Speed detection device, information processing device, and speed detection method

Abstract

[PROBLEM] To accurately detect the speed of an object by extending a speed detection range. [SOLUTION] A speed detection device disclosed herein comprises: a plurality of first transmission antennas which are arranged in a vertical direction substantially orthogonal to a reference plane and transmit a plurality of first chirp signals; a plurality of second transmission antennas which are arranged spaced apart from the plurality of first transmission antennas along the reference plane and arranged in the vertical direction, and which transmit a plurality of second chirp signals; a plurality of reception antennas for receiving a plurality of third chirp signals from an object that reflects the plurality of first chirp signals and the plurality of second chirp signals; a signal processing unit for detecting the speed of the object on the basis of the plurality of third chirp signals received by the plurality of reception antennas; and a chirp generation unit for making the transmission order of the plurality of first chirp signals generated by the plurality of first transmission antennas different from the transmission order of the plurality of second chirp signals generated by the plurality of second transmission antennas.

Description

Speed ​​detection device, information processing device, and speed detection method

[0001] The present disclosure relates to a speed detection device, an information processing device, and a speed detection method.

[0002] Velocity detection devices that use radar to detect the velocity of an object are known. Research is also underway into velocity detection devices that have improved angle estimation capabilities by applying multi-input multi-output (MIMO) radar.

[0003] On the other hand, MIMO radar has a problem in that the range of object velocity detection is narrow. To address this problem, a radar system has been proposed that estimates the velocity-induced phase shift of a virtual array vector and corrects the phase of each element of the virtual array vector based on the velocity-induced phase shift to calculate the correct velocity of an object (see Patent Document 1).

[0004] Also, a two-dimensional MIMO (hereinafter referred to as 2D-MIMO) has been proposed in which transmitting antennas are arranged in the horizontal and vertical directions to improve the azimuth angle resolution and the elevation angle resolution (see Non-Patent Document 1).

[0005] Special table 2019-522220 publication

[0006] Design guide: TIDEP-01012 Imaging Radar Reference Design Using Cascaded mmWave Sensors (https: / / www.ti.com / jp / lit / ug / jaju737a / jaju737a.pdf?ts=1717389488440&ref_url=https%253A%252F%252Fwww.bing.com%252F)

[0007] A characteristic of MIMO radar is that the velocity detection range narrows as the number of transmitting antennas increases. Therefore, to calculate the correct velocity of an object using 2D-MIMO, it is necessary to expand the radar's velocity detection range according to the number of transmitting antennas arranged horizontally and vertically.

[0008] However, the technique of Patent Document 1 does not assume application to 2D-MIMO, and the speed detection range cannot be expanded in accordance with the number of transmitting antennas arranged in the vertical direction. Furthermore, Non-Patent Document 1 does not describe the expansion of the speed detection range in 2D-MIMO.

[0009] Therefore, the present disclosure provides a speed detection device, an information processing device, and a speed detection method that can expand the speed detection range and accurately detect the speed of an object.

[0010] In order to solve the above problems, according to the present disclosure, there is provided a system comprising: a plurality of first transmitting antennas arranged in a vertical direction substantially perpendicular to a reference plane, and transmitting a plurality of first chirp signals with a time lag between each of the first transmitting antennas; a plurality of second transmitting antennas arranged along the reference plane at a distance from the plurality of first transmitting antennas, and arranged in the vertical direction, and transmitting a plurality of second chirp signals with a time lag between each of the second transmitting antennas; a plurality of receiving antennas receiving a plurality of third chirp signals from an object that reflects the plurality of first chirp signals and the plurality of second chirp signals; a signal processing unit that detects the velocity of the object based on the plurality of third chirp signals received by the plurality of receiving antennas; and a chirp generating unit that either changes the transmission order of the plurality of first chirp signals generated by the plurality of first transmitting antennas and the transmission order of the plurality of second chirp signals generated by the plurality of second transmitting antennas, or transmits a plurality of chirp signals having a plurality of first phase patterns, each of which has a different phase from the plurality of first phase patterns, in parallel from the plurality of first transmitting antennas and the plurality of second transmitting antennas, and then transmits a plurality of chirp signals having a plurality of second phase patterns, each of which has a different phase from the plurality of first phase patterns, in parallel from the plurality of first transmitting antennas and the plurality of second transmitting antennas, When the third chirp signal includes the plurality of first phase patterns and the plurality of second phase patterns, the signal processing unit generates a plurality of third phase patterns and a plurality of fourth phase patterns, each having a different phase, which are transmitted in parallel from the plurality of first transmitting antennas and the plurality of second transmitting antennas, based on the plurality of first phase patterns and the plurality of second phase patterns, and associates the plurality of third phase patterns with the plurality of first chirp signals and the plurality of fourth phase patterns with the plurality of second chirp signals so that the phase order of the plurality of first chirp signals and the phase order of the plurality of second chirp signals are different.

[0011] The plurality of first transmitting antennas and the plurality of second transmitting antennas may be in one-to-one correspondence, and the phase differences between the first chirp signals and the second chirp signals transmitted by the corresponding ones of the plurality of first transmitting antennas and the corresponding ones of the plurality of second transmitting antennas may be different from each other.

[0012] The chirp generation unit may increase the number of speed folding values ​​that the phase difference can have by making the phase differences between corresponding ones of the plurality of first transmitting antennas and the plurality of second transmitting antennas different from each other, thereby widening the speed extension range.

[0013] The signal processing unit may assume a plurality of velocity wraparound values, select the plurality of velocity wraparound values ​​in turn, correct the phase difference between corresponding ones of the plurality of first transmitting antennas and the plurality of second transmitting antennas based on the selected velocity wraparound value, and detect the velocity of the object based on the corrected phase difference.

[0014] The signal processing unit may correct the waveform representing the phase difference so that it has a continuous sine wave shape.

[0015] The signal processing unit may detect a signal reception strength for each of the plurality of velocity aliasing values ​​based on the corrected phase difference, and compare the detected signal reception strengths for each of the plurality of velocity aliasing values ​​to detect the velocity of the object.

[0016] The signal processing unit may detect peak values ​​of the signal reception strength of the third chirp signals for each of the plurality of velocity wraparound values, and detect the velocity of the object based on the plurality of peak values ​​corresponding to the plurality of velocity wraparound values.

[0017] The signal processing unit may detect the velocity of the object from the velocity wraparound value when the peak value is maximized.

[0018] The signal processing unit may calculate the signal reception strengths by performing FFT (Fast Fourier Transform) or DFT (Discrete Fourier Transform) processing on the third chirp signals.

[0019] The chirp generator may time-division multiplex the plurality of first chirp signals and time-division multiplex the plurality of second chirp signals.

[0020] The chirp generator may reverse the transmission order of the plurality of first chirp signals and the transmission order of the plurality of second chirp signals.

[0021] The chirp generation unit may include an encoding unit that generates the plurality of chirp signals having the plurality of first phase patterns and the plurality of second phase patterns multiplexed by phase division, and the signal processing unit may include a decoding unit that performs decoding processing to extract the plurality of first phase patterns and the plurality of second phase patterns from the third chirp signal.

[0022] At least a portion of the phases of the plurality of first phase patterns may differ from those of the plurality of second phase patterns.

[0023] The first transmitting antennas may transmit the first chirp signals at uniform time intervals, and the second transmitting antennas may transmit the second chirp signals at uniform time intervals.

[0024] The plurality of first transmitting antennas may transmit each of the plurality of first chirp signals consecutively without any gaps, and the plurality of second transmitting antennas may transmit each of the plurality of second chirp signals consecutively without any gaps, or the plurality of first transmitting antennas may transmit each of the plurality of first chirp signals with gaps between them, and the plurality of second transmitting antennas may transmit each of the plurality of second chirp signals with gaps between them.

[0025] The first plurality of transmitting antennas may transmit the first plurality of chirp signals at non-uniform time intervals, and the second plurality of transmitting antennas may transmit the second plurality of chirp signals at non-uniform time intervals.

[0026] The plurality of first transmitting antennas may transmit at least some of the plurality of first chirp signals with or without a predetermined gap between them, and the plurality of second transmitting antennas may transmit at least some of the plurality of second chirp signals with or without a predetermined gap between them.

[0027] The first transmitting antennas, the second transmitting antennas, and the receiving antennas may form a two-dimensional MIMO (Multi-Input Multi-Output) array.

[0028] According to the present disclosure, a chirp generation unit is provided that either changes the transmission order of a plurality of first chirp signals generated by a plurality of first transmitting antennas arranged in a vertical direction substantially perpendicular to a reference plane and changes the transmission order of a plurality of second chirp signals generated by a plurality of second transmitting antennas arranged along the reference plane at a distance from the plurality of first transmitting antennas and arranged in the vertical direction, or transmits a plurality of chirp signals having a plurality of first phase patterns, each of which has a different phase, from the plurality of first transmitting antennas and the plurality of second transmitting antennas in parallel, and then transmits a plurality of chirp signals having a plurality of second phase patterns, each of which has a different phase from the plurality of first phase patterns in parallel; and a signal processing unit that detects the velocity of an object based on a plurality of third chirp signals transmitted from the object that reflects the plurality of first chirp signals and the plurality of second chirp signals and received by a plurality of receiving antennas, and, if the plurality of third chirp signals include the plurality of first phase patterns and the plurality of second phase patterns, generates a plurality of third phase patterns and a plurality of fourth phase patterns, each having different phases, transmitted in parallel by the plurality of first transmitting antennas and the plurality of second transmitting antennas, based on the plurality of first phase patterns and the plurality of second phase patterns, and associates the plurality of third phase patterns with the plurality of first chirp signals and the plurality of fourth phase patterns with the plurality of second chirp signals so that the phase order of the plurality of first chirp signals and the phase order of the plurality of second chirp signals are different.

[0029] Furthermore, according to the present disclosure, the transmission order of a plurality of first chirp signals generated by a plurality of first transmitting antennas arranged in a vertical direction substantially perpendicular to a reference plane is made different from the transmission order of a plurality of second chirp signals generated by a plurality of second transmitting antennas arranged along the reference plane at a distance from the plurality of first transmitting antennas and arranged in the vertical direction, or a plurality of first chirp signals having a plurality of first phase patterns each having a different phase from the plurality of first phase patterns are transmitted in parallel from the plurality of first transmitting antennas and the plurality of second transmitting antennas, and then a plurality of second chirp signals having a plurality of second phase patterns each having a different phase from the plurality of first phase patterns are transmitted in parallel from the plurality of first transmitting antennas and the plurality of second transmitting antennas, a velocity detection method for detecting a velocity of an object based on a plurality of third chirp signals transmitted from the object that reflects the plurality of first chirp signals and the plurality of second chirp signals and received by a plurality of receiving antennas; and, if the plurality of third chirp signals include the plurality of first phase patterns and the plurality of second phase patterns, generating a plurality of third phase patterns and a plurality of fourth phase patterns, each having different phases, transmitted in parallel by the plurality of first transmitting antennas and the plurality of second transmitting antennas, based on the plurality of first phase patterns and the plurality of second phase patterns; and associating the plurality of third phase patterns with the plurality of first chirp signals and the plurality of fourth phase patterns with the plurality of second chirp signals such that the phase order of the plurality of first chirp signals and the phase order of the plurality of second chirp signals are different.

[0030] 12A is a block diagram showing a configuration of a velocity detection device according to a first embodiment of the present disclosure. FIG. 12B is a diagram showing a configuration of a plurality of transmitting antennas according to a first embodiment of the present disclosure. FIG. 12C is a diagram showing a configuration of a plurality of receiving antennas according to a first embodiment of the present disclosure. FIG. 12D is a diagram showing a concept of horizontal MIMO. FIG. 12E is a diagram showing a concept of vertical MIMO. FIG. 12F is a diagram showing a concept of vertical MIMO. FIG. 12G is a diagram showing a velocity detection range by radar. FIG. 12H is a diagram showing a velocity detection range when TDM-MIMO is used. FIG. 12H is a diagram showing a velocity detection method according to a first embodiment of the present disclosure. FIG. 12G is a diagram showing a relationship between the chirp signal and the reflected chirp signal of FIG. 10. FIG. 12H is a waveform diagram showing a relationship between a reflection value and a phase error component according to a first embodiment of the present disclosure. FIG. 12H is an enlarged view of FIG. 12A. FIG. 12G is a diagram showing a transmission time chart of a chirp signal according to a modification of FIG. 10. 10 is a waveform diagram showing an example of a virtual phase vector formed by a MIMO forming unit. FIG. 11 is a waveform diagram showing a virtual phase vector properly corrected by a MIMO phase correction processing unit. FIG. 12 is a diagram showing a simulation result of power values ​​for each azimuth angle and elevation angle. FIG. 13 is a diagram showing a simulation result of power values ​​for each azimuth angle. FIG. 14 is a diagram showing a simulation result of power values ​​for each elevation angle. FIG. 15 is a diagram showing a simulation result for each aliasing value according to the first embodiment of the present disclosure. FIG. 16 is a waveform diagram showing a peak power value for each aliasing value according to the first embodiment of the present disclosure. A transmission time chart of a chirp signal according to a comparative example. A waveform diagram showing a relationship between aliasing values ​​and phase error components according to a comparative example. A diagram showing a simulation result for each aliasing value according to a comparative example. A waveform diagram showing a peak power value for each aliasing value according to a comparative example. A block diagram showing a configuration of a speed detection device according to a second embodiment of the present disclosure. A signal waveform diagram of a chirp signal according to the second embodiment of the present disclosure. A block diagram showing an example of a schematic configuration of a vehicle control system. An explanatory diagram showing an example of installation positions of an outside vehicle information detection unit and an imaging unit.

