Rader device and transmission / reception method of radar device

Abstract

To provide a radar device with which a target is detected efficiently.SOLUTION: The radar device comprises: a first radar circuit having a plurality of first transmit antennas and a plurality of first receive antennas; and a second radar circuit having a plurality of second transmit antennas and a plurality of second receive antennas. The plurality of first transmit antennas transmit a first transmit signal having a prescribed center frequency. The plurality of second transmit antennas transmit a second transmit signal having a prescribed center frequency. The plurality of first receive antennas receive at least one of a first reflected wave signal corresponding to the first transmit signal and a second reflected wave signal corresponding to the second transmit signal, and the plurality of second receive antennas receive at least one of the first reflected wave signal and the second reflected wave signal. The minimum interval of the plurality of first transmit antennas in a first direction and the minimum interval of the plurality of second transmit antennas in the first direction are 0.5 wavelengths and over to less than 1 wavelength of the first and second transmit signals.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a radar device and a transmission and reception method for the radar device. [Background technology]

[0002] In recent years, radar devices using short-wavelength radar transmission signals (hereinafter also referred to as TxSig) including microwaves or millimeter waves that can provide high resolution have been studied. For example, a radar device has been proposed that includes multiple antennas (array antennas) in the transmitter as well as the receiver, and performs beam scanning by signal processing using the transmitting and receiving array antennas (sometimes referred to as MIMO (Multiple Input Multiple Output) radar) (see, for example, Non-Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Publication No. 2020 / 0300965 [Patent Document 2] US Patent Publication No. 2022 / 0244370 [Patent Document 3] JP 2020-148754 A [Patent Document 4] JP 2020-204603 A [Non-patent literature]

[0004] [Non-Patent Document 1] J. Li, and P. Stoica, "MIMO Radar with Colocated Antennas", Signal Processing Magazine, IEEE Vol. 24, Issue: 5, pp. 106-114, 2007 [Non-Patent Document 2] E. Fishler, A. Haimovich, R. Blum, D. Chizhik, L. Cimini, and R. Valenzuela, "MIMO radar: an idea whose time has come," Proceedings of the 2004 IEEE Radar Conference, 2004, pp. 1-11. 71-7

Outdoor Tools3

Outdoor Tools 4

Direct Environment 5

Outdoor Configuration 6

[0005] However, a method for detecting a target in a radar device (eg, a MIMO radar) has not been fully considered.

[0006] Non-limiting embodiments of the present disclosure contribute to providing a radar device and a transmission / reception method for the radar device that can efficiently detect targets. [Means for solving the problem]

[0007] A radar device according to an embodiment of the present disclosure includes a first radar circuit having a plurality of first transmitting antennas and a plurality of first receiving antennas, and a second radar circuit having a plurality of second transmitting antennas and a plurality of second receiving antennas, wherein the plurality of first transmitting antennas transmit first transmission signals having a predetermined center frequency, the plurality of second transmitting antennas transmit second transmission signals having the predetermined center frequency, the plurality of first receiving antennas receive at least one of a first reflected wave signal corresponding to the first transmission signal and a second reflected wave signal corresponding to the second transmission signal, and the plurality of second receiving antennas receive at least one of the first reflected wave signal and the second reflected wave signal, and a minimum interval of the plurality of first transmitting antennas in a first direction and a minimum interval of the plurality of second receiving antennas in the first direction are greater than or equal to 0.5 wavelengths and less than 1 wavelength of the first and second transmission signals.

[0008] In addition, these comprehensive or specific embodiments may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium. Effect of the Invention

[0009] According to an embodiment of the present disclosure, a radar device can efficiently detect a target.

[0010] Further advantages and benefits of an embodiment of the present disclosure will become apparent from the specification and drawings. Such advantages and / or benefits may be provided by some of the embodiments and features described in the specification and drawings, respectively, but not necessarily all of them may be provided to obtain one or more identical features. [Brief description of the drawings]

[0011] [Figure 1] A diagram showing an example of a radar device with a mono-static and multi-static configuration. [Diagram 2] FIG. 1 is a diagram showing an example of positioning using a radar device with a multistatic configuration. [Diagram 3] A block diagram showing a configuration example of a radar device. [Figure 4] A block diagram showing a configuration example of a radar device. [Diagram 5] FIG. 1 shows an example of a transmission signal. [Figure 6] A diagram showing an example of a chirp signal. [Figure 7] Diagram showing an example of MIMO antenna arrangement [Figure 8] A diagram showing an example of the placement of virtual receiving antennas [Figure 9] Diagram showing an example of MIMO antenna arrangement [Figure 10] A diagram showing an example of the placement of virtual receiving antennas [Figure 11] Diagram showing an example of MIMO antenna arrangement [Figure 12] A diagram showing an example of the placement of virtual receiving antennas [Figure 13] Diagram showing an example of MIMO antenna arrangement [Figure 14] A diagram showing an example of the placement of virtual receiving antennas [Figure 15] Diagram showing an example of MIMO antenna arrangement [Figure 16] Diagram showing an example of MIMO antenna arrangement [Figure 17] Diagram showing an example of MIMO antenna arrangement [Figure 18]Diagram showing an example of MIMO antenna arrangement [Figure 19] Diagram showing an example of MIMO antenna arrangement [Figure 20] Diagram showing an example of MIMO antenna arrangement [Figure 21] Diagram showing an example of MIMO antenna arrangement DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] MIMO radars are broadly classified into, for example, a "monostatic configuration" and a bistatic or multistatic configuration (hereinafter referred to as a "bi- / multistatic configuration"). Hereinafter, the monostatic configuration will be referred to as an "MNS configuration" and the bi- / multistatic configuration will be referred to as a "BMS configuration."

[0013] In the MNS configuration, for example, a transmitter (eg, including a plurality of transmitting antennas and a high-frequency radio unit) and a receiver (eg, including a plurality of receiving antennas and a high-frequency radio unit) may be included in the same housing.

[0014] Also, in the BMS configuration, for example, the transmitter and the receiver may be included in different housings. For example, in the BMS configuration, each housing is installed at a distance away, and the transmitter and the receiver are connected to a control unit that performs synchronous control. In the bistatic configuration, for example, the transmitter and the receiver are paired, and the transmitter and the receiver are configured at a distance away from each other. In the multistatic configuration, for example, there are multiple transmitters and / or multiple receivers. The multistatic configuration is disclosed in, for example, Non-Patent Document 2.

[0015] Hereinafter, in a non-limiting embodiment of the present disclosure, attention will be given to the BMS configuration. For example, in a non-limiting embodiment of the present disclosure, a BMS configuration using a MIMO radar with a plurality of MNS configurations will be described. The BMS configuration using a MIMO radar with a plurality of MNS configurations may be called, for example, a "mono- and multi-static configuration."

[0016] FIG. 1 shows an example of a radar device with a mono- and multistatic configuration in which radar #1 and radar #2, which are MIMO radars with an MNS configuration, are used.

[0017] Radar #1 is, for example, a “first MNS-configured MIMO radar” that outputs radar transmission waves (also called TxSig) from a radar transmitting antenna group Tx #1 and receives reflected wave signals from a target #1 by a radar receiving antenna group Rx #1 in the same housing (e.g., path (1)).

[0018] Similarly, radar #2 is, for example, a “second MNS-configured MIMO radar” that outputs radar transmission waves from a radar transmitting antenna group Tx #2 and receives reflected wave signals from a target #3 by a radar receiving antenna group Rx #2 in the same housing (e.g., path (2)).

