Radar device, signal processing method, and program

Abstract

To provide a setup capable of suppressing a decrease in angle resolution.SOLUTION: A radar device comprises multiple transmission antennas for continuously transmitting multiple transmission signals as transmission waves, multiple reception antennas for receiving scattered waves generated by scattering of the transmission waves by a target and for generating reception signals, and a signal control section for controlling signal processing based on the reception signals. The multiple transmission antennas and the multiple reception antennas are disposed such that positions of at least one portion of multiple elements for composing a virtual array antenna formed by the multiple transmission antennas and the multiple reception antennas overlap, and the signal processing section generates IQ signals on the basis of the transmission signals and the reception signals for each element, calculates a correction value for correcting a phase difference of the IQ signals of the multiple elements in which the positions overlap, and corrects the IQ signals on the basis of the calculated correction value.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a radar device, a signal processing method, and a program. [Background technology]

[0002] In recent years, radar devices have been used to estimate various parameters such as the distance to a target, the relative velocity of the target, or the relative angle of the target. The distance to a target is estimated, for example, from the delay time of a signal. The relative velocity of the target is estimated, for example, from the frequency change of a signal due to the Doppler effect. The relative angle of a target is estimated, for example, from the phase difference between antennas of received signals.

[0003] As a technology related to such radar devices, a technology for forming a virtual array antenna by MIMO (Multi-Input & Multi-Output) has attracted attention. For example, Patent Document 1 below proposes a technology for improving the angular resolution when measuring angles using a virtual array antenna formed by MIMO. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2020-125948 Summary of the Invention [Problem to be solved by the invention]

[0005] The radar device disclosed in the above Patent Document 1 estimates the target velocity and then corrects, based on the estimated target velocity, phase fluctuations caused by distance fluctuations between the transmitter and receiver as the target moves while switching the transmitting antenna that transmits the signal. As a result, the accuracy of target velocity estimation determines the angular resolution, and in environments where the accuracy of velocity estimation is poor, the angular resolution is poor.

[0006] Therefore, the present invention has been made in consideration of the above problems, and an object of the present invention is to provide a mechanism capable of suppressing a decrease in angular resolution. [Means for solving the problem]

[0007] In order to solve the above problem, according to one aspect of the present invention, there is provided a radar device comprising: a plurality of transmitting antennas that continuously transmit a plurality of transmission signals as transmission waves; a plurality of receiving antennas that receive scattered waves generated when the transmission waves are scattered by a target and generate reception signals; and a signal processing unit that controls signal processing based on the reception signals, wherein the plurality of transmitting antennas and the plurality of receiving antennas are arranged so that positions of a plurality of elements that constitute a virtual array antenna formed by the plurality of transmitting antennas and the plurality of receiving antennas overlap at least partially; and the signal processing unit generates an IQ signal for each of the elements based on the transmission signals and the reception signals, calculates a correction value for correcting a phase difference of the IQ signals of the plurality of elements whose positions overlap, and corrects the IQ signal based on the calculated correction value.

[0008] The signal processing unit may calculate the correction value so that the phases of the IQ signals of a plurality of elements that are positioned overlapping each other are aligned.

[0009] The signal processing unit may correct the IQ signals of one or more of the elements to be corrected among the multiple elements whose positions overlap and one or more other elements that share the transmitting antenna based on the correction value.

[0010] The signal processing unit may estimate an angle of arrival of the scattered wave based on the corrected IQ signal.

[0011] The signal processing unit may generate the IQ signal by performing a first FFT on a beat signal generated by mixing the transmission signal and the reception signal, and performing a second FFT on the signals obtained by the first FFT arranged in the time direction at intervals equal to the transmission interval of the transmission signal.

[0012] The transmission signal may be a chirp signal whose frequency changes over time.

[0013] In order to solve the above-mentioned problem, according to another aspect of the present invention, there is provided a signal processing method executed by a computer that controls a radar device, the radar device having a plurality of transmitting antennas that continuously transmit a plurality of transmission signals as transmission waves, and a plurality of receiving antennas that receive scattered waves generated when the transmission waves are scattered by a target and generate received signals, the plurality of transmitting antennas and the plurality of receiving antennas being arranged so that positions of a plurality of elements that constitute a virtual array antenna formed by the plurality of transmitting antennas and the plurality of receiving antennas overlap at least partially, the signal processing method including: generating an IQ signal based on the transmission signals and the received signals for each of the elements; calculating a correction value for correcting a phase difference of the IQ signals of the plurality of elements whose positions overlap; and correcting the IQ signal based on the calculated correction value.

