Sensing system, receiving device, control circuit, storage medium, sensing method, and receiving method

Abstract

The sensing system (50) comprises a transmitting device (10) having a plurality of transmitting antenna elements (18), which controls the timing of generating a radar signal, generating a code, and generating a carrier signal which divides an available frequency band into a plurality of subbands and switches periodically, multiplies the radar signal by a code for each of the plurality of transmitting antenna elements (18), generates a high-frequency signal of the subband bandwidth using the radar signal multiplied by the code and the carrier signal, and transmits the high-frequency signal from the plurality of transmitting antenna elements (18); and a receiving device (20) having a plurality of receiving antenna elements (22) which receives the high-frequency signal transmitted from the transmitting device (10) and reflected or scattered by an object to be measured, generates transmission path information using the carrier signal, the radar signal, and the code to identify the position of the object to be measured, performs focus correction to generate an image of the object to be measured, and uses the image to determine an extraction position for vibration information of the object to be measured and extracts it from the transmission path information.

Description

[Technical field]

[0001] The present disclosure relates to a sensing system, a receiving device, a control circuit, a storage medium, a sensing method, and a receiving method that measure a measurement target using electromagnetic waves. [Background technology]

[0002] In recent years, there has been an increasing need for sensing technology that can remotely grasp the surrounding environment in order to realize a safe and secure society. For example, such sensing technology is used in on-board radars that allow cars to grasp the situation of people and vehicles around them, and in the future, it is expected that it will also be used to collect environmental information in digital twins and cyber-physical systems. On the other hand, there is also a need to analyze the environment of objects from information caused by sound, such as heart sound tests using stethoscopes and electrocardiograms, and aging deterioration surveys of bridges. However, these methods require measurements to be made in direct contact with the object due to the impedance mismatch between the object and the air. Therefore, in order to obtain this information remotely, implementation using radar devices that utilize electromagnetic waves is being considered.

[0003] For example, Patent Document 1 discloses a technology using a MIMO (Multiple Input Multiple Output) radar device. The MIMO radar device described in Patent Document 1 uses multiple transmitting elements and multiple receiving elements to collect vibration information from multiple points on the human body, and extracts vibrations on the surface of the human body caused by heartbeats from the collected vibration information. The MIMO radar device described in Patent Document 1 irradiates a radar signal in the direction of the human body, receives, among the reflected signals from the human body, signals that are incident from a directional direction that can be realized by the number of antennas mounted on the MIMO radar device, and obtains a rough frequency fluctuation of the heartbeat. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7001244 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the MIMO radar device described in Patent Document 1 has a small number of elements that can be mounted on the receiving antenna, and the directivity is wide and the direction in which it can be pointed is limited, making it difficult to always select the optimal beam shape for extracting vibration information. Therefore, the MIMO radar device described in Patent Document 1 has the problem that it can only point the beam in an appropriate direction and average or select after measuring at multiple points, and cannot extract vibration information at the optimal position.

[0006] The present disclosure has been made in consideration of the above, and has an object to provide a sensing system capable of extracting vibration information of a measurement target with high accuracy. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the object, a sensing system disclosed herein has a plurality of transmitting antenna elements, and controls the timing of generating a radar signal, generating a code for separating high-frequency signals transmitted from the plurality of transmitting antenna elements into high-frequency signals transmitted from each transmitting antenna element by a receiving device, and generating a carrier signal by dividing an available frequency band into a plurality of subbands and periodically switching the subbands used in the high-frequency signals transmitted from the plurality of transmitting antenna elements so that the entire frequency band is used, multiplying the radar signal by the code for each of the plurality of transmitting antenna elements, and generating a carrier signal. a transmitting device that generates a high-frequency signal of a subband bandwidth using a radar signal and a rear signal, and transmits the signal from a plurality of transmitting antenna elements; and a receiving device that has a plurality of receiving antenna elements and receives the high-frequency signal transmitted from the transmitting device and reflected or scattered by the object to be measured, generates transmission path information indicating the state of the transmission path between the transmitting device and the receiving device using the carrier signal, radar signal, and code, identifies the position of the object to be measured using the transmission path information, performs focus correction on the object to be measured to generate an image of the object to be measured, determines an extraction position for vibration information of the object to be measured using the image, and extracts the vibration information of the object to be measured using the extraction position from the transmission path information. Effect of the Invention

[0008] The sensing system according to the present disclosure has an effect of being able to extract vibration information of a measurement target with high accuracy. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing an overview of measurements assumed in a sensing system according to a first embodiment. [Diagram 2] FIG. 1 is a diagram showing a configuration example of a sensing system according to a first embodiment; [Diagram 3] FIG. 1 is a diagram showing an example of a high-frequency signal transmitted from a transmission device according to a first embodiment; [Figure 4] 1 is a flowchart showing the operation of the sensing system according to the first embodiment. [Diagram 5]A flowchart showing the operation of the transmitting device according to the first embodiment. [Figure 6] Flowchart showing the operation of the receiving device according to the first embodiment [Figure 7] FIG. 1 is a diagram showing an example of the configuration of a processing circuit that realizes a receiving device according to a first embodiment when the processing circuit is realized by a processor and a memory. [Figure 8] FIG. 1 is a diagram showing an example of a processing circuit for implementing a receiving device according to a first embodiment when the processing circuit is configured with dedicated hardware; [Figure 9] FIG. 13 is a diagram showing a configuration example of a sensing system according to a second embodiment; [Figure 10] 11 is a flowchart showing the operation of a sensing system according to a second embodiment. [Figure 11] Flowchart showing the operation of the receiving device according to the second embodiment [Figure 12] FIG. 13 is a diagram showing an outline of measurements assumed in a sensing system according to a third embodiment. [Figure 13] FIG. 1 is a first diagram showing a configuration example of a sensing system according to a third embodiment; [Figure 14] FIG. 2 is a second diagram showing a configuration example of a sensing system according to a third embodiment; [Figure 15] FIG. 13 is a diagram showing an outline of measurements assumed in a sensing system according to a fourth embodiment. [Figure 16] FIG. 13 is a diagram showing an outline of measurements assumed in a sensing system according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] A sensing system, a receiving device, a control circuit, a storage medium, a sensing method, and a receiving method according to embodiments of the present disclosure will be described in detail below with reference to the drawings.

[0011] Embodiment 1 FIG. 1 is a diagram showing an overview of measurements assumed in a sensing system 50 according to the first embodiment. The sensing system 50 is a system including a transmitting device 10 and a receiving device 20, and measures a measurement object 40. In the sensing system 50, the transmitting device 10 irradiates the measurement object 40 with radio waves from a transmitting array 17 consisting of a plurality of transmitting antenna elements 18, and the receiving device 20 measures the measurement object 40 by receiving reflected waves, scattered waves, etc. from the measurement object 40 with a receiving array 21 consisting of a plurality of receiving antenna elements 22. In the first embodiment, the transmitting device 10 transmits a high-frequency signal as the irradiation of radio waves. In the transmitting device 10, the transmitting array 17 has N transmitting antenna elements 18 as the plurality of transmitting antenna elements 18. T In the receiving device 20, the receiving array 21 includes a plurality of receiving antenna elements 22, each of which is a single antenna element. R The sensing system 50 includes N receiving antenna elements 22, as described below. T 18 transmitting antenna elements and N R N T ×N R Information on the measurement target 40 is extracted from the pieces of transmission line information.

[0012] 2 is a diagram showing an example of the configuration of a sensing system 50 according to the first embodiment. As described above, the sensing system 50 includes a transmitting device 10 and a receiving device 20. The transmitting device 10 includes a synchronization unit 11, a radar signal generating unit 12, a code generating unit 13, a carrier signal generating unit 14, an encoding unit 15, a high frequency signal generating unit 16, and a transmitting array 17. As described above, the transmitting array 17 includes N T The antenna 10 includes transmitting antenna elements 18.

[0013] The synchronization unit 11 adjusts the timing of the operation of each unit of the transmitting device 10 and the receiving device 20. The synchronization unit 11 controls the timing of the generation of the radar signal by the radar signal generation unit 12, the generation of the code by the code generation unit 13, and the generation of the carrier signal by the carrier signal generation unit 14 in the transmitting device 10. The radar signal generation unit 12 generates a radar signal at a baseband or an intermediate frequency. The radar signal is a periodic wideband signal as described later. The code generation unit 13 generates a code for separating a high-frequency signal transmitted from a transmitting array 17 including a plurality of transmitting antenna elements 18 into high-frequency signals transmitted from each transmitting antenna element 18 in the receiving device 20. The carrier signal generation unit 14 generates a reference carrier for generating a final high-frequency signal. As described later, the carrier signal generation unit 14 divides the frequency band available to the transmitting device 10 into a plurality of subbands, periodically switches the subbands used in the high-frequency signals transmitted from the plurality of transmitting antenna elements 18, and generates a carrier signal so that the entire frequency band is used.