[0031] Hereinafter, embodiments of a speed detection device, an information processing device, and a speed detection method will be described with reference to the drawings. The following description will focus on the main components of the speed detection device, the information processing device, and the speed detection method, but the speed detection device, the information processing device, and the speed detection method may include components and functions that are not shown or described. The following description does not exclude components and functions that are not shown or described.

[0032] (First embodiment) Fig. 1 is a block diagram showing the configuration of a speed detection device 1 according to a first embodiment of the present disclosure. The speed detection device 1 is used to detect the speed of an object 2. The object 2 is, for example, a moving body. More precisely, the speed detection device 1 detects the relative speed of the object 2 as seen from the speed detection device 1 (hereinafter also simply referred to as speed). Therefore, the object 2 may be stationary and the speed detection device 1 may be moving.

[0033] The speed detection device 1 includes an antenna unit 3 and an information processing device 10. The antenna unit 3 includes a plurality of transmitting antennas 4 and a plurality of receiving antennas 5. The plurality of transmitting antennas 4 transmit chirp signals Tx to the object 2. The plurality of receiving antennas 5 receive reflected chirp signals rTx that are generated when the chirp signals Tx are reflected by the object 2.

[0034] The multiple transmitting antennas 4 and the multiple receiving antennas 5 form a MIMO, which is a technique for virtually increasing the aperture length (i.e., the receiving area of ​​the antenna) by disposing the multiple transmitting antennas 4 in a spatially offset manner relative to the multiple receiving antennas 5.

[0035] The multiple transmitting antennas 4 are arranged in both the horizontal and vertical directions. As a result, the antenna unit 3 forms a 2D-MIMO system in which the receiving area of ​​the antenna is virtually expanded in two dimensions. Here, the horizontal direction refers to a direction along the reference plane on which the speed detection device 1 is installed, and does not necessarily have to be parallel to the reference plane. The vertical direction refers to a direction approximately perpendicular to the reference plane, and does not necessarily have to be a normal direction to the reference plane.

[0036] The information processing device 10 controls the transmission of chirp signals Tx from multiple transmitting antennas 4. The information processing device 10 also detects the velocity of the object 2 based on the chirp signals Tx and the reflected chirp signals rTx. The information processing device 10 has a chirp generator 11, a beat signal generator 12, and a signal processor 13. The transmitting antennas 4 and the chirp generator 11 are included in the transmitter, and the receiving antennas 5, the beat signal generator 12, and the signal processor 13 are included in the receiver.

[0037] The chirp generator 11 has a plurality of chirp generators 14 provided for each transmitting antenna 4. The plurality of chirp generators 14 generate chirp signals Tx to be transmitted by the corresponding transmitting antennas 4, respectively.

[0038] The beat signal generator 12 amplifies the reflected chirp signal RX received by the receiving antenna 5 and generates a beat signal based on the chirp signal Tx and the reflected chirp signal rTx. The beat signal includes a signal component of the chirp signal Tx and a signal component of the reflected chirp signal rTx.

[0039] The signal processing unit 13 includes a beat signal acquisition unit 15, a MIMO formation unit 16, a MIMO phase correction processing unit 17, an aliasing determination unit 18, and a velocity calculation unit 19. The beat signal acquisition unit 15 acquires the beat signal generated by the beat signal generation unit 12. The MIMO formation unit 16 forms a virtual array vector by replicating the reflected chirp signal RX based on the multiple transmitting antennas 4. The MIMO phase correction processing unit 17 corrects the phase of each element of the virtual array vector. The aliasing determination unit 18 acquires a velocity aliasing value indicating a velocity detection range in which the velocity of the object 2 can be detected based on the corrected virtual array vector. The velocity calculation unit 19 calculates the true velocity of the object 2 based on the velocity aliasing value. The detailed operation of the signal processing unit 13 will be described later.

[0040] 2 is a diagram showing the configuration of multiple transmitting antennas 4 according to the first embodiment of the present disclosure. The multiple transmitting antennas 4 are arranged in the horizontal and vertical directions. More specifically, the multiple transmitting antennas 4 include multiple first transmitting antennas 4a and multiple second transmitting antennas 4b.

[0041] The first transmitting antennas 4a are arranged in a vertical direction Z that is substantially perpendicular to the reference plane. The vertical direction Z may refer to the mounting height direction of the antennas (the first transmitting antenna 4a, the second transmitting antenna 4b, and the receiving antenna 5) or the longitudinal direction of the antennas.

[0042] The second transmitting antennas 4b are arranged along the reference plane at a distance from the first transmitting antennas 4a, and are also arranged in a vertical direction Z that is substantially perpendicular to the reference plane.

[0043] 2 illustrates an example in which the multiple transmitting antennas 4 include first transmitting antennas TX1 to TX4 and second transmitting antennas TX5 to TX8. The up-down direction in FIG. 2 is the vertical direction Z, and the lateral direction in FIG. 2 is the horizontal direction (first direction X). The first transmitting antennas TX1 to TX4 and the second transmitting antennas TX5 to TX8 are arranged spaced apart in the first direction X.

[0044] The first transmitting antennas TX4, TX3, TX2, and TX1, and the second transmitting antennas TX8, TX7, TX6, and TX5 are arranged in this order in the first direction X. The first transmitting antennas TX1 to TX4 are arranged in this order with a shift in the higher direction. The second transmitting antennas TX5 to TX8 are arranged in this order with a shift in the higher direction.

[0045] The first transmitting antennas TX1 to TX4 and the second transmitting antennas TX5 to TX8 are in one-to-one correspondence. Specifically, the first transmitting antenna TX1 and the second transmitting antenna TX5, the first transmitting antenna TX2 and the second transmitting antenna TX6, the first transmitting antenna TX3 and the second transmitting antenna TX7, and the first transmitting antenna TX4 and the second transmitting antenna TX8 are pairs of antennas arranged at corresponding heights.

[0046] As described above, Fig. 2 shows an example in which the first transmitting antennas TX1 to TX4 are arranged with a stagger in the first direction X. However, the present invention is not limited to this, and the first transmitting antennas TX1 to TX4 may also be arranged with a stagger in the second direction Y. Furthermore, the first transmitting antennas TX1 to TX4 may also be arranged side by side in the vertical direction Z without being staggered in the first direction X or the second direction Y. The same applies to the second transmitting antennas TX5 to TX8.

[0047] Hereinafter, in this specification, the chirp signals transmitted by the first transmitting antennas TX1 to TX4 may be referred to as first chirp signals Tx1 to Tx4. Furthermore, the chirp signals transmitted by the second transmitting antennas TX5 to TX8 may be referred to as second chirp signals Tx5 to Tx8. Furthermore, the reflected chirp signals obtained by reflecting the first chirp signals Tx1 to Tx4 and the second chirp signals Tx5 to Tx8 from the object 2 may be referred to as reflected chirp signals (third chirp signals) rTx1 to rTx8.

[0048] 3 is a diagram showing the configuration of multiple receiving antennas 5 according to the first embodiment of the present disclosure. The multiple receiving antennas 5 are arranged, for example, in a first direction X. Fig. 3 shows an example in which the multiple receiving antennas 5 have eight receiving antennas RX1 to RX8.

[0049] 4A and 4B are schematic diagrams illustrating the concept of horizontal MIMO. Fig. 4A shows a first transmitting antenna TX1 and a second transmitting antenna TX5 spaced apart horizontally. As a result, as shown in Fig. 4B, receiving antennas RX1 to RX8 are replicated and arranged in a first direction X to form virtual receiving antennas RXV1 to RXV8. The receiving area of ​​the antenna is virtually expanded in the horizontal direction by the replicated virtual receiving antennas RXV1 to RXV8.

[0050] The receiving antennas RX1 to RX8 in Fig. 4A receive a reflected chirp signal rTx based on the chirp signal Tx transmitted by the first transmitting antenna TX1 and the second transmitting antenna TX5. As shown in Fig. 4B, the reflected chirp signal rTx based on the chirp signal Tx transmitted by the first transmitting antenna TX1 is received by the receiving antennas RX1 to RX8 and the virtual receiving antennas RXV1 to RXV8, thereby virtually increasing the number of receiving antennas in the horizontal direction (first direction X).

[0051] 5A and 5B are schematic diagrams illustrating the concept of vertical MIMO. FIG. 5A shows first transmitting antennas TX1, TX2, and TX3 arranged vertically. As a result, virtual virtual antenna groups RXVa and RXVb are formed as shown in FIG. 5B. The virtual antenna groups RXVa and RXVb each include eight receiving antennas that are copies of the receiving antennas RX1 to RX8. The virtual antenna groups RXVa and RXVb are arranged in the vertical direction Z relative to the receiving antennas RX1 to RX8. This virtually expands the receiving area of ​​the antenna in the vertical direction.

[0052] 6 is a schematic diagram showing the concept of 2D-MIMO. A plurality of virtual antenna groups RXVc are formed by the plurality of transmitting antennas 4 shown in FIG. 2 and the plurality of receiving antennas 5 shown in FIG.

[0053] 2, the first transmitting antennas TX1 to TX4 (and the second transmitting antennas TX5 to TX8) are arranged with a shift in the first direction X, and therefore the multiple virtual antenna groups RXVc are also formed with a shift in the first direction X. As a result, a parallelogram-shaped 2D-MIMO is formed by the receiving antennas RX1 to RX8 and the multiple virtual antenna groups RXVc.

[0054] The velocity detection device 1 of the present disclosure detects the velocity of an object 2 based on a signal group 20 obtained by extracting reflected chirp signals rTx into a rectangular shape from a parallelogram-shaped 2D-MIMO, for example.

[0055] It should be noted that a rectangular 2D-MIMO can be formed if the first transmitting antennas TX1 to TX4 etc. are not shifted in the first direction X and the second direction Y. In this case, it is not necessary to cut out the signal group 20.

[0056] MIMO includes TDM (Time Division Multiplexing)-MIMO, in which a plurality of chirp signals Tx are transmitted with a shifted transmission timing for each transmitting antenna 4, and BPM (Binary Phase Modulation)-MIMO, in which a plurality of chirp signals Tx are transmitted with a shifted phase for each transmitting antenna 4. Hereinafter, in the first embodiment of the present disclosure, a velocity detection method using TDM-MIMO will be described.

[0057] 7 is a diagram illustrating a speed detection range by a radar. First, in FIG. 7, a speed detection range when MIMO is not used, that is, when speed detection is performed using one transmitting antenna 4, is explained.

[0058] 7, a transmitting antenna 4 transmits a chirp signal Tx of wavelength λ every fixed chirp period Tc. A receiving antenna 5 receives a reflected chirp signal rTx, which is the chirp signal Tx reflected by an object 2. In the example of FIG. 7, chirp signals Txa, Txb, Txc, and Txd are transmitted in this order, and corresponding reflected chirp signals rTxa, rTxb, rTxc, and rTxd are received.

[0059] Furthermore, the object 2 is assumed to move at a constant velocity v. That is, the amount of movement of the object 2 per chirp period Tc is Tc×v.

[0060] Due to the Doppler effect, a phase shift occurs between the chirp signal Tx and the reflected chirp signal rTx. The phase differences between the chirp signals Txa, Txb, Txc, and Txd and the reflected chirp signals rTxa, rTxb, rTxc, and rTxd are φ0, φ0 + φd, φ0 + 2×φd, and φ0 + 3×φd, respectively. As described above, the phase differences between the chirp signals Txa, Txb, Txc, and Txd and the reflected chirp signals rTxa to rTxd each include a different phase change amount φd, and the phase change amount φd changes over time. The phase change amount φd is proportional to the displacement amount Tc×v of the object 2 and is given by equation (1). Furthermore, equation (1) can be transformed into equation (2) for the velocity v:

[0061] The phase change amount φd can be calculated by performing a fast Fourier transform (FFT) on the reflected chirp signal rTx, etc. By calculating the phase change amount φd, the velocity v of the object 2 can be calculated from equation (2).

[0062] However, due to the sampling theorem, the phase change amount φd can only be detected between -π and +π. Therefore, the velocity v of the object 2 that can be detected by the radar is also limited to a predetermined range. From equation (2), the velocity detection range Vrange that can be detected by the radar can be calculated as shown in equation (3).

[0063] The velocity detection range Vrange in equation (3) is a range in which the velocity v is uniquely determined for the phase change amount φd. Outside the range of equation (3), the velocity v becomes ambiguous, and the velocity of the object 2 cannot be detected correctly. Hereinafter, the ambiguous velocity v will also be referred to as a tentative velocity Vmeas.

[0064] 8 is a diagram illustrating the speed detection range when TDM-MIMO is used. In MIMO, as shown in FIG. 8, multiple transmitting antennas 4 transmit chirp signals Tx in turn, with a chirp period Tc between them. Therefore, the interval between when one transmitting antenna 4 (e.g., the first transmitting antenna TX1) transmits the first chirp signal Txa and when it transmits the second chirp signal Txb is N×Tc (N is the number of transmitting antennas 4).

[0065] In this specification, the interval from when one transmitting antenna 4 transmits a chirp signal to when it transmits the next chirp signal is also referred to as a burst interval Tb (Tb=N×Tc).

[0066] The burst interval Tb is the interval between multiple chirp signals Tx from the same transmitting antenna 4 when the chirp signals Tx multiplexed among the multiple transmitting antennas 4 are separated for each transmitting antenna 4.

[0067] Accordingly, the amount of movement of the object 2 from the transmission of the first chirp signal Txa to the transmission of the second chirp signal Txb is N × Tc × v. The amount of phase change φd, the tentative velocity Vmeas, and the velocity detection range Vrange that can be detected by the radar are calculated using the following equations (4), (5), and (6).

