient. It is conceivable to set a weighting factor γ _{x, y of a term} to a large value. Similarly, the equations (4) to (6) can be modified as the following equations (4-1) to (6-1).

  In this way, by assigning weights so as to change according to the position (x, y), the positioning environment can be determined by the positioning method that satisfies the required positioning accuracy according to the features of the design area and the needs of the user. The effect of being able to design and achieving the desired positioning environment can be expected.

Second Embodiment
The second embodiment will be described below. In addition, since 2nd Embodiment is based on the structure and effect | action of the estimation apparatus 10 in 1st Embodiment, description may be abbreviate | omitted about the same structure and effect | action.

  In the present embodiment, first, various examples of assumed positioning methods will be described.

  As a positioning method, there is a positioning method using the radio wave intensity of the radio wave transmission device. In this case, radio waves such as a WiFi (registered trademark) signal and a BLE (registered trademark) signal can be used as the medium. As shown in FIG. 12, in the case of the method using radio wave intensity, the position of the user is determined by three-point positioning based on the distance between each of a plurality of (three in FIG. 12) radio wave transmission devices in the vicinity of the user It is a method to derive. In this method, the distance between the user (terminal) and the radio wave transmission device is derived based on the intensity value of the radio wave transmitted by the radio wave transmission device detected by the terminal owned by the user.

  In addition, as a positioning method, there is a positioning method (TOA: time of arrival) that utilizes delay times of radio waves, sound waves, and lasers. In this case, radio waves such as WiFi (registered trademark) UWB (Ultra Wide Band), sound waves, lasers, and the like can be used as the medium. As shown in FIG. 13, in the case of the method using delay time, the user is determined by three-point positioning based on the distance between the user and a plurality of (three in FIG. 13) transmitters that transmit media in the vicinity of the user. Is a method of deriving the position of In this method, the distance (da to dc) between each transmission device and the user is derived based on the delay time detected by the terminal owned by the user. In addition, the following two types are mentioned as a measuring method of "delay time." The first method is a method of measuring a delay time from transmission of a medium from the transmission device side to reception by the terminal side between the time-synchronized transmission device and a terminal owned by the user. The second method is a method of measuring the delay time using the phase difference between two different frequencies, and the method can measure the delay time more precisely than the first method. .

  Further, as a positioning method, there is a positioning method (AOA: Angle of Arrival) that uses an angle (direction) at which radio waves, sound waves and the like arrive. In this case, radio waves such as WiFi (registered trademark) and sound waves can be used as the medium. As shown in FIG. 14, in the case of the system using angles (directions), the user holds a medium transmitter and the angle of the medium coming from the transmitter in a plurality of (three in FIG. 14) receivers It is a method of measuring and deriving the position of the transmitting device, that is, the position (x, y, z) of the user based on the angles ∠a to ∠c of the medium and the distances D1 and D2 between the transmitting devices. Specifically, in FIG. 14, ∠a ′ and ∠b ′ represent angles obtained by projecting ∠a and ∠b onto the xy plane, respectively, and ∠a ′ ′ and ∠c ′ ′ indicate ∠a and ∠a, respectively. represents the angle of projection of c onto the yz plane. From the combination of ∠a ', 3b' and distance D1, and the combination of ∠a '', ∠c '' and distance D2, the position (x, y, z) of the three-dimensional space indicating the position of the user is obtained. To derive.

  Further, as a positioning method, there is a positioning method in which the position of the user is measured by directly measuring the distance from the transmitting device such as laser and light to the user. In this case, a laser, light or the like can be used as the medium. As shown in FIG. 15, in the case of the direct measurement method, a plurality of sets (3 sets in FIG. 15) of a combination of a transmitter and a receiver are provided, and a medium transmitted from the transmitter transmits a reflected wave reflected by the user. The distance (da to dc) from the transmission device to the user is directly measured by receiving the signal, and the position (x, y, z) of the user is determined by three-point positioning based on the measured distance (da to dc) To derive.

  In any of the above positioning methods, the positioning principle has the following features. That is, using the characteristics of the medium that convert radio wave intensity, delay time, arrival angle of radio wave, etc. into distance, two-point positioning, three-point positioning, multi-point positioning, and k-means for the converted distance. By applying a position calculation method such as, for example, to derive a position.