[0014] In order to solve the above-mentioned problems, according to another aspect of the present invention, there is provided a program executed by a computer that controls a radar device, the radar device having a plurality of transmitting antennas that continuously transmit a plurality of transmission signals as transmission waves, and a plurality of receiving antennas that receive scattered waves generated when the transmission waves are scattered by a target and generate reception signals, the program causing the computer to function as a signal processing unit that controls signal processing based on the reception signals, the signal processing unit generating an IQ signal for each of the elements based on the transmission signals and the reception signals, calculating a correction value for correcting a phase difference of the IQ signals of the elements that are positioned overlapping, and correcting the IQ signals based on the calculated correction value. [Effects of the Invention]

[0015] As described above, according to the present invention, a mechanism capable of suppressing a decrease in angular resolution is provided. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram illustrating an example of the configuration of a radar device according to an embodiment of the present invention. [Figure 2] 10 is a graph schematically illustrating an example of transmission signals transmitted by a plurality of transmission antennas. [Figure 3] FIG. 2 is a diagram illustrating an example of an antenna arrangement in the radar device according to the present embodiment. [Figure 4] FIG. 4 is a diagram showing a virtual array antenna formed in the antenna arrangement shown in FIG. [Figure 5] 6 is a flowchart showing an example of the flow of signal processing executed by an angle measurement unit according to the present embodiment. [Figure 6] FIG. 2 is a block diagram showing an example of a hardware configuration of the information processing device according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant explanations will be omitted.

[0018] <1. Configuration> Fig. 1 is a diagram illustrating an example of the configuration of a radar device 100 according to an embodiment of the present invention. As illustrated in Fig. 1, the radar device 100 includes a signal generating unit 101, a plurality of transmitting antennas 102 (102-1 to 102-2), a plurality of receiving antennas 103 (103-1 to 103-4), a plurality of mixers 104 (104-1 to 104-4), a plurality of low pass filters (LPFs) 105 (105-1 to 105-4), a plurality of analog-to-digital converters (ADCs) 106 (106-1 to 106-4), a first fast Fourier transform (FFT) unit 107, a second FFT unit 108, a power summing unit 109, a detection unit 110, and an angle measuring unit 111. Hereinafter, the transmitting antenna 102 may be referred to as Tx, and the receiving antenna 103 may be referred to as Rx.

[0019] The signal generation unit 101, mixer 104, LPF 105, ADC 106, first FFT unit 107, second FFT unit 108, power summing unit 109, detection unit 110, and angle measurement unit 111 are examples of signal processing units in this embodiment. In particular, the signal generation unit 101 controls signal processing related to a transmission signal transmitted from the transmitting antenna 102. On the other hand, the mixer 104, LPF 105, ADC 106, first FFT unit 107, second FFT unit 108, power summing unit 109, detection unit 110, and angle measurement unit 111 control signal processing based on a reception signal received by the receiving antenna 103.

[0020] The components of the radar device 100 will be described in detail below.

[0021] (Signal generation unit 101) The signal generator 101 generates a transmission signal whose frequency changes over time. Such a transmission signal is also called a chirp signal. For example, the transmission signal may be a signal whose frequency increases uniformly over time.

[0022] (Transmitting antenna 102) Each of the multiple transmitting antennas 102 continuously transmits multiple transmission signals as transmission waves. That is, the multiple transmitting antennas 102 continuously transmit chirp signals in a time-division manner. Specifically, the transmitting antenna 102-1 continuously emits the multiple transmission signals generated by the signal generating unit 101 as transmission waves. Thereafter, the transmitting antenna 102-2 continuously emits the multiple transmission signals generated by the signal generating unit 101 as transmission waves. An example of the transmission signals transmitted by the transmitting antenna 102 will be described below with reference to FIG. 2.

[0023] 2 is a graph showing a schematic example of transmission signals transmitted by multiple transmitting antennas 102. The horizontal axis of this graph represents time, and the vertical axis represents frequency. As shown in FIG. 2, first, multiple chirp signals are transmitted by transmitting antenna 102-1 (Tx1), and then multiple chirp signals are transmitted by transmitting antenna 102-2 (Tx2). When the transmitting antenna 102 that transmits the transmission signals is switched, a switching time ST occurs.

