JP2015117961A - Detector, detection method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect the direction of an object in a short measuring time.SOLUTION: The detector includes a complex difference transfer function calculation unit and a direction detection unit. The complex difference transfer function calculation unit calculates a complex difference transfer function. The complex difference transfer function is the difference between a first complex transfer function indicating a signal propagation path between a plurality of reception elements and at least one transmission element when an object exists, and a second complex transfer function indicating a signal propagation path between the plurality of reception elements and at least one transmission element when no object exists. The direction detection unit detects a first direction, which is the direction of the object from at least the reception elements, on the basis of the complex difference transfer function.

Description

  The present invention relates to a detection device, a detection method, and a program.

  As a security system (security system) or a security device for detecting an intrusion of an object (for example, a person) into a predetermined area, a detection device using a radio signal has been proposed. For example, Non-Patent Document 1 is information that transmits a radio signal to a predetermined area, receives the signal by an array antenna including a plurality of antennas, and indicates a propagation path of the signal. A method for detecting the direction of an object by analyzing propagation channel information is disclosed. Specifically, in the method described in Non-Patent Document 1, the propagation channel information obtained by measurement for a certain time is expressed in the form of a matrix called a propagation channel matrix, and each element of the propagation channel matrix is Fourier transformed ( (Fourier transform). Then, for example, by extracting only information on a frequency range in which the human body that is the object is assumed to have an influence from the Fourier-transformed propagation channel matrix, the direction of the object can be detected.

  Here, in Non-Patent Document 1, as an algorithm for obtaining the direction of an object from a signal received by an array antenna, there is a method called a MUSIC (Multiple Signal Classification) method disclosed in Non-Patent Document 2. It is used.

Konno, Nanko, Honma, Nishimori, Takemura, Mitsui, Sato, Tsunekawa, “Biological Direction Estimation Method Using Microwave Sensor in Multiwave Environment”, IEICE Society Conference, September 2013, B-1-191 R. Schmidt, “Multiple emitter location and Signal parameter estimation,” IEEE Transactions on Antennas and Propagation, Vol. 34, Issue 3, pp. 276-280, March, 1986

  However, according to the method of Non-Patent Document 1 described above, when calculating the propagation channel matrix in order to detect the direction of the object, it is necessary to measure the propagation channel information for a certain time, for example, about 10 seconds or more. is there. Therefore, when the object is moving, the position and direction of the object during measurement change greatly, and it is difficult to accurately detect the direction.

  On the other hand, when only the MUSIC method described in Non-Patent Document 2 is used, in principle, the direction of the object can be detected in a shorter time. However, in the MUSIC method, in a noisy environment such as an indoor environment where there are multiple reflected waves from other than the object, the direction of the object is accurately detected due to the influence of these noises. There was a problem that was difficult.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is a new and improved technique capable of more accurately detecting the direction of an object in a shorter measurement time. Another object of the present invention is to provide a detection device, a detection method, and a program.

  In order to solve the above problem, according to an aspect of the present invention, a first complex transfer function representing a propagation path of a signal between at least one transmitting element and a plurality of receiving elements when an object exists. And a complex differential transfer function that is a difference between a second complex transfer function representing a signal propagation path between at least one of the transmitting elements and the plurality of receiving elements when the object does not exist. A complex difference transfer function calculating unit for calculating, and a direction detecting unit for detecting at least a first direction that is a direction of the object from the receiving element based on the complex difference transfer function. A detection device is provided.

  According to the present invention, the direction of the object from the receiving element is determined based on the complex difference transfer function that is the difference between the complex transfer function when the object exists and the complex transfer function when the object does not exist. Detected. As described above, by using the complex difference transfer function representing the difference in the propagation path with and without the object, the direction of the object can be detected in a shorter measurement time.

  A reception correlation matrix calculating unit for calculating a reception correlation matrix representing a correlation of the plurality of reception elements with respect to the transmission element based on the complex differential transfer function; and a plurality of the reception elements based on the reception correlation matrix And an evaluation function calculation unit that calculates an evaluation function that indicates the arrival direction of the signal at, and the direction detection unit may detect the first direction based on the evaluation function.

  According to the present invention, the evaluation function indicating the arrival direction of the signal at the receiving element is calculated using the reception correlation matrix calculated based on the complex differential transfer function. Therefore, since the evaluation function reflects the difference in the propagation path depending on the presence or absence of the target object, for example, even without using the complex transfer function measured for a certain period of time, it can be received from the receiving element in a shorter measurement time. It becomes possible to detect the direction of the object.

  Further, the complex difference transfer function calculating unit calculates the complex difference transfer functions for the plurality of transmitting elements and the plurality of receiving elements, and the direction detecting unit is configured to calculate the transmitting element based on the complex difference transfer functions. A position where the second direction, which is the direction of the object from, is further detected, and the position of the object relative to the receiving element and the transmitting element is detected based on the first direction and the second direction You may further provide a detection part.

  According to the present invention, in addition to the direction of the object from the receiving element, the direction of the object from the transmitting element is also detected. Further, the position of the object relative to the receiving element and the transmitting element is detected based on the direction of the object from the receiving element and the direction of the object from the transmitting element. Further, the direction of the object from the transmitting element is also detected based on a complex difference transfer function that is a difference between a complex transfer function when the object exists and a complex transfer function when the object does not exist. . Therefore, both the detection of the direction of the object from the receiving element and the detection of the direction of the object from the transmitting element can be performed in a shorter measurement time, so that the position of the object with respect to the receiving element and the transmitting element can be detected. However, it is possible to perform the measurement with a shorter measurement time.

  A transmission correlation matrix calculating unit for calculating a transmission correlation matrix representing a correlation of the plurality of transmission elements with respect to the reception element based on the complex differential transfer function; and a plurality of the transmission elements based on the transmission correlation matrix And an evaluation function calculating unit that calculates an evaluation function indicating a starting direction of the signal in the direction, and the direction detecting unit may detect the second direction based on the evaluation function.

  According to the present invention, the evaluation function indicating the starting direction of the signal in the transmitting element is calculated using the transmission correlation matrix calculated based on the complex differential transfer function. Therefore, since the evaluation function reflects the difference in the propagation path depending on the presence or absence of the target object, for example, even without using the complex transfer function measured for a certain period, the transmission element from the transmitting element can be obtained in a shorter measurement time. It becomes possible to detect the direction of the object.

  A reception correlation matrix calculating unit that calculates a reception correlation matrix that represents the correlation of the plurality of reception elements with respect to the transmission element; and a transmission correlation matrix that calculates a transmission correlation matrix that represents the correlation of the plurality of transmission elements with respect to the reception element. A calculation unit, and the position detection unit, when there are a plurality of objects, an inner product value of an eigenvector of the reception correlation matrix and a steering vector corresponding to the first direction in the reception element, Based on the inner product value of the eigenvector of the transmission correlation matrix and the steering vector corresponding to the second direction in the transmission element, the eigenvalue of the reception correlation matrix, and the eigenvalue of the transmission correlation matrix, the first From the position corresponding to the intersection of the straight line indicating the direction and the straight line indicating the second direction, the position of the virtual image where the object does not exist is removed. It may detect the position of the object.

  According to the present invention, the object from which the position of the virtual image is removed from the position corresponding to the intersection of the straight line indicating the direction of the object from the receiving element and the straight line indicating the direction of the object from the transmitting element. The position of is detected. Therefore, it is possible to detect the position of the object more accurately without the influence of the virtual image.

  In addition, when the eigenvalues of the reception correlation matrix and the eigenvalues of the transmission correlation matrix are rearranged in descending order, the eigenvalues are located in the same order, including at least the largest eigenvalues that are first eigenvalues in the descending order. The first direction corresponding to the steering vector of the receiving element that maximizes the inner product value with the eigenvector corresponding to the eigenvalue of the reception correlation matrix, and the eigenvector corresponding to the eigenvalue of the transmission correlation matrix. The position of the object may be detected based on the second direction corresponding to the steering vector of the transmitting element that maximizes the inner product value.

  According to the present invention, the eigenvalue of the reception correlation matrix and the eigenvalue of the transmission correlation matrix are associated with the object, and the position of the object with respect to the reception element and the transmission element is detected. Therefore, it is possible to detect the position of the object more accurately without the influence of the virtual image.

  In order to solve the above problem, according to another aspect of the present invention, there is provided a first path representing a signal propagation path between at least one transmission element and a plurality of reception elements when an object exists. A complex difference, which is a difference between a complex transfer function and a second complex transfer function representing a signal propagation path between at least one transmitting element and a plurality of receiving elements when the object does not exist A detection method comprising: calculating a transfer function; and detecting at least a first direction which is a direction of the object from the receiving element based on the complex difference transfer function. Is provided.

  According to the present invention, the direction of the object from the receiving element is determined based on the complex difference transfer function that is the difference between the complex transfer function when the object exists and the complex transfer function when the object does not exist. Detected. As described above, by using the complex difference transfer function representing the difference in the propagation path with and without the object, the direction of the object can be detected in a shorter measurement time.

  In order to solve the above problem, according to another aspect of the present invention, a computer represents a signal propagation path between at least one transmitting element and a plurality of receiving elements when an object exists. A difference between a first complex transfer function and a second complex transfer function representing a propagation path of a signal between at least one transmitting element and a plurality of receiving elements when the object does not exist A program for realizing a function of calculating a complex differential transfer function and a function of detecting at least a first direction that is a direction of the object from the receiving element based on the complex differential transfer function Provided.

  According to the present invention, the direction of the object from the receiving element is determined based on the complex difference transfer function that is the difference between the complex transfer function when the object exists and the complex transfer function when the object does not exist. Detected. As described above, by using the complex difference transfer function representing the difference in the propagation path with and without the object, the direction of the object can be detected in a shorter measurement time.

  As described above, according to the present invention, the direction of an object can be detected more accurately in a shorter measurement time.

It is explanatory drawing for demonstrating the outline | summary of the detection process of the target object in the 1st Embodiment of this invention. It is a functional block (block) figure showing an example of 1 composition of a detecting device concerning a 1st embodiment of the present invention. It is a flow figure showing an example of a processing procedure of a detection method concerning a 1st embodiment of the present invention. It is a graph which shows the result of the detection process of the target object in the 1st Embodiment of this invention. It is explanatory drawing for demonstrating the outline | summary of the detection process of the target object in the 2nd Embodiment of this invention. It is a functional block diagram which shows the example of 1 structure of the detection apparatus which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows an example of the process sequence of the detection method which concerns on the 2nd Embodiment of this invention. It is explanatory drawing for demonstrating the outline | summary of the detection process of the target object in the 3rd Embodiment of this invention. It is a functional block diagram which shows one structural example of the detection apparatus which concerns on the 3rd Embodiment of this invention. It is a graph which shows an example of evaluation function _Pr ((theta) _r ) in 3rd Embodiment. It is a flowchart which shows an example of the process sequence of the detection method which concerns on the 3rd Embodiment of this invention. It is a block diagram which shows an example of the hardware constitutions of the detection apparatus which concerns on 1st, 2nd and 3rd embodiment of this invention.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

<1. First Embodiment>
[1-1. Overview of First Embodiment]
First, an outline of the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is an explanatory diagram for explaining an outline of an object detection process according to the first embodiment of the present invention.

  In the object detection process according to the first embodiment of the present invention, first, a signal is transmitted from a transmission antenna 112 of a transmission device 111 (hereinafter also referred to as Tx 111) toward a predetermined region. Then, a signal reflected by the object 510 (for example, a person) existing in the predetermined area is received by the receiving array antenna 122 of the receiving device 121 (hereinafter also referred to as Rx 121). The following [1-2. The direction of the object 510 from the receiving array antenna 122 is detected by performing the processing described in detail in “Configuration of the Detection Device”.

  Here, the signals exchanged by the transmission device 111 and the reception device 121 are radio waves such as microwaves, for example. However, the present embodiment is not limited to such an example, and as the signal, electromagnetic waves in other frequency bands or other types of signals that can propagate in the air may be used.

  The transmission device 111 has one transmission antenna 112 and transmits a signal from the transmission antenna 112 toward a predetermined region. The transmission device 111 may include a drive circuit that drives the transmission device 111 and transmits a signal having a predetermined characteristic. The drive circuit includes, for example, a signal source that generates a signal, a modulation circuit that modulates the signal, an amplifier that amplifies the signal, and the like, and can transmit a signal having a predetermined characteristic (eg, amplitude, frequency, phase, etc.) Composed. Here, the specific configuration of the transmission device 111 and its drive circuit may be the same as the configuration of a general existing transmission device configured to be capable of transmitting various signals such as radio waves. Description is omitted. The transmission antenna 112 is an example of a transmission element that is configured to transmit a signal toward the outside, and the transmission element included in the transmission device 111 is not limited to such an example. The transmission device 111 only needs to be configured to transmit a signal toward a predetermined area, and may have a configuration other than the transmission antenna 112 as a transmission element.

  The reception device 121 includes a reception array antenna 122 configured by a plurality of reception antennas 123, and receives signals by the reception array antenna 122. The reception device 121 may include a drive circuit that drives the reception device 121 and receives a signal having a predetermined characteristic. The driving circuit includes, for example, a demodulation circuit that demodulates a signal and an amplifier that amplifies the signal, and is configured to be able to receive a signal having the characteristic according to the characteristic of the signal transmitted by the transmission device 111. Here, the specific configuration of the receiving device 121 and its driving circuit may be the same as the configuration of a general existing receiving device configured to be able to receive various signals such as radio waves, and thus the detailed configuration thereof. Description is omitted. The reception antenna 123 that constitutes the reception array antenna 122 is an example of a reception element that is configured to receive a signal, and the reception element included in the reception device 121 is not limited to this example. The reception device 121 only needs to be configured to receive the signal transmitted by the transmission device 111, and may have a configuration other than the reception antenna 123 as a reception element.

  In the example shown in FIG. 1, a transmission device 111, a reception device 121, and a room 500 having a substantially rectangular parallelepiped shape in which one side of a quadrangle constituting the bottom surface (floor surface) is length L and the other side is length W. An object 510 is arranged. In addition, a plurality of glass windows 520 are disposed on one side of the side wall of the room 500.