  The present embodiment relates to a technology of designing a positioning system by optimizing the position and number of positioning devices (at least one of a transmitting device and a receiving device) by utilizing the features of the positioning principle described above. That is, the technology of the present embodiment described below is applicable to all the positioning methods described above.

  In the positioning system design technology of the present embodiment, the determination process of the optimal number of positioning devices includes the process of determining the optimal arrangement of positioning devices. The determination process of the optimal arrangement of the positioning device is a process of determining the arrangement position of the transmitting device according to the positioning system and the positioning method by maximizing and minimizing the area of the area where the medium is superimposed and the like. The placement design of the positioning device is performed by the process.

  On the other hand, the process of determining the optimum number of positioning devices performs the process of determining the above-mentioned optimum arrangement of positioning devices under a plurality of conditions in which the number of positioning devices is changed, and the evaluation function f (under each condition This is a process of determining the number of positioning devices suitable for the positioning environment and the positioning method by determining the number of positioning devices with the smallest value of x), and the number of positioning devices is designed by the process.

  That is, in the present embodiment, a plurality of positioning devices (in the present embodiment, transmission devices) are assumed, and processing for deriving the optimal arrangement and evaluation function f (x) is performed for each assumed number, and the evaluation function is performed. When the value of f (x) is the smallest, the number of transmitters and the position of the transmitters are optimized.

  The method of determining the optimum number of transmission devices includes an area (hereinafter referred to as “medium area”) reached by the medium in a state where positioning of each transmission device is possible according to the positioning method etc. The installation position of the transmission device is optimized by optimizing the area of the area divided by the number of overlapping waves such as sound waves and light waves. The method is basically the same as the method of the first embodiment described with reference to FIG.

  In this embodiment, according to the positioning method, an evaluation function f (x) having the area (ratio) of the four types of areas (areas 92 to 98) shown in FIG. 16 as elements is used, and the optimization method is used Automatically estimate the optimal number of transmitters installed and their installation positions (hereinafter simply referred to as "transmitter installation"). The point is that in the present embodiment, the number of overlapping waves such as radio waves, sound waves, light waves, etc. required to realize the positioning is satisfied in the area where the positioning should be realized, according to the positioning method. Estimate the number of transmitters and their positions. That is, depending on the positioning method, the number and location of transmitters installed so that the number of overlapping waves such as radio waves, sound waves, light waves, etc. satisfy the number of overlapping required for the corresponding positioning at the point where positioning should be realized. Estimate

  In all the positioning methods, the area of the area 92 which is the area outside the medium area of all the transmission devices, that is, the area where the radio wave intensity value is less than the threshold value is minimized for all the transmission devices. Moreover, in the positioning method using geofencing, the area of the medium area | region by only one transmission apparatus, ie, the area | region 94 to which several medium area | regions do not overlap, is maximized. Further, in the two-point positioning method, the area 96 where the medium areas of the two transmitters overlap is maximized. Furthermore, in the multipoint positioning method, the area 98 where the medium areas of three or more transmitting devices overlap is maximized.

  The evaluation function f (x) is expressed by the following equation, and the minimum value minf (x) of the evaluation function f (x) is derived by the following equation (2-1).

Note that “I” in the above equation (2-1) is the total number of evaluation points that are grid points when the estimation target area for which the number and location of transmitting devices are estimated is divided into arbitrary grids. It is. Also, “J” is the number of evaluation points included in area 92, “K” is the number of evaluation points included in area 94, and “L” is the number of evaluation points included in area 96. And “N” is the number of evaluation points included in the area 98. Also, “j” is a subscript representing the number of evaluation points in area 92, “k” is a subscript representing the number of evaluation points in area 94, and “l” is an evaluation point in area 96. The “n” is a subscript representing the number of evaluation points in the area 98. Further, “ΣP _j (x, y)” is a ratio of the area 92, and is approximated by the total number of evaluation points j / I. “ΣP _k (x, y)” is a ratio of the area 94 and is approximated by the total number of evaluation points k / I. “ΣP _l (x, y)” is the proportion of the area 96, and is approximated by the total number of evaluation points l / I. Furthermore, “ΣP _n (x, y)” is the ratio of the area 98, and is approximated by the total number of evaluation points n / I. Also, “α _{x, y} ”, “β _{x, y} ”, “γ _{x, y} ” and “δ _{x, y} ” are weighting functions that change according to the position (x, y), and The weighting factor changes accordingly. Also, “κ” is a penalty coefficient (described in detail later).

