JP2020063961A - Terminal owner detection system, terminal owner detection method, and computer program - Google Patents

Abstract

To estimate an owner of a transmission terminal by a necessary minimum calculation amount in a monitoring space in which a strong reflector exists.SOLUTION: A system main device 100 includes: a storage part 110 for storing structure information 111 including the reflection rate of a radio wave at each place in a monitoring space 20, a position of a receiver 300, and a position of a strong reflector having a reflection rate of a prescribed value or more; a theoretical value calculation part 120 for calculating a theoretical value of a radio wave transmitted from a transmission position if a person carries a transmission terminal 41 and received by the receiver 300 on the basis of the structure information 111 and a detection position of the person; and a comparison determination part 150 for determining that the person carries the transmission terminal 41 in the case that difference between a measured value and a theoretical value of a radio wave received by the receiver 300 when the person is detected is equal to or less than a prescribed value. In the case that a path in which the radio wave from the transmission position is reflected only at the strong reflector and received by the receiver exists, a plurality of theoretical values are calculated on a plurality of different conditions, and the plurality of theoretical values are compared with the measured value.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a terminal holder detection system, a terminal holder detection method, and a computer program, in which a receiver receives a radio wave transmitted from a transmission terminal carried by a person to detect the holder of the transmission terminal.

In recent years, in order to prevent information leakage, it has been required to detect a person who has brought a transmitting terminal such as a smartphone into a highly confidential room.
In Patent Document 1, as one of the techniques for estimating the position of a transmitting terminal, when estimating which of a plurality of persons moving indoors owns the transmitting terminal, radio waves are shielded by the person. It is disclosed that the theoretical value of the reception intensity at the receiving device is calculated in consideration of the above, and the theoretical value is compared with the actually measured value.

According to the technique of Patent Document 1, when the structure information such as the indoor structure, the fixtures installed, and the reflectance at various points inside the room is known, the position of the person moving in the room is determined using the position detection device. The owner of the transmitting terminal can be specified by detecting and comparing the theoretical value and the measured value when the radio wave is transmitted from the detected position.
In the technique of Patent Document 1, an increase in the amount of calculation is suppressed by setting an upper limit on the number of times the radio wave is reflected when calculating the theoretical value.

JP, 2017-181137, A

Here, if an array antenna is used for the receiving device, it is possible to determine that the person located in the arrival direction of the radio wave is the owner of the transmitting terminal by detecting the arrival direction of the radio wave of strong intensity.
Typically, the arrival direction can be detected by ignoring the reflection due to the wall or the like and comparing the theoretical value of the direct wave from the transmitting terminal with the measured value.

  However, an object having a high radio wave reflectance, that is, a strong reflector may exist in a room or the like. The radio wave reflected by the strong reflector may reach the receiving device with the same intensity as the direct wave because the attenuation is small. Therefore, even if the array antenna is used, the detection accuracy may be deteriorated by the reflected wave reflected only by the strong reflector.

Further, the calculation of the arrival direction of the radio wave, which is performed by processing the output signal of the array antenna, is easily affected by the error of the structural information and the measurement error of the detection position of the person. Therefore, in the situation where the reflected wave reaches the receiving device with the same intensity as the direct wave, the change in the theoretical value is large. For this reason, if the theoretical value is uniquely determined in the situation where the reflected wave reaches the receiving device with the same intensity as the direct wave, it becomes difficult to ensure the coincidence between the measured value and the theoretical value. On the other hand, if a plurality of theoretical values are prepared, it is possible to match the theoretical value with the measured value, but if a plurality of theoretical values are always generated, the calculation amount will increase.
The present invention has been made to solve the above problems, and an object of the present invention is to estimate the owner of a transmitting terminal with a minimum necessary calculation amount in a monitoring space in which a strong reflector exists.

  According to one aspect of the present invention, a receiving device that receives radio waves from a transmitting terminal in the monitoring space by an array antenna, a position detecting device that detects the position of a person in the monitoring space, and a system main device are provided. Provided is a terminal holder detection system. The system main unit has a storage unit that stores structural information including the reflectance of radio waves at various points in the surveillance space, the position of the receiving device, and the position of a strong reflector having a reflectance of a predetermined value or more; Based on the detected position of the person and the person, the theoretical value calculation unit that calculates the theoretical value of the electric wave transmitted from the transmission position when the person has the transmitting terminal and received by the receiving device, and the person is detected. And a comparison determining unit that determines that a person possesses the transmitting terminal when the difference between the measured value and the theoretical value of the radio wave received by the receiving device is less than or equal to a predetermined value. When there is a route in which the radio wave from the transmission position is reflected only by the strong reflector and is received by the receiving device, the theoretical value calculation unit calculates a plurality of theoretical values under a plurality of different conditions, and the comparison determination unit Compares a plurality of theoretical values with measured values.

  In the terminal holder detection system according to one aspect of the present invention, the theoretical value calculation unit calculates a route through which the radio wave from the transmission position can reach the reception device with a predetermined attenuation amount or less, and the radio wave from the transmission position is strong. If the difference between the path length of the first path that reaches the receiving apparatus after being reflected only by the reflector and the path length of the second path where the radio wave from the transmission position directly reaches the receiving apparatus is less than or equal to a predetermined value Is calculated, and a single theoretical value is calculated when the difference between the route length of the first route and the route length of the second route is larger than a predetermined value.

  In the terminal holder detection system according to one aspect of the present invention, a plurality of theoretical values are calculated when the strong reflector is near the detection position of the person or near the receiving device.

  According to another aspect of the present invention, a receiving device that receives radio waves from a transmitting terminal in a monitoring space by an array antenna, a position detecting device that detects respective positions of a plurality of persons in the monitoring space, and a system A terminal holder detection system including a main device is provided. The main unit of the system is the reflection of radio waves at various points in the surveillance space, the position of the receiving device, structural information including the position of the strong reflector having a reflectance higher than a predetermined value, the shape of the human being and the reflection of the radio wave on the surface of the human being. A storage unit for storing the human model including the ratio, and a model generation for generating a detection model in which the human model is virtually arranged at each of the detection positions of a plurality of persons based on the structural information and the human model. Section and multiple candidates sequentially selected from multiple persons, and based on the detection model, the theoretical value of the radio wave transmitted from the transmission position when the candidate has the transmitting terminal and received by the receiving device. A theoretical value calculation unit that calculates a value and a candidate having the smallest difference between the measured value and the theoretical value by comparing the measured value and the theoretical value of the radio wave received by the receiving device when a plurality of persons are detected. Owns a calling terminal Comprising a comparison determination unit for constant, the. When there is a route where the radio wave from the transmission position is reflected only by the strong reflector and is received by the receiving device, the theoretical value calculation unit calculates a plurality of theoretical values under different conditions and compares them. The deciding unit compares a plurality of theoretical values with measured values.

  According to still another aspect of the present invention, a receiving device that receives radio waves from a transmitting terminal in the monitoring space by an array antenna, a position detecting device that detects the position of a person in the monitoring space, and a system main device There is provided a terminal holder detection system including: The system main unit stores a theoretical value of the reception intensity when the radio waves transmitted from each transmission position in the monitoring space are received by the reception device, in association with each storage position, and a storage unit that stores the theoretical value. When the difference between the theoretical value associated with the transmission position corresponding to the detection position of the person and the actual measurement value of the reception intensity received by the reception device is less than or equal to a predetermined value, the person at the detection position possesses the transmission terminal. And a comparison determination unit that determines this. The storage unit stores a plurality of different conditions corresponding to the transmission position of the route for the route where the radio wave from the transmission position is reflected only by the strong reflector having a reflectance of a predetermined value or more and is received by the receiving device. The plurality of theoretical values thus obtained are stored, and the comparison and determination unit, based on the respective differences between the plurality of theoretical values and the actual measured values, when the plurality of theoretical values are associated with the transmission position corresponding to the detection position. Then, it is determined whether or not the person at the detection position has the transmitting terminal.

  In the terminal holder detection system according to each of the above modes, the plurality of theoretical values are different in phase difference between a radio wave that reaches the receiving device by being reflected only by the strong reflector and a radio wave that directly reaches the receiving device. Required.

  According to still another aspect of the present invention, a receiving step of receiving a radio wave from a transmitting terminal in the monitoring space by a receiving device having an array antenna, a detecting step of detecting a position of a person in the monitoring space, and a monitoring space. Radio wave reflectance in each place in, the position of the receiving device, and the position of the strong reflector having a reflectance of a predetermined value or more, based on the structural information stored in advance in the storage device, the detected position of the person, The theoretical value calculation step of calculating the theoretical value of the radio wave transmitted from the transmission position when the person has the transmitting terminal and received by the receiving device, and the radio wave received by the receiving device when the person is detected. And a theoretical value are less than or equal to a predetermined value, a terminal owner detection method including a comparison and determination step of determining that a person possesses the transmitting terminal. In the terminal holder detection method, if there is a route where the radio wave from the transmission position is reflected only by the strong reflector and is received by the receiving device, multiple theoretical values are calculated under different conditions in the theoretical value calculation step. A plurality of theoretical values and actual measured values are calculated and compared in the comparison determination step.