In the example illustrated in FIG. 1, the transmission device 111 and the reception device 121 have the same direction with respect to the object 510 such that the transmission surface of the transmission antenna 112 and the reception surface of the reception array antenna 122 are substantially the same plane. Are arranged side by side. However, the first embodiment is not limited to this example. For example, as illustrated in FIG. 5 and FIG. 8 described later, the transmission device 111 and the reception device 121 are configured to receive the transmission surface of the transmission antenna 112 and the reception array antenna 122. The surface may be arranged so as to sandwich the region where the object 510 exists. Here, as shown in FIG. 1, in the first embodiment, the direction of the object 510 from the reception array antenna 122 is a normal line with respect to the arrangement direction of the reception antennas 123 in the reception array antenna 122, and It can be expressed as an angle θ _r from a normal passing through the reference point Q _r on the 122 reception surface.

  The detection process of the target object 510 in the first embodiment can be suitably applied to the detection of the target object 510 in the indoor environment as shown in FIG. However, 1st Embodiment is not limited to this example, The detection process of the target object 510 in 1st Embodiment may be applied with respect to other environments, such as the outdoors. Moreover, the environment of the room 500 shown in FIG. 1 is an example of an environment to which the detection processing of the object 510 in the first embodiment can be applied, and the first embodiment is not limited to such an example. For example, the detection processing of the object 510 in the first embodiment can be applied to the room 500 in which the shape of the room 500, the material of the wall, the presence / absence of the glass window 520, the arrangement position, the shape, etc. are appropriately changed It is. Further, in the example illustrated in FIG. 1, the case where the number of the objects 510 is one is illustrated, but the first embodiment is not limited to such an example. The detection process of the target object 510 in the first embodiment can be applied to a plurality of target objects 510.

  The outline of the detection process of the object 510 in the first embodiment of the present invention has been described above with reference to FIG. The following [1-2. In Configuration of Detection Device], a configuration example of the detection device for realizing the detection process of the object 510 in the first embodiment will be described. In addition, the following [1-3. [Processing Procedure of Detection Method] An example of the flow of the processing procedure in the detection processing of the object 510 in the first embodiment will be described. Furthermore, the following [1-4. In Example of First Embodiment], an example of detection processing of the object 510 in the first embodiment will be shown and the effect thereof will be described.

[1-2. Configuration of detection device]
With reference to FIG. 2, a configuration example of the detection apparatus according to the first embodiment of the present invention will be described. FIG. 2 is a functional block diagram showing a configuration example of the detection apparatus according to the first embodiment of the present invention.

  Referring to FIG. 2, the detection apparatus 10 according to the first embodiment includes a transmission unit 110, a reception unit 120, a storage unit 130, and a control unit 140. Note that each function of the detection device 10 illustrated in FIG. 2 may be realized by, for example, a hardware configuration illustrated in FIG.

  The transmission unit 110 is configured by, for example, the transmission device 111 illustrated in FIG. 1 and has a function of transmitting a signal to a predetermined area. The transmission of the transmission unit 110 is controlled by a transmission drive control unit 147 of the control unit 140, which will be described later, and can transmit a signal having a predetermined characteristic to a predetermined region.

  The receiving unit 120 is configured by the receiving device 121 illustrated in FIG. 1, for example, and has a function of receiving a signal transmitted by the transmitting unit 110. The driving of the reception unit 120 is controlled by a reception drive control unit 141 of the control unit 140 described later, and can receive a signal having a predetermined characteristic transmitted by the transmission unit 110. In FIG. 2, a state in which a signal propagates from the transmission unit 110 to the reception unit 120 is schematically indicated by a dashed arrow. In order to avoid complication of the drawing, the illustration is omitted in FIG. 2, but actually, for example, a signal reflected by the object 510 or the like can be received by the receiving unit 120.

The storage unit 130 is configured by various storage devices, for example, and stores various types of information processed by the control unit 140. Specifically, the storage unit 130 includes functions of the control unit 140 described later (a reception drive control unit 141, a transmission drive control unit 147, a complex transfer function measurement unit 142, a complex difference transfer function calculation unit 143, and a reception correlation matrix calculation. Various types of information processed by the unit 144, the evaluation function calculation unit 145, and the direction detection unit 146) and information on the processed results can be stored. For example, the storage unit 130 stores at least information on the second complex transfer function calculated by the complex transfer function measurement unit 142 of the control unit 140 described later. Further, for example, the storage unit 130 may store information about the position of the reference point Q _r in the receiving array antennas 122 (absolute coordinates). Further, the storage unit 130 stores information (driving condition information) about conditions under which the transmission drive control unit 147 of the control unit 140 described later drives the transmission unit 110 and conditions under which the reception drive control unit 141 drives the reception unit 120. May be.

  The control unit 140 includes various processors such as a CPU (Central Processing Unit) and a DSP (Digital Signal Processor), and controls the operation of the detection apparatus 10 in an integrated manner. The control unit 140 includes, as its functions, a reception drive control unit 141, a transmission drive control unit 147, a complex transfer function measurement unit 142, a complex difference transfer function calculation unit 143, a reception correlation matrix calculation unit 144, an evaluation function calculation unit 145, and a direction. A detection unit 146 is included. Each of these functions can be realized by a processor that constitutes the control unit 140 operating according to a predetermined program.

  The transmission drive control unit 147 controls driving of the transmission unit 110. For example, the transmission drive control unit 147 controls the drive of the transmission unit 110 based on predetermined drive condition information, and transmits a signal having a predetermined characteristic from the transmission antenna 112 toward a predetermined region. Further, the transmission drive control unit 147 may control the time when the transmission unit 110 transmits a signal, the interval at which the signal is transmitted, and the like based on the drive condition information. As described above, the drive condition information may include information such as the characteristics of the signal transmitted by the transmission unit 110 and the time and interval at which the signal is transmitted.

  The reception drive control unit 141 controls driving of the reception unit 120. For example, the reception drive control unit 141 controls the driving of the reception unit 120 based on predetermined drive condition information, and causes the reception array antenna 122 to receive a signal having a predetermined characteristic transmitted by the transmission unit 110. Here, the reception drive control unit 141 can acquire drive condition information when the transmission drive control unit 147 drives the transmission unit 110 by referring to the storage unit 130, for example. As described above, since the reception drive control unit 141 can recognize the drive condition when the transmission drive control unit 147 drives the transmission unit 110, the reception drive control unit 141 responds to the drive of the transmission unit 110. The receiving unit 120 can be driven under driving conditions. Therefore, for example, the reception drive control unit 141 drives the reception unit 120 to receive a signal at the same time and interval according to the time when the transmission unit 110 transmits a signal, the interval at which the signal is transmitted, and the like. May be.

  Here, in the first embodiment, the transmission device 111 may include a drive mechanism that changes the direction of the transmission antenna 112, and the reception device 121 may include a drive mechanism that changes the direction of the reception array antenna 122. . The transmission drive control unit 147 can cause the transmission unit 110 to transmit a signal while appropriately changing the direction of the transmission antenna 112 by controlling the drive of the transmission mechanism of the transmission device 111. In addition, the reception drive control unit 141 can cause the reception unit 120 to receive a signal while appropriately changing the direction of the reception array antenna 122 by controlling driving of the drive mechanism of the reception device 121. Note that the change in the direction of the reception array antenna 122 can be performed in conjunction with the change in the direction of the transmission antenna 112. The area where the transmission unit 110 can transmit a signal can be determined by the arrangement position and the arrangement direction of the transmission antenna 112 of the transmission apparatus 111. In addition, an area where the reception unit 120 can receive a signal can be determined by the arrangement position and the arrangement direction of the reception array antenna 122 of the reception device 121. As described above, the direction of the transmission antenna 112 in the transmission device 111 and the direction of the reception array antenna 122 in the reception device 121 can be dynamically changed, so that the object to be detected can be changed dynamically. 510 detection processing can be performed.

  The drive conditions for the transmission drive control unit 147 and the reception drive control unit 141 to drive the transmission unit 110 and the reception unit 120 are, for example, the arrangement position and arrangement direction of the transmission antenna 112 in the transmission device 111, and the reception device. The transmission / reception of signals is performed accurately based on the environment in which the detection processing of the object 510 is performed, such as the position and direction of the reception array antenna 122 in 121 and whether the object 510 exists indoors or outdoors. As described above, it may be set in advance by a user. For example, the driving conditions of the transmission unit 110 and the reception unit 120 may be appropriately set so that signals having characteristics with less attenuation and noise are transmitted and received based on the environment in which the detection processing of the object 510 is performed. Information about the set driving conditions may be stored in the storage unit 130. The transmission drive control unit 147 and the reception drive control unit 141 can drive the transmission unit 110 and the reception unit 120 based on a predetermined drive condition by referring to the storage unit 130.

  The complex transfer function measuring unit 142 measures a complex transfer function representing a signal propagation path between the transmitting antenna 112 and the receiving array antenna 122. Here, the complex transfer function is a function corresponding to propagation channel information which is information representing a propagation path of a signal transmitted and received between the transmission antenna 112 and the reception array antenna 122. For example, the complex transfer function measuring unit 142 can measure the complex transfer function by acquiring information related to the signal received from the receiving unit 120. Further, the complex transfer function measuring unit 142 acquires drive condition information when the transmitting unit 110 and the receiving unit 120 are driven from the storage unit 130, the transmission drive control unit 147, and / or the reception drive control unit 141, and The complex transfer function may be measured further based on information on the characteristics of transmitted and received signals included in the driving condition information, information on the arrangement position and direction of the transmission antenna 112 and the reception array antenna 122, and the like.

Processing performed by the complex transfer function measurement unit 142 will be described in detail. In the first embodiment, the reception unit 120 includes a reception array antenna 122 configured by a plurality of reception antennas 123. Thus, for example, by using a composed receive array antenna 122 by the receive antenna 123 of the _{m r} pieces _{(m r} ≧ 2), which receives signals transmitted by one transmit antenna 112 (i.e., signal of one system) In this case, there are m _r × 1 propagation paths between the transmitting antenna 112 and the receiving array antenna 122. The complex transfer function measurement unit 142 can measure m _r × 1 complex transfer function corresponding to the number of propagation paths.

  Here, in the first embodiment, the complex transfer function measuring unit 142 has no complex transfer function (hereinafter also referred to as a first complex transfer function) and the target object 510 when the target object 510 is present. The complex transfer function of the complex transfer function in the case (hereinafter also referred to as the second complex transfer function) is measured. For example, the second complex transfer function is measured in advance before the measurement process of the first complex transfer function is performed in an environment where the detection process for the object 510 is actually performed.

In the case where the object 510 exists, if the complex transfer function representing the propagation path of the signal received by the i-th (i = 1 to _{m r} ) reception antenna 123 of the reception array antenna 122 is h _i , the reception antenna 123 M _r complex transfer functions h _{1 to} h _mr corresponding to the number m _r can be expressed as a matrix of m _r rows and 1 column with h _i as the (i) component. This matrix is referred to as a complex transfer function matrix H. The complex transfer function matrix H is expressed by the following mathematical formula (1). Although the complex transfer function measuring unit 142 measures the complex transfer functions h _{1 to} h _mr , it can be said that the complex transfer function matrix H is measured. In the following description, the complex transfer function matrix H when the object 510 is present is also referred to as a first complex transfer function matrix H.

……（１）

...... (1)

Similarly, when the object 510 does not exist, if the complex transfer function representing the propagation path of the signal received by the i-th receiving antenna 123 of the receiving array antenna 122 is h _noi , the object 510 does not exist. The complex transfer function matrix H _{no in} is expressed by the following mathematical formula (2). Although complex transfer function measurement unit 142 is to measure the complex transfer function _h no1 _{~h nomr,} it can be said that measuring the complex transfer function matrix _{H no.} In the following description, the complex transfer function matrix H _no when the object 510 is not present is also referred to as a second complex transfer function matrix H _no .

……（２）

(2)

As described above, the complex transfer function measurement unit 142 represents the complex transfer function matrix H in the case where the object 510 exists and the complex transfer function matrix in the case where the object 510 does not exist, in which the complex transfer function is expressed in the form of a matrix. H _no can be measured. The complex transfer function measurement unit 142 obtains information about the second complex transfer function (or information about the second complex transfer function matrix H _no ) measured in advance before the measurement process of the first complex transfer function is performed. For example, it is stored in the storage unit 130. Further, the complex transfer function measurement unit 142 provides the complex difference transfer function calculation unit 143 with information about the measured first complex transfer function (or information about the first complex transfer function matrix H).

  The complex difference transfer function calculation unit 143 calculates a complex difference transfer function that is a difference between the first complex transfer function and the second complex transfer function. For example, the complex difference transfer function calculation unit 143 calculates the complex difference transfer function by subtracting the second complex transfer function from the first complex transfer function. By subtracting the second complex transfer function from the first complex transfer function, for example, the reflection component due to the structure other than the object 510 such as a wall is removed from the complex transfer function, and only the reflection component due to the object 510 is extracted. obtain. The complex difference transfer function calculation unit 143 obtains information about the first complex transfer function from the complex transfer function measurement unit 142, and obtains information about the second complex transfer function by referring to the storage unit 130. A complex difference transfer function can be calculated.

  As shown in the above formulas (1) and (2), the first complex transfer function and the second complex transfer function are expressed in the form of a matrix, so that the complex difference transfer function is also expressed in the form of a matrix. obtain. Specifically, a complex difference transfer function matrix H ′ having a complex difference transfer function in each element is expressed by the following equation (3).

……（３）

...... (3)

  As described above, the complex difference transfer function calculation unit 143 can calculate the complex difference transfer function matrix H ′ in which the complex difference transfer function is expressed in the form of a matrix. The complex difference transfer function calculation unit 143 provides information about the calculated complex difference transfer function matrix H ′ to the reception correlation matrix calculation unit 144.

The reception correlation matrix calculation unit 144 calculates a reception correlation matrix R _r representing the correlation of the plurality of reception antennas 123 of the reception array antenna 122 with respect to the transmission antenna 112 based on the complex difference transfer function matrix H ′. Specifically, the reception correlation matrix R _r is defined by the following mathematical formula (4).

……（４）

...... (4)

Here, the superscript “H” shown at the upper right of H ′ represents a complex conjugate transpose. The reception correlation matrix calculation unit 144 provides information about the calculated reception correlation matrix R _r to the evaluation function calculation unit 145. The reception correlation matrix calculator 144, when calculating a reception correlation matrix R _r, by averaging in the frequency direction the calculated reception correlation matrix in a predetermined frequency band, seeking reception correlation matrix R _r Also good. The accuracy of direction detection can be further improved by the averaging process.