[0068] Comparing equation (3) and equation (6), the velocity detection range Vrange that can be detected by the radar is narrowed by a factor of 1 / N. Furthermore, as shown in equation (6), the velocity detection range Vrange is characterized in that it narrows as N increases, that is, as the number of transmitting antennas 4 increases. In other words, MIMO has the problem that the range in which the velocity of the object 2 can be normally detected narrows.

[0069] The speed detection device 1 of the present disclosure has the feature of being able to solve this problem.

[0070] 9 is a diagram illustrating a velocity detection method according to the first embodiment of the present disclosure. Fig. 9 shows a plurality of velocity ranges 30 arranged on the velocity axis of the object 2. The velocity range 30 is a range in which the velocity v of the object 2 can be uniquely determined from the phase change amount φd, and has a width Vrange (=λ / 2NTc).

[0071] A wrap number (wrap value) Nwrap indicating the number of wraps in the cycle of the phase change amount φd is assigned to each of the multiple velocity ranges 30. Nwrap=0 is assigned to the velocity range 30 where the velocity is -Vmax to +Vmax (Vmax=λ / 4NTc). Nwrap=+1 is assigned to the velocity range 30 where the velocity is +Vmax to +3Vmax, and successive Nwrap numbers are assigned thereafter as the velocity increases. Furthermore, Nwrap=-1 is assigned to the velocity range 30 where the velocity is -3Vmax to -Vmax, and successive Nwrap numbers are assigned thereafter as the velocity decreases.

[0072] Using the wraparound value Nwrap, Vmax indicating the upper limit of the velocity range 30, and the tentative velocity Vmeas calculated by equation (5), the true velocity Vexp of the object 2 can be calculated by the following equation (7).

[0073] That is, if the phase change amount φd and the wraparound value Nwrap can be specified, the true velocity Vexp of the object 2 can be calculated.

[0074] 9, in the velocity detection technique of the present disclosure, the range in which the true velocity Vexp can be detected can be expanded from one velocity range 30 to multiple velocity ranges 30 in which the wraparound value Nwrap can be determined. This is also referred to as radar velocity expansion in this specification.

[0075] 10 is a transmission time chart of the chirp signal Tx according to the first embodiment of the present disclosure, illustrating first chirp signals Tx1 to Tx4 and second chirp signals Tx5 to Tx8.

[0076] In the first embodiment of the present disclosure, the chirp generator 11 in Fig. 1 multiplexes first chirp signals Tx1 to Tx4 in a time-division manner and also multiplexes second chirp signals Tx5 to Tx8 in a time-division manner. The chirp generator 11 controls the first transmitting antennas TX1 to TX4 and the second transmitting antennas TX5 to TX8 to transmit the chirp signals Tx at different timings.

[0077] As shown in Figure 10, the transmission order of the first chirp signals Tx1 to Tx4 is different from the transmission order of the second chirp signals Tx5 to Tx8. Specifically, the first chirp signals Tx1 to Tx4 are transmitted in this order, while the second chirp signals Tx5 to Tx8 are transmitted in the reverse order.

[0078] 10 shows an example in which the first chirp signals Tx1 to Tx4 and the second chirp signals Tx5 to Tx8 are transmitted at equal intervals. Specifically, if the first transmission timing of the first chirp signal Tx1 is defined as reference time 0, the second transmission timing of the first chirp signal Tx1 is the time when the burst interval Tb has elapsed since reference time 0 (hereinafter referred to as time Tb).

[0079] The first chirp signals Tx2 to Tx4 and the second chirp signals Tx5 to Tx8 are transmitted at regular intervals of 1 / 8 Tb, i.e., the first chirp signals Tx2, Tx3, and Tx4, and the second chirp signals Tx8, Tx7, Tx6, and Tx5 are transmitted at times 1 / 8 Tb, 1 / 4 Tb, 3 / 8 Tb, 1 / 2 Tb, 5 / 8 Tb, 3 / 4 Tb, and 7 / 8 Tb, respectively.

[0080] As described above, by making the transmission order of the first chirp signal and the transmission order of the second chirp signal different, the transmission intervals of the paired chirp signals can be made different from each other.

[0081] In the example of Fig. 10, the interval between the transmission of the first chirp signal Tx1 and the transmission of its paired second chirp signal Tx5 is 7 / 8 Tb. Meanwhile, the interval between the transmission of the first chirp signal Tx2 and the transmission of the second chirp signal Tx6 is 5 / 8 Tb. Similarly, the transmission interval between the first chirp signal Tx3 and the second chirp signal Tx7, and the transmission interval between the first chirp signal Tx4 and the second chirp signal Tx8, are 3 / 8 Tb and 1 / 8 Tb, respectively. In other words, the transmission intervals of the paired chirp signals are different from each other.

[0082] 11 is a diagram illustrating the relationship between the chirp signal Tx and the reflected chirp signal rTx according to the first embodiment of the present disclosure. Fig. 11 illustrates the first chirp signals Tx1, Tx2, the second chirp signals Tx5, and Tx6, and the reflected chirp signals rTx1, rTx2, rTx5, and rTx6. Fig. 11 also illustrates the reflected chirp signal rTx1a corresponding to the first chirp signal Tx1a and the reflected chirp signal rTx1b corresponding to the second chirp signal Tx1b.

[0083] 7, a phase difference occurs between the reflected chirp signals rTx1, rTx2, rTx5, and rTx6 due to the Doppler effect, and this phase difference gradually changes depending on the transmission timing of the chirp signal.

[0084] FIG. 11 shows an example in which the phase of the reflected chirp signal rTx1a is set as the reference phase (=0), and the reflected chirp signal rTx1b has a phase difference of φexp.

[0085] In the above case, the reflected chirp signals rTx2, rTx5, and rTx6 have phase differences of 1 / 8φexp, 7 / 8φexp, and 3 / 4φexp with respect to the reflected chirp signal rTx1a, depending on the transmission timing of the corresponding chirp signal.

[0086] The phase difference φexp can be expressed by the following equation (8) using the phase change amount φd (−π≦φd<π) that can be detected by FFT and the wrap number Nwrap.

[0087] The phase difference φ1_5 between the pair of reflected chirp signals rTx1 and rTx5 is 7 / 8φexp. The phase difference φ2_6 between the pair of reflected chirp signals rTx2 and rTx6 is 5 / 8φexp. Similarly, the phase difference φ3_7 between the pair of reflected chirp signals rTx3 and rTx7 and the phase difference φ4_8 between the pair of reflected chirp signals rTx4 and rTx8 are 3 / 8φexp and 1 / 8φexp, respectively.

[0088] Using the above equation (8), the phase differences φ1_5, φ2_6, φ3_7, and φ4_8 can be calculated as shown in the following equations (9) to (12).

[0089] In the first embodiment of the present disclosure, the phase differences φ1_5, φ2_6, φ3_7, and φ4_8 are calculated based on an assumed aliasing value Nwrap, and the reflected chirp signals rTx5 to rTx8 acquired by the receiving antenna 5 are corrected using the calculated phase differences. If the assumed aliasing value Nwrap is correct, the phases of the reflected chirp signals rTx1 to rTx4 and the corrected reflected chirp signals rTx5 to rTx8 can be matched. In this case, when the signal processing unit 13 performs FFT processing, the peak power (described below) is maximized.

[0090] More specifically, in the velocity detection device 1 of the present disclosure, the correct aliasing value Nwrap is obtained by acquiring and comparing the peak power of the received signal strength while changing the aliasing value Nwrap, and the true velocity Vexp of the object 2 can be obtained.

[0091] In this specification, 2π*7 / 8*Nwrap, 2π*5 / 8*Nwrap, 2π*3 / 8*Nwrap, and 2π*1 / 8*Nwrap in equations (9) to (12) are referred to as phase error components φError1_5, φError2_6, φError3_7, and φError4_8 that depend on the wraparound value Nwrap, respectively.

[0092] 12A is a waveform diagram showing the relationship between the aliasing value Nwrap and the above-mentioned phase error components φError1_5, φError2_6, φError3_7, and φError4_8 according to the first embodiment of the present disclosure, where the horizontal axis of FIG. 12A represents the aliasing value Nwrap and the vertical axis represents the phase difference.

[0093] 12B is an enlarged view of the range of the wraparound value Nwrap from −4 to +4 in FIG. 12A. As shown in FIG. 12B, the phase error components φError1_5, φError2_6, φError3_7, and φError4_8 each have a different value within the range of −4≦Nwrap<+4.

[0094] As a result, the wraparound value Nwrap can be determined in the range of -4≦Nwrap<+4, and therefore, with the velocity detection method disclosed herein, the range in which the true velocity Vexp can be detected can be expanded to eight of the velocity ranges 30 in Figure 9.

[0095] As described above, the chirp generator 11 in Fig. 1 differentiates the phase differences of the reflected chirp signals rTx1 to rTx8 for each pair of the first transmitting antennas TX1 to TX4 and the second transmitting antennas TX5 to TX8, respectively, thereby increasing the range in which the wraparound value Nwrap can be determined and expanding the speed extension range.

[0096] The phase error component φError between a pair of first and second transmitting antennas can be generalized as shown in the following equation (13): t1 is the earlier of the chirp signal transmission times from the first transmitting antenna or the second transmitting antenna, and t2 is the later of the two. Tb is the burst period from when a chirp signal is transmitted from any transmitting antenna until the chirp signal is transmitted again from the same transmitting antenna.

[0097] The velocity detection device 1 of the present disclosure can determine the wraparound value Nwrap within the range of 2π (-π≦φError<π) of the period of the phase error component φError. Therefore, it is sufficient to set the transmission times of the first and second chirp signals so that the phase error component φError does not become an integer multiple of 2π with as many wraparound values ​​Nwrap as possible. If this condition can be satisfied, the order and timing of transmission of the first and second chirp signals are not limited to the example shown in FIG. 10 . Furthermore, the number and configuration of the transmitting antennas 4 are not limited to the example shown in FIG. 2 .

[0098] Fig. 13 is a transmission time chart of chirp signals Tx according to a modification of Fig. 10. In Fig. 10, multiple chirp signals Tx (i.e., first chirp signals Tx1 to Tx4 and second chirp signals Tx5 to Tx8) are transmitted at equal intervals and continuously without any gaps. In contrast, Fig. 13 shows an example in which gaps are allocated to at least a portion of the transmission intervals of the multiple chirp signals Tx, resulting in discontinuous transmission. Furthermore, in the example of Fig. 13, the multiple chirp signals Tx are transmitted at non-uniform time intervals.

[0099] In the example of Figure 13, the phase error component φError shown in equation (13) can also be formed. For example, the phase error component between the first transmitting antenna TX4 and the second transmitting antenna TX8 in Figure 13 is φError4_8 = 2π × (4.8Tc - 3.5Tc) / 11Tc × Nwrap = 2π × 1.3 / 11 × Nwrap. This allows the speed extension range to be expanded, as in the example of Figure 10.

[0100] In addition to the example of FIG. 13, the speed detection device 1 may allocate a uniform vacant time between each transmission interval of a plurality of chirp signals Tx, and transmit the plurality of chirp signals Tx discontinuously and at equal intervals.

[0101] Fig. 14 is a flowchart showing the operation of the signal processing unit 13 according to the first embodiment of the present disclosure. Before starting the processing of Fig. 14, the multiple transmitting antennas 4 transmit multiple chirp signals Tx multiplexed in a time-division manner, as shown in Fig. 10 etc. The multiple receiving antennas 5 receive reflected chirp signals rTx resulting from the chirp signals Tx reflected by the object 2. The beat signal generating unit 12 generates beat signals from the chirp signals Tx and the reflected chirp signals rTx. The beat signal acquiring unit 15 acquires the beat signals.

[0102] The signal processing unit 13 performs Range-Doppler FFT based on the beat signal (step S1), thereby calculating the tentative velocity of the object 2.

[0103] Next, the MIMO forming unit 16 forms a MIMO based on the beat signal and the positional relationship between the plurality of transmitting antennas 4 and the plurality of receiving antennas 5 (step S2). Specifically, in step S2, a virtual phase vector, which will be described below, is generated.

[0104] The beat signal includes a reflected chirp signal rTx based on chirp signals multiplexed among a plurality of transmitting antennas 4. The multiplexed reflected chirp signals rTx can be separated for each transmitting antenna 4.

[0105] The signal processing unit 13 can extract, for example, a reflected chirp signal rTx1 corresponding to the first transmitting antenna TX1 and a reflected chirp signal rTx5 corresponding to the second transmitting antenna TX5 from the multiplexed reflected chirp signal rTx.

[0106] The signal processing unit 13 acquires the phase of the reflected chirp signal rTx1 when it is received by the receiving antennas RX1 to RX8. The receiving antennas RX1 to RX8 are placed at different positions and are at different distances from the object 2. Therefore, the phases of the reflected chirp signal rTx1 acquired by the receiving antennas RX1 to RX8 are different from each other.

[0107] For example, if the receiving antennas RX1 to RX8 are arranged at equal intervals, the phase vector Ptx1 = [Ptx1_rx1 Ptx1_rx2 Ptx1_rx3 ... Ptx1_rx7 Ptx1_rx8] = [0 φa 2φa ... 6φa 7φa] can be constructed using the phase difference φa between the antennas. The elements Ptx1_rx1 to Ptx1_rx8 of the phase vector Ptx1 are the phases of the receiving antennas RX1 to RX8 when the receiving antenna RX1 is set to the reference phase (Ptx1_rx1 = 0).