[0019] 1 may transmit radar transmission waves from a group of transmitting antennas Tx#1 of radar #1 and receive reflected wave signals from a target #2 at a group of receiving antennas Rx#2 of radar #2. A radar device that performs this operation may be regarded as, for example, a "MIMO radar with a first BMS configuration" (e.g., path (3)).

[0020] Similarly, the radar #2 may transmit radar transmission waves from the transmitting antenna group Tx#2 and receive reflected wave signals from the target #2 at the receiving antenna group Rx#1 of the radar #1. A radar device that performs this operation may be regarded as, for example, a "MIMO radar with a second BMS configuration" (e.g., path (4)).

[0021] To use the radar as a BMS radar in addition to the MNS radar, for example, a synchronization unit may be used that performs synchronization control between a plurality of MNS radars installed at distant locations. For example, in FIG. 1, when a frequency modulated FMCW (Frequency modulated continuous wave) signal (e.g., a "chirp signal") is used as a radar transmission wave, the synchronization unit may generate a chirp signal and supply the chirp signal to radar #1 and radar #2 in common. This allows the radar to be used as a first MNS MIMO radar and a second MNS MIMO radar, and also allows the radar to be used as a first BMS MIMO radar and a second BMS MIMO radar.

[0022] The radar device shown in FIG. 1 may generate TxSig in the synchronization section and supply TxSig in common to radar #1 and radar #2.

[0023] For example, if the first and second MNS radars operate simultaneously using the same radar transmission waves, mutual interference may occur, making false detection or non-detection more likely to occur, and the positioning accuracy or detection performance of the radar may deteriorate. Therefore, for example, multiplexing transmission using time division multiplexing (TDM) or code division multiplexing (CDM) may be applied to the transmission of radars in a BMS configuration using the first and second MNS radars.

[0024] The radar device according to an embodiment of the present disclosure may be mounted on a moving body such as a vehicle. For example, the radar device may be mounted near a corner of at least one of the front and rear of the vehicle, or near the center of at least one of the front and rear of the vehicle or from the center to the corner.

[0025] The positioning output (information regarding the estimation results) of the radar device mounted on the moving body may be output to a control ECU (Electronic Control Unit) (not shown), such as an Advanced Driver Assistance System (ADAS) that improves collision safety or an autonomous driving system, and may be used for vehicle drive control or alarm call control.

[0026] Moreover, the radar device according to an embodiment of the present disclosure may be attached to a relatively high structure (not shown), such as a roadside utility pole or a traffic light. Such a radar device may be used, for example, as a sensor in a support system for improving the safety of passing vehicles or pedestrians, or in a system for preventing intrusion of suspicious persons. Furthermore, the positioning output of the radar device may be output to a control device (not shown) in the support system for improving safety or the system for preventing intrusion of suspicious persons, and may be used for alarm generation control or abnormality detection control.

[0027] The uses of the radar device are not limited to these, and the device may be used for other purposes.

[0028] Moreover, a target is an object to be detected by a radar device, and includes, for example, vehicles (including four-wheeled and two-wheeled vehicles), people, blocks, curbs, and the like.

[0029] Hereinafter, an embodiment according to an example of the present disclosure will be described in detail with reference to the drawings. In the embodiment, the same components are denoted by the same reference numerals, and the description thereof will be omitted to avoid duplication.

[0030] For example, an MNS-configured MIMO radar performs angle measurement processing on the assumption that far-field approximation holds. In this case, the emission direction (or transmission direction, Direction of Departure (DOD)) of the target reflected wave coincides with the arrival direction (or reception direction, Direction of Arrival (DOA)) of the target reflected wave, making it possible to apply an angle measurement method (or positioning method, azimuth estimation method) using a virtual receiving antenna (see, for example, Non-Patent Document 1).

[0031] In the angle measurement process of a BMS-configured MIMO radar, for example, for targets that exist at a distance where far-field approximation holds (hereinafter referred to as "distant targets"), the DOD and DOA are nearly identical, just like in an MNS-configured MIMO radar, and an angle measurement method using a virtual receiving antenna can be applied.

[0032] On the other hand, in the angle measurement process in a BMS-configured MIMO radar, for targets (hereinafter referred to as "nearby targets") that exist closer than the distance where the far-field approximation is valid, the DOD and DOA do not match, so the angle measurement error is likely to be large when an angle measurement method using a virtual receiving antenna is applied. In the angle measurement process for nearby targets in a BMS-configured MIMO radar, it is desirable to, for example, estimate the DOD and DOA individually (or jointly), or to find the target position from at least one of the DOD or DOA and the target distance.

[0033] For example, the distance at which the far-field approximation holds is the distance between the MIMO radars in the BMS configuration (hereinafter, "D BMS For example, the distance dF at which the far-field approximation holds is dF=2D BMS 2 For example, when the center frequency of the chirp signal is 77 GHz, D BMS are 0.1m, 0.25m, and 0.5m, respectively, then dF is approximately 5.1m, 32m, and 128m.

[0034] For example, the distance D between the MIMO radars in the BMS configurationBMS Depending on the relationship between the radar detection distance and the radar detection range, there may be cases where a nearby target is present within the radar detection range, or cases where both nearby and distant targets are included.

[0035] Therefore, for a mono- and multi-static MIMO radar in which nearby targets are included in the radar detection range, a MIMO antenna arrangement is expected that takes into account both the angle measurement for nearby targets in the BMS configuration and the angle measurement in the MNS configuration. Also, for example, when a distant target is included in the radar detection range in the BMS configuration, a MIMO antenna arrangement is expected that takes into account the angle measurement for distant targets in the BMS configuration.

[0036] Possible MIMO antenna arrangements include the following examples:

[0037] (Layout example 1) For example, the spacing between transmitting antennas (or receiving antennas) of radar #1 constituting the BMS is half the wavelength of the transmitted signal, and the spacing between receiving antennas (or transmitting antennas) of radar #2 is at least one wavelength of the transmitted signal (see, for example, Patent Document 1).

[0038] (Layout example 2) For example, the spacing between transmitting antennas (or the spacing between receiving antennas) of radar #1 constituting the BMS is at least one wavelength of the transmitted signal, and the spacing between receiving antennas (or the spacing between transmitting antennas) of radar #2 is at least one wavelength of the transmitted signal, and the spacings are arranged so that they are mutually prime (see, for example, Patent Document 2).

[0039] In the BMS configuration, for example, when a transmission wave is directly irradiated to a target P from radar #1 and the reflected wave is directly received by radar #2 as shown in Fig. 2 (hereinafter, such a reflected wave from the target P received by radar #2 is called a "target direct wave"), the target P exists on an ellipse that satisfies the target distance (for example, on an ellipse with radars #1 and #2 as its focus). In this case, the radar can determine the target position (x, y) by determining the intersection point P with the ellipse determined by the direction specified by the DOD and DOA by specifying at least one of the DOD and DOA.

[0040] Note that the "ellipse satisfying the target distance" is, for example, an elliptical curve defined by a trajectory in which the sum of the distances between the target and each of the two foci and the two radars #1 and #2 is constant, with each of the two radars having two foci. In addition, when a transmission wave is directly irradiated from radar #1 to the target P and radar #2 directly receives the reflected wave, the distance to the target P measured by radar #2 can be used as the target distance.

[0041] The above-mentioned target position specification applies to the case where the target exists in a two-dimensional plane. When the target exists in three dimensions, the radar can determine the target position in three dimensions by using an ellipsoid and DOD or DOA having azimuth and elevation components.