  According to still another aspect of the present invention, the step of inputting to the computer the measured value of the radio wave received by the receiving device that receives the radio wave from the transmitting terminal in the surveillance space by the array antenna, and the person in the surveillance space. The step of inputting the detected position of the person detected by the position detecting device for detecting the position of, the reflectance of the radio wave in each place in the monitoring space, the position of the receiving device, and the strong reflector having a reflectance of a predetermined value or more. The theoretical value of the electric wave transmitted from the transmission position when the person owns the transmission terminal and received by the reception device based on the structural information stored in advance in the storage device including the position and the detected position of the person. Comparing the theoretical value calculation step for calculating and the person determining that the person possesses the transmitting terminal when the difference between the measured value and the theoretical value of the radio wave received by the receiving device when the person is detected is less than a predetermined value Computer program for executing a constant step, is provided. In this computer program, when there is a path in which the radio wave from the transmission position is reflected only by the strong reflector and is received by the receiving device, a plurality of theoretical values are calculated under different conditions in the theoretical value calculation step. , A plurality of theoretical values and measured values are compared in the comparison and determination step.

  According to the present invention, when there is a route where a radio wave reflected only by a strong reflector reaches the receiving device, a plurality of theoretical values obtained under different conditions are compared with measured values to determine the radio wave transmission position. To do. Therefore, even if it is difficult for the theoretical value and the actual measurement value to match due to the error in the detected position of the person and the limit of the accuracy of the structural information for calculating the theoretical value of the reception strength, it is possible to calculate multiple values under different conditions. If any of the theoretical values of (1) and (2) match the measured value or the difference is small, the transmission position of the radio wave can be determined. Furthermore, since a plurality of theoretical values are calculated when there is a path in which the radio wave reflected only by the strong reflector reaches the receiving device, the calculation amount of the theoretical value can be suppressed to the necessary minimum and the increase of the calculation amount can be avoided. .

It is a schematic diagram of an example of a mode that the terminal holder detection system of embodiment of this invention is installed and operated. It is a bird's-eye view which looked down at an example of a mode that the terminal owner detection system of an embodiment of the present invention is installed and operated. It is a block diagram of an example of a schematic structure of a terminal holder detection system of a 1st embodiment of the present invention. It is explanatory drawing of an example of the calculation method of the theoretical value of receiving intensity when the electric wave transmitted in the monitoring space is received in the position of a receiver. 5 is a schematic diagram of an example of an array antenna built in the receiving device 300. FIG. It is explanatory drawing of an example of the change of the pattern of the angle spectrum of receiving intensity by the phase difference of a direct wave and a reflected wave. It is a figure which shows an example of the simulation result of the angle spectrum of the reception intensity of a synthetic wave. It is a schematic diagram of an example of a synthetic wave theoretical value and a direct wave theoretical value. It is a flowchart of the operation example of the terminal holder detection system of the first embodiment of the present invention. It is a block diagram of an example of schematic structure of a terminal possession person detection system of a 2nd embodiment of the present invention. It is a flowchart of the operation example of the terminal holder detection system of 2nd Embodiment of this invention. It is a block diagram of an example of schematic structure of a terminal possession person detection system of a 3rd embodiment of the present invention. It is explanatory drawing of an example of the calculation method of a strong reflection area | region. It is a flowchart of the operation example of the terminal holder detection system of 3rd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. The following embodiments of the present invention exemplify devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention includes the structure, arrangement, etc. of components. Are not specified below. Various changes can be added to the technical idea of the present invention within the technical scope defined by the claims described in the claims.

Hereinafter, as a preferred embodiment of the present invention, a case where a terminal holder detection system for detecting a holder of a radio wave transmission terminal is installed and operated in a highly confidential room will be exemplified. Hereinafter, a highly confidential room in which the terminal holder detection system according to the embodiment of the present invention is installed is an example of a “monitoring space” described in the claims.
In recent years, smartphones and tablet terminals have become smaller, and even if such a terminal is hidden in a bag or clothes, it cannot be seen from the outside, so it can be easily brought into a room that handles confidential information.

In addition, these terminals are capable of transmitting a large amount of information with a simple operation due to high performance. For this reason, there is a risk of information leakage using these terminals, and when the terminal is brought into a room that handles confidential information, it is required to discover and identify the owner.
Therefore, in the embodiment described below, a smartphone or a tablet terminal is assumed as the transmitting terminal. However, the transmitting terminal is not limited to these terminals, and may be any other type of terminal as long as it is a terminal that transmits radio waves.

FIG. 1 is a schematic diagram showing how the terminal holder detection system according to the embodiment is installed and operated.
FIG. 1 is a schematic diagram of a room 20 having high confidentiality. In the room 20, there is a person 40 who hides the transmission terminal 41 in his clothes.
The purpose of the terminal owner detection system in this example is to determine whether or not the person 40 possesses the calling terminal.

The room 20 is surrounded by a wall surface A23, a wall surface B24, a wall surface C25, and a wall surface D28 (not shown) as shown in FIG. 1, and is also divided by a floor surface 21 and a ceiling surface 22. There is also a door 26.
The walls are made of general building materials, and although they are not perfect electromagnetic wave absorbers, they have the property of reflecting electric waves at a much lower intensity than the strong reflectors described later.

Further, the room 20 is equipped with an office locker 210 made of a thin iron plate which is a general material. The iron used in the rocker 210 has a reflectance of radio waves of a predetermined value or more, and even if the radio waves are reflected, there is almost no decrease in strength before and after the reflection, and it is a strong reflector that does not easily attenuate. It has been known.
The above-mentioned information regarding the internal structure of the room 20 is expressed in the world coordinate system and is known, and is stored as structural information in the storage unit of the system main unit, as will be described later.

The room 20 is equipped with a position detection device 200. The position detection device 200 is means for outputting the relative position of the person existing in the room 20 as seen from the position detection device 200 as a detection position. In the example of FIG. 1, the position of the person 40 is detected.
The position detection device 200 is installed so as to detect the person 40, and as shown in FIG. 1, it is preferable that the position detection device 200 is installed at the height of the waist to shoulders of the person in the corner of the room. A plurality of position detection devices 200 may be provided.

  The position detection device 200 can be realized by a laser radar type distance sensor. In addition, an image sensor having a camera as an image processing means may be used, or a pressure sensor may be spread over the entire bottom surface of the floor surface 21 to detect the position based on the weight of a person. Good.

  The receiving device 300 is installed on the ceiling surface 22 of the room 20 and includes an antenna device for receiving radio waves. The receiving device 300 is provided with an array antenna so that it can detect not only the reception intensity of the radio wave transmitted from the transmission terminal 41 but also the arrival direction thereof. Since the receiving device is appropriately realized by a well-known technique, detailed description thereof will be omitted.

  When an array antenna is used, the arrival direction of a radio wave, that is, the arrival angle can be measured by using, for example, the known Beamformer method, MUSIC (Multiple Signal Classification) method, or the like. For these methods, see, for example, "The Institute of Electronics, Information and Communication Engineers, Knowledge Base, Knowledge Forest, Group 4, Volume-2, Chapter-8-4, Direction of Arrival Estimation http://www.ieice-hbkb.org/files/04/04gun_02hen_08.pdf. # page = 11 ”.

  FIG. 2A is a bird's-eye view of the room 20 shown in FIG. 1 looking down from the ceiling toward the floor. FIG. 2B shows a coordinate system that defines the arrival direction of a radio wave that arrives at the receiving device 300. In this coordinate system, the front surface of the receiving device 300, that is, the front surface of the antenna is defined to be 0 degree, the right side is 90 degrees, and the left side is −90 degrees, and the x axis of FIG. The direction and the y-axis direction correspond to 0 degrees and 90 degrees, respectively.

(First embodiment)
FIG. 3 shows a block diagram of an example of a schematic configuration of the terminal holder detection system of the first embodiment. The terminal holder detection system 10 includes the system main device 100 in addition to the receiving device 300 and the position detecting device 200 which have already been described.

  In addition, between the receiving device 300 and the position detecting device 200 and the system main device 100, for example, a wired system conforming to standards such as Ethernet (registered trademark), RS232C, RS485, or Wi-Fi (registered trademark), Bluetooth. A communication method based on a wireless system using (registered trademark) or the like may be used, and a description thereof will be omitted.

The system main device 100 includes a storage unit 110, a theoretical value calculation unit 120, a theoretical value buffer 130, a measured value buffer 140, a comparison determination unit 150, and an output unit 160.
The system main device 100 includes a processor such as a CPU (Central Processing Unit) or MPU (Micro-Processing Unit). By executing the computer program stored in the storage unit 110, this processor realizes the functions of the theoretical value calculation unit 120, the theoretical value buffer 130, the measured value buffer 140, the comparison determination unit 150, and the output unit 160.