[0108] Furthermore, the pair of the first transmitting antenna TX1 and the second transmitting antenna TX5 differ in distance from the object 2. For example, if the distance between the first transmitting antenna TX1 and the second transmitting antenna TX5 is eight times the distance between the adjacent receiving antennas 5, then a phase difference ΔPtx5 of the inter-antenna distance component ΔPtx5 = [ΔPtx5_rx1 ΔPtx5_rx2 ΔPtx5_rx3 ... ΔPtx5_rx7 ΔPtx5_rx8] = [8φa 9φa 10φa ... 14φa 15φa] can be added to the phase of the reflected chirp signal rTx5 received by the receiving antennas RX1 to RX8.

[0109] Furthermore, the phase vector Ptx5 of the reflected chirp signal rTx5 received by the receiving antennas RX1 to RX8, relative to the phase of the reflected chirp signal rTx1 received by the receiving antenna RX1, can be expressed as the sum of the phase difference ΔPtx5 of the inter-antenna distance component and the phase difference φ1_5_exp of the transmission interval component, i.e., Ptx5 = [Ptx5_rx1 Ptx5_rx2 Ptx5_rx3 ... Ptx5_rx7 Ptx5_rx8] = ΔPtx5 + φ1_5_exp = [8φa + φ1_5_exp 9φa + φ1_5_exp 10φa + φ1_5_exp ... 14φa + φ1_5_exp 15φa + φ1_5_exp].

[0110] In step S2 of FIG. 14, the MIMO forming unit 16 concatenates the phase vectors Ptx1 and Ptx5 to obtain a virtual phase vector P 1_5 Generate P 1_5= [Ptx1_rx1 Ptx1_rx2 Ptx1_rx3 ... Ptx5_rx7 Ptx5_rx8] = [0 φa 2 φa ... 14 φa + φ1_5_exp 15 φa + φ1_5_exp].

[0111] FIG. 15A shows the virtual phase vector P 1_5 15A is a waveform diagram showing an example of the phase vector P. The vertical axis of FIG. 15A represents amplitude, and the horizontal axis represents horizontal position. More specifically, the horizontal axis represents the corresponding elements of the virtual phase vector P for each receiving antenna 5 number RX#. The curve in FIG. 15A is a sine wave in the range of the phase vector Ptx1 and the range of the phase vector Ptx5. Meanwhile, in the virtual phase vector P, a phase difference φ1_5 of the transmission interval component is added to the phase vector Ptx5. Therefore, the curve is discontinuous at the boundary between the phase vectors Ptx1 and Ptx5.

[0112] Similarly, for the reflected chirp signals rTx2 to rTx4 and the reflected chirp signals rTx6 to rTx8, the virtual phase vector P 2_6 , P 3_7 , and P 4_8 can be formed.

[0113] After step S2 in FIG. 14, the MIMO phase correction processing unit 17 changes the wraparound value Nwrap while adjusting the virtual phase vector P 1_5 ~P 4_8 First, the MIMO phase correction processing unit 17 resets the wrapping value Nwrap (step S3). For example, when searching for the wrapping value Nwrap in the range of −4≦Nwrap<+4 as shown in FIG. 12B, the MIMO phase correction processing unit 17 sets the wrapping value Nwrap to −4.

[0114] The MIMO phase correction processing unit 17 performs velocity phase correction based on the set wrap value Nwrap (step S4). Specifically, the virtual phase difference φ1_5 can be calculated from equation (9). The MIMO phase correction processing unit 17 calculates the virtual phase vector P 1_5 Among the elements of the phase vector Ptx5, a correction is performed to remove the phase difference φ1_5 from the phase vector Ptx5.

[0115] If the correction by the MIMO phase correction processing unit 17 is appropriate (i.e., φ1_5=φ1_5_exp), the appropriate virtual phase vector Pc 1_5 can be calculated. 1_5 = [Ptx1_rx1 Ptx1_rx2 Ptx1_rx3 ... Pc_tx5_rx7 Pc_tx5_rx8] = [0 φa 2φa ... 14φa 15φa].

[0116] FIG. 15B shows the virtual phase vector Pc 1_5 1 is a waveform diagram showing a corrected virtual phase vector Pc 1_5 Based on this, a continuous sine wave can be formed.

[0117] If the correction by the MIMO phase correction processing unit 17 is not appropriate (i.e., φ1_5≠φ1_5_exp), the corrected virtual phase vector P 1_5 , a discontinuous curve is formed similar to that in FIG. 15A.

[0118] The MIMO phase correction processing unit 17 calculates the virtual phase vector P 2_6 , P 3_7 , and P 4_8 Similarly, provisional phase differences φ2_4, φ3_7, and φ4_8 are calculated from equations (10) to (12) and corrected.

[0119] The signal processing unit 13 calculates the virtual phase vector P 1_5 ~P 4_8 An azimuth FFT is performed based on the result of the azimuth FFT (step S5). An elevation FFT is also performed based on the result of the azimuth FFT (step S6). Furthermore, peak power (signal reception strength) is detected from the result of the elevation FFT (step S7).

[0120] 16 to 18 are diagrams showing simulation results of azimuth angle FFT and elevation angle FFT. FIG. 16 is a diagram showing power values ​​for each azimuth angle and elevation angle, with the horizontal axis showing azimuth angle (Azimuth [deg]) and the vertical axis showing elevation angle (Elevation [deg]), and the shading in the diagram showing power values ​​(Power [db]). FIG. 17 is a waveform diagram showing power values ​​for each azimuth angle, with the horizontal axis showing azimuth angle (Azimuth [deg]) and the vertical axis showing power values ​​(Power [db]). FIG. 18 is a waveform diagram showing power values ​​for each elevation angle, with the horizontal axis showing elevation angle (Elevation [deg]) and the vertical axis showing power values ​​(Power [db]).

[0121] 16 to 18, the power value for each azimuth angle and elevation angle can be obtained by the azimuth angle FFT and the elevation angle FFT. In step S7 of Fig. 14, the signal processing unit 13 detects the maximum power value as the peak power from the power values ​​for each azimuth angle and elevation angle.

[0122] Next, the signal processing unit 13 determines whether the estimation of the wraparound value Nwrap has been completed within a predetermined range (e.g., −4≦Nwrap<+4) (step S8). If the estimation of the wraparound value Nwrap has not been completed, the signal processing unit 13 changes (e.g., increments) the wraparound value Nwrap (step S9). The signal processing unit 13 calculates the virtual phase vector P 1_5 ~P 4_8 Then, the peak power is detected in steps S6 to S8.

[0123] The signal processing unit 13 determines that estimation of the aliasing value Nwrap is complete when the aliasing value Nwrap reaches, for example, +3. The aliasing determination unit 18 compares the peak power detected at each aliasing value Nwrap and extracts the aliasing value Nwrap at which the maximum peak power is detected as the true aliasing value Nwrap.

[0124] In step S8, the virtual phase vector P 1_5 ~P 4_8 If the correction of the virtual phase vector P is appropriate, that is, 1_5 ~P 4_8When a continuous sine wave as shown in FIG. 15B is formed by

[0125] The velocity calculation unit 19 calculates the true velocity Vexp of the object 2 from the above-mentioned true wrap value Nwrap using equation (7) (step S10).

[0126] 14, as shown in steps S3 to S9, the signal processing unit 13 assumes a plurality of wraparound values ​​Nwrap and selects the plurality of wraparound values ​​Nwrap in turn. Furthermore, in step S4, the signal processing unit 13 corrects the phase difference between the corresponding pair of first and second transmitting antennas based on the selected wraparound value Nwrap. In step S10, the signal processing unit 13 detects the true velocity Vexp of the object 2 based on the corrected phase difference.

[0127] In the example of FIG. 14, an example is described in which the peak power value and the like are calculated by FFT processing, but the peak power value and the like may also be calculated by DFT (Discrete Fourier Transform) processing or the like.

[0128] Fig. 19 is a diagram showing a simulation result of an elevation angle FFT for each aliasing value Nwrap according to the first embodiment of the present disclosure. Fig. 19 shows, for example, a simulation result when the aliasing value Nwrap is 0 to 9. Each waveform diagram in Fig. 19 is a waveform diagram showing a power value for each elevation angle, similar to Fig. 18. Fig. 19 also shows a simulation result when chirp signals Tx are transmitted from eight transmitting antennas 4 in the order shown in Fig. 10.

[0129] 19, the power waveforms for the elevation angles are different when the wraparound value Nwrap is between 0 and 7. When the wraparound value Nwrap is 8 or greater, the period wraps around. Therefore, the power waveform when the wraparound value Nwrap is between 8 and 9 is the same as the power waveform when the wraparound value Nwrap is between 0 and 1.

[0130] 19 shows an example in which the peak power is maximum (Peak_Max) when the wrap value Nwrap is 0. Due to the wrap of the period, the maximum peak power is also detected when the wrap value Nwrap is 8.

[0131] Fig. 20 is a waveform diagram showing peak power values ​​for each aliasing value Nwrap according to the first embodiment of the present disclosure. Fig. 20 illustrates peak power values ​​obtained by a simulation similar to that of Fig. 19. The horizontal axis of Fig. 20 represents the aliasing value Nwrap, and the vertical axis represents the peak power value (Max [db]). In the example of Fig. 20, as in Fig. 19, the maximum peak power value is detected every time the aliasing value Nwrap changes by ±8.

[0132] 19 and 20, the true speed Vexp can be calculated when the wraparound value Nwrap is in the range of 0 to 7 (i.e., −4≦Nwrap<+4). That is, by detecting the peak power value using the method of FIG. 14, the speed range 30 in FIG. 9 can be expanded to eight ranges.

[0133] Fig. 21 is a transmission time chart of chirp signals Tx according to a comparative example, which differs from the transmission time chart of Fig. 10 in that first chirp signals Tx1 to Tx4 and second chirp signals Tx5 to Tx8 are transmitted in this order.

[0134] In the case of Figure 21, the transmission intervals of the pair of first chirp signal Tx1 and second chirp signal Tx5, the transmission intervals of the pair of first chirp signal Tx2 and second chirp signal Tx6, the transmission intervals of the pair of first chirp signal Tx3 and second chirp signal Tx7, and the transmission intervals of the pair of first chirp signal Tx4 and second chirp signal Tx8 are all the same 1 / 2Tb.

[0135] As a result, the phase differences φ1_5, φ2_6, φ3_7, and φ4_8 of the reflected chirp signals are the same as shown in equation (14).

[0136] The phase error component φError in equation (14) is 2π*½*Nwrap. Figure 22 is a waveform diagram showing the relationship between the wraparound value Nwrap and the phase error component φError in the case of Figure 21. In the waveform diagram of Figure 22, the phase difference oscillates in a shorter period than in the waveform diagram of Figure 12A. Specifically, in Figure 22, the phase error component φError oscillates between +π and 0 every time Nwrap increases or decreases by two.

[0137] 22, the wraparound value Nwrap can only be determined within the range of −1≦Nwrap<+1. Therefore, the range in which the true velocity Vexp can be detected can only be expanded to two of the velocity ranges 30 in FIG.

[0138] 23 is a diagram showing a simulation result of an elevation angle FFT for each aliasing value Nwrap according to a comparative example. In the comparative example, too, the peak power value can be calculated for each aliasing value Nwrap by the FFT processing shown in FIG.

[0139] In one comparative example, the cycle folds over every time the wrapping value Nwrap increases or decreases by 2, and therefore the maximum peak power is detected every time the wrapping value Nwrap increases or decreases by 2. In the example of Fig. 23, the peak power is maximum when the wrapping value Nwrap is 0, 2, 4, 6, and 8.

[0140] Fig. 24 is a waveform diagram showing peak power values ​​for each wrap value Nwrap according to a comparative example. In the example of Fig. 24, similar to Fig. 23, the maximum peak power value is detected every time the wrap value Nwrap changes by ±2.

[0141] As shown in FIGS. 23 and 24, in the velocity detection method according to the comparative example, even by the FFT processing shown in FIG. 14, the velocity range can only be expanded by two velocity ranges 30.

[0142] In contrast to the comparative example, the speed detection method according to the present disclosure can expand the speed range by an amount corresponding to the burst interval Tb, as shown in equation (13). In the example of Fig. 10, the speed range can be expanded up to eight speed ranges 30. In other words, the speed detection method according to the present disclosure can detect the true speed Vexp over a range several times larger than that of the comparative example.

[0143] In this way, the speed detection device 1 according to the first embodiment of the present disclosure configures 2D-MIMO using first transmitting antennas TX1 to TX4, second transmitting antennas TX5 to TX8 arranged horizontally spaced apart from the first transmitting antennas, and receiving antennas RX1 to RX8.

[0144] Furthermore, the velocity detection device 1 differs the transmission timing of two chirp signals transmitted from the corresponding first transmitting antennas TX1 to TX4 and the corresponding second transmitting antennas TX5 to TX8, thereby differentiating the phase differences of the chirp signals reflected by the object 2, thereby expanding the velocity detection range in which the true velocity Vexp can be detected.

[0145] Specifically, the order of chirp signal transmission is reversed between the first transmitting antennas TX1 to TX4 and the second transmitting antennas TX5 to TX8. This allows the aliasing period of the phase difference of the chirp signal reflected by the object 2 to be several times longer than when the transmission order is the same, and the velocity detection range in which the true velocity Vexp can be detected also becomes several times larger.