[0014] The encoding unit 15 performs code multiplication for each of the multiple transmitting antenna elements 18, multiplying the radar signal generated by the radar signal generating unit 12 by the code generated by the code generating unit 13. The high-frequency signal generating unit 16 generates a high-frequency signal to be transmitted from the transmitting antenna element 18, using the signal obtained by multiplying the radar signal by the code generated by the encoding unit 15 and the reference carrier generated by the carrier signal generating unit 14, for each transmitting antenna element 18. The high-frequency signal generating unit 16 is, for example, an up-converter or a multiplier, and generates a high-frequency signal of a subband bandwidth using the radar signal multiplied by the code and the carrier signal, and transmits the high-frequency signal from the multiple transmitting antenna elements 18. In the transmitting array 17, the transmitting antenna elements 18 transmit the high-frequency signal generated by the high-frequency signal generating unit 16.

[0015] The receiving device 20 includes a receiving array 21, a signal conversion unit 23, a detection unit 24, a correlation processing unit 25, a MIMO transmission path regeneration unit 26, a layer extraction unit 27, a focus correction unit 28, a position determination unit 29, and a vibration information extraction unit 30. As described above, the receiving array 21 includes NR The receiving antenna element 22 is provided.

[0016] In the receiving array 21, the receiving antenna elements 22 receive high-frequency signals transmitted from the transmitting device 10, which are reflected waves or scattered waves from the object to be measured 40. That is, the receiving antenna elements 22 receive reflected waves or scattered waves of the high-frequency signals transmitted from the transmitting device 10. The receiving antenna elements 22 can also directly receive the high-frequency signals transmitted from the transmitting device 10, depending on the positional relationship, orientation relationship, etc. between the transmitting antenna elements 18 of the transmitting device 10 and the receiving antenna elements 22 of the receiving device 20. The signal conversion unit 23 converts the high-frequency signals received by the receiving antenna elements 22 into baseband or intermediate frequency signals, i.e., down-converts them, for each receiving antenna element 22. The signal conversion unit 23 is, for example, a down-converter, and converts the high-frequency signals received by the multiple receiving antenna elements 22 into receiving signals in the frequency band of the radar signal used to generate the high-frequency signals in the transmitting device 10, using the carrier signal used to generate the high-frequency signals in the transmitting device 10.

[0017] The detection unit 24 is disposed for each receiving antenna element 22, and detects the baseband or intermediate frequency received signal converted by the signal conversion unit 23 using the radar signal generated by the radar signal generation unit 12 of the transmitting device 10 to obtain reception information. The reception information is a reflected wave or scattered wave of the high frequency signal received by each receiving antenna element 22, and includes high frequency signals transmitted from the multiple transmitting antenna elements 18. Note that the receiving device 20 may obtain the reception information by mixing the baseband or intermediate frequency received signal converted by the signal conversion unit 23 using a mixer. The following describes the case where the detection unit 24 performs detection. The correlation processing unit 25 is arranged for each receiving antenna element 22, and uses the code generated by the code generation unit 13 of the transmitting device 10 to perform correlation processing on the received information obtained by detection in the detection unit 24, thereby separating the received information into signals from each transmitting antenna element 18 of the transmitting device 10, i.e., separating the received signals received by multiple receiving antenna elements 22 into signals for each transmitting antenna element 18 transmitted from the transmitting device 10 for each receiving antenna element 22.

[0018] The MIMO transmission path regeneration unit 26 regenerates the state of the transmission path between the transmitting device 10 and the receiving device 20 using the signals separated for each transmitting antenna element 18 and each receiving antenna element 22 by the correlation processing unit 25, and generates MIMO transmission path information indicating the state of the transmission path. The MIMO transmission path regeneration unit 26 generates MIMO transmission path information for each frequency bin described later. In the following description, the MIMO transmission path regeneration unit may be simply referred to as the transmission path regeneration unit, and the MIMO transmission path information may be simply referred to as the transmission path information. The layer cutout unit 27 identifies the position of the measurement target 40 using the MIMO transmission path information. The layer cutout unit 27 cuts out the measurement target 40 with a specific curved surface from the MIMO transmission path information reproduced by the MIMO transmission path regeneration unit 26. Specifically, the layer cutout unit 27 identifies the position of the measurement target 40 by extracting reflection point information of a layer corresponding to the distance in the depth direction of the measurement target 40 as viewed from the multiple receiving antenna elements 22 from the MIMO transmission path information. The focus correction unit 28 performs focus correction on the measurement target 40 whose position has been specified, and generates and outputs an image which is image information of the measurement target 40. As focus correction of the measurement target 40, the focus correction unit 28 performs focus correction on the extracted reflection point information according to the layer position.

[0019] The position determination unit 29 determines the extraction position of the vibration information of the measurement target 40 using the image of the measurement target 40 generated by the focus correction unit 28. The extraction position of the vibration information is, for example, the optimal position for extracting the vibration information to be measured, i.e., the desired vibration information, and is a position indicated by a layer and a focus that makes it easy to extract the vibration information. For example, if the measurement target 40 is a human body and the vibration information to be measured, i.e., the desired vibration information, is the heartbeat of the human body that is the measurement target 40, the extraction position of the vibration information is a position where the heartbeat can be measured in the human body. The relationship between the measurement target 40 and the extraction position of the vibration information may be set in advance by the user or manufacturer of the sensing system 50, or may be set by the user of the sensing system 50 each time a measurement is performed. The vibration information extraction unit 30 extracts the vibration information of the measurement target 40 from the MIMO transmission path information generated by the MIMO transmission path regeneration unit 26 using the extraction position determined by the position determination unit 29. The vibration information extraction unit 30, for example, weights each transmission path information based on the MIMO transmission path information, generates a virtual beam shape that acquires reflection information from the direction of the position indicated by the extraction position, and extracts vibration information from the obtained information, i.e., the reflection information from the direction of the extraction position. The vibration information extraction unit 30 can extract vibration information from, for example, the period of change of the obtained reflection information. In this way, in the sensing system 50, the transmitting device 10 does not actually perform beam control, but the receiving device 20 performs beam control virtually.

[0020] The following describes the operation of the sensing system 50. In the transmitting device 10, the synchronization unit 11 controls the radar signal generation timing of the radar signal generation unit 12, the code generation timing of the code generation unit 13, and the carrier frequency switching timing of the carrier signal generation unit 14, based on a frame configuration described later.

[0021] Fig. 3 is a diagram showing an example of a high-frequency signal transmitted from the transmitting device 10 according to the first embodiment. Fig. 3 shows an example in which an up-chirp is used as the radar signal generated by the radar signal generating unit 12, but the radar signal is not limited to an up-chirp, and may be any signal whose spectrum spreads over a specific frequency band, such as an up-down chirp, a ZC (Zadoff-Chu) sequence, a pseudo noise (hereinafter referred to as a PN (Pseudo Noise)) signal, an OFDM (Orthogonal Frequency Division Multiplexing) signal, a frequency step signal whose frequency changes stepwise in the time direction, or a general spread signal. The frequency band available to the sensing system 50 is a bandwidth f B Partial N with B In Figure 3, the N B Bands are divided into subbands 1 to N B This band, i.e., subband 1 to subband N B may partially overlap each other.

[0022] The radar signal generator 12 generates a periodic wideband signal, typically a chirp signal, in each subband as a radar signal. At this time, the synchronization unit 11 instructs the radar signal generator 12 of the start timing of each period. The period of the wideband signal is a chip period T C That is, the code generator 13 sets the code chip period T C The code generator 13 generates a code having a code length of M chips to be used by each transmitting antenna element 18. As shown in FIG. 3, the code period T SC =M×T CAt this time, the synchronization unit 11 indicates the start timing of the code period to the code generation unit 13. The encoding unit 15 performs code multiplication, which multiplies the radar signal generated by the radar signal generation unit 12 by the code generated by the code generation unit 13. The code is generally expressed as ±1. The encoding unit 15 performs multiplication processing as phase modulation, amplitude modulation, frequency modulation, or a combination of these.

[0023] The transmitter 10 transmits at least a code period T SC However, by using repeated codes, the radar signal is transmitted with a code period of T SC For example, the time T shown in FIG. B The radar signal may be transmitted for a period of T B The period is a subband switching period.