Hereinafter, each part of the system main device 100 will be described.
The storage unit 110 is a storage unit realized by a known unit such as a magnetic medium such as a hard disk drive (HDD: Hard Disk Drive) or a semiconductor memory. In addition to programs that control the operation of the entire system main unit 100, program modules that configure each unit of the system main unit 100, parameters such as threshold values, an area for temporarily storing data during processing, and structure information 111 are stored. Remember. The stored information is appropriately exchanged with each unit of the system main unit 100.

The structure information 111 is information on the elements that define the room 20, and is used to obtain the theoretical value of the reception intensity in each receiving device.
For example, as shown in FIG. 2A, a coordinate system (world coordinate system) having a corner of the floor as an origin is defined, and wall surfaces A23 to D28, a ceiling surface 22, a floor surface 21, a door 26, and furniture not shown. Geometrical information such as the size and position of a class, mathematical information that defines the shape of a surface such as a wall surface, surface material information, and radio wave reflectance are expressed by a modeling method such as BIM (Building Information Model). Information.

Furthermore, in this example, the structure information 111 records the information of the locker 210 as the information of the strong reflector. As the information of the locker 210, position information indicating the position of the locker 210 in the room 20 in the world coordinate system, the size, and the reflectance of the radio wave on the surface are stored.
As the information of the strong reflector, the structural information 111 includes information on office cabinets such as the locker 210 and other objects having a thin iron plate housing, such as an electric distribution board and a large air conditioner. Be done. The cabinets for offices, distribution boards for electric systems, large-sized air conditioners and the like are examples of the “strong reflector” described in the claims, but the strong reflector is not limited to these. The strong reflector may be another type of object as long as it has an electric wave reflectance of a predetermined value or more.

Office cabinets such as lockers 210, electrical distribution boards, large air conditioners and the like generally use thin iron plates for their housings, and the radio waves emitted from the transmitting terminal 41 are reflected on the surface thereof. However, there is almost no attenuation due to reflection. The reflectance is about 90 to 100%.
When the strong reflector is present in the room 20, the propagation path of the reflected wave in which the radio wave emitted from the transmitting terminal 41 reaches the receiving device 300 by being reflected only on the surface of the strong reflecting body, and the transmitting device 41 to the receiving device 300. The distance difference of the propagation path of the direct wave that reaches directly to may become small. In this case, the reflected wave reflected only by the strong reflector and the direct wave reach the receiving device 300 with the same intensity. These radio waves reach the receiving device 300 with a dominant intensity as compared with the radio waves reflected by an object other than the strong reflector and reaching the receiving device 300, and are measured as a composite wave.

In this way, a region formed by a set of transmission positions of radio waves that reach the receiving device 300 with a reflected wave reflected only on the surface of a strong reflector and a direct wave is called a “strong reflection region”. write.
Such a strong reflection area is a range of the transmission position where the radio wave transmitted from the transmission terminal 41 reaches the receiving device 300 without being attenuated by the reflection on the surface of the strong reflector, and for example, in the vicinity of the rocker 210 or the like. Exists. In addition, a strong reflection region may occur even when a strong reflector exists near the receiving device 300.

  The theoretical value calculation unit 120 inputs the detected position of the person 40 output from the position detection device 200. The detected position output from the position detection device 200 is the azimuth and distance from the position detection device 200 to the person 40. The theoretical value calculation unit 120 refers to the structure information 111 of the storage unit 110 and calculates the coordinates representing the detected position of the person 40 in the world coordinate system in the room 20.

The theoretical value calculation unit 120, when the transmission terminal 41 is present at the detection position of the person 40, as the theoretical value of the reception intensity when the radio wave transmitted from this detection position is received at the position of the receiving device 300, Two kinds of theoretical values, that is, a synthetic wave theoretical value and a direct wave theoretical value are calculated.
The synthetic wave theoretical value is transmitted to the receiving device 300 in a state in which the reflected wave reflected by the rocker 210 is combined with the direct wave that directly reaches the receiving device 300 from the detection position of the person 40 to be a combined wave. Is the theoretical value of the strength of the radio wave received by the receiver.

The theoretical value of the direct wave is a theory of the strength of the radio wave received by the receiving device 300 in a state where the reflected wave reflected by the strong reflector is not combined with the direct wave that directly reaches the receiving device 300 from the detection position of the person 40. It is a value.
The direct wave theoretical value is such that the transmitting terminal 41 is at a position outside the strong reflection region, such as a position away from the rocker 210, and there is a large difference between the propagation paths of the direct wave and the reflected wave. This is the theoretical value of the reception strength when it can be distinguished. Alternatively, the direct wave theoretical value is a theoretical value of the reception intensity when the reflected wave is repeatedly reflected inside the room 20 before reaching the receiving device 300 and is attenuated to such an extent that it cannot be actually measured.

The synthetic wave theoretical value and the direct wave theoretical value are, for example, as shown in FIG. 2B, when the room 20 is looked down from above with respect to the receiving apparatus 300 as shown in FIG. For the measurable angle range of 0 degree in front of 300 and ± 90 degrees to the left and right, it is calculated as an angle spectrum of reception intensity in which the intensities of radio waves coming from each angle are arranged.
In the example of FIG. 2A, when the person 40 has the transmission terminal 41, the maximum intensity (peak) is approximately -60 degrees, ignoring the reflection on the locker 210.

  The theoretical value calculation unit 120 refers to the structure information 111 stored in the storage unit 110 and considers reflection on furniture such as the wall surface and the locker 210 when the transmission terminal 41 is present at the detection position of the person 40. After calculating the propagation path of the radio wave, the theoretical wave composite value or the direct wave theoretical value of the radio wave that can be received by the receiving apparatus 300 is calculated. The propagation path may be calculated based on, for example, a method according to the ray tracing method well known in the field of computer graphics.

Next, an example of a theoretical value calculation method will be described with reference to FIG. FIG. 4 shows the room 20 shown in FIG. 1 looking down from the ceiling toward the floor.
The theoretical value calculation unit 120 determines a route in which the radio wave is omnidirectionally transmitted when the transmitting terminal 41 is present at the detection position of the person 40 and reaches the receiving device 300 in consideration of the reflection by the wall surface or the furniture. calculate.

  FIG. 4A shows an arrow extending around the transmission terminal 41 when the second broken line from the left and the second broken line from the top intersect with each other in the same figure. This arrow is obtained as a path (propagation path) through which the radio wave transmitted from the transmission terminal 41 can propagate. The propagation path is formed in each direction in three dimensions centering on the transmission terminal 41, but in the present embodiment, for the sake of simplicity, a propagation path on a plane viewed from above as shown in FIG. 4 will be described.

The theoretical value calculation unit 120 refers to the structure information 111 stored in the storage unit 110, virtually thinks a straight line called “ray” in each direction from the transmission terminal 41, and considers reflection on a wall surface, a ceiling, or the like. It is calculated as a propagation path to each receiving device. This is based on a method called the ray tracing method.
The theoretical value calculation unit 120 determines the propagation distance until the radio wave is attenuated to a predetermined attenuation amount, as the length of the ray, that is, the maximum distance that the radio wave can propagate. The theoretical value calculation unit 120 can determine the length of the ray by setting an upper limit on the number of times of reflection by other than the strong reflector. For example, the maximum number of reflections can be set to two.

FIG. 4A shows that many rays extend from the transmitting terminal 41. That is, part of the radio wave directly reaches the receiving device 300 (direct wave), part of the electric wave reaches the receiving device 300 after being reflected by the rocker 210 (reflected wave), and part of the electric wave reaches the receiving device 300. It shows that the signal is attenuated without reaching and is not measured by the receiving device 300.
In FIG. 4A, nine rays are shown for simplification of the drawing, and the maximum distance of each ray is not shown. Since the angular resolution of the ray affects the calculation of the theoretical value, it is determined in consideration of the balance between the processing speed and the required accuracy of estimating the position of the transmitting terminal 41. For example, the ray can be calculated once.

Unlike FIG. 4A, FIG. 4B shows a ray when the transmitting terminal 41 is present at a position where the seventh broken line from the left intersects with the fifth broken line from the top. . In FIG. 4B, only a small part of the radio waves reach the receiving device 300, and most of the radio waves are attenuated by the reflection on the wall and do not reach the receiving device 300.
Although the ray reflected by the rocker 210 is not shown in the drawing, it is not measured by the receiving apparatus 300 because it is also reflected and attenuated by a wall or the like in this positional relationship.

  Comparing FIG. 4A and FIG. 4B, there is a direct wave that directly reaches the receiving device 300 from the transmitting terminal 41 in both FIG. 4A and FIG. 4B. However, in the case of FIG. 4B, the reflected wave reflected by the rocker 210 does not exist, or even if it exists, the wave is attenuated because it is far from the receiving apparatus 300 and is not measured.