[0042] Therefore, for example, by using a MIMO antenna arrangement such as Arrangement Example 1, it is possible to locate nearby targets in a BMS configuration. Even if gratings occur in DOD and DOA, the radar can determine the target position by selecting an angle at which an intersection point P on an ellipse that satisfies the target distance is obtained from a combination of candidate angles of DOD and DOA including the grating direction. Therefore, for example, by using a MIMO antenna arrangement such as Arrangement Example 2, it is possible to locate nearby targets in a BMS configuration.

[0043] On the other hand, when the reflected wave received by the radar is not a direct target wave (hereinafter, such a reflected wave received by the radar is referred to as an "indirect target wave"), for example, when the reflection path of the radar transmission wave includes a reflection path other than the direct target wave (for example, a path reflected by a wall or a road surface), no object exists on the ellipse with the radars #1 and #2 as its focus that satisfies the target distance. For this reason, when the radar receives an indirect target wave, it is difficult to accurately determine the target position of a nearby target.

[0044] When Arrangement Example 1 is applied to the indirect wave of a nearby target in such a BMS configuration, the radar may output an erroneous positioning result because either DOD or DOA is used. Also, when Arrangement Example 2 is applied to the indirect wave of a nearby target in a BMS configuration, for example, if the DOD or DOA of the indirect wave of the target coincides with the grating direction, the radar may output an erroneous positioning result.

[0045] In a non-limiting embodiment of the present disclosure, an antenna arrangement is described that enables removal of indirect target waves from nearby targets in a BMS configuration in multiple MIMO radars with mono- and multistatic configurations, and improves the angle measurement performance of the MNS configuration and the BMS configuration.

[0046] The following describes a configuration (e.g., a MIMO radar configuration) in which a radar device transmits different transmit signals simultaneously multiplexed from multiple transmit antennas in a transmit branch, and a receive branch separates each transmit signal for receiving processing.

[0047] In addition, the following describes, as an example, the configuration of a radar system using a frequency-modulated pulse wave such as a chirp pulse (also called fast chirp modulation). However, the modulation system is not limited to frequency modulation. For example, an embodiment of the present disclosure is also applicable to a radar system using a pulse compression radar that transmits a pulse train after phase modulation or amplitude modulation.

[0048] (Embodiment) [Radar device configuration] The radar device (also called a radar system) according to this embodiment may have, for example, a plurality of radar units (corresponding to radar circuits, for example, MIMO radar). The radar device according to this embodiment may also have, for example, a synchronization unit that performs synchronization control between the plurality of radar units, and an integration unit (for example, corresponding to a control circuit) that integrates the positioning outputs of the plurality of radar units.

[0049] For example, the radar device 1 shown in FIG. 3 is a radar system including a first radar section 10 (or radar section 10-1) having multiple transmitting and receiving antennas (not shown), and a second radar section 10 (or radar section 10-2) having multiple transmitting and receiving antennas (not shown).

[0050] 3, the synchronization unit 20 performs synchronization control between the first radar unit 10 and the second radar unit 10. For example, the synchronization unit 20 may generate a chirp signal or a reference clock signal (also called a reference signal) as a synchronization control signal to the first radar unit 10 and the second radar unit 10 for the synchronization control.

[0051] Here, the reference signal is, for example, a reference signal of a VCO (Voltage Controlled Oscillator) that generates a chirp signal, and is a high-frequency signal of about several tens to several hundreds of MHz. When the synchronization unit 20 uses a reference signal as a synchronization control signal, the system cost can be reduced compared to when a chirp signal (for example, on the order of GHz) is used. Note that when the synchronization unit 20 uses a reference signal, the chirp signal is generated individually in each of the first radar unit 10 and the second radar unit 10, so that the matching of the phases of the first radar unit 10 and the second radar unit 10 is not guaranteed, and a phase shift that causes a drift and displacement may occur. The radar device 1 may, for example, measure and correct the drift component of the phase between the first radar unit 10 and the second radar unit 10 in advance.

[0052] For example, the radar device 1 may transmit a transmission signal from multiple transmission antennas of a transmission unit 100-1 of the first radar unit 10. For example, the radar device 1 may receive a reflected wave signal, which is the transmission signal of the first radar unit 10 reflected by a target #1 (corresponding to the target #1 in FIG. 1), in a reception unit 200-1 having multiple reception antennas of the first radar unit 10, and perform a positioning process of the target #1 (for example, radar positioning using an MNS configuration).

[0053] Furthermore, the radar device 1 may receive, for example, a reflected wave signal, which is the transmission signal of the first radar unit 10 reflected by target #2 (corresponding to target #2 in Figure 1), in a receiving unit 200-2 having multiple receiving antennas of the second radar unit 10, and perform positioning processing of target #2 (for example, radar positioning using a BMS configuration).

[0054] Similarly, for example, the radar device 1 may transmit a transmission signal from multiple transmitting antennas of the radar transmitter 100-2 of the second radar unit 10. For example, the radar device 1 may receive a reflected wave signal, which is the transmission signal of the second radar unit 10 reflected by a target #3 (corresponding to the target #3 in FIG. 1), in the receiver 200-2 having multiple receiving antennas of the second radar unit 10, and perform a positioning process of the target #3 (for example, radar positioning using an MNS configuration).

[0055] Furthermore, the radar device 1 may receive, for example, a reflected wave signal, which is a transmission signal of the second radar unit 10 reflected by target #2 (corresponding to target #2 in Figure 1), in a receiving unit 200-1 having multiple receiving antennas of the first radar unit 10, and perform positioning processing of target #2 (for example, radar positioning using a BMS configuration).

[0056] The reception processing in the first radar unit 10 and the second radar unit 10 may be performed using, for example, a MIMO virtual antenna.

[0057] Furthermore, in this embodiment, the radar device 1 may transmit the transmission signal transmitted from the first radar unit 10 and the transmission signal transmitted from the second radar unit 10 using time division multiplexing, Doppler multiplexing, or code multiplexing, and the same effect can be obtained using any type of multiplexing.

[0058] For example, each of the first radar unit 10 and the second radar unit 10 may have a separation unit that separates, from the received signal, a reflected wave signal corresponding to a transmission signal from the transmission unit 100 of that radar unit, and separates a reflected wave signal corresponding to a transmission signal from the transmission unit 100 of the other radar unit.

[0059] Also, for example, each of the first radar unit 10 and the second radar unit 10 may have a first angle measurement unit that performs angle measurement using a reflected wave signal of a transmission signal from the transmission unit 100 of the radar unit separated in the separation unit, and a second angle measurement unit that performs angle measurement using a reflected wave signal of a transmission signal from the transmission unit 100 of the other radar unit separated in the separation unit.

[0060] 3, the integrating unit 30 may perform target positioning by integrating, for example, the positioning output (e.g., the first and second positioning outputs) from the first radar unit 10 and the positioning output (e.g., the first and second positioning outputs) from the second radar unit 10. Note that the positioning is information including the direction, distance, and Doppler frequency.

[0061] With this configuration, the radar device 1 receives reflected wave signals at the receiving units 200-1 and 200-2, separates the received signals depending on whether they are reflected wave signals due to a transmission signal from its own radar unit or a reflected wave signal due to a transmission signal from another radar unit, and can appropriately perform positioning processing based on the position information of the first radar unit 10 and the second radar unit 10.

[0062] 3, the first radar section 10 and the second radar section 10 may be installed at locations separate from each other. In this case, the radar device 1 can be used as a so-called BMS configuration.

[0063] In addition, since the first radar section 10 and the second radar section 10 shown in FIG. 3 have similar configurations, they will be collectively referred to and described below as the “radar section 10,” and different operations between the first radar section 10 and the second radar section 10 will be distinguished and described.