[0024] The transmitting device 10 transmits the subbands at a subband switching period T B After completing the transmission of the radar signal, the frequency is switched, i.e., the subband is switched. The carrier signal generator 14 generates a carrier signal for converting the radar signal encoded by the encoder 15 into a high-frequency signal of each subband. The carrier signal generator 14 receives an instruction from the synchronizer 11 and generates a subband switching period T B The radio frequency signal generator 16 uses the carrier signal generated by the carrier signal generator 14 to convert the radar signal encoded by the encoder 15 into a radio frequency signal of each subband, and transmits the signal from the transmitting antenna elements 18 of the transmitting array 17. The transmitter 10 switches between subbands 1 to N. B That is, N B The period during which the radar signal is transmitted over the frequency band of all the subbands is defined as the frame period T f =N B ×T B The transmitting device 10 transmits subbands 1 to N shown in FIG. B If a high-frequency signal up to 1 frame is considered as one frame, then one frame period T fOne measurement is completed.

[0025] The code generated by the code generation unit 13 is used to identify signals between elements of the transmitting antenna elements 18. For this purpose, the code generation unit 13 generates so-called orthogonal codes or quasi-orthogonal codes that have small cross-correlation between the elements of the transmitting antenna elements 18. Note that, although M sequences, Gold codes, Walsh-Hadamard codes, PN sequences, and the like are known as the codes generated by the code generation unit 13 and used to identify the elements of the transmitting antenna elements 18, any code having a high degree of orthogonality may be used, and therefore the codes are not limited to these.

[0026] In the sensing system 50, the transmitting device 10 and the receiving device 20 are synchronized in time and frequency, and operate under the instruction of the same synchronization unit 11. The sensing system 50 may have a bistatic configuration in which the transmitting device 10 and the receiving device 20 are physically located at separate positions. In this case, the transmitting device 10 and the receiving device 20 can be synchronized using not only a wired connection but also a Global Positioning System (GPS) or various wireless links. For example, the sensing system 50 may have a configuration in which the carrier signal generating unit 14 is arranged independently of the transmitting device 10 and the receiving device 20, and a reference signal and a reference signal for adjusting the frequency are shared by the transmitting device 10 and the receiving device 20. Here, the operation of the transmitting device 10 and the receiving device 20 will be described using a configuration in which the functional units of the transmitting device 10 and the receiving device 20 are connected by wires as shown in FIG. 2.

[0027] The receiving device 20 receives, at the receiving antenna elements 22 of the receiving array 21, high-frequency signals that are irradiated from the transmitting device 10 to the object to be measured 40 and reflected or scattered by the object to be measured 40. The signal conversion unit 23 converts, i.e., down-converts, the high-frequency signals received at the receiving antenna elements 22 of the receiving array 21 into baseband or intermediate frequency signals using the carrier signals corresponding to each subband generated by the carrier signal generation unit 14. The detection unit 24 is disposed for each receiving antenna element 22, and detects the baseband or intermediate frequency signals converted by the signal conversion unit 23 using the radar signal generated by the radar signal generation unit 12 of the transmitting device 10 to obtain reception information. The reception information includes N T 1 includes signals transmitted from all transmit antenna elements 18 as received at a particular receive antenna element 22 .

[0028] The correlation processor 25 performs correlation processing on the received information obtained by detection in the detector 24 using the code generated in the code generator 13 of the transmitter 10, thereby separating the received information into signals from each transmitting antenna element 18 of the transmitter 10. In the receiver 20, the processing of the correlation processor 25 is performed for each receiving antenna element 22, so that the transmission path information for each subband is N T ×N R The number of signals obtained is determined by the number of radar signals. The detection process in the detection unit 24 differs depending on the type of signal used as the radar signal, so a detailed description will be omitted here. In the first embodiment, the detection process in the detection unit 24 may be a general-purpose processing method.

[0029] Subband bandwidth f B The extent to which the bandwidth f of the subband is to be widened depends on the frequency band used by the sensing system 50, various architectures, and the like. In particular, when the sensing system 50 uses an ultra-high frequency band such as the terahertz band, there is a high possibility that a large variation in frequency characteristics will occur within the subband. For this reason, the sensing system 50 uses the bandwidth f of the subband BAlternatively, the transmission path information may be calculated by dividing each subband into multiple frequency bins. In general, the frequency bin is set to a bandwidth in which the frequency fluctuation within the band is considered to be constant. In the receiving device 20, the MIMO transmission path regenerator 26 divides each subband into N F 1. The MIMO transmission path regenerator 26 divides the subbands into N frequency bins and calculates information about the transmission path formed by sandwiching the target 40 between the transmission array 17 of the transmission device 10 and the reception array 21 of the reception device 20 shown in FIG. T ×N R ×N F ×N B It is possible to obtain MIMO transmission path information consisting of elements. In the following description, frequency bin may be expressed as frequency bin.

[0030] In this way, the transmitting device 10 divides the available frequency band into multiple subbands, and transmits the high-frequency signal so that the entire frequency band is used by periodically switching the subbands used in the high-frequency signal transmitted from the multiple transmitting antenna elements 18. At this time, the MIMO transmission path regenerator 26 generates, as the MIMO transmission path information, the number of the multiple transmitting antenna elements 18 of the transmitting device 10, the number of the multiple receiving antenna elements 22 of the receiving device 20, the number of subbands, and the number of frequency bins when the bandwidth of the subband is divided into multiple frequency bins.

[0031] In addition, spatially, N T ×N R In order to generate MIMO channel information, we use N T ×N R We have described a method of using real antenna elements. On the other hand, we have also proposed a method of reducing the number of real antenna elements by using approximation techniques, such as interpolation and extrapolation, while increasing the number of real antenna elements to N T ×N R It is also possible to generate MIMO channel information. Since this processing itself is a common technique, a detailed description will be omitted here.

[0032] As with the detection process, different methods are used for generating the MIMO transmission path information depending on the type of radar signal, detection method, etc., so the method for generating the MIMO transmission path information is not limited here. For example, when a chirp signal as shown in Fig. 3 is used as the radar signal, the receiving device 20 obtains a carrier signal with a frequency difference Δf according to the distance to the reflection point after detection. When there are multiple reflection points, carrier signals with multiple frequencies are superimposed. From this information, the receiving device 20 calculates the phase, amplitude characteristics, etc. of each frequency bin.

[0033] The obtained MIMO transmission path information includes all reflection point information of the measurement target 40. The layer cutout unit 27 cuts out only reflection point information on a specific curved surface determined from the arrangement of the transmitting antenna element 18 and the receiving antenna element 22. The specific curved surface may be a specific flat surface. The focus correction unit 28 can obtain a tomographic image of an arbitrary part of the measurement target 40 by focusing on the above-mentioned curved surface. The processing of the layer cutout unit 27 and the processing of the focus correction unit 28 are performed in no particular order. The position determination unit 29 uses the tomographic image obtained from the focus correction unit 28 to determine an optimal extraction position for extracting vibration information of the measurement target 40. The optimal extraction position includes the setting values ​​of the layer and the focus. The vibration information extraction unit 30 weights each transmission path information of the MIMO transmission path information using the extraction position determined by the position determination unit 29, generates a virtual beam shape that obtains reflection information from the direction of the position indicated by the extraction position, and calculates a code period T SCVibration information is extracted in units of time. The reflected information from the direction of the position indicated by the extraction position may be reflected information only from the extraction position, or may be reflected information within a specified range including the extraction position, depending on the vibration information to be measured, i.e., the desired vibration information. The number of subbands used in the stage of determining the extraction position of the vibration information may be different from the number of subbands used in the stage of continuously acquiring the vibration information. That is, the transmitting device 10 and the receiving device 20 may use different numbers of subbands in the stage of determining the extraction position of the vibration information and the stage of extracting the vibration information. This is because it is assumed that the stage of determining the extraction position requires spatial resolution including the depth direction, while the stage of acquiring the vibration information requires only acquiring information such as a predetermined azimuth angle and elevation angle. For example, this corresponds to a case where reflection occurs only on the skin surface and information separation in the depth direction is not required. When acquiring vibration information, there is a need to increase the resolution in the time direction, in other words, to capture vibrations of high frequency. For this reason, it is also possible to reduce the number of subbands used in the stage of acquiring the vibration information and to speed up the measurement period.

[0034] 4 is a flowchart showing the operation of the sensing system 50 according to the first embodiment. In the sensing system 50, the transmitting device 10 generates a high-frequency signal (step S11) and transmits it from the transmitting array 17 toward the measurement target 40 (step S12). When the receiving device 20 receives the high-frequency signal transmitted from the transmitting device 10 and reflected or scattered by the measurement target 40 (step S13), it generates MIMO transmission path information indicating the state of the transmission path between the transmitting device 10 and the receiving device 20 using the carrier signal, the radar signal, and the code (step S14), identifies the position of the measurement target 40 using the MIMO transmission path information, and performs focus correction on the measurement target 40 to generate an image of the measurement target 40 (step S15). The receiving device 20 uses the generated image to determine an optimal extraction position for extracting vibration information of the measurement target 40 (step S16), extracts reflection information of the determined extraction position from the MIMO transmission path information, and extracts vibration information of the measurement target 40 (step S17).