[0146] The true velocity Vexp can be calculated by identifying the foldback value Nwrap. The information processing device 10 according to the first embodiment of the present disclosure can increase the number of selectable foldback values ​​Nwrap, select the foldback values ​​Nwrap in turn, and calculate the phase difference between the pair of first and second transmitting antennas using the selected foldback value Nwrap. Based on the calculated phase difference, the velocity phase of the chirp signal is corrected, and a process of acquiring the peak power value obtained by FFT processing or the like is repeated. The true velocity Vexp can be determined by identifying the true foldback value Nwrap using the maximum peak power value.

[0147] As described above, the velocity detection device 1 according to the first embodiment of the present disclosure can accurately detect the velocity of an object over a wide velocity detection range even in 2D-MIMO.

[0148] Second Embodiment In the first embodiment, a method for extending the rate range applicable to TDM-MIMO has been described. In the second embodiment, a method for extending the rate range applicable to BPM-MIMO will be described.

[0149] Fig. 25 is a block diagram showing the configuration of a velocity detection device 1a according to a second embodiment of the present disclosure. The velocity detection device 1a in Fig. 25 transmits a plurality of chirp signals Tx having binary-coded phases to an object 2.

[0150] The speed detection device 1a in Fig. 25 includes multiple transmitting antennas 4 (e.g., first transmitting antennas TX1 to TX4 and second transmitting antennas TX5 to TX8), multiple receiving antennas 5, a chirp generator 11a, and a signal processor 13a. The chirp generator 11a in Fig. 25 performs different processing from the chirp generator 11 in Fig. 1. Similarly, the signal processor 13a in Fig. 25 performs different processing from the signal processor 13 in Fig. 1. Furthermore, the chirp signals Tx transmitted by the multiple transmitting antennas 4 in Fig. 25 are different from the chirp signals Tx transmitted by the multiple transmitting antennas 4 in Fig. 1. Furthermore, the reflected chirp signals rTx received by the multiple receiving antennas 5 in Fig. 25 are different from the reflected chirp signals rTx received by the multiple receiving antennas 5 in Fig. 1.

[0151] 26 is a signal waveform diagram of a plurality of chirp signals Tx (i.e., first chirp signals Tx1 to Tx4 and second chirp signals Tx5 to Tx8) transmitted by the first transmitting antennas TX1 to TX4 and the second transmitting antennas TX5 to TX8. Fig. 26 is an example, and the signal waveforms of the first chirp signals Tx1 to Tx4 and second chirp signals Tx5 to Tx8 are not limited to those shown in Fig. 26.

[0152] The multiple transmitting antennas 4 transmit multiple chirp signals Tx in parallel, each having multiple first phase patterns PP1 with different phases, and then transmit multiple chirp signals Tx in parallel, each having multiple second phase patterns PP2 with different phases.

[0153] As described above, the multiple transmitting antennas 4 multiplex multiple chirp signals Tx using phase division, thereby realizing BPM-MIMO.

[0154] In the example of Figure 26, the first transmitting antennas TX1 to TX4 and the second transmitting antennas TX5 to TX8 transmit first chirp signals Tx1 to Tx4 and second chirp signals Tx5 to Tx8 in parallel, each having four cycles of a plurality of first phase patterns PP1, during the period from time 0 to 4.8*Tc, and then transmit first chirp signals Tx1 to Tx4 and second chirp signals Tx5 to Tx8 in parallel, each having four cycles of a plurality of second phase patterns PP2, during the period from time 4.8*Tc to 11*Tc.

[0155] From time 11*Tc onwards, first chirp signals Tx1 to Tx4 and second chirp signals Tx5 to Tx8 having a plurality of first phase patterns PP1, and first chirp signals Tx1 to Tx4 and second chirp signals Tx5 to Tx8 having a plurality of second phase patterns PP2 are transmitted alternately.

[0156] For example, the first chirp signal Tx1 in Fig. 26 includes a first phase pattern PP1 of "0000" followed by a second phase pattern PP2 of "0000". The first chirp signal Tx2 includes a first phase pattern PP1 of "0π0π" followed by a second phase pattern PP2 of "0π0π".

[0157] The above phase "0" is approximately the same as the reference phase (e.g., the phase of the first chirp signal Tx1 transmitted at time 0), and the phase "π" is a phase shifted by π from the reference phase.

[0158] The first phase patterns PP1 of the first chirp signals Tx1 to Tx4 in Fig. 26 are different from one another, and the second phase pattern PP2 of each of the first chirp signals Tx1 to Tx4 is the same as the first phase pattern PP1.

[0159] On the other hand, the first phase patterns PP1 included in the second chirp signals Tx5 to Tx8 in Fig. 26 are different from each other. Also, the second phase pattern PP2 is different from the first phase pattern PP1 for each of the second chirp signals Tx5 to Tx8.

[0160] As described above, at least some of the phases of the multiple first phase patterns PP1 and the multiple second phase patterns PP2 are different. In the example of Fig. 26, the four first phase patterns PP1 and the four second phase patterns PP2 included in the second chirp signals Tx5 to Tx8 are different. In contrast, the four first phase patterns PP1 and the four second phase patterns PP2 included in the first chirp signals Tx1 to Tx4 are the same.

[0161] A plurality of chirp signals Tx, each including a first phase pattern PP1 and a second phase pattern PP2, are generated by a chirp generator 11a. The chirp generator 11a includes Tx1 chirp generators through Txn chirp units 14 corresponding to the plurality of first transmitting antennas TX1 to TX4 and the plurality of second transmitting antennas TX5 to TX8, and an encoding unit (phase encoding unit) 41. The number of Tx1 chirp generators through Txn chirp units 14 provided is equal to the total number of first transmitting antennas TX1 to TX4 and second transmitting antennas TX5 to TX8. Therefore, if the total number of first transmitting antennas TX1 to TX4 and second transmitting antennas TX5 to TX8 is eight, eight Tx1 chirp generators through Tx8 chirp generators 14 are provided.

[0162] The encoding unit 41 performs encoding processing to generate a plurality of first phase patterns PP1 and a plurality of second phase patterns PP2 included in a plurality of chirp signals Tx. The Tx1 to Txn chirp generation units 14 transmit a plurality of chirp signals Tx having a plurality of first phase patterns PP1, and then transmit a plurality of chirp signals Tx having a plurality of second phase patterns PP2.

[0163] The first transmitting antennas TX1 to TX4 and the second transmitting antennas TX5 to TX8 may transmit a plurality of chirp signals Tx having a plurality of first phase patterns PP1 and a plurality of chirp signals Tx having a plurality of second phase patterns PP2 at uniform time intervals.

[0164] Alternatively, the first transmitting antennas TX1 to TX4 and the second transmitting antennas TX5 to TX8 may transmit the plurality of chirp signals Tx consecutively without any idle time, or alternatively, the first transmitting antennas TX1 to TX4 and the second transmitting antennas TX5 to TX8 may transmit the plurality of chirp signals Tx with an idle time between them each time the phase of any of the plurality of first phase patterns PP1 and the plurality of second phase patterns PP2 is switched.

[0165] Furthermore, the first transmitting antennas TX1 to TX4 and the second transmitting antennas TX5 to TX8 may transmit a plurality of chirp signals Tx at non-uniform time intervals.

[0166] The multiple chirp signals Tx transmitted from the multiple first transmitting antennas TX1 to TX4 and the multiple second transmitting antennas TX5 to TX8 are reflected by an object 2, and the multiple reflected chirp signals rTx from the object 2 are received by the multiple receiving antennas 5.

[0167] 25, the signal processing unit 13a includes a decoding unit (phase decoding unit) 42 in addition to the configuration of the signal processing unit 13a in Fig. 1. The decoding unit 42 performs decoding processing on the reflected chirp signals rTx to extract a plurality of first phase patterns PP1 and a plurality of second phase patterns PP2.

[0168] The decoding unit 42 associates each of the multiple first phase patterns PP1 with one of the first transmitting antennas TX1 to TX4, and associates each of the multiple second phase patterns PP1 with one of the second transmitting antennas TX5 to TX8.

[0169] Specifically, the decoding unit 42 generates a plurality of third phase patterns PP3 for each unit time transmitted in parallel from the first transmitting antennas TX1 to TX4 and the second transmitting antennas TX5 to TX8, based on the plurality of first phase patterns PP1. Similarly, the decoding unit 42 generates a plurality of fourth phase patterns PP4 for each unit time transmitted in parallel from the first transmitting antennas TX1 to TX4 and the second transmitting antennas TX5 to TX8, based on the plurality of second phase patterns PP2. For example, in the example of Fig. 26, the decoding unit 42 alternately generates four third phase patterns PP3 and four fourth phase patterns PP4 extending vertically and aligned horizontally in Fig. 26.

[0170] The decoding unit 42 associates the four third phase patterns PP3 with the four first chirp signals Tx1 to Tx4 transmitted by the four first transmitting antennas TX1 to TX4, and associates the four fourth phase patterns PP4 with the four second chirp signals Tx5 to Tx8 transmitted by the four second transmitting antennas TX5 to TX8. In this case, the decoding unit 42 associates the multiple third phase patterns PP3 with the first chirp signals Tx1 to Tx4 and the multiple fourth phase patterns PP4 with the second chirp signals Tx5 to Tx8 so that the phase order of the multiple first chirp signals Tx1 to Tx4 differs from the phase order of the multiple second chirp signals Tx5 to Tx8.

[0171] 26, the decoding unit 42 associates (decodes) the four third phase patterns PP3 arranged along the time axis with the first chirp signals Tx1, Tx2, Tx3, and Tx4 in that order, and also associates (decodes) the four fourth phase patterns PP4 arranged along the time axis with the second chirp signals Tx8, Tx7, Tx6, and Tx5 in that order.

[0172] That is, in the example of FIG. 26, the decoding orders of the first chirp signals Tx1 to Tx4 and the second chirp signals Tx5 to Tx8 are reversed.

[0173] 26, the third phase pattern PP3 of the first chirp signals Tx1 to Tx4 associated with the decoding unit 42 is the same as the first phase pattern PP1 and second phase pattern PP2 of the first chirp signals Tx1 to Tx4 transmitted by the first transmitting antennas TX1 to TX4, respectively. On the other hand, the fourth phase pattern PP4 of the second chirp signals Tx5 to Tx8 associated with the decoding unit 42 is different from the first phase pattern PP1 and second phase pattern PP2 of the second chirp signals Tx5 to Tx8 transmitted by the second transmitting antennas TX5 to TX8, respectively.

[0174] More specifically, the fourth phase pattern PP4 of the second chirp signals Tx5, Tx6, Tx7, and Tx8 associated with the decoding unit 42 is the same as the first phase pattern PP1 and the second phase pattern PP2 of the transmitted second chirp signals Tx8, Tx7, Tx6, and Tx5, respectively.

[0175] As a result, the phase differences shown in equations (9) to (12) can be realized in the first chirp signals Tx1 to Tx4 and the second chirp signals Tx5 to Tx8 associated with the decoding unit 42, as in the case of FIG. 10 (or FIG. 13).

[0176] 26 is merely an example, and the phase order of the first chirp signals Tx1 to Tx4 and the phase order of the second chirp signals Tx5 to Tx8 may be different from each other.

[0177] As a result, the signal processing unit 13a in Figure 25 can expand the velocity detection range and accurately detect the velocity of an object using a processing procedure similar to that of the signal processing unit 13a in the first embodiment (see Figure 14).

[0178] In this way, in the second embodiment, multiple chirp signals having a first phase pattern PP1 and a second phase pattern PP2 are transmitted by multiple first transmitting antennas TX1 to TX4 and multiple second transmitting antennas TX5 to TX8 through phase division and multiplexing. The multiple chirp signals are then decoded by the receiving side to generate multiple third phase patterns PP3 and multiple fourth phase patterns PP4 transmitted in parallel by the multiple first transmitting antennas TX1 to TX4 and multiple second transmitting antennas TX5 to TX8. By associating the multiple third phase patterns PP3 with multiple first chirp signals and the fourth phase pattern PP4 with multiple second chirp signals, the phase order of the first chirp signals can be made different from the phase order of the second chirp signals. This allows the velocity detection range to be expanded and the velocity of an object to be detected with high accuracy, even in BPM-MIMO, using the same processing procedure as in the first embodiment.

[0179] (Application Examples) The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body, such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, a robot, construction machinery, or agricultural machinery (tractor).

[0180] 27 is a block diagram showing a schematic configuration example of a vehicle control system 7000, which is an example of a mobile object control system to which the technology according to the present disclosure can be applied. The vehicle control system 7000 includes a plurality of electronic control units connected via a communication network 7010. In the example shown in FIG. 27 , the vehicle control system 7000 includes a drive system control unit 7100, a body system control unit 7200, a battery control unit 7300, an outside-vehicle information detection unit 7400, an inside-vehicle information detection unit 7500, and an integrated control unit 7600. The communication network 7010 connecting these multiple control units may be an in-vehicle communication network conforming to any standard, such as a Controller Area Network (CAN), a Local Interconnect Network (LIN), a Local Area Network (LAN), or FlexRay (registered trademark).

[0181] Each control unit includes a microcomputer that performs arithmetic processing according to various programs, a memory unit that stores the programs executed by the microcomputer or parameters used in various calculations, and a drive circuit that drives various controlled devices. Each control unit includes a network I / F for communicating with other control units via a communication network 7010, and a communication I / F for communicating with devices or sensors inside and outside the vehicle via wired or wireless communication. Figure 27 illustrates the functional configuration of the integrated control unit 7600, including a microcomputer 7610, a general-purpose communication I / F 7620, a dedicated communication I / F 7630, a positioning unit 7640, a beacon receiving unit 7650, an in-vehicle device I / F 7660, an audio / video output unit 7670, an in-vehicle network I / F 7680, and a memory unit 7690. The other control units also include a microcomputer, a communication I / F, a memory unit, and the like.