[0064] FIG. 4 shows an example of the configuration of a radar device 1 that uses a frequency-modulated chirp signal as a radar transmission wave.

[0065] The radar device 1 in Fig. 4 shows details of the first radar unit 10-1 and the synchronization unit 20 in Fig. 3. For example, the first radar unit 10-1 corresponds to the radar unit 10. Note that Fig. 4 shows a configuration example that also supports radars other than the first radar unit 10-1 and the second radar unit 10-2 in Fig. 3, and the other radar units 10 are omitted.

[0066] In addition, the radar device 1 in FIG. 4 illustrates, as an example, a configuration in which the transmission signal transmitted from the first radar section 10 and the transmission signal transmitted from the second radar section 10 are transmitted in a time division multiplexed manner.

[0067] 4 illustrates a configuration in which the transmission signals transmitted from the multiple transmission antennas in each radar unit 10 are Doppler multiplexed (DDM) transmitted. Note that the multiplexed transmission in each radar unit 10 is not limited to DDM, and may be time division multiplexed transmission or code division transmission, and the same effects can be obtained.

[0068] The radar unit 10 includes, for example, a transmission unit (corresponding to a transmission branch or a radar transmission circuit) 100 and a reception unit (corresponding to a reception branch or a radar reception circuit) 200.

[0069] The transmitter 100 transmits, for example, TxSig generated by the synchronization unit 20 at a predetermined transmission cycle using a transmission array antenna constituted by a plurality of transmission antennas 103-1 to 103-Nt.

[0070] The receiving unit 200 receives, for example, a reflected wave signal, which is TxSig reflected by a target (corresponding to targets #1 to #3 in FIG. 1), using a receiving array antenna including multiple receiving antennas 202-1 to 202-Na. The receiving unit 200 performs signal processing on the reflected wave signal received by each receiving antenna 202, and performs, for example, detection of the presence or absence of the target or positioning.

[0071] The synchronization unit 20 generates, for example, a predetermined frequency modulated wave (for example, a frequency chirp signal or a chirp signal) and supplies it to the multiple radar units 10. Note that the synchronization unit 20 may output a reference signal and generate the predetermined frequency modulated wave in the radar unit 10.

[0072] [Example of configuration of synchronization unit 20] The synchronization unit 20 includes, for example, a generation unit 301 and a control unit 304 .

[0073] The generating unit 301 generates TxSig, for example, under control of the control unit 304. The generating unit 301 outputs the generated TxSig to a plurality of radar units 10 (for example, the transmitting unit 100). Therefore, each of the plurality of radar units 10 transmits a transmission signal based on the TxSig.

[0074] The generating unit 301 includes, for example, a modulating signal generating unit 302 and a VCO 303. Each component of the generating unit 301 will be described below.

[0075] The modulation signal generating unit 302 periodically generates a modulation signal having, for example, a sawtooth shape. Here, the transmission period of TxSig is denoted as Tr.

[0076] The VCO 303 generates a chirp signal based on the modulated signal output from the modulated signal generating unit 302, and outputs the chirp signal to the transmitting unit 100 (for example, Doppler shift units 102-1 to 102-Nt) and the receiving unit 200 (a mixer unit 204 described later) of the radar unit 10. Hereinafter, the Doppler shift unit is also referred to as a DS unit.

[0077] The control unit 304 controls the generation unit 301 (for example, the modulation signal generation unit 302 and the VCO 303) to generate TxSig. For example, the control unit 304 controls the generation unit 301 to generate a chirp signal for each transmission period Tr for one radar positioning. c Parameters (eg, modulation parameters) for the chirp signal may be set to transmit the chirp signal a number of times.

[0078] Fig. 5(a) shows an example of a chirp signal transmitted from the first radar unit 10, and Fig. 5(b) shows an example of a chirp signal transmitted from the second radar unit 10. The chirp signals in Fig. 5(a) and (b) are set to the same center frequency.

[0079] The chirp signal generated by the generating unit 301 of the synchronization unit 20 is output to the transmitting unit 100 and the receiving unit 200 of the radar unit 10. In the example of Fig. 5, the control unit 304 outputs a transmission switching control signal to the switch (SW) unit 101 of the transmitting unit 100 of each radar unit 10 so that the transmission signal transmitted from the first radar unit 10 and the transmission signal transmitted from the second radar unit 10 are alternately switched in a time-division manner for each transmission period Tr.

[0080] Hereinafter, the control unit 304 sets the transmission period in which the transmission signal is output from each radar unit 10 as "N sw ×T r " is written as ". sw is a predetermined integer value equal to or greater than 2. In the example of FIG. sw =2.

[0081] For example, the radar device 1 transmits chirp signals c The chirp signal is transmitted N times, and the reflected wave signal is recorded by the target. c By measuring N times, the time variation of the target positioning result can be detected as the Doppler frequency. c Transmission period T r Each transmission period is represented by an index "m", where m=1 to N c is an integer.

[0082] As shown in FIG. 6, the modulation parameters for the chirp signal include, for example, a center frequency f c , frequency sweep bandwidth B w , sweep start frequency f cstart , sweep end frequency f cend , frequency sweep time T sw , and the frequency sweep rate of change D m may be included. Note that D m =B w / Tsw Also, B w = f cend -f cstart and f c =(f cstart +f cend ) / 2.

[0083] In addition, the frequency sweep time T sw The frequency sweep time T corresponds to, for example, a time range (also called a range gate) for capturing A / D sample data in the A / D conversion unit 207 of the receiving unit 200, which will be described later. sw may be set to the entire section of the chirp signal as shown in FIG. 6(a) or to a part of the section of the chirp signal as shown in FIG. 6(b).

[0084] Note that while Figures 5 and 6 show examples of up-chirp waveforms in which the modulation frequency gradually increases over time, down-chirp waveforms may also be applied, and regardless of which is used, the present disclosure can achieve similar effects.

[0085] Each chirp signal output from the synchronization unit 20 is input, for example, to each mixer unit 204 of the receiving unit 200 and to the Nt DS units 102, respectively.

[0086] [Example of configuration of the transmitting unit 100] In Fig. 4, the transmitting unit 100 of the radar unit 10 includes, for example, an SW unit 101, DS units 102-1 to 102-Nt, and transmitting antennas 103-1 to 103-Nt (for example, Tx#1 to Tx#Nt). Each transmitting antenna 103 may be connected to an individual DS unit 102. Furthermore, the radar unit 10 in Fig. 4 corresponds to the first radar unit 10, but hereinafter, the radar unit 10 including the second radar unit 10 and onward will be referred to as the qth radar unit 10. Here, q indicates an index for identifying the multiple radar units 10 included in the radar device 1, and may be, for example, q=1 or 2. In the following description, each element included in the qth radar unit 10 will be described with "-q" added.

[0087] Based on the transmission switching control signal input from the control unit 304, the SW unit 101 of the qth radar unit 10 outputs the chirp signal input from the VCO 303 to the DS unit 102 at the timing (transmission period) when the transmission signal is transmitted from the qth radar unit 10.

[0088] The DS unit 102 of the q-th radar unit 10 calculates a Doppler shift amount (hereinafter also referred to as "DS amount") DOP n In order to give (q), the transmission period of the chirp signal T r Phase rotation Φ n,q and outputs the Doppler-shifted signal to the transmitting antenna 103.

[0089] Also, for example, the number of transmitting antennas 103 in each of the q-th radar units 10 may be the same or different. Hereinafter, the number of transmitting antennas in the q-th radar unit 10 is represented as "Nt(q)" (or simply "Nt"). Here, Nt(q)≧1. Also, n=1 to Nt(q).