  By the way, in general, as shown in the price competitiveness curve and the accuracy competitiveness curve of FIG. 17A, the less the number of installed media transmission devices is, the cost for the entire system for performing positioning (initial investment cost and operation Although the cost etc. is low cost (high price competitiveness), the accuracy of positioning decreases, while the more the number of transmitters, the more expensive the overall system costs, but the higher the accuracy of positioning ( Accuracy competitiveness tends to be high). That is, the accuracy of positioning and the cost of the entire system are in a trade-off relationship. Also, once the number of transmitting devices is determined, the accuracy of positioning and the cost for the entire system are determined. In the conventional adjustment based on the human rule of thumb, the price / performance competitive curve does not change because the number of transmitters to be installed, the position, etc. are only adjusted. For this reason, even if the number of transmitters is changed after the adjustment, either one of the price and the performance is improved, but the other is sacrificed and corrupted.

  By applying the technology of the present embodiment, as shown in FIG. 17B, the price competitiveness curve and the accuracy competitiveness curve change as shown in the upper graph, so that the positioning accuracy is improved, and the transmission device is installed. The number can also be reduced. Therefore, it is possible to construct a positioning system that achieves the accuracy (performance) desired by the user with an inexpensive system.

  In order to realize the positioning accuracy according to the user's request, the area for improving the positioning accuracy and the area where the positioning accuracy may be low are specified in the estimation target area, and reflected in the design, specifically In practice, the positioning system is reflected in the evaluation function f (x). As a result, the number of transmitting devices can be reduced, cost can be reduced, and a positioning system having accuracy according to the user's desire can be constructed. For example, the case where a positioning system is built in the estimation target area shown in FIG. 18 will be described.

  As shown in FIG. 19, when constructing a positioning system in the estimation target area and realizing navigation, for example, the frequency for use by users such as elevators for moving between floors, escalators, near entrances and exits of buildings, and toilets. In a high area of the area 100 and an area 100 in which the distance between shops is narrow, high accuracy is required, and it is required to perform three-point positioning in which an arbitrary position is measured. The point is that positioning must be performed with high accuracy in areas where space and space are connected, such as between buildings or between floors, and areas where large errors can not be tolerated, such as areas where toilets and stores are densely populated That's what it means. On the other hand, in the other area 102, it is sufficient to realize guidance (navigation) of the aisle-like area, and as in the case of guidance at the aisle, positioning accuracy may not be high (may be low). It is sufficient to perform two-point positioning to measure

Therefore, in the present embodiment, in area 100, a large value is set to weighting coefficient δ _{x, y} corresponding to three-point positioning in the above equation (2-1), and in area 102, the above equation (2-1) is established. A large value is set to the weighting coefficient γ _{x, y} corresponding to the two-point positioning in In this way, by setting the weighting factor corresponding to the positioning method to be designed for each area to be large or small, it is suitable for the shape of any environment and the environmental and accuracy needs of any user. It becomes possible to design various positioning systems.

It is to be noted that the fifth term in the above equation (2-1) indicates that each transmission device AP is extended as shown in FIG. 20 so that the installation interval of each transmission device is extended as much as possible. When the distance between (AP _{1 to} AP _N ) becomes smaller than the radius dr of the medium area, it functions as a penalty term. Therefore, the fifth term functions when the following condition is satisfied, and does not function when the following condition is not satisfied. That is, a restriction is added such that when the distance between the installation positions of the respective transmitters becomes smaller than the radius dr of the medium area, the value becomes larger than zero.