[0035] FIG. 5 is a flowchart showing the operation of the transmitting device 10 according to the first embodiment. The flowchart shown in FIG. 5 shows details of the operation of step S11 and step S12 of the flowchart shown in FIG. 4. In the transmitting device 10, the synchronization unit 11 controls the generation of the radar signal in the radar signal generating unit 12, the generation of the code in the code generating unit 13, and the generation of the carrier signal in the carrier signal generating unit 14, that is, the timing of each operation (step S21). The radar signal generating unit 12 generates a radar signal that is a wideband signal under the control of the synchronization unit 11 (step S22). The code generating unit 13 generates a code for separating the high-frequency signals transmitted from the multiple transmitting antenna elements 18 into the high-frequency signals transmitted from each transmitting antenna element 18 in the receiving device 20 under the control of the synchronization unit 11 (step S23). The encoding unit 15 multiplies the radar signal by the code for each of the multiple transmitting antenna elements 18 (step S24). The carrier signal generating unit 14, under the control of the synchronizing unit 11, divides the frequency band available to the transmitting device 10 into a plurality of subbands, and periodically switches the subbands used in the high-frequency signals transmitted from the plurality of transmitting antenna elements 18 to generate carrier signals so that the entire frequency band is used (step S25). The high-frequency signal generating unit 16 uses the code-multiplied radar signal and the carrier signal to generate high-frequency signals of the subband bandwidth (step S26). The plurality of transmitting antenna elements 18 transmit the high-frequency signals (step S27).

[0036] FIG. 6 is a flowchart showing the operation of the receiving device 20 according to the first embodiment. The flowchart shown in FIG. 6 shows the details of the operation from step S13 to step S17 of the flowchart shown in FIG. 4. In the receiving device 20, the multiple receiving antenna elements 22 receive the reflected or scattered waves of the high-frequency signal transmitted from the transmitting device 10 having the multiple transmitting antenna elements 18 and reflected or scattered by the measurement target 40 (step S31). The signal conversion unit 23 converts the reflected or scattered waves of the high-frequency signal received by the multiple receiving antenna elements 22 into a received signal in the frequency band of the radar signal used to generate the high-frequency signal by the transmitting device 10, using the carrier signal used to generate the high-frequency signal by the transmitting device 10 (step S32). The detection unit 24 detects the received signal using the radar signal generated by the transmitting device 10, and obtains reception information including the reflected or scattered waves of the high-frequency signal received by each receiving antenna element 22 and transmitted from the multiple transmitting antenna elements 18 (step S33). The correlation processing unit 25 performs correlation processing on the received information using the code used when the radar signal was encoded by the transmitting device 10, and separates the received signal into signals for each transmitting antenna element 18 transmitted from the transmitting device 10 for each receiving antenna element 22 (step S34). The MIMO transmission path regeneration unit 26 generates MIMO transmission path information indicating the state of the transmission path between the transmitting device 10 and the receiving device 20 using the separated signals (step S35). The layer extraction unit 27 specifies the position of the measurement target 40 using the MIMO transmission path information (step S36). The focus correction unit 28 performs focus correction on the measurement target 40 whose position has been specified, and generates an image of the measurement target 40 (step S37). The position determination unit 29 uses the image of the measurement target 40 generated by the focus correction unit 28 to determine the extraction position of the vibration information of the measurement target 40 (step S38). The vibration information extraction unit 30 extracts vibration information of the measurement target 40 from the MIMO transmission path information generated by the MIMO transmission path regeneration unit 26, using the extraction position determined by the position determination unit 29 (step S39).

[0037] Next, the hardware configuration of each device of the sensing system 50 will be described. In the receiving device 20, the receiving array 21 is composed of a plurality of receiving antenna elements 22. The signal conversion unit 23, the detection unit 24, the correlation processing unit 25, the MIMO transmission path regeneration unit 26, the layer extraction unit 27, the focus correction unit 28, the position determination unit 29, and the vibration information extraction unit 30 are realized by processing circuits. The processing circuit may be a processor and memory that executes a program stored in a memory, or may be dedicated hardware. The processing circuit is also called a control circuit.

[0038] FIG. 7 is a diagram showing a configuration example of a processing circuit 90 in the case where the processing circuit for realizing the receiving device 20 according to the first embodiment is realized by a processor 91 and a memory 92. The processing circuit 90 shown in FIG. 7 is a control circuit and includes a processor 91 and a memory 92. When the processing circuit 90 is configured with the processor 91 and the memory 92, each function of the processing circuit 90 is realized by software, firmware, or a combination of software and firmware. The software or firmware is described as a program and stored in the memory 92. In the processing circuit 90, each function is realized by the processor 91 reading and executing the program stored in the memory 92. That is, the processing circuit 90 includes a memory 92 for storing a program that results in the processing of the receiving device 20 being executed. This program can also be said to be a program for causing the receiving device 20 to execute each function realized by the processing circuit 90. This program may be provided by a storage medium in which the program is stored, or may be provided by other means such as a communication medium.

[0039] The program includes a signal conversion step in which the signal conversion unit 23 converts the reflected waves or scattered waves of the high frequency signal received by the multiple receiving antenna elements 22 into a received signal in the frequency band of the radar signal used to generate the high frequency signal by the transmitting device 10, using the carrier signal used to generate the high frequency signal by the transmitting device 10; a detection step in which the detection unit 24 detects the received signal using the radar signal to obtain received information which is the reflected waves or scattered waves of the high frequency signal received by each receiving antenna element 22 and includes the high frequency signal transmitted from the multiple transmitting antenna elements 18; a correlation processing step in which the correlation processing unit 25 performs correlation processing on the received information using the code used to encode the radar signal by the transmitting device 10, and separates the received signal into signals for each receiving antenna element 22 and for each transmitting antenna element 18 transmitted from the transmitting device 10; and a MIMO transmission step in which the correlation processing unit 25 performs correlation processing on the received information using the code used to encode the radar signal by the transmitting device 10, and separates the received signal into signals for each transmitting antenna element 18 transmitted from the transmitting device 10. It can also be said that the program causes the receiving device 20 to execute the following steps: a transmission path reproduction step in which the transmission path reproduction unit 26 generates MIMO transmission path information indicating the state of the transmission path between the transmitting device 10 and the receiving device 20 using the separated signal; a layer extraction step in which the layer extraction unit 27 identifies the position of the measurement object 40 by extracting, from the MIMO transmission path information, reflection point information of a layer corresponding to the depth distance of the measurement object 40 as seen from the multiple receiving antenna elements 22; a focus correction step in which the focus correction unit 28 corrects the focus of the measurement object 40 whose position has been identified to generate an image of the measurement object 40; a position determination step in which the position determination unit 29 determines an extraction position for vibration information of the measurement object 40 using the image; and a vibration information extraction step in which the vibration information extraction unit 30 extracts vibration information of the measurement object 40 from the MIMO transmission path information using the extraction position.

[0040] Here, the processor 91 is, for example, a CPU (Central Processing Unit), a processing device, an arithmetic device, a microprocessor, a microcomputer, or a DSP (Digital Signal Processor), etc. Also, the memory 92 is, for example, a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable ROM), an EEPROM (Electrically EPROM), a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, or a DVD (Digital Versatile Disc), etc.

[0041] Fig. 8 is a diagram showing an example of a processing circuit 93 in the case where the processing circuit for realizing the receiving device 20 according to the first embodiment is configured with dedicated hardware. The processing circuit 93 shown in Fig. 8 corresponds to, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination of these. The processing circuit may be partly realized with dedicated hardware and partly realized with software or firmware. In this way, the processing circuit can realize each of the above-mentioned functions by dedicated hardware, software, firmware, or a combination of these.

[0042] Although the hardware configuration of the receiving device 20 has been described, the hardware configuration of the transmitting device 10 is also similar. In the transmitting device 10, the transmitting array 17 is composed of a plurality of transmitting antenna elements 18. The synchronization unit 11, the radar signal generating unit 12, the code generating unit 13, the carrier signal generating unit 14, the encoding unit 15, and the high frequency signal generating unit 16 are realized by processing circuits. The processing circuit may be a processor and memory that executes a program stored in a memory, or may be dedicated hardware. The processing circuit is also called a control circuit.

[0043] As described above, according to this embodiment, in the sensing system 50, the receiving device 20 generates an image of the measurement target 40, determines an optimal position for extracting vibration information of the measurement target 40, and extracts vibration information from MIMO transmission path information based on the determined position information. This allows the sensing system 50 to extract vibration information of the measurement target 40 with high accuracy without controlling the transmission wave. The sensing system 50 does not actually perform beam control in the transmitting device 10, but performs virtual beam control in the receiving device 20. Note that in this embodiment, the number of transmitting antenna elements 18 of the transmitting device 10 in the sensing system 50 is multiple, but the same effect can be obtained by the same operation even in the case of a single antenna.