[0090] For example, the q-th radar unit 10 may have a predetermined phase rotation φ that imparts a different Doppler shift to each of the transmitting antennas 103 used for multiplex transmission in the MNS configuration. n,q (m) may be added and output.

[0091] In addition, the q-th radar unit 10 performs a predetermined phase rotation Φ that imparts a Doppler shift that results in a different DS amount pattern between the radar units 10 that perform multiplex transmission in a BMS configuration, for example. n,q(m) may be added to the TxSig and output. For example, the pattern of each DS amount (also called Doppler shift pattern) added to the TxSig transmitted from each of the multiple transmitting antennas 103 of the first radar unit 10 may be different from the pattern of each DS amount in the second radar unit 10. The DS amount pattern may be set according to, for example, at least one of the Doppler multiplexing interval (also called Doppler shift interval or Doppler interval; also referred to as "DDM interval") and the Doppler multiplexing number (hereinafter also referred to as "DDM number"). Alternatively, the qth radar unit 10 may, for example, apply a predetermined phase rotation Φ n,q (m) may be added and output (an example of operation will be described later).

[0092] The output signal of the DS unit 102 is amplified to a predetermined transmission power and radiated into space from each transmitting antenna 103 (for example, Tx#1 to Tx#Nt).

[0093] [Example of configuration of receiving unit 200] 4, the receiver 200 includes Na receiving antennas 202 (for example, Rx#1 to Rx#Na) to configure an array antenna. The receiver 200 also includes Na system processors 201, a CFAR (Constant False Alarm Rate) unit 210, a separator 211, and an angle measuring unit 212.

[0094] Here, the number of receiving antennas 202 in each of the q-th radar units 10 may be the same or different. Hereinafter, the number of receiving antennas in the q-th radar unit 10 is represented as "Na(q)" (or simply "Na"), where Na(q) is ≧1.

[0095] The system processing unit 201 may be provided corresponding to each of the Na(q) receiving antennas 202. The CFAR unit 210, the separator 211, and the angle measuring unit 212 may be provided corresponding to each of the q radar units 10, for example.

[0096] Each of the Na(q) receiving antennas 202 receives a reflected wave signal that is generated when TxSig transmitted from each of the multiple radar units 10 is reflected by a target (e.g., a reflecting object including a radar measurement target), and outputs the reflected wave signal to the corresponding system processing unit 201 as a received signal.

[0097] Each system processing unit 201 includes a radio reception unit 203 and an analysis unit 206 .

[0098] The receiving radio unit 203 has a mixer unit 204 and an LPF (low pass filter) 205. In the receiving radio unit 203, the mixer unit 204 mixes the received reflected wave signal (received signal) with a chirp signal, which is a transmitted signal. In addition, by passing the output of the mixer unit 204 through the LPF 205, a beat signal is extracted, the frequency of which corresponds to the delay time of the reflected wave signal. For example, the difference frequency between the frequency of the transmitted signal (transmitted frequency modulated wave) and the frequency of the received signal (received frequency modulated wave) is obtained as the beat frequency (or beat signal). Note that the beat frequency is within the passband of the LPF 205.

[0099] In FIG. 4, the analysis unit 206 of each system processing unit 201-z (where z=1 to Na(q)) has an A / D conversion unit 207, a beat analysis unit 208, and a Doppler analysis unit 209 (also called a “DA unit”).

[0100] The signal (eg, beat signal) output from the LPF 205 is converted by the A / D converter 207 in the analyzer 206 into discrete sample data that has been discretely sampled.

[0101] The beat analysis unit 208 analyzes the transmission period T r For each time, N data The discrete sample data are subjected to FFT processing. Here, the range gate is a frequency sweep time T swmay be set. As a result, the analysis unit 206 outputs a frequency spectrum in which a peak appears at a beat frequency corresponding to the delay time of the reflected wave signal (radar reflected wave). Note that, when performing FFT processing, the beat analysis unit 208 may multiply, for example, a window function coefficient such as a Han window or a Hamming window. By using the window function coefficient, it is possible to suppress side lobes that occur around the beat frequency peak.

[0102] Here, the beat frequency response (hereinafter also referred to as "BF response") output from the beat analysis unit 208 in the zth analysis unit 206 obtained by transmitting the mth chirp pulse of the chirp signal is referred to as "RFT z (f b , m) where f b represents the beat frequency index, which corresponds to the FFT index (bin number). For example, f b =0,~,N data / 2-1, z is an integer from 1 to Na, and m is an integer from 1 to N C The beat frequency index f b The smaller the beat frequency, the smaller the delay time of the reflected wave signal (e.g., the closer the distance to the target).

[0103] Also, the beat frequency index f b is calculated by using equation (1) in the case of MNS configuration and equation (2) in the case of BMS configuration, and the distance information R(f b ) in the following. Therefore, in the following, the beat frequency index f b Let "distance index f b The distance index is also called the "R-Index."

number

number

[0104] Here, B wrepresents the frequency sweep bandwidth within the range gate of the chirp signal, and C0 represents the speed of light.

[0105] The DA section 209 of the zth analysis section 206 calculates N C BF response RFT obtained by transmitting chirp pulses once z (f b , m) to perform Doppler analysis for each R-Index (for example, m = 1 to N C ).

[0106] In the following description, as shown in FIG. 5, in the BMS configuration, the transmission signal transmitted from the first radar unit 10 and the transmission signal transmitted from the second radar unit 10 are transmitted at a transmission period T r An example of the operation of the DA unit 209 when the data is alternately switched every 10 seconds will be described.

[0107] In the q-th radar unit 10, the z-th DA unit 209 C BF response RFT obtained by transmitting chirp pulses once z (f b , m), a Doppler analysis is performed for each R-Index using a BF response (for example, a BF response when m is an odd number in the first radar unit 10, and a BF response when m is an even number in the second radar unit 10) obtained from a received signal when the qth radar unit 10 outputs a transmitted signal. Hereinafter, the DA unit 209 (Doppler analysis unit 209-1 in FIG. 4) that performs Doppler analysis using such reflected wave signals is also referred to as the "first Doppler analysis (DA) unit 209" or the "mono reception Doppler analysis (DA) unit."

[0108] In addition, in the qth radar unit 10, the DA unit 209 performs Doppler analysis for each R-Index using a BF response (for example, a BF response when m is an even number in the first radar unit 10, and a BF response when m is an odd number in the second radar unit 10) obtained from a received signal when a radar unit 10 different from the qth radar unit 10 outputs a transmission signal. Hereinafter, the DA unit 209 (Doppler analysis unit 209-2 in FIG. 4) that performs Doppler analysis using such reflected wave signals is also referred to as a "second Doppler analysis (DA) unit 209" or a "multiple reception Doppler analysis (DA) unit."

[0109] For example, the DA unit 209 of the q-th radar unit 10 is VFT =N c / N sw If is a power of 2, FFT processing can be applied in Doppler analysis. In this case, the FFT size of the mono receiving DA unit and the multi receiving DA unit is N VFT The maximum Doppler frequency at which aliasing does not occur, derived from the sampling theorem (hereinafter referred to as "DFreq"), is ±1 / (2N sw T r ) Also, the DFreq index (also called "DF-Index") f s The DFreq interval is 1 / (N c ×T r ), and f s The range of f s = -N VFT / 2, ~, 0, ~, N VFT / 2-1.