The evaluation function calculation unit 145 calculates an evaluation function P _r (θ _r ) indicating the arrival direction of the signal at the reception array antenna 122 based on the reception correlation matrix R _r . Since the evaluation function P _r (θ _r ) indicates the arrival direction of the signal at the receiving array antenna 122, the evaluation function P _r (θ _r ) includes the arrival direction of the signal reflected by the object 510. That is, it can be said that the information about the direction of the object 510 from the receiving array antenna 122 is included. Here, as the evaluation function P _r (θ _r ), evaluation functions in various arrival direction estimation methods for estimating the arrival direction of signals in the array antenna may be used. In the first embodiment, the evaluation function calculation unit 145 can calculate the evaluation function P _r (θ _r ) in various known arrival direction estimation methods. Here, as an example, a case where the evaluation function calculation unit 145 calculates the evaluation function P _r (θ _r ) in the MUSIC method will be described.

The calculation process of the evaluation function P _r (θ _r ) performed by the evaluation function calculation unit 145 will be described in detail. First, the evaluation function calculating unit 145 by eigenvalue decomposition reception correlation matrix _{R r,} and eigenvector U of the reception correlation matrix _{R r} (eigen vector U), the ^{U H} is the complex conjugate transpose vector of the eigenvector U calculate. The eigenvalue decomposition of the reception correlation matrix R _r is expressed by the following mathematical formula (5).

……（５）

...... (5)

Here, the eigenvector U is a matrix constituted by the eigenvector u _i of the reception correlation matrix R _r and is expressed by the following equation (6). Note that u _i represents the eigenvector of the _i- th column, and the number of elements is _mr .

……（６）

...... (6)

D _r is a diagonal matrix whose diagonal elements are the eigenvalues λ _r1 ,..., Λ _rmr of the reception correlation matrix R _r , and is represented by the following formula (7). In the following description, the eigenvalues λ _r1 ,..., Λ _rmr of the reception correlation matrix R _r are collectively referred to as an eigen value λ _r .

……（７）

...... (7)

Next, the evaluation function calculation unit 145 calculates an evaluation function P _r (θ _r ) expressed by the following mathematical formula (8).

……（８）

...... (8)

Here, L is the number of objects 510 that are targets of direction detection. From the equation (8), in the first embodiment, the number m _r of receiving antenna 123 provided in the receiving array antenna 122, it is determined greater than the number L of the object 510. In other words, the number m _r of receiving antenna 123 constituting the receiving array antenna 122, in the case greater than the number L of the object 510, can be applied detection processing of the object 510 in the first embodiment It can be said that there is.

……（９） Further, a _r (θ _r ) is a steering vector in the receiving array antenna 122 and is represented by the following mathematical formula (9).

...... (9)

Steering vector a _{r (θ r)} is a vector representing the amplitude ratio and phase difference of each receiving antenna 123 constituting the receiving array antennas 122 for the angle theta _r, the angle at the time of detecting the direction of the object 510 theta _r Is determined based on the position of each receiving antenna 123 with respect to the position (reference point Q _r shown in FIG. 1). A specific method for setting the steering vector a _r (θ _r ) may be the same as the method for setting the steering vector in the general MUSIC method. The evaluation function calculation unit 145 provides information about the calculated evaluation function P _r (θ _r ) to the direction detection unit 146.

The direction detection unit 146 detects at least the direction of the object 510 from the reception array antenna 122 based on the evaluation function P _r (θ _r ). As described above, since the evaluation function P _r (θ _r ) indicates the arrival direction of the signal at the reception array antenna 122, the evaluation function P _r (θ _r ) is reflected by the object 510. It can be said that information on the direction of arrival of the received signal, that is, the direction of the object 510 from the receiving array antenna 122 is included. Specifically, the characteristic expressed by the evaluation function P _r (θ _r ) shown in the above equation (8) is called a MUSIC spectrum (spectrum), and the peak (peak) in the evaluation function P _r (θ _r ). ) The angle θ _r corresponding to the position corresponds to the direction in which the object 510 from the receiving array antenna 122 exists. Therefore, the direction detection unit 146 can obtain the angle θ _r indicating the direction in which the object 510 exists with respect to the reception array antenna 122 by extracting the peak position in the evaluation function P _r (θ _r ). The direction of the object 510 from the antenna 122 can be detected. When a plurality of objects 510 exist, a plurality of angles θ _r corresponding to the peak positions in the evaluation function P _r (θ _r ) are extracted. In the following description, the direction of the object 510 from the reception array antenna 122 detected based on the reception correlation matrix R _r is also referred to as a first direction.

As shown in FIG. 1, the angle θ _r is an angle based on the reference point Q _r set on the reception surface of the reception array antenna 122, and thus the reception array antenna detected by the direction detection unit 146. direction of the object 510 from 122 can be said to strictly a direction of the object 510 from the reference point Q _r. However, the reference point Q _r only needs to be set on the reception surface of the reception array antenna 122, and the position can be appropriately set by the user, for example. Therefore, depending on the position where the reference point Q _r is set, the direction of the object 510 from the reception array antenna 122 detected by the direction detection unit 146 is, for example, from any of the reception antennas 123 constituting the reception array antenna 122. It can also be the direction of the object 510. In the following description, the direction of the object 510 (that is, the first direction) detected by the direction detection unit 146 based on the evaluation function P _r (θ _r ) is referred to as the reception array antenna 122 for convenience. Although it referred to as direction, etc. of the object 510 from, in the first embodiment, the first direction detected by the direction detection unit 146 may be a direction of the object 510 from the reference point Q _r Alternatively, the direction may be the direction of the object 510 from any one of the reception antennas 123 constituting the reception array antenna 122.

  Information about the first direction detected by the direction detection unit 146 is stored in the storage unit 130, for example. Although not clearly shown in FIG. 1, the detection device 10 has functions such as a display unit that displays various types of information on a display screen and a communication unit that transmits and receives various types of information to and from other external devices. Further, it may be provided. The information about the first direction detected by the direction detection unit 146 is displayed on the display unit and notified to the user, or transmitted to another external device via the communication unit. You may preserve | save in the memory | storage part of the said other apparatus. Thus, in the first embodiment, the destination to which the information about the first direction detected by the direction detection unit 146 is output may be arbitrary. For example, the detection result may be displayed in real time on the display unit of the detection device 10 or the display unit of another external device, or the storage unit 130 of the detection device 10 or the storage of another external device. The detection result of a predetermined period may be stored in the part as a history.

  The configuration example of the detection apparatus 10 according to the first embodiment of the present invention has been described above with reference to FIG. As described above, in the first embodiment, the complex transfer function measurement unit 142 causes the complex transfer function (first complex transfer function) when the object 510 exists and the complex when the object 510 does not exist. Both transfer functions (second complex transfer functions) are measured. Further, the complex difference transfer function calculation unit 143 calculates a complex difference transfer function that is a difference between the first complex transfer function and the second complex transfer function. Then, the direction of the object 510 from the reception array antenna 122 is detected based on the complex difference transfer function. As described above, in the first embodiment, by using the complex difference transfer function that represents the difference in the propagation path with or without the object 510, the direction of the object 510 can be detected in a shorter measurement time. it can.

  Here, for example, in the method described in Non-Patent Document 1 described above, in order to detect the direction of an object, it is necessary to measure propagation channel information (that is, complex transfer function) for a certain time, for example, about 10 seconds or more. there were. However, in the first embodiment, as soon as a signal is received by the receiving array antenna 122, the first complex transfer function can be measured and the complex difference transfer function can be calculated. The direction of the object 510 can be detected in a very short time.

  In the first embodiment, a complex transfer function matrix in which a complex transfer function is expressed in the form of a matrix is used. The complex transfer function matrix can easily correspond to a so-called multipath environment in which a plurality of signals are included in the received signal. Therefore, according to the first embodiment, the direction of the object 510 can be detected with higher accuracy in a shorter measurement time even in a multipath environment.

In the first embodiment, the arithmetic processing performed by the evaluation function calculation unit 145 may be the same as the arithmetic processing generally performed in the MUSIC method. Therefore, the calculation process of the evaluation function P _r (θ _r ) in the first embodiment is a reception correlation matrix R shown in the above equation (4) as the correlation matrix used in the calculation process of the evaluation function in the general MUSIC method. It may be substituted with _r .

In the above description, the case where the MUSIC method is used as a method for estimating the arrival direction of a signal has been described. However, the first embodiment is not limited to such an example. In the first embodiment, the evaluation function calculation unit 145 may calculate an evaluation function in another method for estimating the arrival direction, and the direction detection unit 146 uses the object 510 based on the evaluation function in the other method. May be detected. As another method for estimating the arrival direction, for example, a beamformer method, a Capon method, a linear prediction method, or the like can be used. The evaluation function calculation unit 145 generally replaces the correlation matrix used in the calculation process of the evaluation function of each of these methods with the reception correlation matrix R _r shown in the above equation (4), so that each of these methods is used. A corresponding evaluation function can be calculated. In addition, as a specific calculation method of the evaluation function in the beamformer method, the Capon method, and the linear prediction method, various known methods used in each of these methods can be used, and thus detailed description thereof is omitted. .

  Further, the functional configuration of the detection apparatus 10 according to the first embodiment is not limited to the example illustrated in FIG. For example, the function of the detection apparatus 10 illustrated in FIG. 2 is not necessarily realized by a single apparatus, and may be realized by cooperation of a plurality of apparatuses connected to each other by a network. For example, each function of the control unit 140 illustrated as a functional block in FIG. 2 is performed by the control units of a plurality of information processing apparatuses connected to each other via a network, thereby performing various arithmetic processes performed in each function. This can be performed in parallel, and a further reduction in calculation time associated with the detection process can be realized. Further, for example, among the functions of the detection device 10, the transmission unit 110 and the reception unit 120 and other functions may be configured by separate devices. For example, a terminal that includes at least a transmission unit 110 and a reception unit 120 is installed in an environment where detection processing of an object 510 is performed, and the workstation specialized in arithmetic processing installed on the terminal, for example, a cloud Each function of the detection device 10 may be realized by connecting an information processing device such as a (workstation) to be communicable with each other via a wired or wireless network. By installing only a terminal including at least the transmission unit 110 and the reception unit 120 in an environment where the detection processing of the target object 510 is performed, the terminal can be further downsized.

[1-3. Procedure of detection method]
Next, with reference to FIG. 3, the processing procedure of the detection method according to the first embodiment of the present invention will be described. FIG. 3 is a flow diagram illustrating an example of a processing procedure of the detection method according to the first embodiment of the present invention. Each process illustrated in FIG. 3 can be realized by the functional configuration of the detection device 10 described above. For example, the processing included in the control unit 140 of the detection device 10 is performed according to a predetermined program. obtain.

Referring to FIG. 3, in the detection method according to the first embodiment of the present invention, first, for example, the complex transfer function measurement unit 142 represents a signal propagation path between the transmission antenna 112 and the reception array antenna 122. A complex transfer function is measured (step S101 (step S101)). In the processing shown in step S101, both the complex transfer function (first complex transfer function) when the target object 510 exists and the complex transfer function (second complex transfer function) when the target object 510 does not exist are measured. Is done. For example, the second complex transfer function is measured in advance before the first complex transfer function is measured. Further, since there can exist as many complex transfer functions as the number m _r × 1 of signal propagation paths between the transmitting antenna 112 and the receiving array antenna 122, it can be expressed in the form of a matrix. Therefore, in the process in step S101, the complex transfer function matrix H in the case where the object 510 exists and the complex transfer function matrix H _{no in the} case where the object 510 does not exist are measured. Can be done.

Next, for example, the complex difference transfer function calculation unit 143 calculates a complex difference transfer function that is a difference between the complex transfer function when the object 510 exists and the complex transfer function when the object 510 does not exist ( Step S103). Actually, since the complex transfer function can be expressed in the form of a matrix, the complex transfer function matrix H when the target object 510 exists and the complex transfer when the target object 510 does not exist are calculated by the complex difference transfer function calculation unit 143. A complex difference transfer function matrix H ′ that is a difference from the function matrix H _no can be calculated.

Next, for example, the reception correlation matrix calculation unit 144 calculates a reception correlation matrix R _r representing the correlation of the plurality of reception antennas 123 of the reception array antenna 122 with respect to the transmission antenna 112 based on the complex difference transfer function matrix H ′. (Step S105). The reception correlation matrix R _r can be calculated using, for example, the above equation (4).

Then, for example, by the evaluation function calculation unit 145, the received correlation matrix _{R r} is the eigenvalue decomposition, eigenvalue lambda _r of reception correlation matrix _{R r,} eigenvectors U and steering vectors _{a r} a reception correlation matrix _{R r (θ r)} is calculated (Step S107). Similarly, for example, the evaluation function calculation unit 145 calculates the evaluation function P _r (θ _r ) indicating the arrival direction of the signal at the reception array antenna 122 based on these calculation results (step S109). The steering vector a _r (θ _r ) and the evaluation function P _r (θ _r ) can be calculated using, for example, the above formula (9) and the above formula (8), respectively.

Next, for example, the direction detection unit 146 detects at least the direction of the object 510 from the reception array antenna 122 based on the evaluation function P _r (θ _r ) (step S111). Since the evaluation function P _r (θ _r ) indicates the arrival direction of the signal at the receiving array antenna 122, the evaluation function P _r (θ _r ) includes the arrival direction of the signal reflected by the object 510, That is, it can be said that the information about the direction of the object 510 from the receiving array antenna 122 is included. For example, in the evaluation function P _r (θ _r ), the angle θ _r corresponding to the peak position corresponds to the direction in which the object 510 exists. Accordingly, in the process shown in step S111, the direction detection unit 146 extracts the peak position in the evaluation function P _r (θ _r ), thereby the angle θ _r indicating the direction in which the object 510 is present with respect to the reception array antenna 122. And the direction of the object 510 from the receiving array antenna 122 can be detected.

The processing procedure of the detection method according to the first embodiment of the present invention has been described above with reference to FIG. In the above description, in the process shown in step S109, the evaluation function P _r (θ _r ) in the MUSIC method shown in the mathematical formula (8) is calculated as the evaluation function P _r (θ _r ). Embodiments are not limited to such examples. In the first embodiment, in the process shown in step S109, the evaluation function calculation unit 145 may calculate an evaluation function in another method for estimating the arrival direction. In the process shown in step S111, the direction detection unit 146 Thus, the direction of the object 510 may be detected based on the evaluation function in the other method. As another method for estimating the arrival direction of the signal, for example, a beam former method, a Capon method, a linear prediction method, or the like may be used.

[1-4. Example in the first embodiment]
Next, an example in the first embodiment will be described. In order to confirm the effects of the present invention, the present inventors conducted an experiment for detecting the direction of the object 510 by the processing procedure shown in FIG. 3 using the detection apparatus 10 according to the first embodiment described above. went.