On the other hand, in FIG. 4A, not only the direct wave but also the reflected wave reflected only by the rocker 210 arrives at the receiving apparatus 300 with an intensity such that the attenuation due to the reflection can be ignored and is measured.
Therefore, the transmission position as shown in FIG. 4A is the transmission position of the radio wave in which the reflected wave reflected only on the surface of the strong reflector and the direct wave reach the receiving device 300 with the same intensity. A set of such transmission positions becomes a strong reflection area.
In FIG. 4C, an example of a region in which a set of radio wave transmission positions at which reflected waves reflected only by the rocker 210 can reach the receiving device 300 with sufficient intensity is surrounded by an outline is a strong reflection region 410. It is shown.

When a radio wave is emitted from the strong reflection region 410, the intensity of the direct wave and the reflected wave reaching the receiving device 300 becomes substantially equal and the frequencies are equal, so that the direct wave and the reflected wave are combined and cannot be separated from each other. How to obtain the theoretical value of the composite wave in such a case will be described with reference to the model diagram of the array antenna of FIG.
FIG. 5 is a schematic diagram of an example of an array antenna built in the receiving device 300. Referring to FIG. 2A, there is shown a case in which a predetermined number of antenna elements are arranged with the x-axis direction in FIG. 2A as the front (0 degree).
Here, for example, it is assumed that four antenna elements are arranged and an integer k (k = 1 to 4) is used to represent the number of each antenna element (channel).

  Now, the distance to the k-th element with reference to the antenna element of number 1 (channel 1) is represented as dk. Further, the intensity of the direct wave that reaches the receiving device 300 is A1, the intensity of the reflected wave that is reflected only by the strong reflector and reaches the receiving device 300 is A2, and the arrival angle of the direct wave with respect to the front 0 degree is θ1, Similarly, the arrival angle of the reflected wave is θ2, the phase difference of the reflected wave with respect to the direct wave when reaching the receiving device 300 is φ, and the wavelength is λ.

As described below, the composite wave changes depending on the phase difference between the direct wave and the reflected wave, but does not depend on the values of the phase of the direct wave and the phase of the reflected wave itself. Therefore, in the following description, the phase of the direct wave is treated as 0 degree.
The radio wave Ek (t) reaching the k-th antenna element is represented by the following equation (1).

  In the equation (1), the first term is the direct wave and the second term is the reflected wave. Also, since it is assumed that the direct wave and the reflected wave have the same intensity,

When is substituted into the equation (1), the right side of the equation (1) can be transformed into the equation (3) by the addition theorem of trigonometric functions.

  In the above equation (3), the amplitude term is represented by the cosine of the function of dk, λ, θ1, θ2 and φ. Here, dk and λ are constants, and when attention is paid to a certain measurement time, θ1 and θ2 are also constants. Therefore, the amplitude and the sign of the amplitude of the composite wave change with the phase difference φ between the direct wave and the reflected wave as a parameter. That is, the amplitude of the composite wave changes depending on the phase difference φ when the direct wave and the reflected wave reach the receiving device 300.

Here, paying attention to the cosine angle of the amplitude term, when the cosine angle changes, the sign changes at the boundaries of 90 degrees (π / 2) and 270 degrees (3π / 2). In this case, the sign of the entire equation (3) changes, which is equivalent to inverting the sine angle of the phase term by 180 degrees (π).
Here, if the distance between the antenna elements is λ / 2, which is a general value, and sin (θ2) −sin (θ1) = B, then Ek (t) (k = 1, 2, 3, 4) The phase difference φ at which the sine angle of the phase term of is rotated by 180 degrees is π for the antenna of number 1, π (B-1) for the antenna of number 2, and π (for the antenna of number 3. 2B-1), which is π (3B-1) for the antenna with the number 4.

  Then, when the reception intensity in the reception device 300 is obtained based on the well-known Beamformer method, as shown in FIG. 6, φ = 0 to 97, 319 to 360 degrees (reference numerals 600 and 640) for rotation of the phase term, In the four ranges of 97 to 180 degrees (reference numeral 610), 180 to 236 degrees (reference numeral 620), 236 to 319 degrees (reference numeral 630), the patterns of the angular spectrum of the reception intensity are completely different.

In FIG. 7, the angle spectrum of the reception intensity of the combined wave in the receiving apparatus 300 when the direct wave included in the combined wave comes from 0 degrees in front and the reflected wave comes from -18 degrees, is obtained by changing φ. The simulation results are shown.
7A shows a spectrum when φ = 0 to 97, 319 to 360 degrees, FIG. 7B shows a spectrum when φ = 97 to 180 degrees, and FIG. 7C shows φ = The spectrum in the case of 180 to 236 degrees is shown, and the spectrum in the case of φ = 236 to 319 degrees is shown in FIG.
In FIG. 7, the horizontal axis represents the angle in the left-right direction when the front surface of the receiving device 300 is 0 degree as described with reference to FIG.

  In the examples of FIGS. 6 and 7, in the vicinity of the phase difference φ = 97 degrees, 180 degrees, 236 degrees, and 319 degrees, the composite wave in which the reflected waves from the strong reflectors are combined changes greatly due to a slight difference in the phase difference. It is shown that. This phase difference φ is related to the arrival directions θ1 and θ2 of the direct wave and the reflected wave as shown in FIG. 6, and the arrival directions θ1 and θ2 are derived from the transmission position and the structural information 111 based on the detected position of the person.

That is, the theoretical value of the synthetic wave obtained by synthesizing the reflected waves of the strong reflector is easily affected by the error in the detection position of the person and the error in the structural information 111.
Therefore, if a unique theoretical value is calculated for the combined wave in which the reflected waves from the strong reflector are combined, it is difficult to ensure the match between the measured value and the theoretical value.

  Therefore, the theoretical value calculation unit 120 determines whether or not the influence of the strong reflector on the theoretical value cannot be ignored based on the detected position of the person, or the detected position of the person and the position of the receiving device 300, and ignores it. If it is not possible, by calculating a plurality of theoretical values, it is possible to secure the agreement between the measured value and the theoretical value while suppressing the increase in processing to the required limit.

Further, the examples of FIGS. 6 and 7 show that the composite wave that changes in relation to the phase difference φ can be approximated by a finite angular spectrum pattern.
Therefore, it is necessary to increase the processing by setting the theoretical value calculated when the theoretical value calculation unit 120 determines that the influence of the strong reflector on the theoretical value cannot be ignored to be a plurality of theoretical values for the phase difference φ. It is possible to further enhance the effect of ensuring the agreement between the actually measured value and the theoretical value while suppressing the limit.

Therefore, when calculating the theoretical value, the theoretical value calculation unit 120 first determines whether or not the detected position of the person 40 is within the strong reflection region.
For example, the theoretical value calculation unit 120 determines a propagation path of a reflected wave in which a radio wave emitted from the detection position of the person 40 reaches the receiving device 300 by being reflected only on the surface of a strong reflector such as the rocker 210, and a person. The detection position of the person 40 is within the strong reflection area depending on whether or not the distance difference between the propagation path of the direct wave directly reaching the receiving apparatus 300 from the detection position of 40 is smaller than a predetermined threshold value. Determine whether or not.

Further, for example, the theoretical value calculation unit 120 determines that the detection position of the person 40 is within the strong reflection area when the strong reflector is near the detection position of the person 40 or near the receiving device 300.
When the detected position of the person 40 is within the strong reflection area 410, a plurality of theoretical values are calculated for one detected position of the person 40 while changing the calculation conditions, that is, using different calculation conditions. Then, the theoretical value is temporarily stored in the theoretical value buffer 130 as a synthetic wave theoretical value.

As a result, even if it becomes difficult for the theoretical value to match the measured value due to the error in the detected position of the person or the limit of the accuracy of the structural information, one of the theoretical values calculated under different conditions will be the measured value. If there is a match or a small difference, the transmission position of the radio wave can be determined.
For example, the theoretical value calculation unit 120 calculates, as a plurality of calculation conditions, theoretical values when the phase difference φ between the direct wave and the reflected wave is different, and calculates the theoretical value as the synthetic wave theoretical value. It is temporarily stored in the buffer 130.
For example, the expected angle from the receiving device 300 to the verification point 400 is used as the arrival angle θ1 of the direct wave, and the expected angle from the receiving device 300 to the rocker 210 determined by referring to the structure information 111 is used as the arrival angle θ2 of the reflected wave. , The phase difference φ is varied to obtain the theoretical value of the composite wave.

When the detected position of the person 40 is not within the strong reflection area 410, the relative angle and distance between the receiving device 300 and the test point 400 are taken into consideration, considering that the receiving device 300 is realized by the array antenna. Then, the theoretical value can be obtained by the same method as the conventional technique using the array antenna assuming that only the direct wave arrives.
The theoretical value calculation unit 120 temporarily stores the theoretical value thus obtained in the theoretical value buffer 130 as a direct wave theoretical value.