[0024] The transmitting antenna 102 can transmit radio waves in a frequency band with a short wavelength, such as the millimeter wave band (for example, the 79 GHz band).

[0025] The transmission wave radiated by the transmitting antenna 102 is scattered by the target 200, generating a scattered wave. The target 200 is an object for which various parameters such as a relative angle are to be estimated. The target 200 may be, for example, a person, an animal, or a moving object such as a car.

[0026] (receiving antenna 103) Each of the multiple receiving antennas 103 receives a scattered wave generated when the transmission wave radiated from the transmission antenna 102 is scattered by the target 200, and generates a received signal. Then, each of the multiple receiving antennas 103 outputs the generated received signal to each of the multiple mixers 104.

[0027] Here, the multiple transmitting antennas 102 and the multiple receiving antennas 103 are arranged so that the positions of at least some of the multiple elements constituting a virtual array antenna formed by the multiple transmitting antennas 102 and the multiple receiving antennas 103 overlap. Specifically, the inter-antenna distance between at least one pair of transmitting antennas 102 among the multiple transmitting antennas 102 matches the inter-antenna distance between at least one pair of receiving antennas 103 among the multiple receiving antennas 103. An example of a specific antenna arrangement will be described with reference to FIGS. 3 and 4.

[0028] Fig. 3 is a diagram showing an example of antenna arrangement in the radar device 100 according to this embodiment. As shown in Fig. 3, the transmitting antennas 102-1 (Tx1) and 102-2 (Tx2) are arranged at an interval of 3d. The receiving antennas 103-1 (Rx1) to 103-4 (Rx4) are arranged at an interval of d. With this arrangement, the interval 3d between the transmitting antennas Tx1 and Tx2 coincides with the interval 3d between the receiving antennas Rx1 and Rx4.

[0029] Fig. 4 is a diagram showing virtual array antenna 120 formed in the antenna arrangement shown in Fig. 3. In Fig. 4, each of multiple elements 121 (121-1 to 121-8) constituting virtual array antenna 120 is given a reference symbol in which an arrow connects the physical antennas that transmitted and received the signal received by element 121. For example, element 121-1 corresponding to a signal transmitted by transmitting antenna Tx1 and received by receiving antenna Rx1 is given the reference symbol Tx1 → Rx1. Note that virtual array antenna 120 is a set of signals transmitted by multiple transmitting antennas 102 and received by multiple receiving antennas 103, virtually expressed as elements 121 for each combination of transmitting antennas 102 and receiving antennas 103.

[0030] As shown in FIG. 4, the multiple elements 121 constituting the virtual array antenna 120 are arranged at intervals corresponding to the difference in distance between the transmitter and receiver. Here, as described above with reference to FIG. 3, the distance 3d between the transmitting antennas Tx1 and Tx2 and the distance 3d between the receiving antennas Rx1 and Rx4 are the same. Therefore, the distance between the transmitter and receiver when transmitting from the transmitting antenna Tx1 and receiving from the receiving antenna Rx4 is the same as the distance between the transmitter and receiver when transmitting from the transmitting antenna Tx2 and receiving from the receiving antenna Rx1. Therefore, as shown in FIG. 4, the position of element 121-4 (Tx1 → Rx4) corresponding to the signal transmitted by the transmitting antenna Tx1 and received by the receiving antenna Rx4 overlaps with the position of element 121-5 (Tx2 → Rx1) corresponding to the signal transmitted by the transmitting antenna Tx2 and received by the receiving antenna Rx1. The elements 121 whose positions overlap are expected to receive the same signal.

[0031] (Mixer 104) Each of the multiple mixers 104 generates a beat signal by mixing a transmission signal transmitted by each of the multiple transmission antennas 102 with a reception signal received by each of the multiple reception antennas 103. The beat signal indicates the difference between the transmission signal and the reception signal for each element 121. The frequency of the beat signal is proportional to the distance between the transmitter and receiver. Each of the multiple mixers 104 outputs the generated beat signal to each of the multiple LPFs 105.