[0110] For example, among the DA units 209 in the z-th analysis unit 206 of the q-th radar unit 10, the output VFT of the mono reception DA unit z,q Mono (f b , f s ), and the output VFT of the multi-receiving DA section z,q Mul (f b , f s) is shown in the following formulas (3) and (4). Note that j is an imaginary unit, z is an integer between 1 and Na(q), and q is 1, 2. The BF response output from the beat analysis unit 208 in the q-th radar unit 10 is referred to as the “RFT z,q (f b , m)" and so on.

number

number

[0111] The processing in each component of the analysis unit 206 has been described above.

[0112] In FIG. 4, the CFAR section 210 of the q-th radar section 10 may include, for example, a first CFAR section 210-q (or may be referred to as a CFAR section 210-1-q) corresponding to an MNS configuration, and a second CFAR section 210-q (or may be referred to as a CFAR section 210-2-q) corresponding to a multistatic configuration.

[0113] The first CFAR unit 210-q performs CFAR processing (for example, adaptive threshold determination) using the outputs from the first DA units 209 (mono reception DA units) of the first to Na(q)th analyzers 206, and obtains an R-Index (hereinafter, f bp Mono ) and DF-Index (hereafter, f sp Mono Extract the

[0114] Similarly, the second CFAR unit 210-q performs CFAR processing using the outputs from the second DA units 209 (multiple reception DA units) of the first to Na(q)th analyzers 206, and obtains an R-Index (hereinafter, f bp Mul ) and DF-Index (hereafter, f sp Mul (also written as f sp Mono and fsp Mul may include DF-Index for the number of Doppler multiplexes.

[0115] For example, the first CFAR unit 210-q selectively extracts local peaks of a reflected wave signal (referred to as a received signal or a reflected wave signal in an MNS configuration) by TxSig from the qth radar unit 10 in the MNS configuration, using the outputs of the first DA units 209 of the first to Na(q)th analyzers 206. For example, the first CFAR unit 210-q performs CFAR processing for adaptive threshold determination after power addition at an interval that matches the DDM interval set for TxSig from the qth radar unit 10, and bp Mono and f sp Mono and output it to first separation section 211 (an operation example will be described later).

[0116] The transmission unit of the MNS configuration in the qth radar unit 10 is the transmission unit 100 of the qth radar unit 10. Similarly, the transmission unit of the MNS configuration in the qeth radar unit 10 is the transmission unit 100 of the qeth radar unit 10. The qth radar unit 10 and the qeth radar unit 10 are different radar units, and for example, when q=1, qe=2.

[0117] Also, for example, the second CFAR unit 210-q selectively extracts local peaks of the reflected wave signal by TxSig from the qeth radar unit 10 in the BMS configuration (hereinafter referred to as the reflected wave signal in the BMS configuration) using the outputs of the second DA units 209 of the first to Na(q)th analysis units 206.

[0118] For example, the second CFAR unit 210-q performs CFAR processing for adaptive threshold determination after power addition at an interval that matches the DDM interval set in the TxSig from the qe-th radar unit 10 different from the q-th radar unit 10, and bp Mul and f sp Mul and output it to second separation section 211 (an operation example will be described later).

[0119] Moreover, the transmitting section of the BMS configuration in the first radar section 10 is the transmitting section 100 of the second radar section 10. Similarly, the transmitting section 100 of the BMS configuration in the second radar section 10 is the transmitting section 100 of the first radar section 10.

[0120] The separation section 211 of the qth radar section 10 may include a first separation section 211-q (or may be referred to as a separation section 211-1) that performs Doppler multiplex separation (hereinafter also referred to as "DDM separation") processing using the outputs of the first DA section 209 and the first CFAR section 210-q, and a second separation section 211-q (or may be referred to as a separation section 211-2) that performs DDM separation processing using the outputs of the second DA section 209 and the second CFAR section 210-q.

[0121] For example, the first separator 211-q of the q-th radar unit 10 performs DDM separation of the reflected wave signal in the MNS configuration using the output of the first CFAR unit 210-q. Also, the second separator 211-q of the q-th radar unit 10 performs DDM separation of the reflected wave signal in the BMS configuration using the output of the second CFAR unit 210-q.

[0122] The first demultiplexer 211-q outputs, for example, information on the demultiplexed signals to the first angle measuring unit 212-1. The output of the first demultiplexer 211-q may include, for example, an output from the first DA unit 209.

[0123] Furthermore, the second separator 211-q outputs, for example, information about the signal obtained by separating the reflected wave signal in the BMS configuration to the second angle measuring unit 212-2. The output of the second separator 211-q may include, for example, an output from the second DA unit 209.

[0124] The information on the separated signals may include, for example, an R-Index and a DF-Index (hereinafter, sometimes referred to as separated index information) corresponding to the separated signals.

[0125] An example of the operation of the q-th separating unit 211 will be described below together with an example of the operation of the Doppler shift unit 102 and the q-th CFAR unit 210. For example, q may be 1 or 2.

[0126] The operation of the Nu-th demultiplexer 211-q is associated with the operation of the DS section 102 of the transmitter 100-q. Similarly, the operation of the Nu-th CFAR section 210-q is associated with the operation of the DS section 102 of the transmitter 100-q. For example, Nu may be 1 or 2.

[0127] An example of operation of the DS unit 102 will be described below, followed by an example of operation of the Nu-th CFAR unit 210-q and an example of operation of the Nu-th demultiplexing unit 211-q.

[0128] [How to set DS amount] First, an example of a method for setting the amount of DS provided in the DS unit 102 will be described.

[0129] Each of the first to Nt(q)th DS units 102 of the qth radar unit 10 receives a chirp signal from the synchronization unit 20 and transmits a different DS amount DOP at a predetermined DDM interval Δfd(q). n In this case, the DDM interval Δfd(q) may satisfy the following setting condition (1) or (2).

[0130] Setting conditions (1): The DDM intervals between the multiple radar units 10 may be set to be the same. For example, the interval between each DS amount assigned to a TxSig transmitted from each of the multiple transmitting antennas 103 of the first radar unit 10 may be the same as the interval between each DS amount assigned to a TxSig transmitted from each of the multiple transmitting antennas 103 of the second radar unit 10 (for example, Δfd(1)=Δfd(2)).

[0131] Setting condition (2): The DDM intervals between the plurality of radar units 10 may be set to different intervals. For example, the interval between each DS amount given to the TxSig transmitted from each of the plurality of transmission antennas 103 of the first radar unit 10 and the interval between each DS amount given to the TxSig transmitted from each of the plurality of transmission antennas 103 of the second radar unit 10 may be different from each other (for example, Δfd(1)≠Δfd(2)).

[0132] In addition, in setting condition (2), for example, it may be set so that the ratio of Δfd(1) to Δfd(2) does not match an integer. For example, among Δfd(1) and Δfd(2), the ratio of the larger DDM interval to the smaller DDM interval may be different from an integer. For example, Δfd(1) / Δfd(2), or Δfd(2) / Δfd(1) may be set so as not to match an integer (to be different from an integer).

[0133] Hereinafter, a setting example of the DDM interval Δfd(q) will be described.

[0134] In addition, hereinafter, the number of DDMs of the q-th radar unit 10 is denoted as "N DM (q)", and the case where N DM (q)=Nt(q) will be described, but it is not limited thereto. For example, the radar unit 10 may form a transmission beam by bundling some of the plurality of transmission antennas 103 and perform DDM transmission. In this case, N DM (q)<Nt(q). Also, for example, the index n of the DS amount DOP n (q) represents the index of the DDM signal, and n = 1 to N DM (q) is an integer. Also, N DM (q)>1, and q = 1 or 2. When Nt(q)=1, Doppler shift multiplexing may not be used, and the q-th radar unit 10 may not include the DS unit 102.