  Here, the reason that the condition for making the penalty term work with the condition that the medium distance does not exceed the radius dr is because the following disadvantages occur. When the installation position of each transmitter becomes equal to or less than the radius dr of the medium area, the overlapping portion of each medium area becomes larger, while the positionable area corresponding to the line segment connecting the centers of the medium areas becomes smaller. Therefore, since the number of transmitters increases to cover the entire estimation target area, there is a disadvantage that the cost of the entire system becomes expensive. In addition, when the distance between the installation positions of the transmission devices is greatly restricted, for example, to be longer than 2/3 × 2 of the radius, the overlapping part of each medium area becomes small, and an area (only one radio wave covers) The media area (only with one transmitter) is the largest compared to the other areas, and the area where the media areas of the two transmitters that can be positioned overlap becomes smaller. Therefore, in this case as well, the number of transmitters increases to cover the entire estimation target area, resulting in a disadvantage that the cost of the entire system becomes expensive.

In the case of the positioning method using geofencing, the estimation of the installation position of the transmission device is performed by using the second term regarding the area 94 where the medium area does not overlap as the optimization term maximizing the area in the above equation (2-1). It is estimated by the following equation (2-2) as a penalty term minimizing the first, third and fourth terms.

  In this case, an example of an electromagnetic map obtained as an estimation result is shown in FIG. In the example shown in FIG. 21, when the number of transmitting devices is changed to 5 to 20, the area where geofencing can be performed is the largest in six cases, and the other areas are also the smallest.

On the other hand, in the case of the positioning method using two-point positioning, the estimation of the installation position of the transmission device is the area of the third term regarding the area 96 where the medium regions by two transmission devices overlap in the above equation (2-1). The second term relating to the region 94 is defined as a suboptimal dependent term, and the second term relating to the region 94 is estimated by the following equation (2-3) as a penalty term minimizing the first and fourth terms. However, the coefficient α _{x, y} is smaller than the coefficient γ _{x, y in the following} equation (2-3).

  In this case, an example of the electromagnetic map obtained as the estimation result is shown in FIG. In the example shown in FIG. 22, in the case where the number of transmitting devices is changed to 10 to 30, in the case of 20, the two-point positioning is possible with the largest draft area, and the other areas are the smallest.

  On the other hand, in the case of the positioning method using multipoint positioning, the estimation of the installation position of the transmitting device relates to the fourth term regarding the region 98 where the medium region by three or more transmitting devices is superimposed in the above equation (2-1). The optimization terms that maximize the area, and the second and third terms of the area 94 and the area 96 are dependent terms that maximize the semimaximal, and the penalty term that minimizes the first term is the following formula (2-4) Estimated by However, in the following equation (2-4), the coefficient α and the coefficient γ are smaller than the coefficient δ (α <δ, γ <δ).

  In this case, an example of an electromagnetic map obtained as an estimation result is shown in FIG. In the example shown in FIG. 23, when the number of transmission devices is changed to 10 to 30, the area where multipoint positioning can be performed is the largest in the case of 25 and the other areas are also the smallest.

  In FIG. 24, the block diagram of an example of the estimation apparatus 10 of this embodiment is shown. As shown in FIG. 24, the estimation device 10 of the present embodiment includes a weighting function DB 27 instead of the estimation device 10 (see FIG. 6) of the first embodiment and the actual measurement value DB, and replaces the electric field estimation unit 34. , And an estimation unit 35, which differs from the radio wave propagation model unit 36 in that a medium propagation model unit 37 is provided.

  The weighting function DB 27 stores the weighting functions “α”, “β”, “γ”, “δ”, and “κ” at the above-described position (x, y).

  The estimation unit 35 has a function of setting a medium propagation model in the medium propagation model unit 37 and deriving a medium strength value from the set medium propagation model. Further, the estimation unit 35 of the present embodiment derives the medium area of each transmission device based on the medium intensity value input from the medium propagation model unit 37 and the simulation condition acquired from the simulation condition setting unit 20. . Based on the derivation result of the estimation unit 35, the installation position of the transmission device is estimated.

  Next, the operation of the estimation device 10 of the present embodiment will be described.

  The operation of the estimation apparatus 10 of the present embodiment is basically the same as the radio wave propagation model derivation routine (see FIG. 7) described in the first embodiment, but in the radio wave propagation model derivation routine, the following FIG. Repeat the routine shown in.

  In step S200, the estimation device 10 sets the number of transmission devices to an initial value. In the next step S202, the estimation device 10 determines the optimum installation position of the transmission device with respect to the number of transmission devices set in step S200, and derives an evaluation function f (x) at that time.