[0032] (LPF105) Each of the plurality of LPFs 105 removes a predetermined signal component from the beat signal output from each of the plurality of mixers 104. Then, each of the plurality of LPFs 105 outputs the processed beat signal to each of the plurality of ADCs 106.

[0033] (ADC106) Each of the plurality of ADCs 106 converts the beat signal as an analog signal output from each of the plurality of LPFs 105 into a digital signal. Then, each of the plurality of ADCs 106 outputs the beat signal as a digital signal to the first FFT unit 107.

[0034] (1st FFT section 107) The first FFT unit 107 performs an FFT (hereinafter also referred to as a first FFT) on the beat signal for each element 121 output from each of the multiple ADCs 106. The first FFT unit 107 outputs the IQ signal for each element 121 obtained by the first FFT to the second FFT unit 108.

[0035] The IQ signal obtained by the first FFT contains amplitude and phase information for each frequency (proportional to the distance between the transmitter and receiver). Therefore, the IQ signal obtained by the first FFT can be considered as information on the distance component.

[0036] (2nd FFT section 108) The second-time FFT section 108 performs an FFT (hereinafter also referred to as a second-time FFT) on the IQ signal for each element 121 output from the first-time FFT section 107.

[0037] In detail, the second-time FFT unit 108 first arranges the IQ signals for each chirp signal obtained by the first-time FFT in the time domain at intervals equal to the transmission interval of the chirp signal.Then, the second-time FFT unit 108 performs the second FFT for each frequency (i.e., for each distance) on the IQ signals arranged in the time domain.

[0038] The second-time FFT unit 108 performs the above-described second-time FFT on the IQ signal for each element 121. Then, the second-time FFT unit 108 outputs the IQ signal for each element 121 obtained by the second-time FFT to the power summation unit 109 and the angle measurement unit 111.

[0039] The IQ signal obtained by the second FFT contains amplitude and phase information for each combination of distance and velocity, so the IQ signal obtained by the second FFT can be considered as velocity component information.

[0040] (Power summing unit 109) The power summation unit 109 sums the amplitude components of the IQ signals for each element 121 output from the second-time FFT unit 108. Then, the power summation unit 109 outputs the summed amplitude components (hereinafter also referred to as summed power) to the detection unit 110.

[0041] (Detection unit 110) The detection unit 110 detects one or more combinations of distance and speed at which a peak appears in the combined power output from the power summation unit 109. A known technique such as CFAR (Constant False Alarm Rate) may be used to detect the peak. The detection unit 110 then outputs the detection result to the angle measurement unit 111. The detection result here includes the combination of distance and speed at which a peak appears in the combined power.

[0042] (Angle measurement section 111) The angle measurement unit 111 estimates the angle of arrival of the scattered wave based on the IQ signal output from the second FFT unit 108 and the detection result output from the detection unit 110. The angle of arrival of the scattered wave corresponds to the relative angle of the target 200 (for example, the angle of the target 200 on a coordinate axis based on the receiving antenna 103).

[0043] More specifically, for each element 121, the angle measurement unit 111 extracts, from the IQ signals output from the second FFT unit 108, the IQ signals corresponding to the distance and velocity at which the peak was detected by the detection unit 110. Next, the angle measurement unit 111 estimates the angle of arrival of the scattered wave based on the IQ signal extracted for each element 121. Then, the angle measurement unit 111 outputs a combination of the calculated angle and the distance and velocity corresponding to the IQ signal used for the angle calculation.

[0044] The detection unit 110 may detect multiple peaks. In this case, the angle measurement unit 111 calculates the angle for each of the multiple IQ signals corresponding to the multiple peaks, and outputs multiple combinations of angle, distance, and speed.

[0045] However, the angle measurement unit 111 corrects the phase difference of the IQ signals between the transmitting antennas 102. That is, based on the arrangement of the transmitting antennas 102 and the receiving antennas 103, the angle measurement unit 111 calculates a correction value for correcting the phase difference of the IQ signals of multiple elements 121 whose positions overlap in the virtual array antenna 120. Then, the angle measurement unit 111 corrects the phase of the IQ signals based on the calculated correction value, and then estimates the angle of arrival of the scattered wave.