[0135] In this embodiment, the transmission signal transmitted from the first radar unit 10 and the transmission signal transmitted from the second radar unit 10 are time-division multiplexed and transmitted. For example, the control unit 304 may transmit the transmission signal transmitted from the first radar unit 10 and the transmission signal transmitted from the second radar unit 10 at a transmission period T r A transmission switching control signal is output to the SW unit 101 of each transmitting unit 100 so that the transmission switching control signal is switched alternately in a time division manner every N sw Each time the signal is converted to a chirp signal, a phase rotation is applied to the chirp signal to obtain a predetermined DS amount (for example, N SW =2).

[0136] Here, in the DA unit 209 (mono reception DA unit or multi reception DA unit), DFreq f that does not cause aliasing derived from the sampling theorem is d The range is -1 / (2N sw T r ) ≦ f d <1 / (2N sw T r For example, DFreq f d If the range is exceeded, the DA unit 209 sw T r ) ≦ f d <1 / (2N sw T r The Doppler shift applied by the DS unit 102 is −1 / (2N sw T r ) ≦ fd < 1 / (2N sw T r Even if you set it beyond the range of -1 / (2N sw T r ) ≦ fd < 1 / (2N sw T r ) range.

[0137] Therefore, for example, the DS unit 102 sw T r ) ≦ f d <1 / (2N sw Tr ), the maximum DDM interval (e.g., represented as “Δfdmax”) for Nt(q) transmitting antennas 103 (e.g., a number equal to the number of DDMs) is Δfdmax=1 / (T r N sw Nt(q)) = 1 / (T r N sw N DM (q)). The DS unit 102 may set, for example, Δfd(1) and Δfd(2) within the range of Δfdmax. This allows the DS unit 102 to set the Doppler shift within the range of 0 to 2π, which is the phase rotation that gives the Doppler shift.

[0138] As an example, the DDM intervals of the first radar unit 10 and the second radar unit 10 may be set as shown in the following equation (5).

number

[0139] For example, δ q are parameters that determine the DDM interval. δ1 = δ2 ≧ 0, and N DM (1)=N DM With this setting, the DDM intervals between the multiple radar units 10 (for example, between the first radar unit 10 and the second radar unit 10) become the same interval, and the setting condition (1) is satisfied (Δfd(1)=Δfd(2)).

[0140] Or, δ1, δ2≧0, and N DM (1)+δ1≠N DM (2) + δ2 is satisfied, and N DM (1) + δ1 and N DM δ1 and δ2 may be set so that the ratio of δ1 to δ2+δ is not an integer. This setting results in different DDM intervals between multiple radar units 10 (for example, between the first radar unit 10 and the second radar unit 10), satisfying the setting condition (2).

[0141] Each of δ1 and δ2 may be a positive integer or a positive real number. For example, by setting δ1 and δ2 to positive integers, the processing in the first CFAR unit 210 and the second CFAR unit 210 described later can be simplified. In the following, as an example, a case where each of δ1 and δ2 is set to zero or a positive integer will be described, but the present invention is not limited to this and a positive real number may be set.

[0142] An example of setting the DS amount has been described above.

[0143] The DS unit 102 may, for example, use the DDM interval set as described above to set a DS amount corresponding to each transmitting antenna 103, and impart phase rotation that imparts the DS amount to the chirp signal for each transmission period.

[0144] For example, the n-th DS unit 102 of the q-th radar unit 10 outputs a different DS amount DOP for each n-th transmitting antenna 103 for the m-th chirp signal input thereto. n (q) is given by the phase rotation Φ n,q As a result, different Doppler shifts are imparted to the transmission signals transmitted from the multiple transmission antennas 103.

[0145] Here, n is an integer from 1 to Nt(q) and m is an integer from 1 to N c and q is 1 or 2.

[0146] For example, Nt(q) (e.g., Nt(q)=N DM For TxSig from the (q) transmitting antennas 103, the DS amount DOP of the DDM interval Δfd(q) is n (q) is given by the phase rotation Φ n,q (m) is expressed as the following equation (6). Also, equation (7) expresses the DS amount DOP of the DDM interval Δfd(q) as n Represents (q).

number

number

[0147] Here, Φ0 is the initial phase, and ΔΦ0 is the reference Doppler shift phase. α is a coefficient that offsets the DS amount of each DDM signal, and may be a real value. For example, when α=1, the DS amount of the first DDM signal is zero.

[0148] As an example, if Nt(1) = Nt(2) = 3, ΔΦ0 = 0, Φ0 = 0, δ1 = 1, δ2 = 2, the DDM interval is Δfd(1) = 1 / (4N sw T r ), Δfd(2)=1 / (5N sw T r ) is set. For example, the DS amount DOP corresponding to the n-th transmitting antenna 103 is set to n For example, when α=1, (q) is expressed as in the following equation (8).

number

[0149] For example, for the m-th chirp signal input, a different DS amount DOP is assigned to each of the n-th (n=1, 2, 3) transmitting antennas 103. n (q) is given by the phase rotation Φ n,q (m) is expressed as the following equation (9).

number

[0150] For example, when the first radar unit 10 performs DDM transmission using the number of transmitting antennas Nt=3, the first DS unit 102 in the first radar unit 10 performs a phase rotation Φ 1 for the chirp signal input from the synchronization unit 20 every odd-numbered transmission period Tr as shown in the following equation (10): 1,1 The output of the first DS section 102 is output from the first transmitting antenna 103 (Tx#1), ​​for example. Here, cp(t) represents a chirp signal for each transmission period.

number

[0151] Also, for example, when the second radar unit 10 performs DDM transmission using the number of transmission antennas Nt=3, the first DS unit 102 in the second radar unit 10 transmits the chirp signal input from the synchronization unit 20 in an even-numbered transmission period T r For each, a phase rotation Φ 1,2 The output of the first DS section 102 is output from the first transmitting antenna 103 (Tx#1), ​​for example.

number

[0152] An example of setting the DS amount has been described above.

[0153] Next, an example of the operation of the first CFAR unit 210, the second CFAR unit 210, the first separation unit 211, and the second separation unit 211 in the q-th radar unit 10 corresponding to the operation of the DS unit 102 described above will be described.

[0154] [Example of operation of the first CFAR unit 210] For example, the first CFAR unit 210 of the q-th radar unit 10 may perform the following operations to receive a reflected wave signal corresponding to the MNS configuration.

[0155] For example, the first CFAR unit 210 may detect peaks by searching for a power peak that matches the DDM interval set in the TxSig of the q-th radar unit 10 for each R-Index on the power sum values ​​of the outputs from the first DA units 209 of the first to Na(q)-th analysis units 206, and performing adaptive threshold processing (CFAR processing). In peak detection, the first CFAR unit 210 performs, for example, two-dimensional CFAR processing consisting of a distance axis and a DFReq axis (corresponding to relative speed), or CFAR processing that combines one-dimensional CFAR processing (for example, the processing disclosed in Non-Patent Document 4 may be applied).

[0156] Here, for example, in the DS unit 102, δ shown in the formula (5) is q When is set to a positive integer, the interval of the DS amount is Δfd(q) or an interval that is an integer multiple of Δfd(q). Here, q may be 1 or 2. Therefore, each signal that is subjected to DDM can be detected in the DFreq region of the output of the first DA unit 209 as if it were folded back at intervals of Δfd(q). By utilizing such a property, for example, the operation of the first CFAR unit 210 can be simplified as follows.