  In the next step S204, it is determined whether or not the present process is ended. If the above process is repeated a predetermined number of times, or if the number of transmission devices reaches the upper limit value, it is determined whether a predetermined end condition is satisfied. If not satisfied, the determination in step S204 is negative. It transfers to S206. In step S206, the estimation device 10 updates the number of transmission devices, and returns to step S202. Thus, while updating the number of transmission devices until the end condition is satisfied, the process of deriving the optimal installation position according to the number of transmission devices and the evaluation function f (x) is repeated.

  On the other hand, if the end condition is satisfied, the determination in step S204 is affirmative, and the process proceeds to step S208. In step S208, the estimation device 10 determines the number of transmitters and the installation position corresponding to the minimum value among the evaluation functions f (x) derived in step S202 as the optimum value optimum for the estimation target area, End the routine

As described above, the estimation apparatus 10 according to the present embodiment is an estimation apparatus for estimating a position at which a beacon transmitting a radio wave used for positioning is set in an estimation target area to be estimated. The acquisition unit 21 acquires the setting of the number of radio waves transmitted by the beacon whose intensity value is equal to or more than the threshold at the estimation target position in the area, and the strength value of the radio wave of the beacon is less than the threshold in the estimation target area The ratio of the first region, where f2 is the estimation target region, the ratio of the second region, where the intensity value of one radio wave is equal to or greater than the threshold, and f3, the intensity values of two radio waves in the estimation target region The ratio of the third region that is equal to or higher than the threshold, the ratio of the fourth region where the strength value of three or more radio waves is equal to or higher than the threshold among the estimation target regions f4, α _{x, y} , β _{x, y} , γ _{x, y,} and [delta] _x, a _y, according to the position x, y In the case of changing the number of weightings, a desired number of radio waves are received at the estimation target position based on the evaluation function f (x) represented by the above equation (1) and the number acquired by the acquisition unit 21. And an electric field estimation unit 34 for estimating the number and position of beacons to be set in the estimation target area.

  Therefore, according to the estimation device 10 of the present embodiment, the radio wave transmission device can be disposed at the optimum position according to the positioning method.

  In the above embodiments, the Lagrange function (Lagrange multiplier method) is formulated, but other methods may be applied.

  For example, a multi-objective optimization method (a method of simultaneously solving a plurality of objective functions in a trade-off relationship) may be applied. In this case, optimization (maximization and minimization) can be realized while defining each objective function (f1 to f) individually. The merit of using the multi-objective optimization method is that a plurality of Pareto optimal solutions can be obtained, and the Pareto analysis can clarify the allowable range of the installation position of each transmitter. In this way, when a plurality of optimal solutions can be derived, in the actual space where the transmitting device is installed, the location where the transmitting device can be installed and the location where it can not be installed (advertisement, presence, etc.) can be matched. It becomes possible to find a realistic and reasonable optimal solution. In addition, as multi-objective optimization method, Particle Swarm Optimization (Particle Swarm Optimization) described in Reference 1 or Genetic Algorithm (genetic algorithm) described in Reference 2 can be used. .

Reference 1

“Particle Swarm Optimization An Overview”, POLI R., Swarm Intelligence 1 (1), 33-57, 2007

Reference 2

“Genetic Algorithms: An Overview”, Melanie Mitchell, Complexity, 1 (1), 31-39, 1995

  By applying multi-objective optimization to the technology of the present disclosure, given initial values of the estimation variables (the number of transmitters, setting positions), a global optimization solution can be searched by one optimization calculation. it can. A general optimization method (local optimization method) can only obtain local solutions within a certain limited condition (search space). In the local optimization method, it is necessary to perform simulation to determine the setting position many times while updating the number of transmitters, but according to multi-objective optimization, as described above, the simulation is not repeated. It is possible to obtain a global optimum solution.

  In addition, the estimation apparatus 10 of this embodiment can be mounted like an example shown in FIG. 10, for example. The implementation example of the estimation apparatus 10 illustrated in FIG. 10 includes a survey data conversion unit 50, a simulation condition setting file 58, a project file 60, a GUI (Graphical User Interface) unit 62, and a derivation unit 22.