[0044] Embodiment 2 In the first embodiment, when the sensing system 50 tries to extract vibration information in an area with little phase variation, it is possible that interfering vibration information is included in addition to the vibration information to be extracted. For example, when the vibration information to be extracted is heartbeat information, there is vibration information distributed in an area with little phase variation similar to the heartbeat information, such as vibration information caused by breathing, etc. In the second embodiment, a case will be described in which a receiving device filters the obtained vibration information in a sensing system.

[0045] FIG. 9 is a diagram showing a configuration example of a sensing system 50a according to the second embodiment. The sensing system 50a includes a transmitting device 10 and a receiving device 20a. The transmitting device 10 is the same as the transmitting device 10 according to the first embodiment shown in FIG. 2. The receiving device 20a is obtained by adding a filter 31 to the receiving device 20 shown in FIG. 2. The filter 31 filters the vibration information extracted by the vibration information extracting unit 30, and extracts vibration information about a vibration of a desired period from the vibration information extracted by the vibration information extracting unit 30. Specifically, the filter 31 filters the vibration information of a component vibrating at a period lower than a specified frequency from the vibration information extracted by the vibration information extracting unit 30. The filter 31 is, for example, a high-pass filter, a band-pass filter, or the like. By using the filter 31, the receiving device 20a can extract only vibration information of a frequency higher than a specified frequency from the vibration information extracted by the vibration information extracting unit 30. Slow fluctuations, i.e., low-frequency vibrations, include, for example, vital information such as breathing information, body movement information, etc. By filtering this information, the receiving device 20a can extract only vibration information such as pulsation, which has a greater phase change than breathing and body movement and fluctuates at a higher frequency.

[0046] Fig. 10 is a flowchart showing the operation of the sensing system 50a according to the embodiment 2. In the flowchart shown in Fig. 10, the operations from step S11 to step S17 are the same as the operations from step S11 to step S17 in the flowchart of the sensing system 50 according to the embodiment 1 shown in Fig. 4. The receiving device 20a filters the extracted vibration information to remove vibration information with a fluctuation slower than a specified speed (step S18).

[0047] Fig. 11 is a flowchart showing the operation of the receiving device 20a according to the second embodiment. The flowchart shown in Fig. 11 shows details of the operation from step S13 to step S18 in the flowchart shown in Fig. 10. In addition, in the flowchart shown in Fig. 11, the operation from step S31 to step S39 is the same as the operation from step S31 to step S39 in the flowchart of the receiving device 20 according to the first embodiment shown in Fig. 6. The filter 31 filters out vibration information having a fluctuation slower than a specified speed from the vibration information extracted by the vibration information extraction unit 30 (step S40).

[0048] As described above, according to this embodiment, in the sensing system 50a, the receiving device 20a filters the vibration information extracted by the vibration information extraction unit 30 using the filter 31. This allows the receiving device 20a to extract only vibration information having a period higher than a specified frequency from the vibration information extracted by the vibration information extraction unit 30.

[0049] Embodiment 3 In the third embodiment, a case will be described in which a sensing system includes a plurality of transmitting devices 10 and a plurality of receiving devices.

[0050] FIG. 12 is a diagram showing an outline of the measurement assumed in the sensing system 50b according to the third embodiment. The sensing system 50b is a system including a plurality of transmitting devices 10-1 and 10-2, a plurality of receiving devices 20b-1 and 20b-2, and a vibration information extraction device 60, and measures the measurement target 40. That is, in the third embodiment, the sensing system 50b is configured by a plurality of transmitting devices 10-1 and 10-2, a plurality of receiving devices 20b-1 and 20b-2, and a vibration information extraction device 60. The transmitting devices 10-1 and 10-2 each have the same configuration as the transmitting device 10 in the first embodiment, and may be referred to as the transmitting device 10 when the transmitting devices 10-1 and 10-2 are not distinguished from each other. Also, when the receiving devices 20b-1 and 20b-2 are not distinguished from each other, they may be referred to as the receiving device 20b. 12, the multiple transmitting devices 10 are represented as transmitting devices 10-1 and 10-2, and the multiple receiving devices 20b are represented as receiving devices 20b-1 and 20b-2, but the number of the multiple transmitting devices 10 and the number of the multiple receiving devices 20b may be three or more. The sensing system 50b is a system in which multiple sets of transmitting devices 10 and receiving devices 20b exist in the vicinity, and the multiple transmitting devices 10 irradiate radio waves at the same time to perform sensing. In the third embodiment, since the transmitting arrays 17 of the multiple transmitting devices 10 operate in the vicinity, a mechanism for suppressing interference between the transmitting arrays 17 is required.

[0051] FIG. 13 is a first diagram showing a configuration example of a sensing system 50b according to the third embodiment. In the example of FIG. 13, the sensing system 50b includes N transmitting devices 10, receiving devices 20b-1-20b-N, and a vibration information extraction device 60. The configuration of the transmitting device 10-1 shown in FIG. 13 is the same as the configuration of the transmitting device 10 shown in FIG. 2. However, the synchronization unit 11 of the transmitting device 10-1 instructs the operation timing of each component to the other transmitting devices 10-2-10-N and receiving devices 20b-1-20b-N that operate simultaneously. The configuration of the receiving device 20b-1 shown in FIG. 13 is obtained by deleting the position determination unit 29 and the vibration information extraction unit 30 from the configuration of the receiving device 20 shown in FIG. 2. In the third embodiment, the vibration information extraction device 60 includes the position determination unit 29 and the vibration information extraction unit 30. That is, in the sensing system 50b, the receiving devices 20b-1 to 20b-N share the position determining section 29 and the vibration information extracting section 30.

[0052] The configuration of the transmitting devices 10-2 to 10-N may be the same as that of the transmitting device 10-1, or may be a configuration in which the synchronization unit 11 is removed from the transmitting device 10-1. When the configuration of the transmitting devices 10-2 to 10-N is the same as that of the transmitting device 10-1, for example, the synchronization unit 11 of the transmitting device 10-1 becomes the master, the synchronization unit 11 of the transmitting devices 10-2 to 10-N becomes the slave, and the synchronization unit 11 of the transmitting device 10-1 instructs the synchronization unit 11 of the transmitting devices 10-2 to 10-N of the operation timing of each component. As a result, the synchronization unit 11 of the transmitting devices 10-2 to 10-N can instruct the operation timing of each component in the transmitting device based on the instruction from the synchronization unit 11 of the transmitting device 10-1. When the configuration of the transmitting devices 10-2 to 10-N is the same as that of the transmitting device 10-1 except that the synchronization unit 11 has been removed, the synchronization unit 11 of the transmitting device 10-1 directly instructs the operation timing of each component of the transmitting devices 10-2 to 10-N. Hereinafter, a case where the configuration of the transmitting devices 10-2 to 10-N is the same as that of the transmitting device 10-1 except that the synchronization unit 11 has been removed, that is, a case where the transmitting devices 10-2 to 10-N do not include the synchronization unit 11, will be described as an example. The configuration of the receiving devices 20b-2 to 20b-N is the same as that of the receiving device 20b-1.

[0053] The operation of the sensing system 50b will be described. The operation of the transmitting device 10-1 is the same as that of the transmitting device 10 of the first embodiment. The transmitting device 10-K receives an instruction from the synchronization unit 11 of the transmitting device 10-1, and operates the radar signal generating unit 12 and the code generating unit 13 of the transmitting device 10-K at the same timing as the timing when the transmitting device 10-1 operates the radar signal generating unit 12 and the code generating unit 13 of its own device. Note that K is an integer of 2≦K≦N. At this time, the code generating unit 13 of the transmitting device 10-K generates a code that reduces correlation among the transmitting devices 10-1 to 10-N. Examples of the code generated by the code generating unit 13 of the transmitting device 10-K include an M sequence, a Gold code, a Walsh-Hadamard code, and a PN sequence, but is not limited to these as long as it is a code with a high degree of orthogonality. In sensing system 50b, carrier signal generating units 14 and high frequency signal generating units 16 of transmitting devices 10-1 to 10-N perform the same operation in all transmitting devices 10-1 to 10-N, and switch the carrier frequency at the same timing.

[0054] In this way, the radar signal generating unit 12, the code generating unit 13, and the carrier signal generating unit 14 of the multiple transmitting devices 10-1 to 10-N operate in synchronization. Also, the code generating unit 13 of the multiple transmitting devices 10-1 to 10-N generates codes with low correlation between the multiple transmitting devices 10-1 to 10-N. The code generating unit 13 of the multiple transmitting devices 10-1 to 10-N generates orthogonal codes or quasi-orthogonal codes as codes with low correlation between the multiple transmitting devices 10-1 to 10-N. That is, the multiple transmitting devices 10-1 to 10-N operate in synchronization with respect to the generation of radar signals, the generation of codes, and the generation of carrier signals, and generate codes with low correlation between the multiple transmitting devices 10-1 to 10-N.