  The environment in which the experiment was conducted will be described. The experiment was conducted in the indoor environment shown in FIG. Specifically, at one corner of a room 500 having a substantially rectangular parallelepiped shape with a length L of one side of the bottom surface (floor surface) of 7.0 (m) and a length of other side W of 6.0 (m). As shown in FIG. 1, the detection device 10 according to the first embodiment is arranged. The wall around the room 500 is made of concrete, and a plurality of glass windows 520 are arranged on one side of the side wall.

As the receiving array antenna 122 of the detection apparatus 10, an array antenna in which four receiving antennas 123 are arranged at intervals of 0.5 wavelengths in the horizontal direction is used. The transmitting antenna 112 is a single element antenna and is disposed in the vicinity of the receiving array antenna 122. Specifically, as shown in FIG. 1, the transmitting antenna 112 and the receiving array antenna 122 are arranged so that their transmitting and receiving surfaces are located in substantially the same plane. The test frequency was 2.4 (GHz) band, and the transmission power was 10 (dBm). Further, as the object 510, one person is placed at a position where the angle θ _r from the receiving array antenna 122 is θ _r = −40 (deg) and the distance from the receiving array antenna 122 is 2 (m). Arranged. Here, as shown in FIG. 1, the angle θ _r is a normal line with respect to the arrangement direction of the reception antennas 123 in the reception array antenna 122 and is from a normal line passing through the reference point Q _r on the reception surface of the reception array antenna 122. _Is defined as the angle θ _r of

Under the conditions described above, the detection processing of the object 510 was performed using the detection apparatus 10 according to the first embodiment of the present invention by the processing procedure shown in FIG. In FIG. 4, the result of the detection process of the target object 510 in the 1st Embodiment of this invention is shown. FIG. 4 is a graph showing the result of the processing for detecting the object 510 in the first embodiment of the present invention. In FIG. 4, the horizontal axis represents the angle θ _r , and the vertical axis represents the evaluation function P _r (θ _r ). As described above, the angle θ _r corresponding to the peak position in the evaluation function P _r (θ _r ) indicates the direction in which the object 510 from the reception array antenna 122 exists. Further, in FIG. 4, for the sake of explanation, the position of θ _r = −40 (deg), which is an angle corresponding to the direction in which the target object 510 actually exists, is illustrated by a broken line.

In FIG. 4, a curve C indicated by a solid line indicates an evaluation function P _r (θ _r ) (that is, a peak position) indicating the best value after the detection processing of the object 510 in the first embodiment is performed a total of 201 times. The corresponding angle θ _r represents the evaluation function P _r (θ _r )) that is closest to −40 (deg). The curve D indicated by the alternate long and short dash line corresponds to the evaluation function P _r (θ _r ) (that is, the peak position) indicating the worst value after the detection processing of the object 510 in the first embodiment is performed 201 times in total. angle θ _r represents the -40 most aways was the evaluation function _{P r} from _{(deg) (θ r))} . Further, in FIG. 4, for comparison, for example, an evaluation function P _r (θ _r ) obtained by a general MUSIC method described in Patent Document 2 is illustrated as a curve B indicated by a dotted line.

Referring to FIG. 4, it can be seen that in the first embodiment of the present invention, the evaluation function P _r (θ _r ) takes a maximum value corresponding to the direction in which the object 510 exists. As shown in FIG. 4, the angle θ _r corresponding to the maximum value in the evaluation function P _r (θ _r ) showing the best value in the first embodiment is about −38 (deg), and the object is actually It can be said that a value substantially equal to −40 (deg), which is an angle at which 510 exists, is detected. In addition, the angle θ _r corresponding to the maximum value in the evaluation function P _r (θ _r ) showing the worst value in the first embodiment is about −30 (deg), and the angle at which the object 510 actually exists. A deviation of about 10 (deg) from -40 (deg), which is the value, occurred. However, if the object 510 exists at a position 2 (m) from the receiving array antenna 122 and the size of the human body used as the object 510 (particularly the width of the body in the detection direction), The deviation amount of about 10 (deg) can be said to be an acceptable value.

On the other hand, as shown by the curve C, in the evaluation function P _r (θ _r ) obtained by a general MUSIC method, the angle θ _r corresponding to the maximum value is about 1 (deg), and the target actually It is greatly different from −40 (deg), which is the angle at which the object 510 exists. From this result, it can be seen that according to the first embodiment of the present invention, the direction of the object 510 can be detected more accurately as compared with the conventional method described in Non-Patent Document 2, for example.

  The example in the first embodiment has been described above with reference to FIG. As shown in FIG. 4, according to the first embodiment of the present invention, for example, the direction of the object 510 can be detected more accurately than in the conventional method described in Non-Patent Document 2. I understand that Further, as described above, in the first embodiment, by using a complex difference transfer function that represents a difference in propagation path with or without the object 510, for example, compared to the conventional method described in Non-Patent Document 1. Thus, the detection processing of the direction of the object 510 can be performed in a shorter measurement time (for example, a very short time on the order of ms). Thus, according to the first embodiment, it has been found that the direction of the object 510 can be detected more accurately in a shorter measurement time.

<2. Second Embodiment>
[2-1. Outline of Second Embodiment]
Next, an outline of the second embodiment of the present invention will be described with reference to FIG. FIG. 5 is an explanatory diagram for explaining an outline of the object detection process in the second embodiment of the present invention.

  Referring to FIG. 5, a transmission apparatus 211 (hereinafter also referred to as Tx211) having a transmission array antenna 212 composed of a plurality of transmission antennas 213, and a reception apparatus 121 having a reception array antenna 122 composed of a plurality of reception antennas 123. However, they are arranged opposite to each other with a predetermined area interposed therebetween. An object 510 (for example, a person) exists in the predetermined area. In the example shown in FIG. 5, the case where there are four objects 510 is illustrated, but the second embodiment is not limited to such an example, and the number of objects 510 is an arbitrary number. Good.

  The specific configuration of the receiving apparatus 121 may be the same as the configuration of the receiving apparatus 121 in the first embodiment described with reference to FIG. The transmission device 211 corresponds to the transmission device 111 in the first embodiment described with reference to FIG. 1 in which the transmission antenna 112 is replaced with a transmission array antenna 212. Since the configuration (for example, a drive circuit) other than the transmission array antenna 212 in the transmission device 211 may be the same as the configuration of the transmission device 111 illustrated in FIG. 1, detailed description thereof is omitted.

  In the second embodiment, a signal is transmitted from the transmission array antenna 212 of the transmission device 211 toward a predetermined area. Then, the signal reflected by the object 510 existing in the predetermined area is received by the reception array antenna 122 of the reception device 121. The following [2-2. The direction of the object 510 from the reception array antenna 122 and the transmission array antenna 212 is detected by performing the processing detailed in the configuration of the detection apparatus]. Further, by calculating a position corresponding to the intersection of the direction of the object 510 from the receiving array antenna 122 and the direction of the object 510 from the transmitting array antenna 212, the object for the receiving array antenna 122 and the transmitting array antenna 212 is calculated. The position of the object 510 is detected.

In the second embodiment, the direction of the object 510 from the reception array antenna 122 is a normal line to the arrangement direction of the reception antennas 123 in the reception array antenna 122 and is a reference point Q _r on the reception surface of the reception array antenna 122. Can be expressed as an angle θ _r from the normal passing through. In addition, the direction of the object 510 from the transmission array antenna 212 is a normal line to the arrangement direction of the transmission antennas 213 in the transmission array antenna 212 and from a normal line passing through the reference point Q _t on the transmission surface of the transmission array antenna 212. _Can be expressed as an angle θ _t of

  Here, in the first embodiment described above, the reception array antenna 122 is used by using the transmission device 111 having one transmission antenna 112 and the reception device 121 having the reception array antenna 122 including a plurality of reception antennas 123. The direction of the object 510 is detected, and the direction of the object 510 from the transmitting antenna 112 is not detected. On the other hand, as described above, in the second embodiment, the transmission device 211 includes the transmission array antenna 212 including a plurality of transmission antennas 213. An object from the reception array antenna 122 is obtained by using a transmission device 211 having a transmission array antenna 212 composed of a plurality of transmission antennas 213 and a reception device 121 having a reception array antenna 122 composed of a plurality of reception antennas 123. In addition to the direction of 510, the direction of the object 510 from the transmit array antenna 212 is detected. Further, the position of the object 510 with respect to the reception array antenna 122 and the transmission array antenna 212 is detected by detecting the position at the intersection of the detected straight lines indicating these directions.

  The outline of the detection process of the target object 510 in the second embodiment of the present invention has been described above with reference to FIG. Below, the following [2-2. In Configuration of Detection Device], a configuration example of the detection device for realizing the detection processing of the object 510 in the second embodiment will be described. The following [2-3. [Processing Procedure of Detection Method] An example of the flow of the processing procedure in the detection processing of the object 510 in the second embodiment will be described.

[2-2. Configuration of detection device]
With reference to FIG. 6, one structural example of the detection apparatus which concerns on the 2nd Embodiment of this invention is demonstrated. FIG. 6 is a functional block diagram showing a configuration example of the detection apparatus according to the second embodiment of the present invention.

  Referring to FIG. 6, the detection device 20 according to the second embodiment includes a transmission unit 210, a reception unit 120, a storage unit 130, and a control unit 240. Each function of the detection device 20 illustrated in FIG. 6 can be realized by, for example, a hardware configuration illustrated in FIG. Here, the detection device 20 according to the second embodiment corresponds to the detection device 10 according to the first embodiment shown in FIG. 2 in which some functions are changed. Therefore, in the following description of the configuration of the detection device 20, differences from the first embodiment will be mainly described, and detailed description of overlapping items will be omitted.

  The transmission unit 210 includes, for example, the transmission device 211 illustrated in FIG. 5 and has a function of transmitting a signal to a predetermined area. The transmission of the transmission unit 210 is controlled by a transmission drive control unit 147 of the control unit 240 described later, and a signal having a predetermined characteristic can be transmitted to a predetermined region. In FIG. 6, similarly to FIG. 1, the state of signal propagation from the transmission unit 110 to the reception unit 120 is indicated by broken-line arrows.

The functions of the receiving unit 120 and the storage unit 130 may be the same as the functions of the receiving unit 120 and the storage unit 130 of the detection apparatus 10 according to the first embodiment shown in FIG. In the second embodiment, the storage unit 130, along with information about the position of the reference point Q _r in the receiving array antennas 122 (absolute coordinates), the position of the reference point Q _t in the transmission array antenna 212 (absolute coordinates) May be stored.

  The control unit 240 is configured by various processors such as a CPU and a DSP, and controls the operation of the detection device 20 in an integrated manner. The control unit 240 functions as a reception drive control unit 141, a transmission drive control unit 147, a complex transfer function measurement unit 242, a complex difference transfer function calculation unit 143, a reception correlation matrix calculation unit 144, a transmission correlation matrix calculation unit 247, An evaluation function calculation unit 245, a direction detection unit 246, and a position detection unit 248 are included. Each of these functions can be realized by a processor constituting the control unit 240 operating according to a predetermined program.

  The transmission drive control unit 147 controls driving of the transmission unit 210. For example, the transmission drive control unit 147 controls the driving of the transmission unit 210 based on drive condition information that can be set in advance by the user, and transmits a signal having a predetermined characteristic from the transmission array antenna 212 toward a predetermined region. The reception drive control unit 141 controls driving of the reception unit 120. For example, the reception drive control unit 141 controls driving of the reception unit 120 based on drive condition information that can be set in advance by the user, and a signal having a predetermined characteristic transmitted by the transmission unit 210 by the reception array antenna 122. Receive. The functions of the transmission drive control unit 147 and the reception drive control unit 141 are the same as those of the first embodiment shown in FIG. 2 except that the target for which the drive control is performed by the transmission drive control unit 147 is changed from the transmission unit 110 to the transmission unit 210. Since the functions of the transmission drive control unit 147 and the reception drive control unit 141 of the detection apparatus 10 according to the above may be the same, detailed description thereof is omitted.

  The complex transfer function measurement unit 242 measures a complex transfer function representing a signal propagation path between the transmission array antenna 212 and the reception array antenna 122. Here, the complex transfer function is a function corresponding to propagation channel information which is information representing a propagation path of a signal transmitted and received between the transmission array antenna 212 and the reception array antenna 122. For example, the complex transfer function measurement unit 242 can measure the complex transfer function by acquiring information related to the signal received from the reception unit 120. The complex transfer function measurement unit 242 acquires drive condition information when the transmission unit 210 and the reception unit 120 are driven from the storage unit 130, the transmission drive control unit 147, and / or the reception drive control unit 141, and The complex transfer function may be measured further based on information on the characteristics of transmitted and received signals included in the drive condition information, information on the arrangement positions and arrangement directions of the transmission array antenna 212 and the reception array antenna 122, and the like.

Here, in the second embodiment, between m _t (m _t ≧ 2) transmission antennas 213 in the transmission unit 210 and m _r (m _r ≧ 2) reception antennas 123 in the reception unit 120. , M _r × m _t signal propagation paths exist. Therefore, the complex transfer function measurement unit 242 can measure m _r × m _t complex transfer functions corresponding to the number m _r × m _t of the propagation paths. These m _r × m _t complex transfer functions can be expressed as a complex transfer function matrix H of m _r rows and m _t columns each having the complex transfer function as an element. Thus, it can be said that the complex transfer function measurement unit 242 measures the complex transfer function matrix H.

Here, in the first embodiment, the complex transfer function matrix H is expressed as a matrix of _mr rows and columns. The complex transfer function matrix H in the second embodiment corresponds to the complex transfer function matrix H in the first embodiment in which the number of columns is expanded. The function of the complex transfer function measurement unit 242 is different only in the configuration of the complex transfer function matrix H to be measured, and the other functions are the complex transfer function measurement unit of the detection apparatus 10 according to the first embodiment shown in FIG. The function of 142 may be the same. Therefore, also in the second embodiment, similarly to the first embodiment, the complex transfer function measurement unit 242 performs the complex transfer function (first complex transfer function) and the object 510 when the object 510 exists. Measure both complex transfer functions of the complex transfer function (second complex transfer function) in the absence of. The measurement of the second complex transfer function is performed in advance before the measurement of the first complex transfer function is performed, for example, in an environment where the detection process for the object 510 is actually performed.

  In the second embodiment, the complex transfer function matrix H (first complex transfer function matrix H) in the case where the object 510 exists is expressed by the following mathematical formula (10).