FIG. 8 is a schematic diagram of an example of the synthetic wave theoretical value and the direct wave theoretical value calculated by the theoretical value calculating unit 120.
FIG. 8A shows a theoretical value of a synthetic wave when it is assumed that the transmitting terminal 41 is located inside the strong reflection area 410. In the present embodiment, 36 kinds of synthetic wave theoretical values calculated by changing the phase difference φ every 10 degrees at one location inside the strong reflection region 410 are calculated.
The theoretical value of the composite wave is expressed in a table format as an angular spectrum of the reception intensity, in which the intensity value for each angle, for example, for each degree is expressed as a numerical value expressed in a predetermined unit, for example, decibel (dB). .

  FIG. 8B shows the direct wave theoretical value when it is assumed that the transmitting terminal 41 is located outside the strong reflection area 410. As the direct wave theoretical value, one type of direct wave theoretical value is calculated for one position of the transmitting terminal 41. Similar to the synthetic wave theoretical value, the direct wave theoretical value is also expressed in a table format in which the intensity value for each angle, for example, for each degree is expressed as a numerical value expressed in decibels (dB), for example.

  As described above, when the detected position of the person 40 is not included in the strong reflection area 410, one direct wave theoretical value is calculated according to the position and stored in the theoretical value buffer 130. In the case of being included in the region 410, a plurality of synthetic wave theoretical values are calculated according to the phase difference between the direct wave and the reflected wave and stored in the theoretical value buffer 130. For example, 36 are stored when the phase difference φ is changed by 10 degrees.

Further, not only the theoretical value at one time point but also the result at a plurality of time points, that is, when the person 40 is moving, the theoretical value corresponding to the position at each time point is sequentially calculated and stored in the theoretical value buffer 130. You may.
The theoretical value buffer 130 can be appropriately realized by a semiconductor memory or a magnetic disk. It may be a storage device independent of the storage unit 110, or may be realized by securing a certain area in the storage unit 110 and integrating it with the storage unit 110.

  The actual measurement value buffer 140 is a buffer that temporarily stores the actual measurement value of the radio wave transmitted from the receiving device 300 together with the time information. It can be realized by a semiconductor memory or a magnetic disk as appropriate. The measured value buffer 140 may be a storage device that is independent of the theoretical value buffer 130 and the storage unit 110, and secures a certain area in the theoretical value buffer 130 and the storage unit 110 so that the theoretical value buffer 130 and the storage unit 110. May be integrated and realized.

The comparison determination unit 150 compares the theoretical value of the received radio wave stored in the theoretical value buffer with the measured value of the received radio wave stored in the measured value buffer to obtain the difference between the theoretical value and the measured value. For example, this difference may be obtained as the sum of the differences for each angle by normalizing the theoretical value and the actually measured value. Alternatively, the reciprocal of the sum of the differences for each angle may be obtained as a quantity representing the degree of approximation between the theoretical value and the actually measured value, or the normalized correlation between the theoretical value and the actually measured value may be obtained.
When the difference between the theoretical value and the actual measurement value is less than or equal to a predetermined value, the comparison determination unit 150 determines that the person at the position detected by the position detection device 200 has the transmission terminal.

Here, when the detected position of the person 40 is included in the strong reflection area 410, the comparison determination unit 150 causes the differences between the plurality of synthetic wave theoretical values and the actually measured values stored in association with the detected position of the person 40. Ask for.
Even if the difference between any one of the plurality of synthetic wave theoretical values and the measured value is a predetermined value or more, the comparison and determination unit 150 determines that the difference between any one of the other synthetic wave theoretical values and the measured value is the predetermined value. If it is less than the value, it is determined that the person at the position detected by the position detection device 200 has the transmitting terminal.

  When it is determined that the person 40 possesses the transmission terminal, the comparison determination unit 150 notifies the external equipment, the external device, and the external person, for example, the security center or the manager of the room 20 via the output unit 160.

Next, the operation of the terminal holder detection system 10 of the first embodiment will be described with reference to the flowchart shown in FIG.
Before executing the flowchart of FIG. 9, the administrator of the present system causes the storage unit 110 to store the structural information 111 regarding the internal structure of the room 20 using an operation input unit (not shown).

In step S100, the position detection device 200 detects the position of an object, particularly a person, present in the room 20, and transmits the detected position to the system main device 100.
In step S110, the receiving device 300 measures the reception intensity for each arrival direction and obtains the actual measurement value. The result is transmitted to the system main unit 100, and the system main unit 100 stores it in the measured value buffer 140.

In step S120, it is determined whether the actual measurement value of the reception intensity is small and noise is received. When the measured value of the reception intensity is not equal to or more than the predetermined value (step S120: No), the subsequent steps S130 to S170 are not performed.
When the measured value of the reception intensity is equal to or higher than the predetermined value determined as noise (step S120: Yes), the process proceeds to step S130.

  In step S130, the theoretical value calculation unit 120 determines whether the person 40 exists in the strong reflection area 410. When the candidate exists in the strong reflection area 410 (step S130: Yes), the process proceeds to step S140. When the person 40 exists outside the strong reflection area 410 (step S130: No), the process proceeds to step S150.

  In step S140, the theoretical value calculation unit 120 calculates a plurality of synthetic wave theoretical values of the reception intensity when the radio wave transmitted from the detection position of the person 40 is received at the position of the reception device 300. The theoretical value calculation unit 120 temporarily stores the theoretical values of the composite waves in the theoretical value buffer 130. After that, the process proceeds to step S160.

  On the other hand, in step S150, the theoretical value calculation unit 120 calculates the direct wave theoretical value of the reception intensity when the radio wave transmitted from the detection position of the person 40 is received at the position of the receiving device 300. The theoretical value calculation unit 120 temporarily stores the direct wave theoretical value in the theoretical value buffer 130. After that, the process proceeds to step S160.

In step S160, the actual measurement value of the reception intensity stored in the actual measurement value buffer 140 and the theoretical value of the reception intensity stored in the theoretical value buffer 130 are compared to obtain the difference between these values. When the difference between the theoretical value and the actual measurement value is less than or equal to a predetermined value, the comparison determination unit 150 determines that the person at the position detected by the position detection device 200 has the transmission terminal.
In step S170, the output unit 160 outputs the owner information of the calling terminal input from the comparison determination unit 150 to the outside. An external device (not shown) performs, for example, a notification process for calling the owner of the transmitting terminal with attention. After that, the process returns to step S100.

(Effects of the first embodiment)
The terminal possession detection system according to the first embodiment compares a plurality of theoretical values obtained under different conditions with measured values when there is a route where radio waves reflected only by the strong reflector reach the receiving device. Determine the transmission position of the radio wave. Therefore, in the situation where the reflected wave arrives at the receiving device with the same intensity as the direct wave, the angle of the received intensity may vary due to an error in the detected position of the person or an error in the structural information used to calculate the theoretical value of the received intensity. Even if the theoretical value and the actual measurement value are difficult to approximate due to fluctuations in the spectrum pattern, if any of the theoretical values calculated under different conditions match the actual measurement value or the difference is small, the transmission position of the radio wave is determined. You can judge. Furthermore, since a plurality of theoretical values are calculated when there is a path in which the radio wave reflected only by the strong reflector reaches the receiving device, the calculation amount of the theoretical value can be suppressed to the necessary minimum and the increase of the calculation amount can be avoided. .

(Modification)
The configuration and operation of the terminal holder detection system according to the first embodiment have been described above, but the scope of the present invention is not limited thereto.
When the transmitting terminal 41 exists outside the strong reflection area 410, the direct wave from the transmitting terminal 41 to the receiving device 300 becomes dominant in the measurement result.

  Therefore, in this case, the theoretical value calculation unit 120 does not calculate the direct wave theoretical value in accordance with the ray tracing method, but merely the angle of the straight line from the test point 400 to the receiving device 300 (see FIG. 2B). ) May be obtained, and it may be determined whether or not the strength of the radio wave coming from this direction is equal to or higher than the strength threshold value considered to be transmitted from the transmitting terminal 41.

(Second embodiment)
The second embodiment will be described below. In the first embodiment, the description has been made assuming that there is mainly only one person in the room 20, but the scope of the present invention is not limited to this. The terminal holder detection system 10 of the second embodiment determines which person owns the transmitting terminal 41 when a plurality of persons are in the room 20.

If there are a plurality of persons in the room 20 and another person is located between the holder of the transmitting terminal 41 and the receiving device 300, this person acts as a shield that blocks the propagation of radio waves.
Therefore, in the system main device 100 of the second embodiment, at each measurement time point, the theoretical value calculation unit 120 considers attenuation of radio waves by a plurality of persons and calculates the theoretical value in real time according to the ray tracing method described above. It is determined and stored in the theoretical value buffer 130. This method is based on the method disclosed in Patent Document 1.