[0055] The operation of the receiving device 20b-1 is similar to the operation performed by the receiving array 21, the signal conversion unit 23, the detection unit 24, the correlation processing unit 25, the MIMO transmission path regeneration unit 26, the layer extraction unit 27, and the focus correction unit 28 among the components of the receiving device 20 of the first embodiment. The operation of the receiving devices 20b-2 to 20b-N is similar to the operation of the receiving device 20b-1. The correlation processing unit 25 of the receiving device 20b-K performs correlation processing using the code used in the transmitting device 10-K, thereby suppressing signals from other transmitting devices 10 and extracting only the signal from the transmitting device 10-K to generate MIMO transmission path information. In this way, the correlation processing units 25 of the multiple receiving devices 20b-1 to 20b-N perform correlation processing using the code used in the corresponding transmitting device 10.

[0056] The vibration information extraction device 60 determines an extraction position of the vibration information of the measurement target 40 using the image generated by the receiving devices 20b-1 to 20b-N, and extracts the vibration information of the measurement target 40 from the MIMO transmission path information generated by the receiving devices 20b-1 to 20b-N using the extraction position described above. Specifically, in the vibration information extraction device 60, the position determination unit 29 performs the same operation as the position determination unit 29 provided in the receiving device 20 of the first embodiment, but determines the extraction position of the vibration information of the measurement target 40 for the images acquired from the receiving devices 20b-1 to 20b-N, i.e., N images. Also, in the vibration information extraction device 60, the vibration information extraction unit 30 performs the same operation as the vibration information extraction unit 30 provided in the receiving device 20 of the first embodiment, but extracts the vibration information of the measurement target 40 using the extraction position determined by the position determination unit 29 for the MIMO transmission path information acquired from the receiving devices 20b-1 to 20b-N, i.e., N MIMO transmission path information.

[0057] In the third embodiment, the MIMO transmission path regeneration units 26 of the receiving devices 20b-1 to 20b-N, together with the layer extraction units 27, output the generated MIMO transmission path information to the vibration information extraction device 60. In addition, the focus correction units 28 of the receiving devices 20b-1 to 20b-N output the generated images to the vibration information extraction device 60.

[0058] In the third embodiment, the number of the transmitting devices 10 and the number of the receiving devices 20b are assumed to be the same, but in the sensing system 50b, the number of the transmitting devices 10 and the number of the receiving devices 20b do not necessarily have to be the same. For example, when operating with the transmitting devices 10-1 and 10-2, which are two transmitting devices 10, and the receiving device 20bA, which is one receiving device 20b, the receiving device 20bA can generate MIMO transmission path information corresponding to two directions by using the codes used by the transmitting devices 10-1 and 10-2 together by the correlation processing unit 25, and generate and output images corresponding to the two directions. Also, when operating with the transmitting device 10A, which is one transmitting device 10, and the receiving devices 20b-1 and 20b-2, which are two receiving devices 20b, the receiving devices 20b-1 and 20b-2 can obtain images corresponding to their respective positional relationships by using the codes used by the transmitting device 10A. The position determination unit 29 determines, from an image generated by one or more receiving devices 20b, a receiving device 20b and position information suitable for extracting vibration information of the measurement target 40. Based on the receiving device 20b and position information determined by the position determination unit 29, the vibration information extraction unit 30 extracts vibration information of the measurement target 40 from the MIMO transmission path information of the receiving device 20b using the position information.

[0059] As described above, according to this embodiment, in the sensing system 50b, the multiple transmitting devices 10-1 to 10-N transmit high-frequency signals simultaneously, and the multiple receiving devices 20b-1 to 20b-N perform measurement and imaging in parallel. The vibration information extraction device 60 uses the MIMO transmission path information and images generated by the multiple receiving devices 20b-1 to 20b-N to determine the optimal position for extracting vibration information of the measurement target 40, and extracts vibration information from the MIMO transmission path information based on the determined position information. As a result, the sensing system 50b can realize imaging from multiple directions at a higher speed, extract vibration information from the optimal position, and extract the vibration information of the measurement target 40 with higher accuracy.

[0060] It is also possible to add the filter 31 described in the second embodiment to the vibration information extraction device 60 of the sensing system 50b. FIG. 14 is a second diagram showing a configuration example of a sensing system 50c according to the third embodiment. The sensing system 50c includes transmitting devices 10-1 to 10-N, receiving devices 20b-1 to 20b-N, and a vibration information extraction device 60c. The vibration information extraction device 60c is obtained by adding a filter 31 to the vibration information extraction device 60 shown in FIG. 13. The filter 31 is the same as the filter 31 described in the second embodiment. As a result, in the sensing system 50c, the vibration information extraction device 60c can extract only vibration information of a frequency higher than a specified frequency from the vibration information extracted by the vibration information extraction unit 30.

[0061] Embodiment 4 In the first embodiment, there is one measurement target 40 in the sensing system 50. In the fourth embodiment, a case in which there are a plurality of measurement targets 40 in the sensing system 50 will be described.

[0062] Fig. 15 is a diagram showing an outline of measurement assumed in a sensing system 50 according to the fourth embodiment. In the example of Fig. 15, two measurement targets 40 are shown as measurement targets 40-1 and 40-2 as the multiple measurement targets 40. In the fourth embodiment, the configurations of the transmitting device 10 and the receiving device 20 are the same as those of the transmitting device 10 and the receiving device 20 according to the first embodiment shown in Fig. 2. In the fourth embodiment, the image generated by the focus correction unit 28 of the receiving device 20 includes the measurement targets 40-1 and 40-2, i.e., each of the measurement targets 40.

[0063] In the receiving device 20, the position determining unit 29 determines an optimum extraction position for each of the measurement targets 40 from the measurement targets 40-1 and 40-2, i.e., the image of each measurement target 40, to extract vibration information of each measurement target 40. In the receiving device 20, the vibration information extracting unit 30 extracts vibration information of each measurement target 40 from the MIMO transmission path information using the extraction position for each measurement target 40 determined by the position determining unit 29. In the position determining unit 29 and the vibration information extracting unit 30, the processing load may be larger than that in the first embodiment due to the increase in the measurement targets 40, but the operation itself for each measurement target 40 is similar to the operation in the first embodiment.

[0064] As described above, according to this embodiment, in the sensing system 50, when there are multiple measurement targets 40, the receiving device 20 determines, for each measurement target 40, an optimum extraction position for extracting vibration information of each measurement target 40 from the generated image, and extracts vibration information of each measurement target 40 from the MIMO transmission path information using the determined extraction position. This allows the receiving device 20 to extract vibration information of the multiple measurement targets 40 with high accuracy, even when there are multiple measurement targets 40.

[0065] Although not shown, a sensing system 50a in which a receiving device 20a includes a filter 31 is also capable of extracting vibration information from a plurality of measurement targets 40.

[0066] Embodiment 5. In the third embodiment, the sensing system 50b has one measurement target 40. In the fifth embodiment, a case will be described in which the sensing system 50b has a plurality of measurement targets 40.

[0067] FIG. 16 is a diagram showing an outline of the measurement assumed in the sensing system 50b according to the fifth embodiment. In the example of FIG. 16, two measurement targets 40 are shown as measurement targets 40-1 and 40-2 as the multiple measurement targets 40. As in the third embodiment, the sensing system 50b includes N transmission devices 10, N reception devices 20b, and a vibration information extraction device 60 as shown in FIG. 13. In the fifth embodiment, the configurations of the transmission device 10-1, the reception device 20b-1, the vibration information extraction device 60, and the like are the same as the configurations of the transmission device 10-1, the reception device 20b-1, the vibration information extraction device 60, and the like in the third embodiment shown in FIG. 13. In the fifth embodiment, the image generated by the focus correction unit 28 of the reception devices 20b-1 to 20b-N includes the measurement targets 40-1 and 40-2, that is, each measurement target 40.

[0068] In the vibration information extraction device 60, the position determination unit 29 determines an optimum extraction position for each measurement target 40 from the measurement targets 40-1 and 40-2, i.e., the image of each measurement target 40, to extract vibration information of each measurement target 40. In the vibration information extraction device 60, the vibration information extraction unit 30 extracts vibration information of each measurement target 40 from the MIMO transmission path information using the extraction position for each measurement target 40 determined by the position determination unit 29. In the position determination unit 29 and the vibration information extraction unit 30, the processing load may be larger than that in the third embodiment due to the increase in the measurement targets 40, but the operation itself for each measurement target 40 is similar to the operation in the third embodiment.