……（１０）

...... (10)

Similarly, in the second embodiment, the complex transfer function matrix H _no (second complex transfer function matrix H _no ) in the case where the object 510 does not exist is expressed by the following formula (11).

……（１１）

...... (11)

As described above, in the second embodiment, the complex transfer function measurement unit 242 includes the complex transfer function matrix H and the target 510 in the case where the target 510 exists in which the complex transfer function is expressed in the form of a matrix. It is possible to measure the complex transfer function matrix H _no when not. The complex transfer function measurement unit 242 obtains information about the second complex transfer function (or information about the second complex transfer function matrix _Hno ) measured in advance before the measurement process of the first complex transfer function is performed. For example, it is stored in the storage unit 130. Further, the complex transfer function measurement unit 242 provides the information about the measured first complex transfer function (or information about the first complex transfer function matrix H) to the complex difference transfer function calculation unit 143.

The complex difference transfer function calculation unit 143 calculates a complex difference transfer function that is a difference between the first complex transfer function and the second complex transfer function. The complex difference transfer function calculation unit 143 obtains information about the first complex transfer function from the complex transfer function measurement unit 242 and refers to the storage unit 130 to obtain information about the second complex transfer function. A complex difference transfer function can be calculated. Here, the function of the complex difference transfer function calculation unit 143 may be the same as the function of the complex difference transfer function calculation unit 143 of the detection apparatus 10 according to the first embodiment shown in FIG. The complex difference transfer function calculation unit 143 can calculate the complex difference transfer function H ′ by subtracting the second complex transfer function matrix H _no from the first complex transfer function matrix H according to the above equation (3). it can. The complex difference transfer function calculation unit 143 provides information about the calculated complex difference transfer function matrix H ′ to the reception correlation matrix calculation unit 144 and the transmission correlation matrix calculation unit 247.

The reception correlation matrix calculation unit 144 calculates a reception correlation matrix R _r representing the correlation of the plurality of reception antennas 123 of the reception array antenna 122 with respect to the transmission antenna 213 based on the complex difference transfer function matrix H ′. The function of the reception correlation matrix calculation unit 144 may be the same as the function of the reception correlation matrix calculation unit 144 of the detection apparatus 10 according to the first embodiment illustrated in FIG. The reception correlation matrix calculation unit 144 can calculate the reception correlation matrix R _r according to the above equation (4). The reception correlation matrix calculation unit 144 provides information about the calculated reception correlation matrix R _r to the evaluation function calculation unit 245.

The transmission correlation matrix calculation unit 247 calculates a transmission correlation matrix R _t representing the correlation of the plurality of transmission antennas 213 of the transmission array antenna 212 with respect to the reception antenna 123 based on the complex difference transfer function matrix H ′. Specifically, the transmission correlation matrix R _t is defined by the following mathematical formula (12).

……（１２）

(12)

The transmission correlation matrix calculation unit 247 provides information about the calculated transmission correlation matrix R _t to the evaluation function calculation unit 245. Similarly to the reception correlation matrix calculator 144, transmit correlation matrix calculation section 247, when calculating a transmission correlation matrix R _t, averaging in the frequency direction calculated transmission correlation matrix in a predetermined frequency band Thus, the transmission correlation matrix R _t may be obtained. The accuracy of direction detection can be further improved by the averaging process.

The evaluation function calculation unit 245 calculates an evaluation function P _r (θ _r ) indicating the arrival direction of the signal at the reception array antenna 122 based on the reception correlation matrix R _r . Further, the evaluation function calculation unit 245 calculates an evaluation function P _t (θ _t ) indicating the starting direction of the signal in the transmission array antenna 212 based on the transmission correlation matrix R _t . Since the evaluation function P _t (θ _t ) indicates the starting direction of the signal in the transmission array antenna 212, the evaluation function P _t (θ _t ) includes the signal transmitted toward the object 510. It can be said that information about the departure direction, that is, the direction of the object 510 from the transmission array antenna 212 is included. As described above, the evaluation function calculation unit 245, in addition to the function of the evaluation function calculation unit 145 according to the first embodiment illustrated in FIG. 2, evaluates the evaluation function P _t (θ _t )).

As the evaluation functions P _r (θ _r ) and P _t (θ _t ), the evaluation functions in various arrival direction estimation methods and departure direction estimation methods for estimating the arrival direction and departure direction of signals in the array antenna are used. May be used. In the second embodiment, the evaluation function calculation unit 245 can calculate evaluation functions P _r (θ _r ) and P _t (θ _t ) in various known arrival direction estimation methods and departure direction estimation methods. Here, as an example, the case where the evaluation function calculation unit 245 calculates the evaluation functions P _r (θ _r ) and P _t (θ _t ) in the MUSIC method will be described.

Here, the calculation method of the evaluation function P _r (θ _r ) indicating the direction of arrival of the signal in the receiving array antenna 122 is described in [1-2. Since it may be the same as the method described in “Configuration of Detection Device”, detailed description thereof is omitted. Here, the calculation method of the evaluation function P _t (θ _t ) indicating the starting direction of the signal in the transmission array antenna 212 performed by the evaluation function calculation unit 245 will be described in detail.

First, the evaluation function calculating unit 245 by eigenvalue decomposition transmit correlation matrix R _t, is calculated and eigenvectors V of the transmission correlation matrix R _t, the V ^H is a complex conjugate transposed vector of the eigenvectors V. The eigenvalue decomposition of the transmission correlation matrix R _t is expressed by the following mathematical formula (13).

……（１３）

(13)

Here, the eigenvectors V is a matrix composed of eigenvectors v _i of transmission correlation matrix R _t, are expressed by the following equation (14). Note that v _i indicates the eigenvector of the _i- th column, and the number of elements is m _t .

……（１４）

(14)

D _t is a diagonal matrix whose diagonal elements are eigenvalues λ _t1 ,..., Λ _tmt of the transmission correlation matrix R _t , and is represented by the following formula (15). In the following description, the eigenvalues λ _t1 ,..., Λ _tmt of the transmission correlation matrix R _t are collectively referred to as an eigenvalue λ _t .

……（１５）

...... (15)

Next, the evaluation function calculation unit 245 calculates an evaluation function P _t (θ _t ) expressed by the following mathematical formula (16).

……（１６）

...... (16)

Here, L is the number of objects 510 that are targets of direction detection. From the above equation (16), in the second embodiment, the number m _t of transmission antennas 213 provided in the transmission array antenna 212 is required to be larger than the number L of objects 510. In other words, if the number m _t of the transmission antennas 213 constituting the transmission array antenna 212 is larger than the number L of the objects 510, the detection processing of the objects 510 in the second embodiment is applicable. It can be said that there is.

……（１７） Further, a _t (θ _t ) is a steering vector in the transmission array antenna 212 and is represented by the following mathematical formula (17).

...... (17)

Steering vector a _{t (θ t)} is a vector representing the amplitude ratio and phase difference between the transmit antenna 213 constituting the transmitting array antenna 212 for the angle theta _t, the angle at the time of detecting the direction of the object 510 theta _t Is determined based on the position of each transmission antenna 213 with respect to the position (reference point Q _t shown in FIG. 5). Note that a specific method for setting the steering vector a _t (θ _t ) may be the same as the method for setting the steering vector in the general MUSIC method.

The calculation method of the evaluation function P _t (θ _t ) by the evaluation function calculation unit 245 has been described in detail above. The evaluation function calculation unit 245 provides information about the calculated evaluation functions P _r (θ _r ) and P _t (θ _t ) to the direction detection unit 246.

The direction detection unit 246 detects the direction of the object 510 from the reception array antenna 122 based on the evaluation function P _r (θ _r ). Further, the direction detection unit 246 detects the direction of the object 510 from the transmission array antenna 212 based on the evaluation function P _t (θ _t ). As described above, the direction detection unit 246 adds the object from the transmission array antenna 212 based on the evaluation function P _t (θ _t ) in addition to the function of the direction detection unit 146 according to the first embodiment shown in FIG. It has a function of detecting the direction of 510.

Specifically, similarly to the evaluation function P _r (θ _r ), the characteristic expressed by the evaluation function P _t (θ _t ) shown in the equation (16) is called a MUSIC spectrum, and the evaluation function P _The angle θ _t corresponding to the peak position at _t (θ _t ) corresponds to the direction in which the object 510 from the transmission array antenna 212 exists. Therefore, the direction detection unit 246 can obtain the angle θ _t indicating the direction in which the object 510 exists with respect to the transmission array antenna 212 by extracting the peak position in the evaluation function P _t (θ _t ), and the transmission array The direction of the object 510 from the antenna 212 can be detected. When a plurality of objects 510 exist, a plurality of angles θ _t corresponding to the peak positions in the evaluation function P _t (θ _t ) are extracted. In the following description, the direction of the object 510 from the transmission array antenna 212 detected based on the transmission correlation matrix _Rt is also referred to as a second direction.

[1-2. The direction detection unit 246 extracts the angle θ _r corresponding to the peak position in the evaluation function P _r (θ _r ) by a method similar to the method described in the configuration of the detection apparatus], thereby detecting the target for the reception array antenna 122. An angle θ _r indicating the direction in which the object 510 exists can be obtained, and the direction of the object 510 from the receiving array antenna 122 can be detected. The direction detection unit 246 provides information on the detected first direction and second direction to the position detection unit 248. The direction detection unit 246 obtains information about the angles θ _r and θ _t indicating the direction of the object 510 from the reception array antenna 122 and the transmission array antenna 212 as information about the first direction and the second direction. You may provide to the detection part 248.

The position detection unit 248 detects the position of the object 510 with respect to the reception array antenna 122 and the transmission array antenna 212 based on the first direction and the second direction detected by the direction detection unit 246. From the detection result by the direction detecting unit 246, the direction of the object 510 from the receiving array antenna 122 as represented by the angle theta _r is found. Similarly, the direction of the object 510 from the transmission array antenna 212 represented by the angle θ _t is known from the detection result by the direction detection unit 246. Furthermore, the position detection unit 248, for example, by referring to the storage unit 130, the receiving position of the reference point Q _r in the array antenna 122 (absolute coordinates) position of the reference point Q _t in the information and transmitting array antenna 212 for (absolute Information about coordinates) can be obtained. Therefore, the position detection unit 248 receives the position corresponding to the intersection of the straight lines indicated by these directions based on the position of the reception array antenna 122, the position of the transmission array antenna 212, the first direction, and the second direction. It can be detected as a position where the object 510 with respect to the array antenna 122 and the transmission array antenna 212 exists. When there are a plurality of objects 510, the angle θ _r corresponding to the peak position in the evaluation function P _r (θ _r ) and the angle θ _t corresponding to the peak position in the evaluation function P _t (θ _t ) are: Since a plurality of each can be detected, the position detecting unit 248 can detect a position corresponding to each intersection of a plurality of straight lines indicated by the angles as a position where the object 510 exists.

As shown in FIG. 5, the angle θ _r is an angle with reference to the reference point Q _r set on the reception surface of the reception array antenna 122, so that the reception array antenna detected by the direction detection unit 246 is used. direction of the object 510 from 122 can be said to strictly a direction of the object 510 from the reference point Q _r. Similarly, since the angle θ _t is an angle with reference to the reference point Q _t set on the transmission surface of the transmission array antenna 212, the object 510 from the transmission array antenna 212 detected by the direction detection unit 246 is used. direction, it can be said that strictly a direction of the object 510 from the reference point Q _t. However, the reference points Q _r and Q _t may be set on the reception surface of the reception array antenna 122 and the transmission surface of the transmission array antenna 212, respectively, and these positions may be appropriately set by the user, for example. Therefore, depending on the position where the reference point Q _r is set, the direction of the object 510 from the reception array antenna 122 detected by the direction detection unit 246 is, for example, from any of the reception antennas 123 constituting the reception array antenna 122. It can also be the direction of the object 510. Similarly, depending on the position where the reference point Q _t is set, the direction of the object 510 from the transmission array antenna 212 detected by the direction detection unit 246 is, for example, one of the transmission antennas 213 constituting the transmission array antenna 212. It can also be the direction of the object 510 from.

In the following description, the direction of the object 510 (that is, the first direction) detected by the direction detection unit 246 based on the evaluation function P _r (θ _r ) is referred to as the reception array antenna 122 for convenience. Although it referred to as direction, etc. of the object 510 from, in the second embodiment, the first direction detected by the direction detection unit 246 may be a direction of the object 510 from the reference point Q _r Alternatively, the direction may be the direction of the object 510 from any one of the reception antennas 123 constituting the reception array antenna 122. Similarly, in the following description, the direction of the object 510 (that is, the second direction) detected by the direction detection unit 246 based on the evaluation function P _t (θ _t ) is referred to for convenience. In the second embodiment, the second direction detected by the direction detecting unit 246 is the direction of the object 510 from the reference point Q _t . The direction may be the direction, or the direction of the object 510 from any one of the transmission antennas 213 constituting the transmission array antenna 212 may be used. Further, similarly, in the following description, the position of the object 510 detected by the position detection unit 248 based on the first direction and the second direction will be referred to as the reception array antenna 122 and the transmission array. In the second embodiment, the position of the object 510 detected by the position detection unit 248 includes the angle θ _r indicating the first direction and the second position. It may be the position of the object 510 with respect to a position serving as a reference for the angle θ _t indicating the direction.

  The configuration example of the detection device 20 according to the second embodiment of the present invention has been described above with reference to FIG. In the second embodiment, the following effects are obtained in addition to the effects obtained by the first embodiment.

  In the second embodiment, in addition to the direction of the object 510 from the reception array antenna 122 (first direction) detected by the direction detection unit 246 in the first embodiment, The direction (second direction) of the object 510 is detected. The position detection unit 248 then positions the object 510 with respect to the reception array antenna 122 and the transmission array antenna 212 based on the position of the reception array antenna 122, the position of the transmission array antenna 212, the first direction, and the second direction. Is detected.

  Here, also in the detection of the second direction in the second embodiment, the difference between the first complex transfer function and the second complex transfer function is the same as the detection of the first direction in the first embodiment. Detection processing using the complex difference transfer function is performed. Therefore, the detection process in the second direction can also be performed in a shorter measurement time. As described above, in the second embodiment, by using the complex difference transfer function that represents the difference in the propagation path with or without the object 510, for example, compared to the conventional method described in Non-Patent Document 1, for example. The detection processing of the direction of the object 510 from the reception array antenna 122 and the transmission array antenna 212 can be performed in a short measurement time (for example, a very short time on the order of ms). Further, detection of the direction of the object 510 from the reception array antenna 122 and the transmission array antenna 212 can be performed more accurately than the conventional method shown in Non-Patent Document 2, for example, as shown in FIG. Therefore, in the second embodiment, the direction of the object 510 from the reception array antenna 122 and the transmission array antenna 212 is detected, and further, the object for the reception array antenna 122 and the transmission array antenna 212 based on these detected directions. The position of the object 510 can be detected more accurately in a shorter measurement time.