[0182] The drivetrain control unit 7100 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 7100 functions as a control device for a drive force generating device for generating drive force for the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating braking force for the vehicle. The drivetrain control unit 7100 may also function as a control device for an ABS (Antilock Brake System) or an ESC (Electronic Stability Control), etc.

[0183] A vehicle state detection unit 7110 is connected to the drivetrain control unit 7100. The vehicle state detection unit 7110 includes at least one of a gyro sensor that detects the angular velocity of the axial rotational motion of the vehicle body, an acceleration sensor that detects the acceleration of the vehicle, or a sensor that detects the amount of operation of the accelerator pedal, the amount of operation of the brake pedal, the steering angle of the steering wheel, the engine rotation speed, the rotation speed of the wheels, etc. The drivetrain control unit 7100 performs arithmetic processing using signals input from the vehicle state detection unit 7110, and controls the internal combustion engine, the drive motor, the electric power steering device, the brake device, etc.

[0184] The body system control unit 7200 controls the operation of various devices equipped in the vehicle body according to various programs. For example, the body system control unit 7200 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as headlamps, backup lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves transmitted from a portable device that serves as a key or signals from various switches can be input to the body system control unit 7200. The body system control unit 7200 receives these radio waves or signals and controls the vehicle's door lock device, power window device, lamps, etc.

[0185] The battery control unit 7300 controls the secondary battery 7310, which is the power supply source for the drive motor, in accordance with various programs. For example, information such as battery temperature, battery output voltage, or remaining battery capacity is input to the battery control unit 7300 from a battery device equipped with the secondary battery 7310. The battery control unit 7300 performs arithmetic processing using these signals, and controls the temperature regulation of the secondary battery 7310 or a cooling device or the like equipped in the battery device.

[0186] The outside vehicle information detection unit 7400 detects information outside the vehicle equipped with the vehicle control system 7000. For example, at least one of an imaging unit 7410 and an outside vehicle information detection unit 7420 is connected to the outside vehicle information detection unit 7400. The imaging unit 7410 includes at least one of a time-of-flight (ToF) camera, a stereo camera, a monocular camera, an infrared camera, and other cameras. The outside vehicle information detection unit 7420 includes at least one of an environmental sensor for detecting the current weather or climate, or a surrounding information detection sensor for detecting other vehicles, obstacles, pedestrians, etc. around the vehicle equipped with the vehicle control system 7000.

[0187] The environmental sensor may be, for example, at least one of a raindrop sensor that detects rain, a fog sensor that detects fog, a sunshine sensor that detects the degree of sunshine, and a snow sensor that detects snowfall. The surrounding information detection sensor may be at least one of an ultrasonic sensor, a radar device, and a LIDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging) device. The imaging unit 7410 and the outside vehicle information detection unit 7420 may each be provided as an independent sensor or device, or may be provided as a device in which multiple sensors or devices are integrated.

[0188] 28 shows an example of the installation positions of the imaging unit 7410 and the vehicle exterior information detection unit 7420. The imaging units 7910, 7912, 7914, 7916, and 7918 are provided, for example, at least one of the front nose, side mirrors, rear bumper, back door, and upper part of the windshield inside the vehicle cabin of the vehicle 7900. The imaging unit 7910 provided on the front nose and the imaging unit 7918 provided on the upper part of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 7900. The imaging units 7912 and 7914 provided on the side mirrors mainly acquire images of the sides of the vehicle 7900. The imaging unit 7916 provided on the rear bumper or back door mainly acquires images of the rear of the vehicle 7900. The imaging unit 7918 provided on the upper part of the windshield inside the vehicle cabin is mainly used to detect leading vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

[0189] 28 shows an example of the imaging ranges of the imaging units 7910, 7912, 7914, and 7916. Imaging range a indicates the imaging range of the imaging unit 7910 provided on the front nose, imaging ranges b and c indicate the imaging ranges of the imaging units 7912 and 7914 provided on the side mirrors, respectively, and imaging range d indicates the imaging range of the imaging unit 7916 provided on the rear bumper or back door. For example, by overlaying the image data captured by the imaging units 7910, 7912, 7914, and 7916, a bird's-eye view image of the vehicle 7900 viewed from above can be obtained.

[0190] The outside vehicle information detection units 7920, 7922, 7924, 7926, 7928, and 7930 provided on the front, rear, sides, corners, and above the windshield inside the vehicle cabin of the vehicle 7900 may be, for example, ultrasonic sensors or radar devices. The outside vehicle information detection units 7920, 7926, and 7930 provided on the front nose, rear bumper, back door, and above the windshield inside the vehicle cabin of the vehicle 7900 may be, for example, LIDAR devices. These outside vehicle information detection units 7920 to 7930 are mainly used to detect preceding vehicles, pedestrians, obstacles, etc.

[0191] Returning to FIG. 27 , the explanation will be continued. The outside-vehicle information detection unit 7400 causes the imaging unit 7410 to capture an image outside the vehicle and receives the captured image data. The outside-vehicle information detection unit 7400 also receives detection information from the connected outside-vehicle information detection unit 7420. If the outside-vehicle information detection unit 7420 is an ultrasonic sensor, a radar device, or a LIDAR device, the outside-vehicle information detection unit 7400 emits ultrasonic waves or electromagnetic waves and receives information on the received reflected waves. Based on the received information, the outside-vehicle information detection unit 7400 may perform object detection processing or distance detection processing for people, vehicles, obstacles, signs, or text on the road surface. Based on the received information, the outside-vehicle information detection unit 7400 may also perform environment recognition processing for recognizing rainfall, fog, road conditions, etc. Based on the received information, the outside-vehicle information detection unit 7400 may also calculate the distance to an object outside the vehicle.

[0192] The outside vehicle information detection unit 7400 may also perform image recognition processing or distance detection processing to recognize people, vehicles, obstacles, signs, or characters on the road surface based on the received image data. The outside vehicle information detection unit 7400 may perform processing such as distortion correction or alignment on the received image data, and may also generate an overhead image or a panoramic image by combining image data captured by different image capturing units 7410. The outside vehicle information detection unit 7400 may also perform viewpoint conversion processing using image data captured by different image capturing units 7410.

[0193] The interior information detection unit 7500 detects information inside the vehicle. A driver state detection unit 7510 that detects the driver's state is connected to the interior information detection unit 7500, for example. The driver state detection unit 7510 may include a camera that captures an image of the driver, a biosensor that detects the driver's biometric information, or a microphone that collects sound from within the vehicle cabin. The biosensor is provided, for example, on the seat or steering wheel, and detects the biometric information of a passenger sitting in the seat or the driver gripping the steering wheel. The interior information detection unit 7500 may calculate the driver's level of fatigue or concentration based on the detection information input from the driver state detection unit 7510, or may determine whether the driver is dozing off. The interior information detection unit 7500 may perform processing such as noise canceling on the collected audio signal.

[0194] The integrated control unit 7600 controls the overall operation of the vehicle control system 7000 according to various programs. An input unit 7800 is connected to the integrated control unit 7600. The input unit 7800 may be implemented by a device that can be operated by a passenger, such as a touch panel, a button, a microphone, a switch, or a lever. Data obtained by voice recognition of a voice input through a microphone may be input to the integrated control unit 7600. The input unit 7800 may be, for example, a remote control device using infrared or other radio waves, or an externally connected device such as a mobile phone or a personal digital assistant (PDA) that can operate the vehicle control system 7000. The input unit 7800 may be, for example, a camera, in which case the passenger can input information using gestures. Alternatively, data obtained by detecting the movement of a wearable device worn by the passenger may be input. Furthermore, the input unit 7800 may include, for example, an input control circuit that generates an input signal based on information input by the passenger using the input unit 7800 and outputs the input signal to the integrated control unit 7600. Passengers and the like operate this input unit 7800 to input various data to the vehicle control system 7000 and to instruct processing operations.

[0195] The storage unit 7690 may include a ROM (Read Only Memory) that stores various programs executed by the microcomputer, and a RAM (Random Access Memory) that stores various parameters, calculation results, sensor values, etc. The storage unit 7690 may also be realized by a magnetic storage device such as an HDD (Hard Disc Drive), a semiconductor storage device, an optical storage device, a magneto-optical storage device, or the like.

[0196] The general-purpose communication I / F 7620 is a general-purpose communication I / F that mediates communication with various devices present in the external environment 7750. The general-purpose communication I / F 7620 may implement a cellular communication protocol such as GSM (Global System of Mobile communications), WiMAX (registered trademark), LTE (Long Term Evolution), or LTE-Advanced (LTE-A), or other wireless communication protocols such as a wireless LAN (also referred to as Wi-Fi (registered trademark)) or Bluetooth (registered trademark). The general-purpose communication I / F 7620 may connect to a device (e.g., an application server or a control server) present on an external network (e.g., the Internet, a cloud network, or an operator-specific network) via, for example, a base station or an access point. In addition, the general-purpose communication I / F 7620 may connect to a terminal located near the vehicle (e.g., a terminal of a driver, pedestrian, or store, or an MTC (Machine Type Communication) terminal) using, for example, P2P (Peer To Peer) technology.

[0197] The dedicated communication I / F 7630 is a communication I / F that supports a communication protocol designed for use in vehicles. The dedicated communication I / F 7630 may implement a standard protocol such as WAVE (Wireless Access in Vehicle Environment), which is a combination of a lower layer IEEE 802.11p and an upper layer IEEE 1609, DSRC (Dedicated Short Range Communications), or a cellular communication protocol. The dedicated communication I / F 7630 typically performs V2X communication, which is a concept including one or more of vehicle-to-vehicle communication, vehicle-to-infrastructure communication, vehicle-to-home communication, and vehicle-to-pedestrian communication.

[0198] The positioning unit 7640 performs positioning by receiving, for example, GNSS signals from GNSS (Global Navigation Satellite System) satellites (for example, GPS signals from GPS (Global Positioning System) satellites), and generates position information including the latitude, longitude, and altitude of the vehicle. Note that the positioning unit 7640 may identify the current position by exchanging signals with a wireless access point, or may obtain position information from a terminal such as a mobile phone, PHS, or smartphone that has a positioning function.

[0199] The beacon receiving unit 7650 receives, for example, radio waves or electromagnetic waves transmitted from radio stations or the like installed on the road, and acquires information such as the current location, congestion, road closures, required travel time, etc. The function of the beacon receiving unit 7650 may be included in the dedicated communication I / F 7630 described above.

[0200] The in-vehicle device I / F 7660 is a communication interface that mediates connections between the microcomputer 7610 and various in-vehicle devices 7760 present in the vehicle. The in-vehicle device I / F 7660 may establish wireless connections using wireless communication protocols such as wireless LAN, Bluetooth (registered trademark), NFC (Near Field Communication), or WUSB (Wireless USB). Furthermore, the in-vehicle device I / F 7660 may establish a wired connection such as USB (Universal Serial Bus), HDMI (High-Definition Multimedia Interface), or MHL (Mobile High-Definition Link) via a connection terminal (and a cable, if necessary) not shown. The in-vehicle device 7760 may include, for example, at least one of a mobile device or a wearable device owned by a passenger, or an information device carried into or attached to the vehicle. The in-vehicle device 7760 may also include a navigation device that searches for a route to an arbitrary destination. The in-vehicle device I / F 7660 exchanges control signals or data signals with these in-vehicle devices 7760.

[0201] The in-vehicle network I / F 7680 is an interface that mediates communication between the microcomputer 7610 and the communication network 7010. The in-vehicle network I / F 7680 transmits and receives signals in accordance with a predetermined protocol supported by the communication network 7010.

[0202] The microcomputer 7610 of the integrated control unit 7600 controls the vehicle control system 7000 in accordance with various programs based on information acquired via at least one of the general-purpose communication I / F 7620, the dedicated communication I / F 7630, the positioning unit 7640, the beacon receiving unit 7650, the in-vehicle device I / F 7660, and the in-vehicle network I / F 7680. For example, the microcomputer 7610 may calculate control target values ​​for the driving force generating device, the steering mechanism, or the braking device based on the acquired information inside and outside the vehicle, and output control commands to the drivetrain control unit 7100. For example, the microcomputer 7610 may perform cooperative control aimed at realizing functions of an Advanced Driver Assistance System (ADAS), including vehicle collision avoidance or impact mitigation, following driving based on the following distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc. In addition, the microcomputer 7610 may perform cooperative control for the purpose of autonomous driving, in which the vehicle travels autonomously without relying on driver operation, by controlling a driving force generating device, a steering mechanism, a braking device, etc. based on information acquired about the vehicle's surroundings.

[0203] The microcomputer 7610 may generate three-dimensional distance information between the vehicle and objects such as surrounding structures and people, and create local map information including information about the vicinity of the vehicle's current location, based on information acquired via at least one of the general-purpose communication I / F 7620, the dedicated communication I / F 7630, the positioning unit 7640, the beacon receiving unit 7650, the in-vehicle device I / F 7660, and the in-vehicle network I / F 7680. Furthermore, the microcomputer 7610 may predict dangers, such as a vehicle collision, the approach of a pedestrian, or entry into a closed road, based on the acquired information, and generate a warning signal. The warning signal may be, for example, a signal for generating a warning sound or turning on a warning lamp.