FIG. 10 is a block diagram showing an example of a schematic configuration of the terminal holder detection system of the second embodiment. The system main device 100 of the second embodiment has a configuration similar to that of the system main device 100 of the first embodiment described with reference to FIG. 3, and similar components are designated by the same reference numerals. The description of the same function will be omitted.
The system main device 100 of the second embodiment includes a storage unit 110, a theoretical value calculation unit 120, a theoretical value buffer 130, a measured value buffer 140, a comparison determination unit 150, an output unit 160, and a model generation unit 170.

  Further, the storage unit 110 of the second embodiment stores a human model 112 including the shape of a human and the reflectance of radio waves on the surface of the human. The human model 112 is information in which a human who may exist in the room 20 is expressed in a three-dimensional shape by a polygon model or a surface model, and at least a height (170 cm) and a width (60 cm) of a standard human body are expressed. It is a model. The human model 112 has a reflectance of radio waves on its body surface.

The model generation unit 170 refers to the structure information 111 and virtually arranges the human model 112 at the detection position of the person in the room 20 by the position detection device 200, and shows the internal state of the room 20 in which the person is arranged. A modeled detection model is generated and output to the theoretical value calculation unit 120.
The theoretical value calculation unit 120 calculates, based on the detection model, along which route the radio wave transmitted from the transmission terminal 41 can propagate to the reception device, and the above-mentioned synthetic wave theoretical value and direct wave theory are calculated. The value is obtained in real time at each measurement time point.

Specifically, the theoretical value calculation unit 120 sequentially selects, from a plurality of persons detected by the position detection device 200, candidates who are assumed to have the transmission terminal 41.
The theoretical value calculation unit 120, when the radio wave transmitted from the transmission terminal 41 possessed by the selected candidate propagates in the room 20 where the model generation unit 170 virtually arranges the human model 112, the locker 210. The distance difference between the propagation path of the reflected wave that reaches the receiving device 300 after being reflected only on the surface of the strong reflector and the propagation path of the direct wave that reaches the receiving device 300 directly from the transmitting terminal 41 is less than a predetermined threshold value. Is also reduced.

When the distance difference between the propagation path of the reflected wave reflected only on the surface of the strong reflector and the propagation path of the direct wave is smaller than a predetermined threshold, the theoretical value calculation unit 120 causes the candidate to exist in the strong reflection area 410. Then determine.
In this case, in the theoretical value calculation unit 120, the radio wave transmitted from the transmission terminal 41 possessed by the candidate propagates in the room 20 in which the model generation unit 170 virtually arranges the human model 112, and the reception device 300. A plurality of synthetic wave theoretical values of the reception intensity when received at the position are calculated. The theoretical value calculation unit 120 temporarily stores the theoretical values of the composite waves in the theoretical value buffer 130.

  On the other hand, the radio waves transmitted from the transmission terminal 41 possessed by the candidate and propagated through the room 20 in which the human model 112 is virtually arranged by the model generation unit 170 are reflected and received only by the surface of the strong reflector. If there is no reflected wave path reaching the device 300 or if the distance difference between the reflected wave propagation path and the direct wave propagation path is larger than a predetermined threshold, the theoretical value calculation unit 120 determines that the candidate is strong. It is determined that it exists outside the reflection area 410.

  In this case, in the theoretical value calculation unit 120, the radio wave transmitted from the transmission terminal 41 possessed by the candidate propagates in the room 20 in which the model generation unit 170 virtually arranges the human model 112, and the reception device 300. The direct wave theoretical value of the reception intensity when it is received at the position is calculated. The theoretical value calculation unit 120 temporarily stores the direct wave theoretical value in the theoretical value buffer 130.

The comparison determination unit 150 compares the theoretical value calculated for each of a plurality of persons with the actual measurement value of the reception intensity received by the receiving apparatus 300, and the person with the smallest difference between the actual measurement value and the theoretical value transmits. It is determined to possess the terminal 41.
If there are a plurality of people in the room 20 and all of them line up in a straight line when viewed from the receiving device 300, it is difficult to deal with the problems described above. Therefore, it is desirable to prepare a plurality of receiving devices 300. In FIG. 1, the receiving device 300 is illustrated as being mounted above the wall A23, but it is also mounted above the wall B24, for example.

Next, the operation of the terminal holder detection system 10 of the second embodiment will be described with reference to the flowchart shown in FIG.
The processing of steps S200 to S220 is the same as the processing of steps S100 to S120 of FIG.
If the actual measurement value of the reception intensity is equal to or higher than the value determined to be noise and is equal to or higher than the value determined to be likely to possess the transmitting terminal by any person (step S220: Yes), the processing is performed. Advances to step S230.

  In step S230, the model generation unit 170 refers to the structure information 111 and the human model 112 stored in the storage unit 110, and sets the human model 112 at the detected position of each person measured by the position detection device 200 in step S300. A detection model is created by virtually arranging and output to the theoretical value calculation unit 120.

The theoretical value calculation unit 120 sequentially selects, from among the plurality of persons detected by the position detection device 200, candidates who are assumed to have the transmission terminal 41, and performs the following steps S240 to S260 for each candidate. Run.
In step S240, the theoretical value calculation unit 120 determines whether the candidate exists in the strong reflection area 410. When the candidate exists in the strong reflection area 410 (step S240: Yes), the process proceeds to step S250. When the candidate exists outside the strong reflection area 410 (step S240: No), the process proceeds to step S260.

  In step S250, the theoretical value calculation unit 120 causes the radio wave transmitted from the transmission terminal 41 owned by the candidate to propagate in the room 20 in which the human model 112 is virtually arranged in step S230, and the reception device 300. A plurality of synthetic wave theoretical values of the reception intensity when received at the position are calculated. The theoretical value calculation unit 120 temporarily stores the theoretical values of the composite waves in the theoretical value buffer 130. Thereafter, the processing proceeds to step S270.

  In step S260, the theoretical value calculation unit 120 causes the radio wave transmitted from the transmission terminal 41 possessed by the candidate to propagate in the room 20 in which the human model 112 is virtually arranged in step S230, and the reception device 300. The direct wave theoretical value of the reception intensity when it is received at the position is calculated. The theoretical value calculation unit 120 temporarily stores the direct wave theoretical value in the theoretical value buffer 130. Thereafter, the processing proceeds to step S270.

In step S270, the comparison determination unit 150 compares the actual measurement value of the reception intensity stored in the actual measurement value buffer 140 with the theoretical value of the reception intensity stored in the theoretical value buffer 130, and the difference between the actual measurement value and the theoretical value. It is determined that the person with the smallest number possesses the transmitting terminal 41.
In step S280, the output unit 160 outputs the owner information of the calling terminal input from the comparison determination unit 150 to the outside. An external device (not shown) performs, for example, a notification process for calling the owner of the transmitting terminal with attention. After that, the process returns to step S200.

(Effects of Second Embodiment)
According to the terminal holder detection system according to the second embodiment, in the surveillance space 20 in which a strong reflector and a plurality of persons are present, the strong reflector is taken into consideration while considering the shielding condition of the radio wave which changes momentarily due to the movement of the person. It is possible to determine whether or not the pattern of the angular spectrum of the reception intensity is likely to change due to the influence of the reflected wave from. Therefore, in a room where a strong reflector and a plurality of persons are present, it is possible to improve the accuracy of estimating which of a plurality of persons owns a transmitting terminal while avoiding an increase in the amount of calculation.

(Third Embodiment)
The third embodiment will be described below. In the first and second embodiments, the synthetic wave theoretical value and the direct wave theoretical value are described as being obtained in real time at each measurement time point, but the scope of the present invention is not limited to this. The terminal holder detection system 10 of the third embodiment calculates the synthetic wave theoretical value and the direct wave theoretical value in advance and stores them in the storage unit 110, and reads these theoretical values according to the detected position of the person 40. And compare it with the measured value.

  FIG. 12 is a block diagram showing an example of a schematic configuration of the terminal holder detection system of the third embodiment. The system main device 100 of the third embodiment has a configuration similar to that of the system main device 100 of the first embodiment described with reference to FIG. 3, and the same reference numerals are given to the similar components. The description of the same function will be omitted.

The system main device 100 of the third embodiment includes a radio wave information determination unit 180 in addition to the storage unit 110, the theoretical value calculation unit 120, the theoretical value buffer 130, the measured value buffer 140, the comparison determination unit 150, and the output unit 160. .
In addition to the structure information 111, the storage unit 110 also stores strong reflection area information 113, a synthetic wave theoretical value 114, and a direct wave theoretical value 115.

The strong reflection area information 113 is position information of the strong reflection area in the world coordinate system in the room 20, and represents the outline of the strong reflection area 410 as shown in FIG. 4C, for example. The strong reflection area information 113 is generated by the theoretical value calculation unit 120 and stored in the storage unit 110.
An example of a method of generating the strong reflection area information 113 will be described with reference to FIG. FIG. 13 shows the room 20 shown in FIG. 1 looking down from the ceiling toward the floor.