Similar to the first embodiment, in the second embodiment, the arithmetic processing performed by the evaluation function calculation unit 245 may be similar to the arithmetic processing generally performed in the MUSIC method. Therefore, in the calculation process of the evaluation functions P _r (θ _r ) and P _t (θ _t ) in the second embodiment, the correlation matrix used in the calculation process of the evaluation function in the general MUSIC method is expressed by the above equation (4). And the reception correlation matrix R _r or the transmission correlation matrix R _t shown in the equation (12), respectively.

In the above description, the case where the MUSIC method is used as a method for estimating the arrival direction of a signal has been described. However, the second embodiment is not limited to this example. In the second embodiment, the evaluation function calculation unit 245 may calculate the evaluation function in another method for estimating the arrival direction and the departure direction of the signal, and the direction detection unit 246 may calculate the evaluation function in the other method. The direction of the object 510 may be detected based on the above. As another method for estimating the arrival direction and the departure direction, for example, a beam former method, a Capon method, a linear prediction method, or the like can be used. The evaluation function calculation unit 245 generally converts the correlation matrix used in the calculation process of the evaluation function of each of these methods into the reception correlation matrix R _r or the transmission correlation matrix R _t shown in the above equations (4) and (12). By substituting each, it is possible to calculate an evaluation function corresponding to each of these methods.

  Similarly to the first embodiment, the detection apparatus 20 according to the second embodiment also has various configurations not explicitly shown in FIG. 6, for example, a display unit that displays various types of information on the display screen, You may further provide functions, such as a communication part which transmits / receives various information between other apparatuses. Then, information about the first and second directions detected by the direction detection unit 246 and information about the position of the object 510 detected by the position detection unit 248 are displayed on the display unit, for example, to the user. It may be notified, or transmitted to another external device via the communication unit and stored in the storage unit of the other device. As described above, in the second embodiment, information on the first and second directions detected by the direction detection unit 246 and information on the position of the object 510 detected by the position detection unit 248 are output. The destination may be arbitrary. For example, the detection result may be displayed in real time on the display unit of the detection device 20 or the display unit of another external device, or a predetermined value may be displayed on the storage unit 130 of the detection device 20 or the storage unit of another external device. The period detection result may be stored as a history.

  The functional configuration of the detection device 20 according to the second embodiment is not limited to the example illustrated in FIG. Similar to the detection device 10 according to the first embodiment, the function of the detection device 20 according to the second embodiment does not necessarily have to be realized by a single device, but a plurality of devices connected to each other by a network. You may implement | achieve by cooperation of an apparatus.

[2-3. Procedure of detection method]
Next, the processing procedure of the detection method according to the second embodiment of the present invention will be described with reference to FIG. FIG. 7 is a flowchart showing an example of the processing procedure of the detection method according to the second embodiment of the present invention. Each process illustrated in FIG. 7 can be realized by the functional configuration of the detection device 20 described above. For example, the processing that configures the control unit 240 of the detection device 20 operates according to a predetermined program. obtain.

  The processing procedure of the detection method according to the second embodiment shown in FIG. 7 is partly changed from the processing procedure of the detection method according to the first embodiment described with reference to FIG. Corresponds to that. Therefore, in the following description of the processing procedure of the detection method according to the second embodiment, differences from the first embodiment will be mainly described, and detailed descriptions of overlapping items will be omitted. .

Referring to FIG. 7, in the detection method according to the second embodiment of the present invention, first, for example, the complex transfer function measurement unit 242 sets the signal propagation path between the transmission array antenna 212 and the reception array antenna 122. The representing complex transfer function is measured (step S201). In the processing shown in step S201, the number of complex transfer functions calculated corresponds to the number m _r of the reception antennas 123 constituting the reception array antenna 122 and the number m _t of the transmission antennas 213 constituting the transmission array antenna 212. except be extended to _r × m _t may be the same as the process shown in step S101 in the first embodiment shown in FIG. In the process shown in step S201, the complex transfer function matrix H in the case where the object 510 exists and the complex transfer function matrix H _{no in the} case where the object 510 does not exist are measured. obtain.

Next, for example, the complex difference transfer function calculation unit 143 calculates a complex difference transfer function that is a difference between the complex transfer function when the object 510 exists and the complex transfer function when the object 510 does not exist ( Step S103). Next, for example, the reception correlation matrix calculation unit 144 calculates a reception correlation matrix R _r representing the correlation of the plurality of reception antennas 123 of the reception array antenna 122 with respect to the transmission antenna 112 based on the complex difference transfer function matrix H ′ ( Step S105). Since the processes shown in step S103 and step S105 may be the same as the processes shown in step S103 and step S105 in the first embodiment shown in FIG. 3, detailed description thereof is omitted.

In the second embodiment, next, for example, the transmission correlation matrix calculation unit 247 calculates a transmission correlation matrix R _t representing the correlation of the plurality of transmission antennas 213 of the transmission array antenna 212 with respect to the reception antenna 123 (step S206). . The transmission correlation matrix R _t can be calculated using, for example, the above equation (12). Note that either the process of calculating the reception correlation matrix R _r shown in step S105 or the process of calculating the transmission correlation matrix R _t shown in step S206 may be performed first, or performed in parallel. It may be broken.

Then, for example, by the evaluation function calculation unit 245, receives the correlation matrix R _r and transmit correlation matrix R _t is the eigenvalue decomposition, eigenvalue lambda _r of reception correlation matrix R _r, eigenvectors U reception correlation matrix R _r, transmit correlation matrix R _t eigenvalue lambda _t, eigenvectors V and steering vectors _{a r} a transmission correlation matrix _{R t (θ r), a} t (θ t) is calculated (step S207). Similarly, for example, the evaluation function calculation unit 245 indicates the evaluation function P _r (θ _r ) indicating the arrival direction of the signal at the reception array antenna 122 and the departure direction of the signal at the transmission array antenna 212 based on these calculation results. An evaluation function P _t (θ _t ) is calculated (step S209). The steering vectors a _r (θ _r ), a _t (θ _t ) and the evaluation functions P _r (θ _r ), P _t (θ _t ) are, for example, the above formulas (9), (17), (8), (16 ) Respectively.

Next, for example, the direction detection unit 246 detects the direction of the object 510 from the reception array antenna 122 based on the evaluation function P _r (θ _r ), and transmits based on the evaluation function P _t (θ _t ). The direction of the object 510 from the array antenna 212 is detected (step S211). Specifically, the angles θ _r and θ _t corresponding to the peak positions in the evaluation functions P _r (θ _r ) and P _t (θ _t ) are extracted, and the object 510 for the reception array antenna 122 and the transmission array antenna 212 is obtained. By obtaining the angles θ _r and θ _t indicating the existing directions, the direction of the object 510 from the reception array antenna 122 (first direction) and the direction of the object 510 from the transmission array antenna 212 (second Direction) can be detected.

  Next, for example, the position detection unit 248 detects the position of the object 510 with respect to the reception array antenna 122 and the transmission array antenna 212 based on the first direction and the second direction detected in Step S211 (Step S211). S213). Specifically, based on the position of the reception array antenna 122, the position of the transmission array antenna 212, the first direction, and the second direction, the position corresponding to the intersection of the straight lines indicated by these directions is the reception array antenna 122. And the position where the object 510 exists with respect to the transmitting array antenna 212 can be detected.

The processing procedure of the detection method according to the second embodiment of the present invention has been described above with reference to FIG. In the above description, in the process shown in step S209, the evaluation functions P _r (θ _r ) and P _t (θ _t ) are used as the evaluation functions P _r (in the MUSIC method shown in the above formulas (8) and (16). θ _r ) and P _t (θ _t ) are calculated, but the second embodiment is not limited to this example. In the second embodiment, an evaluation function in another method for estimating the arrival direction and departure direction of a signal may be calculated in the process shown in step S209. In the process shown in steps S211 and S213, the other method The direction and position of the object 510 may be detected based on the evaluation function in FIG. As another method for estimating the arrival direction and the departure direction of the signal, for example, a beam former method, a Capon method, a linear prediction method, or the like may be used.

<3. Third Embodiment>
[3-1. Overview of Third Embodiment]
Next, an overview of the third embodiment of the present invention will be described with reference to FIG. FIG. 8 is an explanatory diagram for explaining an outline of the object detection process according to the third embodiment of the present invention.

  Referring to FIG. 8, a transmitting apparatus 211 having a transmitting array antenna 212 composed of a plurality of transmitting antennas 213 and a receiving apparatus 121 having a receiving array antenna 122 composed of a plurality of receiving antennas 123 face each other across a predetermined area. Are arranged. There are a plurality of objects 510 (for example, people) in the predetermined area. The specific configurations of the transmission device 211 and the reception device 121 may be the same as the configurations of the transmission device 211 and the reception device 121 in the second embodiment described with reference to FIG. Is omitted.

  Thus, the configuration shown in FIG. 8 is the same as the configuration in the detection process of the object 510 in the second embodiment shown in FIG. [2-1. As described in Overview of Second Embodiment], in this configuration, it is possible to detect the position of the object 510 with respect to the reception array antenna 122 and the transmission array antenna 212. Specifically, the position of the target object 510 is a position corresponding to the intersection of a straight line indicating the direction of the target object 510 from the receiving array antenna 122 and a straight line indicating the direction of the target object 510 from the transmitting array antenna 212. Can be detected.

Here, consider the case where the positions of a plurality of objects 510 are detected as shown in FIG. Above [2-2. As described in “Configuration of Detection Device”, when a plurality of objects 510 exist, the peak positions in the evaluation functions P _r (θ _r ) and P _t (θ _t ) correspond to the number of objects 510. Appears as many as you want. Therefore, a plurality of angles θ _r and θ _t corresponding to a plurality of peak positions are extracted, and a straight line indicating the direction of the object 510 from the reception array antenna 122 and the object 510 from the transmission array antenna 212 are extracted. A plurality of straight lines indicating directions can also be detected.

  As described above, the object 510 should be present at the intersection of a straight line indicating the direction of the object 510 from the receiving array antenna 122 and a straight line indicating the direction of the object 510 from the transmitting array antenna 212. When there are a plurality of these straight lines, as shown in FIG. 8, there are actually intersections at positions where the object 510 does not exist. Such an intersection that appears at a position where the object 510 does not exist is the same as whether the object 510 exists when the object 510 is actually detected even though the object 510 does not exist. May be detected. The object 510 thus erroneously detected is also referred to as a virtual image. In FIG. 8, some of the virtual image positions 530 that are positions where a virtual image can be detected are illustrated by black circles.

  In the detection process of the object 510 in the third embodiment of the present invention, the following [3-2. By performing the process described in detail in the configuration of the detection apparatus], in the case where there are a plurality of objects 510, the detection process of the object 510 from which the virtual image position 530 is removed can be performed. In this way, the virtual image position 530 is removed from the position corresponding to the intersection of the straight line indicating the direction of the object 510 from the receiving array antenna 122 and the straight line indicating the direction of the object 510 from the transmitting array antenna 212. By detecting the target object 510, it is possible to detect the position of the target object 510 more accurately. The following [3-2. In Configuration of Detection Device], a configuration example of the detection device for realizing the detection processing of the object 510 in the third embodiment will be described. In addition, the following [3-3. [Processing Procedure of Detection Method] An example of the flow of the processing procedure in the detection processing of the object 510 in the third embodiment will be described.

  In the example shown in FIG. 8, the case where there are three objects 510 is illustrated. Also in the following description of the third embodiment, a case where there are three objects 510 will be described as an example, but the third embodiment is not limited to such an example. In the third embodiment, the number of objects 510 is not limited and may be any number greater than one. Even if the number of the objects 510 is other than the above, it is possible to detect the object 510 from which the virtual image position 530 is removed by performing the same process as the process described below.

[3-2. Configuration of detection device]
With reference to FIG. 9, one structural example of the detection apparatus which concerns on the 3rd Embodiment of this invention is demonstrated. FIG. 9 is a functional block diagram showing a configuration example of the detection apparatus according to the third embodiment of the present invention.

  Referring to FIG. 9, the detection device 30 according to the third embodiment includes a transmission unit 210, a reception unit 120, a storage unit 130, and a control unit 340. Each function of the detection device 30 illustrated in FIG. 9 can be realized by, for example, a hardware configuration illustrated in FIG. Here, the detection device 30 according to the third embodiment corresponds to the detection device 20 according to the second embodiment illustrated in FIG. 6 in which some functions are changed. Therefore, in the following description of the configuration of the detection device 30, differences from the second embodiment will be mainly described, and detailed description of overlapping items will be omitted.

  The functions of the transmission unit 210, the reception unit 120, and the storage unit 130 in the detection device 30 may be the same as the functions of the transmission unit 210, the reception unit 120, and the storage unit 130 in the second embodiment illustrated in FIG. Detailed description thereof is omitted.

  The control unit 340 is configured by various processors such as a CPU and a DSP, and controls the operation of the detection device 30 in an integrated manner. The control unit 340 includes, as its functions, a reception drive control unit 141, a transmission drive control unit 147, a complex transfer function measurement unit 242, a complex difference transfer function calculation unit 143, a reception correlation matrix calculation unit 144, a transmission correlation matrix calculation unit 247, An evaluation function calculation unit 245, a direction detection unit 246, and a position detection unit 348 are included. Each of these functions can be realized by a processor constituting the control unit 340 operating according to a predetermined program.

  Here, among the functions of the control unit 340, the reception drive control unit 141, the transmission drive control unit 147, the complex transfer function measurement unit 242, the complex difference transfer function calculation unit 143, the reception correlation matrix calculation unit 144, and the transmission correlation matrix calculation. The functions of the unit 247, the evaluation function calculation unit 245, and the direction detection unit 246 may be the same as those functions of the control unit 240 according to the second embodiment. As described above, the control unit 340 according to the third embodiment corresponds to the control unit 240 according to the second embodiment in which the function of the position detection unit 248 is changed. Therefore, the position detection unit 348 will be described in detail below among the functions of the control unit 340.