  As shown in FIG. 10, the survey data conversion unit 50 includes a measured value DB 26, a survey application 52, a data extraction and shaping unit 54, and a measured data preprocessing unit 56. The survey application 52 is an application that performs so-called site survey in the derivation target area, and the survey application 52 stores data of the measured value of the radio wave intensity of the beacon measured in the measured value DB 26. The data of the actual measurement values stored in the actual measurement value DB 26 is arranged to be usable by the derivation unit 22 by the data extraction / shaping unit 54 and the actual measurement data preprocessing unit 56, and is made into a project file (project file 60). The simulation conditions for defining the derivation target area are stored in the simulation condition setting file 58, and are converted into project files (project file 60). Furthermore, the setting of the measurement method input by the GUI unit 62 is also made into a project file (project file 60).

  Further, as shown in FIG. 10, the derivation unit 22 includes an actual electric field derivation unit 70, a theoretical electric field derivation unit 72, a radio wave propagation model 76, and an evaluation function 78. When estimating the number of installed beacons and the installation position, the actual electric field deriving unit 70 of the deriving unit 22 reads the project file 60, and uses the radio wave propagation model 76 and the evaluation function 78 to derive the estimated layout diagram 11 as described above. And output to the project file 60. The estimated layout drawing 11 output to the project file 60 can be viewed by the user or the like by the GUI unit 62.

  In the embodiment, the estimation apparatus 10 switches the space propagation coefficient of the radio wave propagation model according to the distance from the beacon to derive the electric field area, but the derivation method is not limited to this form. For example, the electric field region may be derived by a method using a conventional radio wave propagation model in which the space propagation coefficient is not switched.

  Further, in the embodiment, when the evaluation function f (x) is derived, in order to maximize the position of the beacons, the equation (the above equation (3) or the like) for deriving the evaluation function f (x) Although the form which provided penalty term f (5) as term 5 was explained, it is good also as a form which does not provide penalty term f (5). In the case where the penalty term f (5) is not provided, the number of estimated beacons installed is larger than in the case where the penalty term f (5) is provided.

  The embodiment is merely an example, and the specific configuration is not limited to the present embodiment, and includes design and the like within a scope not departing from the scope of the present invention, and it goes without saying that changes can be made depending on the situation. Yes. For example, in the embodiments, the present technology has been described mainly for radio waves, but the present technology can be applied to signals other than radio waves. Naturally, the signals resulting from waves that vibrate the space, such as sound waves and light waves, may be a medium that can measure the distance between the oscillator and the receiver by affecting the presence in the space.

For example, in the embodiment, the embodiment using the radio wave propagation model represented by the above equation (1) has been described, but the radio wave propagation model is not limited to this embodiment. It is sufficient if it is one expression represented by an expression including “× log ₁₀ d”. For example, the radio wave propagation model may be an equation that does not include the model coefficient C on the right side of the equation (1).

10 estimation device 22 derivation unit 21 acquisition unit 34 electric field estimation unit

Claims (9)