The theoretical value calculation unit 120 sets a candidate 400 of the position where the calling terminal 41 exists in the room 20. In FIG. 13, 9 × 7 = total 63 black circles (●) arranged in the horizontal direction (x-axis direction) and in the vertical direction (y-axis direction) are described as candidates 400. ing. Hereinafter, a position where the transmitting terminal 41 is present and a radio wave can be transmitted, that is, a point at the transmitting position is referred to as a “verification point”.
For example, it is desirable that the density of the verification points 400 be set for each half wavelength or less with respect to the carrier frequency in the x-axis direction and the y-axis direction. For example, if the radio wave transmitted from the transmitting terminal 41 is 2.4 GHz, it may be set every 1 to 5 cm.

Next, the theoretical value calculation unit 120 determines whether or not each of the test points 400 is included in the strong reflection area. For example, the theoretical value calculation unit 120 uses the propagation path of the reflected wave in which the radio wave transmitted from the test point 400 reaches the receiving device 300 after being reflected only by the surface of the strong reflector such as the rocker 210, and the test point 400. It is determined whether or not the test point 400 is included in the strong reflection region, depending on whether or not the distance difference from the propagation path of the direct wave directly reaching the receiving device 300 becomes smaller than a predetermined threshold value.
Then, the theoretical value calculation unit 120 determines the outline of the set of the test points 400 included in the strong reflection region, and stores the strong reflection region information 113 indicating the region in the storage unit 110.

  Next, the theoretical value calculation unit 120 obtains a theoretical value of the reception intensity when the radio wave transmitted from each verification point 400 is received by the receiving device 300, and stores it in the storage unit 110 in association with each verification point 400. To do. For the test point 400 inside the strong reflection region 410, the theoretical value calculation unit 120 calculates the synthetic wave theoretical value 114. For the verification point 400 that is not inside the strong reflection area 410, the theoretical value calculation unit 120 calculates the direct wave theoretical value 115. The method of calculating the synthetic wave theoretical value 114 and the direct wave theoretical value 115 is the same as in the first embodiment.

Referring to FIG. The propagation information determination unit 180 inputs the detected position of the person 40 output from the position detection device 200. The detected position output from the position detection device 200 is the azimuth and distance from the position detection device 200 to the person 40. The propagation information determination unit 180 refers to the structure information 111 in the storage unit 110 and calculates the coordinates representing the detected position of the person 40 in the world coordinate system in the room 20.
Further, the propagation information determination unit 180 refers to the strong reflection area information 113 stored in the storage unit 110 and determines whether the detected position of the person 40 is included in the strong reflection area.
The propagation information determination unit 180 may determine that the detection position of the person 40 is included in the strong reflection area when the strong reflector is near the detection position of the person 40 or near the reception device 300. .

When the detected position of the person 40 is included in the strong reflection area 410, the synthetic wave theoretical value 114 stored in association with the detected position of the person 40 is read from the storage unit 110 and temporarily stored in the theoretical value buffer 130. .
When the detected position of the person 40 is not included in the strong reflection area 410, the direct wave theoretical value 115 stored in association with the detected position of the person 40 is read from the storage unit 110 and temporarily stored in the theoretical value buffer 130. Let
The operations of the comparison determination unit 150 and the output unit 160 are the same as those in the first and second embodiments.

Next, the operation of the terminal holder detection system 10 of the third embodiment will be described with reference to the flowchart shown in FIG.
Before executing the flowchart of FIG. 14, the administrator of the present system stores the structural information 111 regarding the internal structure of the room 20 in the storage unit 110 using an operation input unit (not shown).

Steps S300 and S310 are initial settings for detecting the terminal holder.
In step S300, the theoretical value calculation unit 120 refers to the structure information 111 of the storage unit 110, and for each of the test points 400 virtually set in the room 20 by the method according to the ray tracing method, the test point 400 concerned. The theoretical value of the reception intensity when the radio wave transmitted from is received by the receiving device 300 is obtained.

  At that time, as described above, the reflection by the strong reflector such as the rocker 210 is not negligible, for example, the radio wave transmitted from the certification point 400 is reflected only on the surface of the strong reflector such as the rocker 210. When the distance difference between the propagation path of the reflected wave reaching the receiving device 300 and the propagation path of the direct wave directly reaching the receiving device 300 from the test point 400 is small, the phase difference φ between the direct wave and the reflected wave is different. Then, the theoretical values of the plurality of reception intensities are obtained and stored in the storage unit 110 as the synthetic wave theoretical value 114. When the reflection by the strong reflector can be ignored, one theoretical value when the direct wave is received for each of the test points 400 is obtained and stored in the storage unit 110 as the direct wave theoretical value 115.

  In step S310, the theoretical value calculation unit 120 specifies the test points 400 that cannot be ignored for reflection by a strong reflector such as the rocker 210 among the test points 400 processed in the previous step S310, and outlines the set. The line is determined and the strong reflection area information 113 indicating the area is stored in the storage unit 110.

The following steps S320 to S400 are repeatedly executed each time the terminal possession detection system 10 outputs one measurement and a determination result.
In step S320, the system main apparatus 100 receives, as the detection position of the person 40 in the room 20 detected by the position detection apparatus 200, for example, the direction and distance of the person 40 viewed from the position detection apparatus 200 as the detection position of the person 40. . The result is input to the propagation information determination unit 180.

  In step S330, the propagation information determination unit 180 determines whether or not the detection result of the position detection device 200 indicates that the person 40 is present in the room 20. If it does not indicate that the person 40 exists (step S330: No), the process returns to step S320 without performing the following steps S340 to S400. When it is indicated that the person 40 exists (step S330: Yes), the process proceeds to step S340.

In step S340, the system main apparatus 100 receives the actual measurement value of the radio wave intensity measured by the reception apparatus 300 and stores it in the actual measurement value buffer 140.
In step S350, the system main apparatus 100 determines whether the reception intensity of the radio wave received by the receiving apparatus 300 is a predetermined value or more, for example, a value considered to be noise or more.

  When the reception intensity is less than the predetermined value (step S350: No), it is determined that the person 40 existing in the room does not have the transmission terminal 41, and the process returns to S320. You may output the effect to the exterior from the output part 160 suitably. If the reception intensity is equal to or higher than the predetermined value (step S350: Yes), the process proceeds to step S360.

  In step S360, the propagation information determination unit 180 determines whether the detected position of the person 40 is included in the strong reflection area 410 based on the position information of the person obtained in step S320. When the detection position is included in the strong reflection area 410 (step S360: Yes), the process proceeds to step S370. When the detected position is not included in the strong reflection region 410 (step S360: No), the process proceeds to step S380.

In step S370, the propagation information determination unit 180 refers to the position information of the person 40 obtained in step S320, reads the synthetic wave theoretical value 114 corresponding to the detected position of the person 40 from the storage unit 110, and outputs the theoretical value buffer. 130.
The comparison determination unit 150 compares the actual measurement value of the reception intensity stored in the actual measurement value buffer 140 with the plurality of synthetic wave theoretical values 114 stored in the theoretical value buffer 130 to obtain differences. Thereafter, the processing proceeds to step S390.

On the other hand, in step S380, the propagation information determination unit 180 refers to the position information of the person obtained in step S320, reads the direct wave theoretical value 115 corresponding to the detected position of the person 40 from the storage unit 110, and calculates the theoretical value. It is stored in the buffer 130.
The comparison determination unit 150 compares the actual measurement value of the reception intensity stored in the actual measurement value buffer 140 with the direct wave theoretical value 115 stored in the theoretical value buffer 130 to obtain a difference.

  In step S390, the comparison determination unit 150 compares the difference obtained in step S370 or step S380 with a predetermined threshold value. If the difference is large (step S390: No), it is determined that the person 40 in the room 20 does not have the transmitting terminal 41, and the process returns to step S320. Alternatively, since both differences are large, the output unit 160 may appropriately output that the room 20 is noisy to the outside.

If the difference is small (step S390: Yes), it is determined that the person 40 at the position detected by the position detection device 200 in step S320 has the calling terminal 41, and the outside is output via the output unit 160, for example, to the outside. Notify the security center and the manager of the room 20. After that, the process returns to step S320.
When the difference between each of the plurality of synthetic wave theoretical values 114 and the actual measurement value is obtained in step S370, the comparison and determination unit 150 determines whether or not the difference between any of the plurality of synthetic wave theoretical values 114 and the actual measurement value is small. If the difference between any one of the theoretical values 114 of the composite wave and the measured value is small, it is determined that the person 40 possesses the transmitting terminal 41.