Position detecting unit 348, and eigenvalues lambda _r of reception correlation matrix _{R r,} and eigenvectors U reception correlation matrix _{R r,} and eigenvalues lambda _t of transmit correlation matrix _{R t,} and eigenvectors V of transmit correlation matrix _{R t,} the receiving array Based on the steering vector a _r (θ _r ) in the antenna 122 and the steering vector a _t (θ _t ) in the transmission array antenna 212, the position of the object 510 from which the virtual image position 530 has been removed is detected. Specifically, the position detection unit 348 calculates the inner product value of the eigenvector U of the reception correlation matrix R _r and the steering vector a _r (θ _r ) corresponding to the first direction in the reception array antenna 122, the transmission correlation matrix R _t. inner product value of the steering vector _{a t (θ t)} corresponding to the second direction of the eigenvector V and transmitting array antenna 212, the eigenvalues lambda _r of reception correlation matrix _{R r,} and the eigenvalues of transmit correlation matrix _{R t} lambda _t The virtual image position 530 is removed from the position corresponding to the intersection of the straight line indicating the direction of the object 510 from the receiving array antenna 122 and the straight line indicating the direction of the object 510 from the transmitting array antenna 212. The position of the target object 510 is detected.

The detection processing of the object 510 in the position detection unit 348 according to the third embodiment will be described with specific numerical values. For example, it is assumed that the number of reception antennas 123 in the reception array antenna 122 and the number of transmission antennas 213 in the transmission array antenna 212 are both four (that is, m _r = 4, m _t = 4). Also, assume that there are three objects 510 as shown in FIG. At this time, when the evaluation function P _r (θ _r ) for the reception array antenna 122 is calculated by the evaluation function calculation unit 245 of the detection device 30, the evaluation function P _r (θ _r ) has, for example, characteristics as shown in FIG. Have FIG. 10 is a graph showing an example of the evaluation function P _r (θ _r ) in the third embodiment.

Referring to FIG. 10, it can be seen that three peaks appear in the evaluation function P _r (θ _r ) corresponding to the number of objects 510. Angle theta _r corresponding to these peak positions, respectively, -42 (deg), - 18 (deg), it is 26 (deg). Thus, from the calculation result by the evaluation function calculation unit 245, for example, the direction detection unit 246 extracts the peak position in the evaluation function P _r (θ _r ) and the angle θ _r corresponding to the peak position.

First, the position detection unit 348 performs the eigenvalue lambda _r of reception correlation matrix R _r, an eigenvalue lambda _t of transmit correlation matrix R _t, together sort in descending order process. The eigenvalues of the reception correlation matrix R _r after sorting in descending order are λ _r1 , λ _r2 , λ _r3 , λ _r4, and the eigenvalues of the transmission correlation matrix R _t after sorting in descending order are λ _t1 , λ _t2 , λ Let _t3 and _λt4 . That is, of the eigenvalues λ _r , the maximum eigenvalue is λ _r1 and the minimum eigenvalue is λ _r4 . Of the eigenvalues λ _t , the maximum eigenvalue is λ _t1 and the minimum eigenvalue is λ _t4 . Here, the eigenvalues lambda _r of reception correlation matrix _{R r,} an eigenvalue lambda _t of transmit correlation matrix _{R t,} the sort both arranged in descending order, eigenvalues between the i-th (i = 1 to 4) is relatively close Value. The i-th eigenvalues can be considered to correspond to the same object 510.

Further, the eigenvalue lambda _r of reception correlation matrix R _r, an eigenvalue lambda _t of transmit correlation matrix R _t, in the case of changing both arranged in descending order, corresponding to the object 510 in order of the value of the eigenvalue is large It is thought that there is. That is, the maximum eigenvalues λ _r1 and λ _t1 correspond to the first object 510, and the next largest eigenvalues λ _r2 and λ _t2 correspond to the second object 510. Then, λ _r3 and λ _t3 which are eigenvalues having the next largest value correspond to the third object 510. Thus, the position detection unit 348, and eigenvalues lambda _r of reception correlation matrix R _r, an eigenvalue lambda _t of transmit correlation matrix R _t, sorted in descending order, by extraction in order of the value is large, The eigenvalues λ _r and λ _t corresponding to each object 510 can be extracted.

Next, the position detection unit 348 obtains information on the peak position of the evaluation function P _r (θ _r ) from the direction detection unit 246 and, based on the information, determines each peak position in the evaluation function P _r (θ _r ). The inner product of the steering vector a _r (θ _r ) corresponding to the indicated angle θ _r and the eigenvectors u ₁ ,..., U ₄ of the reception correlation matrix R _r is calculated for all the combinations. An example of the inner product calculation result is shown in Table 1 below. The eigenvectors u ₁ ,..., U ₄ correspond to the eigenvalues λ _r1 , λ _r2 , λ _r3 , and λ _r4 , respectively, rearranged in descending order.

Focusing on each column in Table 1 (that is, the column corresponding to each eigenvector u ₁ ,..., U ₄ ), the eigenvector u ₁ ,. It can be seen that there is a combination of u ₄ and the steering vector a _r (θ _r ). For example, in the column corresponding to the eigenvectors _{u 1,} the inner product value between _a r (18) corresponding to _{u 1} and θ _r = 18 (deg) is, _{u 1} and another steering vector _{a r (θ r)} and the It has a value larger than the inner product value. In Table 1, for the sake of explanation, the inner product value having the largest value in each column is shown with an underline. In this example, the number of objects 510 is 3, since the object 510 corresponding to the eigenvectors u ₄ would not exist, the description of the underline in the column corresponding to the eigenvectors u ₄ are omitted .

In this way, each eigenvector u _1, · · ·, relative to u _4, steering vector inner product value is maximum a _{r (theta r)} and the steering vector a _r giving the maximum an inner product values corresponding to the respective eigenvectors An angle θ _r corresponding to (θ _r ) is extracted. In the example of Table 1 above, the position detection unit 348 extracts a _r (18) and θ _r = 18 (deg) as the steering vector a _r (θ _r ) and the angle θ _r corresponding to the eigenvector u _1. Then, a _r (26) and θ _r = 26 (deg) are extracted as the steering vector a _r (θ _r ) corresponding to the eigenvector u ₂ and the angle θ _r , and the steering vector a _r (θ _r corresponding to the eigenvector u ₃ is extracted. ) And angle θ _r , extract a _r (−42) and θ _r = −42 (deg).

Similarly, the position detection unit 348 also acquires information on the peak position of the evaluation function P _t (θ _t ) from the direction detection unit 246 for the transmission array antenna 212, and based on this information, the evaluation function P _t and (theta _t) angle showing the respective peak positions in the theta _t to the corresponding steering vector _{a t (θ t),} the eigenvectors _v 1 transmission correlation matrix _{R t,} ···, the inner product of the _{v 4,} all the Calculate for combinations. From the calculation result, the position detection unit 348 determines, for each eigenvector v ₁ ,..., V ₄ , the steering vector a _t (θ _t ) that maximizes the inner product value with each eigenvector and the maximum value. An angle θ _t corresponding to the steering vector a _t (θ _t ) giving the inner product value is extracted.

Based on the extraction results, the position detection unit 348, the angle theta _r and theta _t corresponding to the first object corresponding to the largest eigenvalue lambda _r1 and lambda _t1, eigenvalue with a large value in the second Corresponding to angles θ _r and θ _t corresponding to a second object corresponding to a certain λ _r2 and λ _t2 and a third object corresponding to λ _r3 and λ _t3 which are eigenvalues having the third largest value The angles θ _r and θ _t to be extracted can be extracted. The relationship between the extracted object 510 and the angles θ _r and θ _t is the relationship between the object 510 from which the influence of the virtual image is removed and the angles θ _r and θ _t . Therefore, the position detection unit 348 detects the position of the object 510 based on the extraction result, thereby detecting a straight line indicating the direction of the object 510 from the reception array antenna 122 and the object 510 from the transmission array antenna 212. The position of the object 510 from which the virtual image position 530 is excluded can be detected from the positions corresponding to the intersections with the straight line indicating the direction.

  The configuration example of the detection device 30 according to the third embodiment of the present invention has been described above with reference to FIG. In the third embodiment, the following effects are obtained in addition to the effects obtained by the second embodiment.

In the third embodiment, in addition to the configuration in the second embodiment, the position detection process of the position of the object 510 from which the influence of the virtual image is removed by the position detection unit 348 is performed. Specifically, the position detection unit 348, when the rearranged eigenvalues lambda _t eigenvalues lambda _r and transmit correlation matrix R _t of the received correlation matrix R _r in descending order, eigenvalues each other located in the first one another at least in descending order The steering vector a _r (θ of the reception array antenna 122 having the maximum inner product value with the eigenvector corresponding to the eigenvalue of the reception correlation matrix R _r with respect to eigenvalues located in the same order, including the maximum eigenvalues of _r 2) and the second direction corresponding to the steering vector a _t (θ _t ) of the transmission array antenna 212 in which the inner product value of the first vector corresponding to the eigenvalue corresponding to the eigenvalue of the transmission correlation matrix R _t is maximized. Based on the above, the position of the object 510 is detected. More specifically, the position detection unit 348 rearranges the eigenvalue λ _r of the reception correlation matrix R _{r and} the eigenvalue λ _t of the transmission correlation matrix R _t in descending order, and uses the first eigenvalue in the descending order of the reception correlation matrix R _r. A first direction corresponding to the steering vector a _r (θ _r ) of the receiving array antenna 122 that has the maximum inner product with an eigenvector corresponding to a certain maximum eigenvalue, and the first eigenvalue in descending order of the transmission correlation matrix R _t The position of the first object 510 is detected based on the second direction corresponding to the steering vector a _t (θ _t ) of the transmission array antenna 212 having the maximum inner product with the eigenvector corresponding to the maximum eigenvalue. , steering of the receiving array antenna 122 inner product of the eigenvector corresponding to the second and subsequent eigenvalue in descending order of the reception correlation matrix R _r is maximum Vector a _{r (θ r)} and the first direction corresponding to the transmission correlation matrix R inner product between the eigenvector corresponding to the second and subsequent eigenvalue in descending _t is the maximum transmit array antenna 212 of the steering vector a _t ( Based on the second direction corresponding to θ _t ), the positions of the second and subsequent objects 510 are detected.

Thus, in the third embodiment, the eigenvalues lambda _t eigenvalues lambda _r and transmit correlation matrix R _t of the reception correlation matrix R _r for each object 510 is extracted, the angle theta _r their corresponding eigenvalues , Θ _t are based on the inner product value of the eigenvector U of the reception correlation matrix R _r and the steering vector a _r (θ _r ) and the inner product value of the eigen vector V of the transmission correlation matrix R _t and the steering vector a _t (θ _t ). As a result, the position of the object 510 from which the virtual image position 530 is excluded is detected. Therefore, in the third embodiment, it is possible to detect the position of the object 510 in a shorter measurement time, and realize more accurate position detection of the object 510 from which the influence of the virtual image is removed.

  Similarly to the first and second embodiments, the detection device 30 according to the third embodiment also has various configurations not explicitly shown in FIG. 9, for example, a display unit that displays various types of information on a display screen, In addition, a function such as a communication unit that transmits and receives various types of information to and from other external devices may be further provided. Information about the first and second directions detected by the direction detection unit 246 and information about the position of the object 510 from which the virtual image position 530 detected by the position detection unit 348 is removed are, for example, the display It may be displayed on the unit and notified to the user, or transmitted to another external device via the communication unit and stored in the storage unit of the other device. As described above, in the third embodiment, information on the first and second directions detected by the direction detection unit 246 and the object 510 from which the virtual image position 530 detected by the position detection unit 348 has been removed. The destination to which the information about the position is output may be arbitrary. For example, the detection result may be displayed in real time on the display unit of the detection device 30 or the display unit of another external device, or a predetermined value may be displayed on the storage unit 130 of the detection device 30 or the storage unit of another external device. The period detection result may be stored as a history.

  Further, the functional configuration of the detection apparatus 30 according to the third embodiment is not limited to the example illustrated in FIG. Similar to the detection devices 10 and 20 according to the first and second embodiments, the functions of the detection device 30 according to the third embodiment may not necessarily be realized by a single device, and may be mutually connected by a network. It may be realized by cooperation of a plurality of connected devices.

[3-3. Procedure of detection method]
Next, with reference to FIG. 11, a processing procedure of a detection method according to the third embodiment of the present invention will be described. FIG. 11 is a flowchart showing an example of the processing procedure of the detection method according to the third embodiment of the present invention. Each process illustrated in FIG. 11 can be realized by the functional configuration of the detection device 30 described above. For example, the processing included in the control unit 340 of the detection device 30 operates according to a predetermined program. obtain.

  Further, the processing procedure of the detection method according to the third embodiment shown in FIG. 11 is partially changed from the processing procedure of the detection method according to the second embodiment described with reference to FIG. Corresponds to that. Therefore, in the following description of the processing procedure of the detection method according to the third embodiment, differences from the second embodiment will be mainly described, and detailed descriptions of overlapping items will be omitted. .

Referring to FIG. 11, in the processing procedure of the detection method according to the third embodiment, evaluation functions P _r (θ _r ), P _t (θ _t ) are calculated, and an angle θ _r corresponding to the peak position is calculated. The processes up to extracting θ _t , that is, the processes shown in steps S101 to S211 may be the same as these processes in the second embodiment described above. The processing procedure of the detection method according to the third embodiment is the same as the processing procedure of the detection method according to the second embodiment, the content of the processing shown in step S213, which is processing for detecting the position of the object 510. Corresponds to what has changed. Therefore, in the following, these processes will be described in detail in the processing procedure of the detection method according to the third embodiment.

In the third embodiment, following to the process shown in step S 111 (processing of detecting the direction of the object), for example, by the position detection unit 348, and eigenvalues lambda _r of reception correlation matrix R _r, reception correlation matrix R _r and eigenvectors U of the eigenvalues lambda _t of transmit correlation matrix _{R t,} transmit correlation matrix _R and eigenvectors V of _t, the steering vector _{a r (θ r)} in the receiving array antenna 122, the transmit array steering vector in the antenna 212 _{a t} Based on (θ _t ), a position corresponding to an intersection of a straight line indicating the direction of the object 510 from the receiving array antenna 122 and a straight line indicating the direction of the object 510 from the transmitting array antenna 212 is determined. The position of the object 510 from which the virtual image position 530 has been removed is detected (step S313). About the specific method of position detection of the target object 510 from which the virtual image position 530 has been removed, [3-2. Since it is described in “Configuration of Detection Device], detailed description thereof is omitted.