[0069] As described above, according to this embodiment, in the sensing system 50b, when there are multiple measurement targets 40, the vibration information extraction device 60 determines the optimum extraction position for each measurement target 40 to extract vibration information of each measurement target 40 from the image generated by the receiving devices 20b-1 to 20b-N, and extracts vibration information of each measurement target 40 from the MIMO transmission path information using the determined extraction position. Thus, even when there are multiple measurement targets 40, the vibration information extraction device 60 can extract vibration information of the multiple measurement targets 40 with high accuracy.

[0070] Although not shown, a sensing system 50c in which a vibration information extraction device 60c includes a filter 31 is also capable of extracting vibration information from a plurality of measurement targets 40.

[0071] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or the embodiments may be combined with each other. Also, parts of the configurations may be omitted or modified without departing from the spirit of the invention. [Explanation of symbols]

[0072] 10, 10-1 to 10-N transmitting device, 11 synchronization unit, 12 radar signal generating unit, 13 code generating unit, 14 carrier signal generating unit, 15 encoding unit, 16 high frequency signal generating unit, 17 transmitting array, 18 transmitting antenna element, 20, 20a, 20b-1 to 20b-N receiving device, 21 receiving array, 22 receiving antenna element, 23 signal conversion unit, 24 detection unit, 25 correlation processing unit, 26 MIMO transmission path regeneration unit, 27 layer extraction unit, 28 focus correction unit, 29 position determination unit, 30 vibration information extraction unit, 31 filter, 40, 40-1, 40-2 measurement object, 50, 50a, 50b, 50c sensing system, 60, 60c vibration information extraction device, 90, 93 processing circuit, 91 processor, 92 memory.

Claims

1. a transmitting device having a plurality of transmitting antenna elements, which controls the timing of generating a radar signal, generating a code for separating high-frequency signals transmitted from the plurality of transmitting antenna elements into the high-frequency signals transmitted from each transmitting antenna element by a receiving device, and generating a carrier signal by dividing an available frequency band into a plurality of subbands and periodically switching the subbands used in the high-frequency signals transmitted from the plurality of transmitting antenna elements so that the entire frequency band is used, multiplying the radar signal by the code for each of the plurality of transmitting antenna elements, and using the radar signal multiplied by the code and the carrier signal to generate the high-frequency signal of the bandwidth of the subband and transmit it from the plurality of transmitting antenna elements; a receiving device having a plurality of receiving antenna elements, which receives the high frequency signal transmitted from the transmitting device and reflected or scattered by an object to be measured, which generates transmission path information indicating a state of a transmission path between the transmitting device and the receiving device using the carrier signal, the radar signal, and the code, which identifies a position of the object to be measured using the transmission path information, which performs focus correction on the object to be measured to generate an image of the object to be measured, which determines an extraction position for vibration information of the object to be measured using the image, and which extracts the vibration information of the object to be measured from the transmission path information using the extraction position; A sensing system comprising:

2. The receiving device filters the vibration information to extract vibration information regarding a vibration of a desired period from the vibration information. The sensing system according to claim 1 .

3. The receiving device determines an optimal extraction position for each of the measurement objects for extracting vibration information of the plurality of measurement objects from the image, and extracts vibration information of the plurality of measurement objects from the transmission path information using the extraction position for each of the measurement objects. The sensing system according to claim 1 .

4. A sensing system including a plurality of transmitting devices and a plurality of receiving devices, a plurality of transmitting devices each having a plurality of transmitting antenna elements, the transmitting devices controlling the timing of generating a radar signal, generating a code for separating high-frequency signals transmitted from the plurality of transmitting antenna elements into the high-frequency signals transmitted from each transmitting antenna element by a receiving device, and generating a carrier signal by dividing an available frequency band into a plurality of subbands and periodically switching the subbands used in the high-frequency signals transmitted from the plurality of transmitting antenna elements so that the entire frequency band is used, multiplying the radar signal by the code for each of the plurality of transmitting antenna elements, and using the radar signal multiplied by the code and the carrier signal to generate the high-frequency signal of the bandwidth of the subband and transmitting it from the plurality of transmitting antenna elements; a plurality of receiving devices each having a plurality of receiving antenna elements, each receiving the high frequency signal transmitted from the transmitting device and reflected or scattered by an object to be measured, each generating transmission path information indicating a state of a transmission path between the transmitting device and the receiving device using the carrier signal, the radar signal, and the code, identifying a position of the object to be measured using the transmission path information, and performing focus correction on the object to be measured to generate an image of the object to be measured; a vibration information extraction device that determines an extraction position for vibration information of the measurement object using the image, and extracts the vibration information of the measurement object from the transmission line information using the extraction position; A sensing system comprising:

5. The vibration information extraction device filters the vibration information to extract vibration information regarding vibrations of a desired period from the vibration information.

5. The sensing system according to claim 4.

6. The vibration information extraction device determines an optimal extraction position for each of the measurement objects for extracting vibration information of the plurality of measurement objects from the image, and extracts vibration information of the plurality of measurement objects from the transmission line information using the extraction position for each of the measurement objects.

5. The sensing system according to claim 4.

7. The transmitting device and the receiving device use different numbers of subbands in the vibration information extraction position determination step and the vibration information extraction step.

7. The sensing system according to claim 1, wherein the sensing system comprises: a first sensing element;

8. A receiving device having a plurality of receiving antenna elements, which receives a reflected wave or a scattered wave of a high frequency signal transmitted from a transmitting device having a plurality of transmitting antenna elements and reflected or scattered by a measurement target, a signal conversion unit that converts the reflected waves or the scattered waves of the high frequency signal received by the plurality of receiving antenna elements into a received signal in a frequency band of a radar signal used to generate the high frequency signal in the transmitting device, by using a carrier signal used to generate the high frequency signal in the transmitting device; a detection unit that detects the received signal by using the radar signal and obtains reception information including the reflected wave or the scattered wave of the high frequency signal received by each receiving antenna element and transmitted from a plurality of the transmitting antenna elements; a correlation processing unit that performs correlation processing on the received information using a code used when the radar signal was encoded by the transmitting device, and separates the received signal into signals for each of the receiving antenna elements transmitted from the transmitting device for each of the receiving antenna elements; a transmission path regeneration unit that generates transmission path information indicating a state of a transmission path between the transmitting device and the receiving device using the separated signal; a layer extraction unit that extracts, from the transmission path information, reflection point information of a layer corresponding to a distance in a depth direction of the object to be measured as viewed from the plurality of receiving antenna elements, thereby identifying a position of the object to be measured; a focus correction unit that corrects the focus of the measurement object whose position has been specified to generate an image of the measurement object; a position determination unit that determines an extraction position of the vibration information of the measurement target using the image; a vibration information extraction unit that extracts the vibration information of the measurement target from the transmission path information by using the extraction position; A receiving device comprising:

9. a filter that filters the vibration information to extract vibration information regarding a vibration of a desired period from the vibration information; 9. The receiving device according to claim 8, further comprising:

10. The position determination unit determines an optimal extraction position for extracting vibration information of the plurality of measurement objects from the image, for each of the measurement objects; the vibration information extraction unit extracts vibration information of the plurality of measurement objects from the transmission path information by using the extraction positions for the measurement objects determined by the position determination unit; 10. The receiving device according to claim 8 or 9.

11. In a sensing system having a plurality of transmitting devices and a plurality of receiving devices, the receiving device has a plurality of receiving antenna elements, and receives a reflected wave or a scattered wave of a high frequency signal transmitted from the transmitting device having the plurality of transmitting antenna elements and reflected or scattered by a measurement target, a signal conversion unit that converts the reflected waves or the scattered waves of the high frequency signal received by the plurality of receiving antenna elements into a received signal in a frequency band of a radar signal used to generate the high frequency signal in the transmitting device, by using a carrier signal used to generate the high frequency signal in the transmitting device; a detection unit that detects the received signal by using the radar signal and obtains reception information including the reflected wave or the scattered wave of the high frequency signal received by each receiving antenna element and transmitted from a plurality of the transmitting antenna elements; a correlation processing unit that performs correlation processing on the received information using a code used when the radar signal was encoded by the transmitting device, and separates the received signal into signals for each of the receiving antenna elements transmitted from the transmitting device for each of the receiving antenna elements; a transmission path regeneration unit that generates transmission path information indicating a state of a transmission path between the transmitting device and the receiving device using the separated signal; a layer extraction unit that extracts, from the transmission path information, reflection point information of a layer corresponding to a distance in a depth direction of the object to be measured as viewed from the plurality of receiving antenna elements, thereby identifying a position of the object to be measured; a focus correction unit that corrects the focus of the measurement object whose position has been specified to generate an image of the measurement object; Equipped with the transmission path reproduction unit outputs the transmission path information to a vibration information extraction device including: a position determination unit that determines an extraction position of the vibration information of the measurement object using the image; and a vibration information extraction unit that extracts the vibration information of the measurement object from the transmission path information using the extraction position; The focus correction unit outputs the image to the vibration information extraction device. A receiving device comprising:

12. A control circuit for controlling a sensing system including a transmitting device having a plurality of transmitting antenna elements and a receiving device having a plurality of receiving antenna elements, the control circuit comprising: generating a radar signal, generating a code for separating high frequency signals transmitted from the plurality of transmitting antenna elements into the high frequency signals transmitted from each transmitting antenna element by the receiving device, and generating a carrier signal by dividing an available frequency band into a plurality of subbands and periodically switching the subbands used in the high frequency signals transmitted from the plurality of transmitting antenna elements so that the entire frequency band is used; multiplying the radar signal by the code for each of the plurality of transmitting antenna elements, and generating the high frequency signal of the bandwidth of the subband using the radar signal multiplied by the code and the carrier signal, and transmitting the high frequency signal from the plurality of transmitting antenna elements; a receiving device having a plurality of receiving antenna elements, receiving the high frequency signal transmitted from the transmitting device and reflected or scattered by an object to be measured, generating transmission path information indicating a state of a transmission path between the transmitting device and the receiving device using the carrier signal, the radar signal, and the code, identifying a position of the object to be measured using the transmission path information, performing focus correction on the object to be measured to generate an image of the object to be measured, determining an extraction position for vibration information of the object to be measured using the image, and extracting the vibration information of the object to be measured from the transmission path information using the extraction position; A control circuit that causes the sensing system to implement the above.

13. A control circuit for controlling a receiving device having a plurality of receiving antenna elements and receiving a reflected wave or a scattered wave of a high frequency signal transmitted from a transmitting device having a plurality of transmitting antenna elements and reflected or scattered by a measurement target, converting the reflected waves or the scattered waves of the high frequency signal received by the plurality of receiving antenna elements into a received signal in a frequency band of the radar signal used to generate the high frequency signal in the transmitting device, using a carrier signal used to generate the high frequency signal in the transmitting device; detecting the received signal using the radar signal, and acquiring reception information including the reflected wave or the scattered wave of the high frequency signal received by each receiving antenna element and transmitted from a plurality of the transmitting antenna elements; performing a correlation process on the received information using the code used when the radar signal was encoded by the transmitting device, and separating the received signal into signals for each of the receiving antenna elements transmitted from the transmitting device for each of the receiving antenna elements; generating transmission path information indicating a state of a transmission path between the transmitting device and the receiving device using the separated signal; Identifying a position of the measurement target by extracting reflection point information of a layer corresponding to a distance in a depth direction of the measurement target as viewed from the plurality of receiving antenna elements from the transmission path information; correcting the focus of the measured object whose position has been identified to generate an image of the measured object; determining an extraction position for vibration information of the measurement target using the image; extracting the vibration information of the measurement target from the transmission line information using the extraction position; A control circuit that causes the receiving device to execute the above.

14. A storage medium storing a program for controlling a sensing system including a transmitting device having a plurality of transmitting antenna elements and a receiving device having a plurality of receiving antenna elements, The program is generating a radar signal, generating a code for separating high frequency signals transmitted from the plurality of transmitting antenna elements into the high frequency signals transmitted from each transmitting antenna element by the receiving device, and generating a carrier signal by dividing an available frequency band into a plurality of subbands and periodically switching the subbands used in the high frequency signals transmitted from the plurality of transmitting antenna elements so that the entire frequency band is used; multiplying the radar signal by the code for each of the plurality of transmitting antenna elements, and generating the high frequency signal of the bandwidth of the subband using the radar signal multiplied by the code and the carrier signal, and transmitting the high frequency signal from the plurality of transmitting antenna elements; a receiving device having a plurality of receiving antenna elements, receiving the high frequency signal transmitted from the transmitting device and reflected or scattered by an object to be measured, generating transmission path information indicating a state of a transmission path between the transmitting device and the receiving device using the carrier signal, the radar signal, and the code, identifying a position of the object to be measured using the transmission path information, performing focus correction on the object to be measured to generate an image of the object to be measured, determining an extraction position for vibration information of the object to be measured using the image, and extracting the vibration information of the object to be measured from the transmission path information using the extraction position; A storage medium for causing the sensing system to carry out the above.

15. A storage medium having a program for controlling a receiving device having a plurality of receiving antenna elements and receiving a reflected wave or a scattered wave of a high frequency signal transmitted from a transmitting device having a plurality of transmitting antenna elements and reflected or scattered by a measurement target, The program is converting the reflected waves or the scattered waves of the high frequency signal received by the plurality of receiving antenna elements into a received signal in a frequency band of the radar signal used to generate the high frequency signal in the transmitting device, using a carrier signal used to generate the high frequency signal in the transmitting device; detecting the received signal using the radar signal, and acquiring reception information including the reflected wave or the scattered wave of the high frequency signal received by each receiving antenna element and transmitted from a plurality of the transmitting antenna elements; performing a correlation process on the received information using the code used when the radar signal was encoded by the transmitting device, and separating the received signal into signals for each of the receiving antenna elements transmitted from the transmitting device for each of the receiving antenna elements; generating transmission path information indicating a state of a transmission path between the transmitting device and the receiving device using the separated signal; Identifying a position of the measurement target by extracting reflection point information of a layer corresponding to a distance in a depth direction of the measurement target as viewed from the plurality of receiving antenna elements from the transmission path information; correcting the focus of the measured object whose position has been identified to generate an image of the measured object; determining an extraction position for vibration information of the measurement target using the image; extracting the vibration information of the measurement target from the transmission line information using the extraction position; A storage medium that causes the receiving device to execute the above.

16. a transmitting step in which a transmitting device has a plurality of transmitting antenna elements, and controls the timing of generating a radar signal, generating a code for separating high-frequency signals transmitted from the plurality of transmitting antenna elements into the high-frequency signals transmitted from each transmitting antenna element by a receiving device, and generating a carrier signal by dividing an available frequency band into a plurality of subbands and periodically switching the subbands used in the high-frequency signals transmitted from the plurality of transmitting antenna elements so that the entire frequency band is used, multiplying the radar signal by the code for each of the plurality of transmitting antenna elements, and generating the high-frequency signal of the bandwidth of the subband using the radar signal multiplied by the code and the carrier signal and transmitting the high-frequency signal from the plurality of transmitting antenna elements; a receiving step in which the receiving device has a plurality of receiving antenna elements and receives the high frequency signal transmitted from the transmitting device and reflected or scattered by an object to be measured, generates transmission path information indicating a state of a transmission path between the transmitting device and the receiving device using the carrier signal, the radar signal, and the code, identifies a position of the object to be measured using the transmission path information, performs focus correction on the object to be measured to generate an image of the object to be measured, determines an extraction position for vibration information of the object to be measured using the image, and extracts the vibration information of the object to be measured from the transmission path information using the extraction position; A sensing method comprising:

17. A receiving method for a receiving device having a plurality of receiving antenna elements, the receiving device receiving a reflected wave or a scattered wave of a high frequency signal transmitted from a transmitting device having a plurality of transmitting antenna elements and reflected or scattered by a measurement target, the method comprising the steps of: a signal conversion step in which a signal conversion unit converts the reflected wave or the scattered wave of the high frequency signal received by the plurality of receiving antenna elements into a received signal in a frequency band of the radar signal used to generate the high frequency signal in the transmitting device, by using a carrier signal used to generate the high frequency signal in the transmitting device; a detection step in which a detection unit detects the received signal using the radar signal to obtain reception information including the reflected wave or the scattered wave of the high frequency signal received by each receiving antenna element and transmitted from a plurality of the transmitting antenna elements; a correlation processing step in which a correlation processing unit performs correlation processing on the received information using a code used when the radar signal was encoded by the transmitting device, and separates the received signal into signals for each of the receiving antenna elements transmitted from the transmitting device for each of the receiving antenna elements; a transmission path regeneration step of generating, by a transmission path regeneration unit, transmission path information indicating a state of a transmission path between the transmitting device and the receiving device, using the separated signal; a layer extraction step in which a layer extraction unit extracts, from the transmission path information, reflection point information of a layer corresponding to a distance in a depth direction of the measurement target as viewed from the plurality of receiving antenna elements, thereby identifying a position of the measurement target; a focus correction step in which a focus correction unit corrects the focus of the measurement object whose position has been specified to generate an image of the measurement object; a position determination step in which a position determination unit determines an extraction position of vibration information of the measurement target using the image; a vibration information extraction step in which a vibration information extraction unit extracts the vibration information of the measurement target from the transmission path information by using the extraction position; A receiving method comprising:

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