[0046] Specifically, the angle measurement unit 111 calculates a correction value so that the phases of IQ signals from multiple elements 121 whose positions overlap in the virtual array antenna 120 (i.e., whose transmitting and receiving distances are the same) are aligned. For example, the angle measurement unit 111 calculates a correction value so that the phases of IQ signals from two elements 121-4 and 121-5 whose positions overlap are aligned. This is because these overlapping elements 121 are expected to receive signals with at least the same phase. The angle measurement unit 111 then corrects, based on the correction value, the IQ signals of one or more elements 121 to be corrected among the multiple overlapping elements 121 and one or more other elements 121 that share the transmitting antenna 102. For example, when element 121-5 is the correction target, the angle measurement unit 111 corrects the IQ signals of elements 121-6, 121-7, and 121-8 that share the transmitting antenna 102-2 (Tx2) with element 121-5 by applying the correction value to these IQ signals.

[0047] Then, the angle measurement unit 111 estimates the angle of arrival of the scattered wave based on the corrected IQ signal. For example, the angle measurement unit 111 estimates the angle of arrival of the scattered wave based on the distance between the elements 121 and the phase difference of the IQ signal between the elements 121. Any existing method such as a beamformer method can be used as the angle measurement method.

[0048] <2. Operation processing> Next, an example of the flow of processing executed in the radar device 100 according to this embodiment will be described with reference to FIG.

[0049] 5 is a flowchart showing an example of the flow of signal processing executed by the angle measurement unit 111 according to this embodiment. In the first stage of this flow, various signal processing operations are executed by the signal generation unit 101, the transmitting antenna 102, the receiving antenna 103, the mixer 104, the LPF 105, the ADC 106, the first FFT unit 107, the second FFT unit 108, the power summation unit 109, and the detection unit 110.

[0050] (Step S102) 5, first, the angle measurement unit 111 acquires the IQ signal for each element 121 output from the second-time FFT unit 108. Then, the angle measurement unit 111 extracts, from the IQ signal for each element 121, the IQ signal corresponding to the distance and velocity at which the detection unit 110 detected a peak.

[0051] The IQ signal calculated by the second FFT unit 108 based on the signal transmitted from the transmitting antenna 102-i (1≦i≦I) and received by the receiving antenna 103-k (1≦k≦K) and extracted based on the detection result by the detection unit 110 is defined as sig 1 1,…,sig i k ,…,sig I K It is also called.

[0052] In the antenna arrangements shown in FIGS. 3 and 4, I=2 and K=4, where 1≦i≦2 and 1≦k≦4.

[0053] (Step S104) Next, the angle measurement unit 111 calculates a correction value between the transmitting antennas 102. In detail, the angle measurement unit 111 calculates the IQ signals sig of two elements 121 that are positioned overlapping in the virtual array antenna 120. x1 y1 and sig x2 y2 The correction value z can be calculated by, for example, dividing a complex number as shown in the following equation. z=sig x1 y1 / sig x2 y2 …(1)

[0054] 3 and 4, x1 = 1, x2 = 2, y1 = 4, and y2 = 1. That is, the correction value z can be calculated by dividing complex numbers as shown in the following equation. z=sig 1 4 / sig 2 1…(2)

[0055] (Step S106) Next, the angle measurement unit 111 corrects the phase difference between the transmitting antennas 102 using the correction value z. For example, the angle measurement unit 111 calculates the correction value z based on the IQ signal (i.e., sig x2 1,sig x2 2,…,sig x2 K ) by a correction value z (i.e., complex multiplication) to correct these IQ signals.

[0056] However, the sig used to calculate the correction value z x2 y2 The correction is omitted for sig, and it may not be used in the subsequent processing. x2 y2 is sig x1 y1 and the corrected sig x2 y2 instead of sigx1 y1 This is because it is sufficient to use

[0057] In the antenna arrangement shown in FIGS. 3 and 4, the angle measurement unit 111 measures the IQ signals (i.e., sig 2 2,sig 2 3,sig 2 4) by the correction value z (i.e., complex number multiplication) to correct these IQ signals.

[0058] (Step S108) Next, the angle measurement unit 111 measures the angle based on the corrected IQ signal. In the antenna arrangement shown in FIGS. 3 and 4, the angle measurement unit 111 measures the angle based on the IQ signal sig 1 1,sig 1 2,sig 1 3,sig 1 4, and the corrected IQ signal sig related to the transmitting antenna 102-2. 2 2,sig 2 3,sig 2 4, the angle of arrival of the scattered wave is estimated.