[0204] The audio / image output unit 7670 transmits at least one audio and / or image output signal to an output device capable of visually or audibly notifying vehicle occupants or the outside of the vehicle of information. In the example of FIG. 27 , an audio speaker 7710, a display unit 7720, and an instrument panel 7730 are illustrated as output devices. The display unit 7720 may include, for example, at least one of an on-board display and a head-up display. The display unit 7720 may have an AR (Augmented Reality) display function. The output device may also be other devices, such as headphones, a wearable device such as an eyeglass-type display worn by the occupant, a projector, or a lamp. When the output device is a display device, the display device visually displays results obtained by various processes performed by the microcomputer 7610 or information received from other control units in various formats, such as text, images, tables, and graphs. When the output device is an audio output device, the audio output device converts audio signals, such as reproduced audio data or acoustic data, into analog signals and audibly outputs the analog signals.

[0205] In the example shown in FIG. 27 , at least two control units connected via the communication network 7010 may be integrated into a single control unit. Alternatively, each control unit may be composed of multiple control units. Furthermore, the vehicle control system 7000 may include another control unit not shown. In the above description, some or all of the functions performed by one of the control units may be assigned to another control unit. In other words, as long as information is transmitted and received via the communication network 7010, predetermined arithmetic processing may be performed by one of the control units. Similarly, a sensor or device connected to one of the control units may be connected to another control unit, and multiple control units may transmit and receive detection information to and from each other via the communication network 7010.

[0206] A computer program for realizing each function of the information processing device 10 according to this embodiment described with reference to FIG. 1 can be implemented in any control unit or the like. A computer-readable recording medium storing such a computer program can also be provided. Examples of the recording medium include a magnetic disk, an optical disk, a magneto-optical disk, and a flash memory. The computer program may also be distributed, for example, via a network without using a recording medium.

[0207] In the vehicle control system 7000 described above, the speed detection device 1 according to this embodiment described with reference to Fig. 1 can be applied to the outside-vehicle information detection unit 7420 of the application example shown in Fig. 27. The speed detection device 1 can improve the detection accuracy of the relative speed of a pedestrian outside the vehicle, another vehicle, etc.

[0208] Furthermore, at least some of the components of the information processing device 10 described using Fig. 1 may be realized in a module (for example, an integrated circuit module configured on a single die) for the integrated control unit 7600 shown in Fig. 27. Alternatively, the information processing device 10 described using Fig. 1 may be realized by a plurality of control units of the vehicle control system 7000 shown in Fig. 27.

[0209] The present technology can be configured as follows: (1) A system comprising: a plurality of first transmitting antennas arranged in a vertical direction substantially perpendicular to a reference plane, and transmitting a plurality of first chirp signals with a time lag between each of the first transmitting antennas; a plurality of second transmitting antennas arranged along the reference plane at a distance from the plurality of first transmitting antennas, and arranged in the vertical direction, and transmitting a plurality of second chirp signals with a time lag between each of the second transmitting antennas; a plurality of receiving antennas receiving a plurality of third chirp signals from an object that reflects the plurality of first chirp signals and the plurality of second chirp signals; a signal processing unit that detects the velocity of the object based on the plurality of third chirp signals received by the plurality of receiving antennas; and a chirp generating unit that either changes the transmission order of the plurality of first chirp signals generated by the plurality of first transmitting antennas and the transmission order of the plurality of second chirp signals generated by the plurality of second transmitting antennas, or transmits a plurality of chirp signals having a plurality of first phase patterns with different phases from each of the plurality of first transmitting antennas and the plurality of second transmitting antennas in parallel, and then transmits a plurality of chirp signals having a plurality of second phase patterns with different phases from each of the plurality of first phase patterns in parallel, (2) The velocity detection device according to (1), wherein the plurality of first transmitting antennas and the plurality of second transmitting antennas are in one-to-one correspondence, and wherein the phase differences between the first chirp signal and the second chirp signal transmitted by corresponding ones of the plurality of first transmitting antennas and the plurality of second transmitting antennas are different from each other.(3) The velocity detection device according to (2), wherein the chirp generation unit increases the number of velocity aliasing values ​​that the phase difference can have by varying the phase differences between corresponding ones of the plurality of first transmitting antennas and the plurality of second transmitting antennas, thereby widening the velocity extension range. (4) The velocity detection device according to (3), wherein the signal processing unit assumes a plurality of velocity aliasing values, selects the plurality of velocity aliasing values ​​in turn, corrects the phase differences between corresponding ones of the plurality of first transmitting antennas and the plurality of second transmitting antennas based on the selected velocity aliasing value, and detects the velocity of the object based on the corrected phase differences. (5) The velocity detection device according to (4), wherein the signal processing unit corrects the waveform representing the phase difference so that it has a continuous sine wave shape. (6) The velocity detection device according to (4) or (5), wherein the signal processing unit detects a signal reception strength for each of the plurality of velocity aliasing values ​​based on the corrected phase difference, and compares the detected signal reception strengths for each of the plurality of velocity aliasing values ​​to detect the velocity of the object. (7) The velocity detection device according to (6), wherein the signal processing unit detects a peak value of the signal reception strength of the plurality of third chirp signals for each of the plurality of velocity aliasing values, and detects the velocity of the object based on the plurality of peak values ​​corresponding to the plurality of velocity aliasing values. (8) The velocity detection device according to (7), wherein the signal processing unit detects the velocity of the object from the velocity aliasing value when the peak value is maximum. (9) The velocity detection device according to any one of (6) to (8), wherein the signal processing unit calculates the plurality of signal reception strengths by performing FFT (Fast Fourier Transform) or DFT (Discrete Fourier Transform) processing on the plurality of third chirp signals. (10) The velocity detection device according to any one of (1) to (9), wherein the chirp generation unit multiplexes the plurality of first chirp signals in a time division manner and also multiplexes the plurality of second chirp signals in a time division manner. (11) The velocity detection device according to (10), wherein the chirp generation unit reverses the transmission order of the plurality of first chirp signals and the transmission order of the plurality of second chirp signals.(12) The velocity detector according to any one of (1) to (9), wherein the chirp generation unit includes an encoding unit that generates the plurality of chirp signals having the plurality of first phase patterns and the plurality of second phase patterns multiplexed by phase division, and the signal processing unit includes a decoding unit that performs decoding processing to extract the plurality of first phase patterns and the plurality of second phase patterns from the third chirp signal. (13) The velocity detector according to (12), wherein at least a portion of the phases of the plurality of first phase patterns and the plurality of second phase patterns differ. (14) The velocity detector according to any one of (1) to (13), wherein the plurality of first transmitting antennas transmit the plurality of first chirp signals at uniform time intervals, and the plurality of second transmitting antennas transmit the plurality of second chirp signals at uniform time intervals. (15) The velocity detection device according to (14), wherein the plurality of first transmitting antennas transmit each of the plurality of first chirp signals consecutively without any idle time, and the plurality of second transmitting antennas transmit each of the plurality of second chirp signals consecutively without any idle time, or the plurality of first transmitting antennas transmit each of the plurality of first chirp signals with an idle time therebetween, and the plurality of second transmitting antennas transmit each of the plurality of second chirp signals with an idle time therebetween. (16) The velocity detection device according to any one of (1) to (13), wherein the plurality of first transmitting antennas transmit the plurality of first chirp signals at non-uniform time intervals, and the plurality of second transmitting antennas transmit the plurality of second chirp signals at non-uniform time intervals. (17) The velocity detection device described in (16), wherein the plurality of first transmitting antennas transmit the plurality of first chirp signals with or without a predetermined gap between at least some of the plurality of first chirp signals, and the plurality of second transmitting antennas transmit the plurality of second chirp signals with or without a predetermined gap between at least some of the plurality of second chirp signals.(18) The velocity detection device according to any one of (1) to (17), wherein the plurality of first transmitting antennas, the plurality of second transmitting antennas, and the plurality of receiving antennas form a two-dimensional MIMO (Multi Input Multi Output) array. (19) A chirp generation unit that makes a transmission order of a plurality of first chirp signals generated by a plurality of first transmitting antennas arranged in a vertical direction substantially perpendicular to a reference plane different from a transmission order of a plurality of second chirp signals generated by a plurality of second transmitting antennas arranged along the reference plane and spaced apart from the plurality of first transmitting antennas and arranged in the vertical direction, or that causes the plurality of first transmitting antennas and the plurality of second transmitting antennas to transmit in parallel a plurality of chirp signals having a plurality of first phase patterns each having a different phase from the plurality of first phase patterns, and then causes the plurality of first transmitting antennas and the plurality of second transmitting antennas to transmit in parallel a plurality of chirp signals having a plurality of second phase patterns each having a different phase from the plurality of first phase patterns. and a signal processing unit that detects a velocity of an object that reflects the plurality of first chirp signals and the plurality of second chirp signals based on a plurality of third chirp signals transmitted from the object and received by a plurality of receiving antennas, and, if the plurality of third chirp signals include the plurality of first phase patterns and the plurality of second phase patterns, generates a plurality of third phase patterns and a plurality of fourth phase patterns, each having different phases, transmitted in parallel by the plurality of first transmitting antennas and the plurality of second transmitting antennas, based on the plurality of first phase patterns and the plurality of second phase patterns, and associates the plurality of third phase patterns with the plurality of first chirp signals and the plurality of fourth phase patterns with the plurality of second chirp signals so that a phase order of the plurality of first chirp signals and a phase order of the plurality of second chirp signals are different.(20) The transmission order of a plurality of first chirp signals generated by a plurality of first transmitting antennas arranged in a vertical direction substantially perpendicular to a reference plane is made different from the transmission order of a plurality of second chirp signals generated by a plurality of second transmitting antennas arranged along the reference plane at a distance from the plurality of first transmitting antennas and arranged in the vertical direction, or the plurality of first transmitting antennas and the plurality of second transmitting antennas are made to transmit a plurality of chirp signals having a plurality of first phase patterns each having a different phase from the plurality of first phase patterns in parallel, and then the plurality of chirp signals having a plurality of second phase patterns each having a different phase from the plurality of first phase patterns in parallel are made to transmit a plurality of chirp signals having a plurality of second phase patterns each having a different phase from the plurality of first phase patterns in parallel, a velocity detection method comprising: detecting a velocity of an object based on a plurality of third chirp signals transmitted from the object that reflects the plurality of first chirp signals and the plurality of second chirp signals and received by a plurality of receiving antennas; and, if the plurality of third chirp signals include the plurality of first phase patterns and the plurality of second phase patterns, generating a plurality of third phase patterns and a plurality of fourth phase patterns, each having different phases, transmitted in parallel by the plurality of first transmitting antennas and the plurality of second transmitting antennas, based on the plurality of first phase patterns and the plurality of second phase patterns; and associating the plurality of third phase patterns with the plurality of first chirp signals and the plurality of fourth phase patterns with the plurality of second chirp signals such that a phase order of the plurality of first chirp signals and a phase order of the plurality of second chirp signals are different.(21) A velocity detection device comprising: a plurality of first transmitting antennas arranged in a vertical direction substantially perpendicular to a reference plane and transmitting a plurality of first chirp signals with a time lag between each other; a plurality of second transmitting antennas arranged along the reference plane at a distance from the plurality of first transmitting antennas and arranged in the vertical direction and transmitting a plurality of second chirp signals with a time lag between each other; a plurality of receiving antennas receiving a plurality of third chirp signals from an object that reflects the plurality of first chirp signals and the plurality of second chirp signals; a signal processing unit that detects the velocity of the object based on the plurality of third chirp signals received by the plurality of receiving antennas; and a chirp generating unit that changes the transmission order of the plurality of first chirp signals generated by the plurality of first transmitting antennas from the transmission order of the plurality of second chirp signals generated by the plurality of second transmitting antennas. (22) The velocity detection device according to (21), wherein the chirp generating unit multiplexes the plurality of first chirp signals in a time division manner and also multiplexes the plurality of second chirp signals in a time division manner. (23) The velocity detection device according to (22), wherein the chirp generation unit reverses the transmission order of the plurality of first chirp signals and the transmission order of the plurality of second chirp signals. (24) The velocity detection device according to any one of (21) to (23), wherein the plurality of first transmitting antennas, the plurality of second transmitting antennas, and the plurality of receiving antennas constitute a TDM-MIMO. (25) An information processing device comprising: a chirp generation unit that changes the transmission order of a plurality of first chirp signals generated by a plurality of first transmitting antennas arranged in a vertical direction substantially perpendicular to a reference plane, from the transmission order of a plurality of second chirp signals generated by a plurality of second transmitting antennas that are arranged along the reference plane and spaced apart from the plurality of first transmitting antennas and are arranged in the vertical direction, and a signal processing unit that detects the velocity of an object that reflects the plurality of first chirp signals and the plurality of second chirp signals based on a plurality of third chirp signals transmitted from the object and received by a plurality of receiving antennas.(26) A velocity detection method comprising: changing the transmission order of a plurality of first chirp signals generated by a plurality of first transmitting antennas arranged in a vertical direction substantially perpendicular to a reference plane from the transmission order of a plurality of second chirp signals generated by a plurality of second transmitting antennas arranged along the reference plane at a distance from the plurality of first transmitting antennas and arranged in the vertical direction; and detecting the velocity of an object based on a plurality of third chirp signals transmitted from the object that reflects the plurality of first chirp signals and the plurality of second chirp signals and received by a plurality of receiving antennas. (27) A plurality of first transmitting antennas arranged in a vertical direction substantially perpendicular to a reference plane, each transmitting a plurality of first chirp signals with a time lag; a plurality of second transmitting antennas arranged along the reference plane at a distance from the plurality of first transmitting antennas and arranged in the vertical direction, each transmitting a plurality of second chirp signals with a time lag; a plurality of receiving antennas receiving a plurality of third chirp signals from an object that reflects the plurality of first chirp signals and the plurality of second chirp signals; and a chirp generating unit that causes the plurality of first transmitting antennas and the plurality of second transmitting antennas to transmit in parallel a plurality of chirp signals having a plurality of first phase patterns each having a different phase from the plurality of first phase patterns, and then causes the plurality of first transmitting antennas and the plurality of second transmitting antennas to transmit in parallel a plurality of chirp signals having a plurality of second phase patterns each having a different phase from the plurality of first phase patterns. a signal processing unit that generates, based on the plurality of first phase patterns and the plurality of second phase patterns, a plurality of third phase patterns and a plurality of fourth phase patterns, each having different phases, which are transmitted in parallel from the plurality of first transmitting antennas and the plurality of second transmitting antennas, associates the plurality of third phase patterns with the plurality of first chirp signals and associates the plurality of fourth phase patterns with the plurality of second chirp signals so that the phase sequences of the plurality of first chirp signals and the plurality of second chirp signals are different, and detects the velocity of the object based on the plurality of third chirp signals received by the plurality of receiving antennas.(28) The velocity detection device according to (27), wherein the chirp generation unit has an encoding unit that generates the plurality of chirp signals having the plurality of first phase patterns and the plurality of second phase patterns multiplexed by phase division, and the signal processing unit has a decoding unit that performs decoding processing to extract the plurality of first phase patterns and the plurality of second phase patterns from the third chirp signal. (29) The velocity detection device according to (28), wherein the decoding unit reverses the decoding order of the plurality of first chirp signals and the plurality of second chirp signals. (30) The velocity detection device according to any one of (27) to (29), wherein the plurality of first transmitting antennas, the plurality of second transmitting antennas, and the plurality of receiving antennas constitute a BPM-MIMO. (31) A chirp generating unit that transmits, in parallel, a plurality of chirp signals having a plurality of first phase patterns each having a different phase from a plurality of first transmitting antennas arranged in a vertical direction substantially perpendicular to a reference plane, and a plurality of second transmitting antennas that are arranged along the reference plane and spaced apart from the plurality of first transmitting antennas and arranged in the vertical direction, and then transmits, in parallel, a plurality of chirp signals having a plurality of second phase patterns each having a different phase from the plurality of first phase patterns; and a signal processing unit that detects a velocity of an object based on a plurality of third chirp signals transmitted from the object that reflects the plurality of first chirp signals and the plurality of second chirp signals and received by a plurality of receiving antennas, and generates a plurality of third phase patterns and a plurality of fourth phase patterns, each having different phases, transmitted in parallel by the plurality of first transmitting antennas and the plurality of second transmitting antennas, based on the plurality of first phase patterns and the plurality of second phase patterns, and associates the plurality of third phase patterns with the plurality of first chirp signals and the plurality of fourth phase patterns with the plurality of second chirp signals such that a phase order of the plurality of first chirp signals and a phase order of the plurality of second chirp signals are different.(32) A method for transmitting a plurality of chirp signals in parallel from a plurality of first transmitting antennas arranged in a vertical direction substantially perpendicular to a reference plane and a plurality of second transmitting antennas arranged along the reference plane at a distance from the plurality of first transmitting antennas and arranged in the vertical direction, the plurality of chirp signals having a plurality of first phase patterns each different in phase from the plurality of first phase patterns, and then transmitting a plurality of chirp signals in parallel from the plurality of second phase patterns each different in phase from the plurality of first phase patterns; detecting a velocity of an object based on a plurality of third chirp signals transmitted from the object reflecting the plurality of first chirp signals and the plurality of second chirp signals and received by a plurality of receiving antennas; generating a plurality of third phase patterns and a plurality of fourth phase patterns each different in phase from the plurality of first transmitting antennas and the plurality of second transmitting antennas based on the plurality of first phase patterns and the plurality of second phase patterns; associating the plurality of third phase patterns with the plurality of first chirp signals and the plurality of fourth phase patterns with the plurality of second chirp signals such that the phase order of the plurality of first chirp signals and the phase order of the plurality of second chirp signals are different; Speed ​​detection method.