(Effect of the third embodiment)
According to the terminal holder detection system of the third embodiment, the synthetic wave theoretical value and the direct wave theoretical value are calculated in advance and stored in the storage unit 110, so that the synthetic wave theoretical value is detected every time the person 20 is detected. And it becomes unnecessary to calculate the direct wave theory value in real time. As a result, the calculation load on the system main unit 100 can be reduced, and the speed of estimating the owner of the transmitting terminal can be improved. Further, since a plurality of synthetic wave theoretical values are generated when there is a path in which the radio wave reflected only by the strong reflector reaches the receiving device, the storage capacity for storing the synthetic wave theoretical values in the storage unit 110 can be saved. .

(Modification)
In addition, in the third embodiment, when there are a plurality of people in the room 20, the position detection device 200 detects the position of each person in the room 20. Then, the comparison and determination unit 60 sequentially selects candidates from a plurality of persons and determines that the candidate having the smallest difference between the theoretical value and the actually measured value obtained for each candidate has the transmitting terminal 41. May be.

It should be noted that in any of the embodiments described so far, it may be possible to affect the theoretical value of the reception strength depending on how the owner holds the transmitting terminal 41. Therefore, the theoretical value calculating unit 120 determines the surface of the owner (for example, the side surface of the face, the surface of the chest, the abdomen or the waist when determining the transmitting position of the radio wave, that is, the position where the holder holds the transmitting terminal 41. It is assumed that the transmitting terminal 41 is carried on the side surface) or near the owner. As the near position, for example, the right side, the left side, the front side, and the back side can be considered.
Then, the position detected by the owner may be taken as the transmission position of the radio wave by adding the displacement amount corresponding to the vicinity position based on the human model.
The theoretical value calculation unit 120 may calculate a propagation route in consideration of how to hold the transmitting terminal 41, in addition to the above-described propagation route. For example, the theoretical value calculation unit 120 may calculate theoretical values for each of a plurality of ways of holding the transmitting terminal 41.

  10 ... Terminal holder detection system, 20 ... Room (monitoring space), 41 ... Sending terminal, 100 ... System main unit, 110 ... Storage unit, 111 ... Structural information, 112 ... Human model, 113 ... Strong reflection area information, 114 ... synthetic wave theoretical value, 115 ... direct wave theoretical value, 120 ... theoretical value calculation unit, 130 ... theoretical value buffer, 140 ... measured value buffer, 150 ... comparison determination unit, 160 ... output unit, 170 ... model generation unit, 180 ... Propagation information determination unit, 200 ... Position detection device, 210 ... Rocker (strong reflector), 300 ... Reception device

Claims (8)

A terminal holder detection system comprising: a receiving device for receiving radio waves from a transmitting terminal in a monitoring space by an array antenna; a position detecting device for detecting a position of a person in the monitoring space; and a system main device. hand,
The system main device is
A storage unit that stores structural information including the reflectance of radio waves at various points in the monitoring space, the position of the receiving device, and the position of a strong reflector having the reflectance of a predetermined value or more,
A theoretical value calculation unit that calculates a theoretical value of an electric wave transmitted from the transmission position when the person has the transmission terminal and received by the reception device, based on the structural information and the detected position of the person. When,
When the difference between the measured value and the theoretical value of the radio wave received by the receiving device when the person is detected is a predetermined value or less, a comparison determining unit that determines that the person has the transmitting terminal,
Equipped with
When there is a path in which the radio wave from the transmission position is reflected only by the strong reflector and is received by the receiving device, the theoretical value calculation unit calculates a plurality of theoretical values under different conditions. Then, the comparison determination unit compares the plurality of theoretical values and the measured value,
A terminal holder detection system characterized by the above. The theoretical value calculation unit,
Calculate a route that the radio wave from the transmission position can reach the receiving device with a predetermined attenuation amount or less,
A path length of a first path through which the radio wave from the transmission position is reflected only by the strong reflector to reach the receiving device, and a path length of a second path through which the radio wave from the transmission position directly reaches the receiving device. When the difference of is less than or equal to a predetermined value, the plurality of theoretical values are calculated,
Calculating a single theoretical value when the difference between the path length of the first path and the path length of the second path is larger than a predetermined value;
The terminal holder detection system according to claim 1, wherein.   The theoretical value calculation unit calculates the plurality of theoretical values when the strong reflector is near the detection position of the person or near the receiving device. Terminal owner detection system. A terminal holder including a receiving device that receives radio waves from a transmitting terminal in the monitoring space with an array antenna, a position detecting device that detects the position of each of a plurality of persons in the monitoring space, and a system main device. A detection system,
The system main device is
Radio wave reflectance at various points in the monitoring space, position of the receiving device, structural information including the position of a strong reflector having the reflectance of a predetermined value or more, human shape and radio wave reflectance on the surface of the human. A storage unit for storing a human model including
A model generation unit that generates a detection model in which the human model is virtually arranged at each of the detection positions of the plurality of persons based on the structural information and the human model,
A candidate is sequentially selected from the plurality of persons, and based on the detection model, a radio wave transmitted from a transmission position when the candidate has the transmission terminal and received by the reception device A theoretical value calculation unit that calculates a theoretical value,
When the plurality of persons are detected, the measured value of the radio wave received by the receiving device is compared with the theoretical value, and the candidate having the smallest difference between the measured value and the theoretical value is the transmitting terminal. And a comparison decision unit that decides to possess
Equipped with
When there is a route through which the radio wave from the transmission position is reflected only by the strong reflector and is received by the receiving device, the theoretical value calculation unit determines a plurality of theoretical values under different conditions. Calculate,
The comparison determination unit compares the plurality of theoretical values and the measured value,
A terminal holder detection system characterized by the above. A terminal holder detection system comprising: a receiving device for receiving radio waves from a transmitting terminal in a monitoring space by an array antenna; a position detecting device for detecting a position of a person in the monitoring space; and a system main device. hand,
The system main device is
A storage unit that stores the theoretical value of the reception intensity when the radio waves respectively transmitted from the respective transmission positions in the monitoring space are received by the receiving device, in association with the respective transmission positions.
When the difference between the theoretical value associated with the transmission position corresponding to the detection position of the person and the actual measurement value of the reception intensity received by the reception device is equal to or less than a predetermined value, the detection position is set at the detection position. A comparison determination unit that determines that a person has the transmission terminal;
Equipped with
The storage unit stores a plurality of different paths in which radio waves from the transmission position are reflected by only strong reflectors having a reflectance of a predetermined value or more and are received by the receiving device, in association with the transmission position of the route. Memorize multiple theoretical values obtained under the condition of
When the plurality of theoretical values are associated with the transmission position corresponding to the detection position, the comparison determination unit, based on the respective difference between the plurality of theoretical values and the actual measurement value, the detection position. Determine whether the person in the possession of the originating terminal,
A terminal holder detection system characterized by the above.   The plurality of theoretical values are obtained by differentiating a phase difference between a radio wave that reaches the receiving device by being reflected only by the strong reflector and a radio wave that directly reaches the receiving device. The terminal holder detection system according to any one of 1 to 5. A receiving step of receiving a radio wave from a transmitting terminal in a surveillance space by a receiving device having an array antenna;
A detection step of detecting the position of a person in the surveillance space,
The structure information stored in advance in the storage device, including the reflectance of the radio wave in each place in the monitoring space, the position of the receiving device, and the position of the strong reflector having the reflectance of a predetermined value or more, and the person's position. A theoretical value calculation step of calculating a theoretical value of an electric wave transmitted from the transmission position when the person has the transmission terminal and received by the receiving device, based on the detected position;
When the difference between the measured value and the theoretical value of the radio wave received by the receiving device when the person is detected is a predetermined value or less, a comparison determination step of determining that the person has the transmitting terminal, Including,
When there is a path in which the radio wave from the transmission position is reflected only by the strong reflector and is received by the receiving device, a plurality of theoretical values are calculated under a plurality of different conditions in the theoretical value calculation step. A method of detecting a terminal holder, wherein the plurality of theoretical values and the measured value are compared in the comparison and determination step. On the computer,
A step of inputting an actual measurement value of a radio wave received by a receiving device that receives a radio wave from a transmitting terminal in a monitoring space with an array antenna,
Inputting the detected position of the person detected by a position detection device that detects the position of the person in the surveillance space;
The structure information stored in advance in the storage device, including the reflectance of the radio wave in each place in the monitoring space, the position of the receiving device, and the position of the strong reflector having the reflectance of a predetermined value or more, and the person's position. A theoretical value calculation step of calculating a theoretical value of an electric wave transmitted from the transmission position when the person has the transmission terminal and received by the receiving device, based on the detected position;
When the difference between the measured value and the theoretical value of the radio wave received by the receiving device when the person is detected is a predetermined value or less, a comparison determination step of determining that the person has the transmitting terminal, Run
When there is a path in which the radio wave from the transmission position is reflected only by the strong reflector and is received by the receiving device, a plurality of theoretical values are calculated under a plurality of different conditions in the theoretical value calculation step. A computer program characterized in that, in the comparing and determining step, the plurality of theoretical values are compared with the actually measured values.

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