[0059] (Step S110) Then, the angle measurement unit 111 outputs the angle measurement result. Specifically, the angle measurement unit 111 outputs a combination of the calculated angle and the distance and speed corresponding to the IQ signal used for the angle calculation.

[0060] <3. Effects> The configuration and operation processing of this embodiment have been described above. The effects of the radar device 100 according to this embodiment will now be described in detail in comparison with the prior art.

[0061] In FMCW (Frequency Modulated Continuous Wave) radar, the transmission interval of a chirp signal determines the maximum detection speed of a position parameter. In contrast, the radar device 100 according to this embodiment transmits chirp signals continuously from each transmitting antenna 102, thereby minimizing the transmission interval of the chirp signals and maximizing the maximum detection speed. In other words, the radar device 100 according to this embodiment can improve the maximum detection speed compared to when the transmitting antenna 102 is switched every time a chirp signal is transmitted.

[0062] However, as described above with reference to Fig. 2, a switching time ST occurs when switching the transmitting antenna 102 that transmits the chirp signal. If the target 200 moves, a phase difference occurs between the transmitting antennas 102 during this switching time ST due to the change in distance between the transmitter and receiver as the target 200 moves. Therefore, the phase difference between the elements 121 corresponding to different transmitting antennas 102 includes a component due to the movement of the target 200, which may reduce the angular resolution.

[0063] In this regard, the radar device disclosed in Patent Document 1 estimates the target velocity and corrects the phase difference caused by the fluctuation in distance between the transmitter and receiver due to the movement of the target during the switching time ST based on the estimated target velocity. As a result, it is possible to improve the maximum detection speed and the angular resolution.

[0064] However, in the radar device disclosed in Patent Document 1, the angular resolution is determined by the accuracy of target velocity estimation, and the angular resolution is reduced in environments where the velocity estimation accuracy is reduced. One example of an environment where the velocity estimation accuracy is reduced is a frequency band with a short wavelength. In a frequency band with a short wavelength (e.g., a millimeter wave band such as the 79 GHz band), the phase changes more significantly over a short distance than in a frequency band with a long wavelength, and therefore the velocity estimation accuracy tends to be reduced.

[0065] In this regard, the radar device 100 according to this embodiment can associate the phases between the transmitting antennas 102 by using the overlap of the positions of the elements 121 in the virtual array antenna 120 instead of the speed. Note that associating the phases between the transmitting antennas 102 means matching the phases between the transmitting antennas 102.

[0066] The radar device 100 according to this embodiment correlates the phases between the transmitting antennas 102, thereby correcting (i.e., removing) the phase difference between the transmitting antennas 102 that occurs during the switching time ST due to the fluctuation in the distance between the transmitting and receiving antennas as the target 200 moves. This makes it possible to properly form the virtual array antenna 120 even when multiple chirp signals are transmitted consecutively from each transmitting antenna 102. That is, the phase difference between the elements 121 corresponding to different transmitting antennas 102 can be properly adapted to the difference in distance between the transmitting and receiving antennas. As a result, it is possible to improve the angular resolution while maintaining a high maximum detection speed.

[0067] Furthermore, the radar device 100 according to this embodiment does not use velocity for angle estimation, and therefore can suppress a decrease in angular resolution even in an environment where the velocity estimation accuracy decreases.

[0068] <4. Hardware configuration example> Next, the hardware configuration of the information processing device according to this embodiment will be described with reference to Fig. 6. Fig. 6 is a block diagram showing an example of the hardware configuration of the information processing device according to this embodiment. Note that the information processing device 900 shown in Fig. 6 can realize, for example, the radar device 100 shown in Fig. 1. Information processing by the radar device 100 according to this embodiment is realized by cooperation between software and hardware described below.

[0069] As shown in FIG. 6, the information processing device 900 includes a CPU (Central Processing Unit) 901, a ROM (Read Only Memory) 902, a RAM (Random Access Memory) 903, a host bus 904, a bridge 905, an external bus 906, an interface 907, an input device 908, an output device 909, a storage device 910, and a communication device 911.