[0210] The aspects of the present disclosure are not limited to the individual embodiments described above, but include various modifications that may be conceived by those skilled in the art, and the effects of the present disclosure are not limited to the above-described contents. In other words, various additions, modifications, and partial deletions are possible within the scope of the conceptual idea and spirit of the present disclosure, which is derived from the contents defined in the claims and their equivalents.

[0211] REFERENCE SIGNS LIST 1, 1a Velocity detection device, 2 Object, 3 Antenna unit, 4 Transmitting antenna, 4a First transmitting antenna, 4b Second transmitting antenna, 5 Receiving antenna, 10 Information processing device, 11, 11a Chirp generation unit, 12 Beat signal generation unit, 13, 13a Signal processing unit, 14 Chirp generation unit, 15 Beat signal acquisition unit, 16 MIMO formation unit, 17 MIMO phase correction processing unit, 18 Alias ​​determination unit, 19 Velocity calculation unit, 20 Signal group, 30 Velocity range, 41 Encoding unit, 42 Decoding unit

Claims

1. A system comprising: a plurality of first transmitting antennas arranged in a vertical direction substantially perpendicular to a reference plane, each transmitting a plurality of first chirp signals with a time lag; a plurality of second transmitting antennas arranged along the reference plane at a distance from the plurality of first transmitting antennas and arranged in the vertical direction, each transmitting a plurality of second chirp signals with a time lag; a plurality of receiving antennas receiving a plurality of third chirp signals from an object that reflects the plurality of first chirp signals and the plurality of second chirp signals; a signal processing unit that detects the velocity of the object based on the plurality of third chirp signals received by the plurality of receiving antennas; and a chirp generating unit that either changes the transmission order of the plurality of first chirp signals generated by the plurality of first transmitting antennas and the transmission order of the plurality of second chirp signals generated by the plurality of second transmitting antennas, or transmits a plurality of chirp signals having a plurality of first phase patterns, each having a different phase from the plurality of first transmitting antennas and the plurality of second transmitting antennas, in parallel, and then transmits a plurality of chirp signals having a plurality of second phase patterns, each having a different phase from the plurality of first phase patterns, in parallel, When the third chirp signal includes the plurality of first phase patterns and the plurality of second phase patterns, the signal processing unit generates a plurality of third phase patterns and a plurality of fourth phase patterns, each having a different phase, which are transmitted in parallel from the plurality of first transmitting antennas and the plurality of second transmitting antennas, based on the plurality of first phase patterns and the plurality of second phase patterns, and associates the plurality of third phase patterns with the plurality of first chirp signals and the plurality of fourth phase patterns with the plurality of second chirp signals so that the phase order of the plurality of first chirp signals and the phase order of the plurality of second chirp signals are different.

2. The velocity detection device according to claim 1, wherein the plurality of first transmitting antennas and the plurality of second transmitting antennas are in one-to-one correspondence, and the phase differences between the first chirp signals and the second chirp signals transmitted by corresponding ones of the plurality of first transmitting antennas and the plurality of second transmitting antennas are different from each other.

3. The velocity detection device according to claim 2, wherein the chirp generation unit increases the number of velocity folding values ​​that the phase difference can have by varying the phase differences between corresponding ones of the plurality of first transmitting antennas and the plurality of second transmitting antennas, thereby widening the velocity extension range.

4. The velocity detection device according to claim 3, wherein the signal processing unit assumes a plurality of velocity wraparound values, selects one of the plurality of velocity wraparound values ​​in turn, corrects the phase difference between corresponding ones of the plurality of first transmitting antennas and the plurality of second transmitting antennas based on the selected velocity wraparound value, and detects the velocity of the object based on the corrected phase difference.

5. The velocity detection device according to claim 4, wherein the signal processing unit corrects the waveform representing the phase difference so that it has a continuous sine wave shape.

6. The velocity detection device according to claim 4, wherein the signal processing unit detects the signal reception strength for each of the plurality of velocity aliasing values ​​based on the corrected phase difference, and compares the detected signal reception strength for each of the plurality of velocity aliasing values ​​to detect the velocity of the object.

7. The velocity detection device according to claim 6, wherein the signal processing unit detects peak values ​​of the signal reception strength of the third chirp signals for each of the plurality of velocity aliasing values, and detects the velocity of the object based on the plurality of peak values ​​corresponding to the plurality of velocity aliasing values.

8. The velocity detection device according to claim 7, wherein the signal processing unit detects the velocity of the object from the velocity wraparound value when the peak value is maximum.

9. The speed detection device according to claim 6, wherein the signal processing unit calculates the signal reception strengths by performing FFT (Fast Fourier Transform) or DFT (Discrete Fourier Transform) processing on the third chirp signals.

10. The velocity detection device according to claim 1, wherein the chirp generation unit multiplexes the plurality of first chirp signals in a time-division manner and multiplexes the plurality of second chirp signals in a time-division manner.

11. The velocity detection device according to claim 10, wherein the chirp generation unit reverses the transmission order of the plurality of first chirp signals and the transmission order of the plurality of second chirp signals.

12. A velocity detection device according to claim 1, wherein the chirp generation unit has an encoding unit that generates the plurality of chirp signals having the plurality of first phase patterns and the plurality of second phase patterns multiplexed by phase division, and the signal processing unit has a decoding unit that performs decoding processing to extract the plurality of first phase patterns and the plurality of second phase patterns from the third chirp signal.

13. The velocity detection device according to claim 12, wherein at least a portion of the phases of the plurality of first phase patterns and the plurality of second phase patterns differ from each other.

14. The velocity detection device according to claim 1, wherein the plurality of first transmitting antennas transmit the plurality of first chirp signals at uniform time intervals, and the plurality of second transmitting antennas transmit the plurality of second chirp signals at uniform time intervals.

15. A velocity detection device according to claim 14, wherein the plurality of first transmitting antennas transmit each of the plurality of first chirp signals consecutively without any gaps, and the plurality of second transmitting antennas transmit each of the plurality of second chirp signals consecutively without any gaps, or the plurality of first transmitting antennas transmit each of the plurality of first chirp signals with gaps between them, and the plurality of second transmitting antennas transmit each of the plurality of second chirp signals with gaps between them.

16. The velocity detection device according to claim 1, wherein the plurality of first transmitting antennas transmit the plurality of first chirp signals at non-uniform time intervals, and the plurality of second transmitting antennas transmit the plurality of second chirp signals at non-uniform time intervals.

17. A velocity detection device according to claim 16, wherein the plurality of first transmitting antennas transmit at least some of the plurality of first chirp signals with or without a predetermined gap between them, and the plurality of second transmitting antennas transmit at least some of the plurality of second chirp signals with or without a predetermined gap between them.

18. The velocity detection device according to claim 1, wherein the plurality of first transmitting antennas, the plurality of second transmitting antennas, and the plurality of receiving antennas form a two-dimensional MIMO (Multi-Input Multi-Output) array.

19. A chirp generation unit that either differentiates the transmission order of a plurality of first chirp signals generated by a plurality of first transmitting antennas arranged in a vertical direction substantially perpendicular to a reference plane from the transmission order of a plurality of second chirp signals generated by a plurality of second transmitting antennas arranged along the reference plane at a distance from the plurality of first transmitting antennas and arranged in the vertical direction, or transmits a plurality of chirp signals having a plurality of first phase patterns, each of which has a different phase, from the plurality of first transmitting antennas and the plurality of second transmitting antennas in parallel, and then transmits a plurality of chirp signals having a plurality of second phase patterns, each of which has a different phase from the plurality of first phase patterns in parallel; and a signal processing unit that detects a velocity of an object that reflects the plurality of first chirp signals and the plurality of second chirp signals based on a plurality of third chirp signals transmitted from the object and received by a plurality of receiving antennas, and, if the plurality of third chirp signals include the plurality of first phase patterns and the plurality of second phase patterns, generates a plurality of third phase patterns and a plurality of fourth phase patterns, each having different phases, transmitted in parallel by the plurality of first transmitting antennas and the plurality of second transmitting antennas, based on the plurality of first phase patterns and the plurality of second phase patterns, and associates the plurality of third phase patterns with the plurality of first chirp signals and the plurality of fourth phase patterns with the plurality of second chirp signals so that a phase order of the plurality of first chirp signals and a phase order of the plurality of second chirp signals are different.

20. The transmission order of a plurality of first chirp signals generated by a plurality of first transmitting antennas arranged in a vertical direction substantially perpendicular to a reference plane is made different from the transmission order of a plurality of second chirp signals generated by a plurality of second transmitting antennas arranged along the reference plane at a distance from the plurality of first transmitting antennas and arranged in the vertical direction, or a plurality of first chirp signals having a plurality of first phase patterns each having a different phase from the plurality of first phase patterns are transmitted in parallel from the plurality of first transmitting antennas and the plurality of second transmitting antennas, and then a plurality of second chirp signals having a plurality of second phase patterns each having a different phase from the plurality of first phase patterns are transmitted in parallel; a velocity detection method comprising: detecting a velocity of an object based on a plurality of third chirp signals transmitted from the object that reflects the plurality of first chirp signals and the plurality of second chirp signals and received by a plurality of receiving antennas; and, if the plurality of third chirp signals include the plurality of first phase patterns and the plurality of second phase patterns, generating a plurality of third phase patterns and a plurality of fourth phase patterns, each having different phases, transmitted in parallel by the plurality of first transmitting antennas and the plurality of second transmitting antennas, based on the plurality of first phase patterns and the plurality of second phase patterns; and associating the plurality of third phase patterns with the plurality of first chirp signals and the plurality of fourth phase patterns with the plurality of second chirp signals such that a phase order of the plurality of first chirp signals and a phase order of the plurality of second chirp signals are different.

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