  The processing procedure of the detection method according to the third embodiment of the present invention has been described above with reference to FIG. According to the third embodiment, in addition to the processing procedure of the detection method according to the second embodiment, the position of the object 510 from which the virtual image position 530 has been removed is detected, so that the object can be measured in a shorter measurement time. The position of 510 can be detected, and more accurate position detection of the object 510 from which the influence of the virtual image is removed is realized.

<4. Hardware configuration>
Next, an example of the hardware configuration of the detection apparatus according to the first, second, and third embodiments of the present invention will be described with reference to FIG. FIG. 12 is a block diagram illustrating an example of a hardware configuration of the detection apparatus according to the first, second, and third embodiments of the present invention. In addition, the detection apparatus 900 shown in FIG. 12 can implement | achieve the detection apparatuses 10, 20, and 30 shown in FIG.2, FIG6 and FIG.9, for example.

  The detection apparatus 900 includes a CPU 901, a ROM 903 (Read Only Memory 903), and a RAM 905 (Random Access Memory 905). The detection device 900 includes a host bus 907 (host bus 907), a bridge 909 (bridge 909), an external bus 911, an interface 913 (interface 913), a transmission device 914, a reception device 916, an input device 915, an output device 917, A storage device 919 (storage device 919), a communication device 921, a drive 923 (drive 923), and a connection port 925 (connection port 925) may be included. The detection apparatus 900 may include a processing circuit called a DSP or ASIC (Application Specific Integrated Circuit) instead of or in addition to the CPU 901.

  The CPU 901 functions as an arithmetic processing device and a control device, and the entire operation in the detection device 900 or a part thereof according to various programs recorded in the ROM 903, the RAM 905, the storage device 919, or the removable recording medium 929 (removable recording medium 929). To control. The ROM 903 stores programs used by the CPU 901, calculation parameters (parameters), and the like. The RAM 905 temporarily stores programs used in the execution of the CPU 901, parameters at the time of execution, and the like. The CPU 901, the ROM 903, and the RAM 905 are connected to each other by a host bus 907 configured by an internal bus such as a CPU bus. Further, the host bus 907 is connected to an external bus 911 such as a PCI (Peripheral Component Interconnect / Interface) bus via a bridge 909. In the present embodiment, the CPU 901 corresponds to, for example, the control units 140, 240, and 340 of the detection devices 10, 20, and 30 described above.

  The host bus 907 is connected to an external bus 911 such as a PCI (Peripheral Component Interconnect / Interface) bus via a bridge 909.

  The transmission device 914 has at least one transmission antenna, and transmits a signal including a radio wave such as a microwave toward the predetermined area from the transmission antenna. The transmission device 914 may include a drive circuit that drives the transmission device 914 and transmits a signal having a predetermined characteristic. The drive circuit includes, for example, a signal source that generates a signal, a modulation circuit that modulates the signal, an amplifier that amplifies the signal, and the like, and can transmit a signal having a predetermined characteristic (eg, amplitude, frequency, phase, etc.) Composed. In this embodiment, the transmission device 914 corresponds to, for example, the transmission devices 111 and 211 shown in FIGS. 1, 5, and 8 described above, and configures the transmission units 110 and 210 of the detection devices 10, 20, and 30. Can do.

  The receiving device 916 includes at least one receiving antenna, and receives a signal including a radio wave such as a microwave by the receiving antenna. The receiving device 916 may include a drive circuit that drives the receiving device 916 to receive a signal having a predetermined characteristic. The drive circuit includes, for example, a demodulation circuit that demodulates a signal and an amplifier that amplifies the signal, and is configured to be able to receive a signal having the characteristic according to the characteristic of the signal transmitted by the transmission device 914, for example. . In this embodiment, the receiving device 916 corresponds to, for example, the receiving device 121 illustrated in FIGS. 1, 5, and 8 described above, and can constitute the receiving unit 120 of the detecting devices 10, 20, and 30.

  The input device 915 includes, for example, a device operated by a user, such as a mouse, a keyboard, a touch panel, a button, a switch, and a lever. The input device 915 may be, for example, a remote control device that uses infrared rays or other radio waves, or an external connection device 931 such as a mobile phone or a PDA that supports the operation of the detection device 900. It may be. Furthermore, the input device 915 includes an input control circuit that generates an input signal based on information input by the user using the above-described operation means and outputs the input signal to the CPU 901, for example. The user of the detection device 900 can input various data (data) to the detection device 900 and instruct a processing operation by operating the input device 915. In the present embodiment, for example, the user uses the input device 915 to perform various information and instructions related to the direction detection and position detection of the object 510 (for example, the driving conditions of the reception unit 120 and the transmission units 110 and 210). Information, direction detection or position detection start instruction, etc.) may be input to the detection apparatus 900.

  The output device 917 is a device that can notify the user of the acquired information visually or audibly. Such devices include display devices such as CRT display devices, liquid crystal display devices, plasma display devices, EL display devices and lamps, speakers, headphones, and the like. There are an audio output device, a printer device, and the like. The output device 917 outputs, for example, results obtained by various processes performed by the detection device 900. Specifically, the display device visually displays the results obtained by various processes performed by the detection device 900 in various formats such as text (text), image (image), table, and graph. In the present embodiment, the display device corresponds to, for example, the display unit (not shown in FIGS. 2, 6, and 9) of the detection devices 10, 20, and 30 described above. In the present embodiment, information about the direction and position of the detected object 510 may be displayed on the display device. On the other hand, the audio output device converts an audio signal composed of reproduced audio data, acoustic data, and the like into an analog signal and outputs it audibly.

  The storage device 919 is a data storage device configured as an example of a storage unit of the detection device 900. The storage device 919 includes, for example, a magnetic storage device such as an HDD, a semiconductor storage device, an optical storage device, or a magneto-optical storage device. The storage device 919 stores programs executed by the CPU 901, various data, various data acquired from the outside, and the like. In this embodiment, the storage device 919 corresponds to, for example, the storage unit 130 of the detection devices 10, 20, and 30 described above. In the present embodiment, various types of information processed by the detection devices 10, 20, and 30 (for example, information about the direction and position of the detected object 510) may be stored in the storage device 919.

  The communication device 921 is a communication interface configured with, for example, a communication device for connecting to a communication network (network) 927. The communication device 921 is, for example, a communication card for wired or wireless LAN (Local Area Network), Bluetooth (registered trademark), or WUSB (Wireless USB). Further, the communication device 921 may be a router for optical communication, a router for ADSL (Asymmetric Digital Subscriber Line), a modem for various communication, or the like. The communication device 921 can transmit and receive signals and the like according to a predetermined protocol (protocol) such as TCP / IP, for example, with the Internet or other communication devices. The network 927 connected to the communication device 921 is configured by a wired or wireless network, for example, the Internet, a home LAN, infrared communication, radio wave communication, satellite communication, or the like. Also good. In this embodiment, the communication device 921 corresponds to, for example, the communication unit (not shown in FIGS. 2, 6, and 9) of the detection devices 10, 20, and 30 described above. In this embodiment, various types of information processed by the detection devices 10, 20, and 30 (for example, information about the direction and position of the detected object 510) are transmitted to other devices via the network 927 by the communication device 921. May be transmitted to and received from.

  The drive 923 is a reader / writer for a recording medium, and is built in or externally attached to the detection device 900. The drive 923 reads information recorded on a removable recording medium 929 such as a mounted magnetic disk (disk), optical disk, magneto-optical disk, or semiconductor memory (memory) and outputs the information to the RAM 905. The drive 923 can also write information to a removable recording medium 929 such as a mounted magnetic disk, optical disk, magneto-optical disk, or semiconductor memory. The removable recording medium 929 is, for example, a DVD medium (medium), an HD-DVD medium, a Blu-ray (registered trademark) medium, or the like. Further, the removable recording medium 929 may be a CompactFlash (registered trademark) (CompactFlash: CF), a flash memory, an SD memory card (Secure Digital memory card), or the like. Further, the removable recording medium 929 may be, for example, an IC card (Integrated Circuit card) on which a non-contact IC chip (chip) is mounted, an electronic device, or the like. In the present embodiment, various types of information processed in the detection devices 10, 20, 30 (for example, information about the direction and position of the detected object 510) are read from the removable recording medium 929 by the drive 923, It may be written on a removable recording medium 929.

  The connection port 925 is a port for directly connecting a device to the detection apparatus 900. Examples of the connection port 925 include a USB (Universal Serial Bus) port, an IEEE 1394 port, a SCSI (Small Computer System Interface) port, and the like. As another example of the connection port 925, there are an RS-232C port, an optical audio terminal, an HDMI (registered trademark) (High-Definition Multimedia Interface) port, and the like. By connecting the external connection device 931 to the connection port 925, the detection apparatus 900 acquires various data directly from the external connection device 931 or provides various data to the external connection device 931. In the present embodiment, various types of information processed by the detection devices 10, 20, and 30 (for example, information about the direction and position of the detected object 510) are acquired from the external connection device 931 via the connection port 925. Or may be output to the externally connected device 931.

  Heretofore, an example of a hardware configuration capable of realizing the function of the detection apparatus 900 according to the embodiment of the present disclosure has been shown. Each component described above may be configured using a general-purpose member, or may be configured by hardware specialized for the function of each component. Therefore, it is possible to change the hardware configuration to be used as appropriate according to the technical level at the time of carrying out this embodiment.

  The functions of the detection devices 10, 20, and 30 according to the first, second, and third embodiments shown in FIGS. 2, 6, and 9 are configured using general-purpose members and circuits. It may be configured by hardware specialized for each function. These functions may be performed by a processor such as a CPU. Therefore, it is possible to appropriately change the configuration to be used according to the technical level at the time of carrying out the present embodiment.

  It is possible to create a computer program (computer program) for realizing the functions of the detection devices 10, 20, 30, and 900 according to the present embodiment as described above and mount the computer program on a PC or the like. In addition, a computer-readable recording medium storing such a computer program can be provided. The recording medium is, for example, a magnetic disk, an optical disk, a magneto-optical disk, a flash memory, or the like. Further, the above computer program may be distributed via a network, for example, without using a recording medium.

<5. Supplement>
The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

10, 20, 30 Detection device 110, 210 Transmission unit 120 Reception unit 130 Storage unit 140, 240, 340 Control unit 141 Reception drive control unit 142, 242 Complex transfer function measurement unit 143 Complex difference transfer function measurement unit 144 Reception correlation matrix calculation Units 145, 245 Evaluation function calculation unit 146, 246 Direction detection unit 147 Transmission drive control unit 247 Transmission correlation matrix calculation unit 248, 348 Position detection unit

Claims (8)

A first complex transfer function representing a signal propagation path between at least one transmitting element and a plurality of receiving elements in the presence of an object; and at least one transmitting element in the absence of the object; A complex difference transfer function calculating unit for calculating a complex difference transfer function, which is a difference between a second complex transfer function representing a signal propagation path between the plurality of receiving elements, and
A direction detection unit that detects a first direction that is at least a direction of the object from the receiving element based on the complex difference transfer function;
A detection apparatus comprising: A reception correlation matrix calculation unit for calculating a reception correlation matrix representing a correlation of the plurality of reception elements with respect to the transmission element based on the complex differential transfer function;
Based on the reception correlation matrix, an evaluation function calculation unit that calculates an evaluation function indicating directions of arrival of signals in the plurality of reception elements;
Further comprising
The direction detection unit detects the first direction based on the evaluation function;
The detection apparatus according to claim 1, wherein: The complex difference transfer function calculation unit calculates the complex difference transfer function for a plurality of the transmitting elements and a plurality of the receiving elements,
The direction detection unit further detects a second direction that is a direction of the object from the transmission element based on the complex difference transfer function,
A position detector that detects the position of the object relative to the receiving element and the transmitting element based on the first direction and the second direction;
The detection apparatus according to claim 1 or 2, wherein A transmission correlation matrix calculation unit that calculates a transmission correlation matrix representing the correlation of the plurality of transmission elements with respect to the reception element based on the complex differential transfer function;
Based on the transmission correlation matrix, an evaluation function calculation unit that calculates an evaluation function indicating a starting direction of signals in the plurality of transmission elements;
Further comprising
The direction detection unit detects the second direction based on the evaluation function;
The detection device according to claim 3, wherein: A reception correlation matrix calculation unit for calculating a reception correlation matrix representing a correlation of a plurality of the reception elements with respect to the transmission element;
A transmission correlation matrix calculation unit for calculating a transmission correlation matrix representing the correlation of the plurality of transmission elements with respect to the reception element;
Further comprising
The position detection unit, when there are a plurality of the objects, the inner product value of the eigenvector of the reception correlation matrix and the steering vector corresponding to the first direction in the receiving element, the eigenvector of the transmission correlation matrix and the Based on the inner product value with the steering vector corresponding to the second direction in the transmission element, the eigenvalue of the reception correlation matrix, and the eigenvalue of the transmission correlation matrix, the straight line indicating the first direction and the second Detecting the position of the object from which the position of the virtual image where the object does not exist is removed from the position corresponding to the intersection with the straight line indicating the direction of
The detection device according to claim 3 or 4, wherein When the eigenvalues of the reception correlation matrix and the eigenvalues of the transmission correlation matrix are rearranged in descending order, at least eigenvalues that are located in the same order, including the largest eigenvalues that are the first eigenvalues in the descending order. for,
The inner product value of the first direction corresponding to the steering vector of the receiving element that maximizes the inner product value with the eigenvector corresponding to the eigenvalue of the reception correlation matrix and the eigenvector corresponding to the eigenvalue of the transmission correlation matrix is maximum. Detecting the position of the object based on the second direction corresponding to the steering vector of the transmitting element,
The detection device according to claim 5, wherein: A first complex transfer function representing a signal propagation path between at least one transmitting element and a plurality of receiving elements in the presence of an object; and at least one transmitting element in the absence of the object; Calculating a complex differential transfer function, which is a difference between a second complex transfer function representing a signal propagation path between the plurality of receiving elements;
Detecting at least a first direction that is a direction of the object from the receiving element based on the complex differential transfer function;
The detection method characterized by including. On the computer,
A first complex transfer function representing a signal propagation path between at least one transmitting element and a plurality of receiving elements in the presence of an object; and at least one transmitting element in the absence of the object; A function of calculating a complex differential transfer function, which is a difference between a second complex transfer function representing a signal propagation path between the plurality of receiving elements, and
A function of detecting at least a first direction which is a direction of the object from the receiving element based on the complex differential transfer function;
A program to realize

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