[0070] The CPU 901 functions as an arithmetic processing unit and control unit, and controls the overall operation of the information processing device 900 in accordance with various programs. The CPU 901 may also be a microprocessor. The ROM 902 stores programs used by the CPU 901, calculation parameters, etc. The RAM 903 temporarily stores programs used in execution by the CPU 901, and parameters that change as appropriate during execution. These are connected to each other by a host bus 904 that is composed of a CPU bus, etc. The CPU 901 may form, for example, the first FFT unit 107, second FFT unit 108, power summation unit 109, detection unit 110, and angle measurement unit 111 shown in FIG. 1 .

[0071] The host bus 904 is connected to an external bus 906, such as a PCI (Peripheral Component Interconnect / Interface) bus, via a bridge 905. It is not necessary to configure the host bus 904, bridge 905, and external bus 906 separately, and these functions may be implemented on a single bus.

[0072] The input device 908 is composed of input means for the user to input information, such as a mouse, keyboard, touch panel, button, microphone, switch, and lever, and an input control circuit that generates an input signal based on the user's input and outputs it to the CPU 901. By operating this input device 908, the user who operates the information processing device 900 can input various data to the information processing device 900 and instruct the information processing device 900 to perform processing operations.

[0073] The output device 909 includes, for example, a display device such as a CRT (Cathode Ray Tube) display device, a liquid crystal display (LCD) device, an OLED (Organic Light Emitting Diode) device, or a lamp, and an audio output device such as a speaker.

[0074] The storage device 910 is a device for storing data. The storage device 910 may include a storage medium, a recording device that records data on the storage medium, a reading device that reads data from the storage medium, and a deletion device that deletes data recorded on the storage medium. The storage device 910 is configured, for example, with an HDD (Hard Disk Drive). This storage device 910 drives a hard disk and stores programs executed by the CPU 901 and various data.

[0075] The communication device 911 is a communication interface that performs communication in accordance with any communication standard. In particular, the communication device 911 has a configuration that performs various signal processing for wireless communication. The communication device 911 may form, for example, the signal generation unit 101, the transmitting antenna 102, the receiving antenna 103, the mixer 104, the LPF 105, and the ADC 106 shown in FIG. 1 .

[0076] The above describes an example of a hardware configuration capable of realizing the functions of the information processing device 900 according to this embodiment. Each of the above components may be realized using general-purpose components, or may be realized by hardware specialized for the function of each component. Therefore, the hardware configuration used can be changed as appropriate depending on the technical level at the time of implementing this embodiment.

[0077] <5. Supplementary Information> Although the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to these examples. It is clear that a person skilled in the art to which the present invention pertains can conceive of various modifications and alterations within the scope of the technical ideas set forth in the claims, and it is understood that these also naturally fall within the technical scope of the present invention.

[0078] In the above embodiment, an example has been described in which the target 200 is a moving object, but the present invention is not limited to such an example. The target 200 may be a stationary object such as a wall or a building. When the radar device 100 is mounted on a moving object such as an automobile, the relative position of the target 200 changes even if the target 200 is a stationary object, and therefore the effects of the present embodiment described above are similarly achieved.

[0079] In the above embodiment, an example has been described in which the transmission wave is a millimeter wave band radio wave, but the present invention is not limited to this example. The transmission wave may be a radio wave other than a millimeter wave band, or may be a sound wave, an ultrasonic wave, or the like.

[0080] In the above embodiment, an example has been described in which the radar device 100 has two transmitting antennas 102 and four receiving antennas 103, but the present invention is not limited to such an example. The radar device 100 may have three or more transmitting antennas 102, and may have two, three, five or more receiving antennas 103.

[0081] In the above embodiment, an example has been described in which the number of elements 121 whose positions overlap in the virtual array antenna 120 is two, but the present invention is not limited to such an example. The number of elements 121 whose positions overlap in the virtual array antenna 120 may be three or more.

[0082] In the above embodiment, an example in which the angle is measured based on the corrected IQ signal has been described, but the present invention is not limited to such an example. Other parameters, such as the distance to the target 200 or the relative velocity of the target 200, may also be estimated based on the corrected IQ signal.

[0083] Each device described in this specification may be realized as a single device, or some or all of them may be realized as separate devices. For example, among the functional configuration example of the radar device 100 shown in Fig. 1, the angle measurement unit 111 may be provided in a device such as a server connected to the other components via a network or the like.