An estimation apparatus for estimating a position at which a radio wave transmitting apparatus for transmitting radio waves used for positioning is installed in an estimation target area to be estimated.
An acquisition unit configured to acquire the setting of the number of radio waves transmitted by the radio wave transmission device, the intensity value of which is equal to or greater than a threshold at an estimation target position in the estimation target area;
The ratio of the first area where the radio wave intensity value of the radio wave transmission device is less than the threshold in the estimation target area f1, the intensity value of one of the radio waves in the estimation target area f2 is the threshold Among the estimation target areas, the ratio of the second area, the ratio of the third area where the intensity value of the two radio waves is equal to or more than the threshold, and f4 are three of the estimation target areas The ratio of the fourth region in which the intensity value of the radio wave is equal to or more than the threshold, α _{x, y 1} , β _{x, y 1} , γ _{x, y 1} and δ _{x, y} In the case of a weighting coefficient that changes accordingly, the desired number at the estimation target position based on the evaluation function f (x) represented by the following equation (1-1) and the number acquired by the acquisition unit Radio transmission equipment installed in the estimation target area to receive radio waves of And the electric field estimation unit configured to estimate the number and location of,
Estimation device equipped with
Each of the weighting coefficients is determined according to the number of radio waves acquired by the acquisition unit and the estimation target position.
The estimation device according to claim 1. The electric field estimation unit includes a space propagation coefficient whose value increases as the distance between the radio wave transmission device and the estimation target position decreases, and the space decreases as the distance between the radio wave transmission device and the estimation target position decreases. The intensity at the estimation target position of the radio wave emitted from the radio wave transmitting device at the estimation target position, obtained based on the radio wave propagation model represented by a logarithmic function, in which the frequency at which the propagation coefficients are different often increases Estimate using
The estimation apparatus of Claim 1 or Claim 2. The evaluation function f (x) further includes f5 'which is a term for maximizing the distance between the radio wave transmission devices, with к as a weighting coefficient with respect to the equation (1-1) described below ((1) 2) expressed by
The f 5 ′ functions as a penalty term when the distance is smaller than the radius of the circle when the range in which positioning by the radio wave emitted by the radio wave transmission device is possible is represented by a circle.
The estimation apparatus according to any one of claims 1 to 3.
The electric field estimation unit
Performing an optimization process that alternately performs the change of the number of radio wave transmission devices installed in the estimation target area and the optimization of the evaluation function f (x);
The estimation apparatus according to any one of claims 1 to 4. In order to perform positioning using at least one wave of radio waves, sound waves, and light waves in indoor space, it is an estimation device that estimates the arrangement position of a wave transmission device that is a device that transmits the waves,
An acquisition unit that acquires a cover area which is an area where waves emitted by the first wave transmission device can be used for positioning, and n which is the number of cover areas of the second wave transmission device to be overlapped with the cover area When,
Maximize the area where the number of the cover area of the first wave transmitting device and the cover area of the second wave transmitting device in the indoor space is n, and cover of any wave transmitting device in the indoor space An estimation unit configured to estimate installation positions of the first wave transmission device and the second wave transmission device so as to minimize an area not included in the area;
Estimation device equipped with An estimation apparatus for estimating a position at which a transmitting device for transmitting a wave used for positioning is installed in an estimation target area to be estimated.
An acquisition unit configured to acquire the setting of the number of waves transmitted by the transmission device whose intensity value is equal to or greater than a threshold at an estimation target position in the estimation target area;
The ratio of the first region in which the strength value of the wave of the transmission device is less than the threshold in the estimation target region f1, the strength value of one of the waves in the estimation target region is the threshold or more A ratio of the second region, f3 a ratio of a third region where the strength value of the two waves is equal to or more than the threshold in the estimation target region, f4 three or more of the estimation target regions Ratio of the fourth region where the intensity value of the wave is equal to or more than the threshold value, α _{x, y 1} , β _{x, y 1} , γ _{x, y 1} and δ _{x, y according} to the estimation target position x, y In the case of a weighting coefficient that changes as described above, a desired number of the estimation target positions are obtained based on the evaluation function f (x) represented by the following equation (1-1) and the number acquired by the acquisition unit: Estimate the number and location of the transmitters installed in the area of And a estimation unit that,
The wave is any one of radio wave, sound wave and light wave,
Estimator.
It is an estimation method in an estimation apparatus for estimating a position where a radio wave transmission device for transmitting radio waves used for positioning is installed in an estimation target area to be estimated.
Acquiring a setting of the number of the radio waves transmitted by the radio wave transmission device, the intensity value of which is equal to or greater than a threshold at an estimation target position in the estimation target area;
In the electric field estimation unit, the ratio of the first area where the electric wave of the electric wave transmission device does not reach out of the estimation target area by f1, the electric wave of one of the electric wave transmission devices in the estimation target area is f2. The ratio of the second area reached, the ratio f3 of the third area to which the radio waves of the two radio transmission devices reach, of the estimated area, the ratio f4 of the estimated area A ratio of a fourth area reached by the radio waves of the at least two radio wave transmission devices, α _{x, y} , β _{x, y} , γ _{x, y} , and δ _{x, y,} to the estimation target position x, y When the weighting coefficient is changed according to the following equation (1-1), it is desired to obtain the desired estimation target position based on the evaluation function f (x) represented by the following equation (1-1) and the set number of acquired radio waves. The radio set in the estimation target area to receive radio waves of the number of Estimating the number and position of the transmitter,
Estimation method including the processing of
  The program for functioning a computer as each part of the estimation apparatus in any one of Claims 1-7.