[0084] The series of processes performed by each device described herein may be implemented using software, hardware, or a combination of software and hardware. The software programs may be stored in advance, for example, on a recording medium (more specifically, a non-transitory computer-readable storage medium) internal or external to each device. Each program may be loaded into a random access memory (RAM) and executed by a processing circuit such as a central processing unit (CPU). The recording medium may be, for example, a magnetic disk, an optical disk, a magneto-optical disk, or a flash memory. The computer program may be distributed, for example, via a network without using a recording medium. The computer may be an application-specific integrated circuit (ASIC), a general-purpose processor that executes functions by loading a software program, or a computer on a server used in cloud computing. The series of processes performed by each device described herein may be centrally processed by a single computer or distributed across multiple computers. Furthermore, in each of the above embodiments, two or more communication means present in one device may be physically implemented on a single medium.

[0085] Furthermore, the processes described herein using flowcharts or sequence diagrams do not necessarily have to be performed in the order shown. Some process steps may be performed in parallel. Furthermore, additional process steps may be employed, and some process steps may be omitted. [Explanation of symbols]

[0086] 100 radar equipment 101 signal generation unit 102 transmitting antenna 103 Receiving Antenna 104 Mixer 105 LPF 106 ADC 107 1st FFT section 108 2nd FFT section 109 Power Addition Unit 110 Detector 111 Angle measurement section 120 Virtual Array Antenna 121 elements 200 targets

Claims

1. a plurality of transmitting antennas for continuously transmitting a plurality of transmission signals as transmission waves; a plurality of receiving antennas that receive scattered waves generated by scattering the transmitted waves by a target and generate received signals; a signal processing unit that controls signal processing based on the received signal; Equipped with the plurality of transmitting antennas and the plurality of receiving antennas are arranged so that positions of at least a portion of a plurality of elements constituting a virtual array antenna formed by the plurality of transmitting antennas and the plurality of receiving antennas overlap; The signal processing unit generating an IQ signal for each of the elements based on the transmission signal and the reception signal; calculating a correction value for correcting a phase difference between the IQ signals of the plurality of elements whose positions overlap; correcting the IQ signals based on the calculated correction value; Radar equipment.

2. the signal processing unit calculates the correction value so that the phases of the IQ signals of the plurality of elements whose positions overlap are aligned. The radar device according to claim 1 .

3. The signal processing unit corrects the IQ signals of one or more elements to be corrected among the plurality of elements whose positions overlap and one or more other elements that share the transmitting antenna, based on the correction value. The radar device according to claim 1 .

4. The signal processing unit estimates an arrival angle of the scattered wave based on the corrected IQ signal. The radar device according to claim 1 .

5. the signal processing unit performs a first FFT on a beat signal generated by mixing the transmission signal and the reception signal, and performs a second FFT on the signals obtained by the first FFT, which are arranged in the time direction at intervals corresponding to the transmission intervals of the transmission signals, thereby generating the IQ signal. The radar device according to claim 1 .

6. The transmission signal is a chirp signal whose frequency changes over time. The radar device according to claim 1 .

7. A signal processing method executed by a computer that controls a radar device, comprising: The radar device a plurality of transmitting antennas for continuously transmitting a plurality of transmission signals as transmission waves; a plurality of receiving antennas that receive scattered waves generated by scattering the transmitted waves by a target and generate received signals; and the plurality of transmitting antennas and the plurality of receiving antennas are arranged so that positions of at least a portion of a plurality of elements constituting a virtual array antenna formed by the plurality of transmitting antennas and the plurality of receiving antennas overlap; The signal processing method includes: generating an IQ signal for each of the elements based on the transmission signal and the reception signal; Calculating a correction value for correcting a phase difference between the IQ signals of the plurality of elements whose positions overlap; correcting the IQ signals based on the calculated correction value; A signal processing method comprising:

8. A program executed by a computer that controls a radar device, The radar device a plurality of transmitting antennas for continuously transmitting a plurality of transmission signals as transmission waves; a plurality of receiving antennas that receive scattered waves generated by scattering the transmitted waves by a target and generate received signals; and The program causes the computer to: a signal processing unit that controls signal processing based on the received signal; It functions as The signal processing unit generating an IQ signal for each of the elements based on the transmission signal and the reception signal; calculating a correction value for correcting a phase difference between the IQ signals of the plurality of elements whose positions overlap; correcting the IQ signals based on the calculated correction value; program.

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