[0157] The first CFAR unit 210 of the qth radar unit 10 detects a Doppler peak by using a threshold value for a power sum value obtained by adding up the received power of the reflected wave signal for each range (e.g., the range of Δfd(q)) corresponding to each interval of the DS amount respectively assigned to TxSig within the DFreq range to be subjected to CFAR processing output from the first DA unit 209.

[0158] For example, the first CFAR unit 210 performs a step of dividing the outputs from the first DA units 209 of the first to Na(q)-th analysis units 206 at intervals of Δfd(q) (for example, N Δfd(q) Power value q FT(f b , f s ) is added to the power addition value PowerDDM q (f b , f sdc ) and perform CFAR processing. This type of CFAR processing is called, for example, "Doppler domain compression CFAR processing" and written as "DC-CFAR." Note that DC-CFAR is described in, for example, Patent Document 4, and a detailed description thereof will be omitted.

number

number

[0159] where f sdc =-N VFT / 2,~,-N VFT / 2+N Δfd(q) -1, and N Δfd(q) =round(Δfd(q) / (1 / (T r N c )). Also, round(x) is an operator that rounds off a real number x to output an integer value.

[0160] As a result, the range of DFreq to be CFAR-processed in the first CFAR unit 210 is expanded to the entire range (for example, −N VFT / 2~N VFT / 2-1) 1 / (Nt(q)+δ q )=1 / (N DM (q)+δ q ), it is possible to reduce the amount of calculation required for CFAR processing.

[0161] The first CFAR unit 210 adaptively sets a threshold value, for example, and calculates f bp Mono , f sp Mono As f bp mono , f sdcp mono , and received power information (PowerFT q mono (f bp mono , f sdcp mono +(ndm-1)×N Δfd(q) )) to the first separation unit 211. Here, ndm=1 to N DM (q)+δ q is an integer.

[0162] [Operation example of first separation unit 211] The first separation unit 211 of the q-th radar unit 10 receives, for example, f bp mono , f sp mono , and based on the received power information, the output of the first DA unit 209 is used to perform DDM separation of the first reflected wave signal in the MNS configuration.

[0163] <δq If =0:> In the first separation section 211, for example, δ q If =0, the target's DFreq is -1 / (2T r N sw N DM (q) ≦ f d <1 / (2T r N sw N DM (q)) may be assumed as the case.

[0164] <δ q If 0: In the first separation unit 211, for example, the DFreq of the target is −1 / (2T r N sw ) ≦ f d <1 / (2T r N sw ) may be assumed to be the highest N received power. DM The reception levels of (q) DF-Indexes and the top N DM DF-Index and different δ q This may be utilized because the difference between the reception levels of the DF-Indexes is large (for example, the difference is equal to or greater than a threshold). For example, first demultiplexing section 211 compares reception power information input from first CFAR section 210 to determine DFreq. Note that an example of the operation of first demultiplexing section 211 is disclosed in, for example, Patent Document 3, and therefore description of the example of the operation will be omitted here.

[0165] For example, first demultiplexing section 211 outputs information about the demultiplexed signals to first angle measuring section 212. The information about the demultiplexed signals may include an R-Index corresponding to the demultiplexed received signal, and demultiplexing index information of the DDM signal. Furthermore, the output of first demultiplexing section 211 may include an output from first DA section 209. The demultiplexing index information of the DDM signal is δ q DF-Index and the top N with the highest received power DM The qth radar unit 10 transmits the signal based on the relationship with the DF-Index. DMThe amount of DS of the DDM signal added to (q) and f sdcp mono +(ndm-1)×N Δfd(q) The first demultiplexing unit 211 converts this associated information into demultiplexing index information f Tx (q)=(f dmlTx#1 (q),~,f dmlTx#NDM (q)) to the first angle measuring unit 212.

[0166] where f dmlTx#n (q) denotes the DF-Index of the reflected wave signal by TxSig from the n-th transmitting antenna 103 (Tx#n) of the q-th radar unit 10.

[0167] [Example of operation of the second CFAR unit 210] For example, the second CFAR section 210 of the qth radar section 10 may perform the following operation in order to receive the reflected wave signal by TxSig from the qeth radar section 10.

[0168] Here, qe represents the radar number of a radar unit 10 different from the q-th radar unit 10. For example, in the case of the first radar unit 10 (q=1), qe=2 may be used, and in the case of the second radar unit 10 (q=2), qe=1 may be used.

[0169] For example, the second CFAR unit 210 of the qth radar unit 10 may detect the peaks by searching for a power peak that matches the DDM interval set in the TxSig of the qeth radar unit 10 for each R-Index in the power sum values ​​of the outputs from the second DA units 209 of the first to Na(q)th analysis units 206, and performing adaptive threshold processing (CFAR processing).

[0170] The operation of the second CFAR unit 210 of the qth radar unit 10 differs in that the output from the second DA unit 209 is used instead of the output from the first DA unit 209 in the operation of the first CFAR unit 210, and that the DDM interval set in TxSig of the qeth radar unit 10 is used instead of the DDM interval set in TxSig of the qth radar unit 10; however, other than these, the operation is the same as in the first CFAR unit 210, so a detailed explanation of the operation will be omitted.

[0171] The second CFAR unit 210 adaptively sets a threshold value, for example, and calculates an R-Index f bp mul , DFreq index f sdcp mul , and received power information (PowerFT q mul (f bp mul , f sdcp mul +(ndm-1)×N Δfd(qe) )) to the second separation unit 211. Here, ndm=1 to N DM (qe)+δ qe In the following description, the CFAR processing in second CFAR unit 210 described above is also referred to as "multiple reception CFAR."

[0172] [Example of operation of second separator 211] The second separation unit 211 of the q-th radar unit 10 receives, for example, f bp mul , f sp mul , and based on the received power information, the output of the second DA unit 209 is used to perform DDM separation of the second reflected wave signal in the BMS configuration.

[0173] The operation of the second separation unit 211 is performed by dividing the f bp mono , f sp mono , and f input from the second CFAR unit 210 instead of the received power information. bpmul , f sp mul , and received power information is used, and the output of second DA unit 209 is used instead of the output of first DA unit 209; other than that, the operation is the same as that of first separation unit 211, so description thereof will be omitted.

[0174] For example, the second separator 211 separates Δ qe DF-Index and the top N with the highest received power DM Based on the relationship with the (qe) DF-Indexes, the DS amount of the DDM signal transmitted from the qe-th radar unit 10 and f sdcp mul +(ndm-1)×N Δfd(qe) The separation index information f of the DDM signal is Tx (qe) and output it to the second angle measuring unit 212. Here, f Tx (qe) denotes the DF-Index of the reflected wave signal by TxSig from each transmitting antenna 103 of the qe-th radar unit 10.

[0175] Furthermore, the second demultiplexing unit 211 outputs, for example, information relating to the demultiplexed signal to the second angle measuring unit 212. The information relating to the demultiplexed signal may include, for example, an R-Index corresponding to the demultiplexed received signal and demultiplexed index information of the DDM signal. The output of the second demultiplexing unit 211 may include an output from the second DA unit 209. Note that the detectable DFreq range is ±1 / (2TrN sw )

[0176] [Example of operation of first angle measuring unit 212] The first angle measuring unit 212 of the q-th radar unit 10 receives, for example, information input from the first separation unit 211 (for example, R-Index f bp mono (q), and the separation index information f of the DDM signal Tx Based on (q), an angle measurement process is performed for the first reflected wave signal in the MNS configuration.

[0177] For example, the first angle measuring unit 212 is f bp mono(q) and the separation index information f of the DDM signal Tx Based on (q), the output from the first DA unit 209 is extracted, and the q-th virtual receiving array correlation vector h q (f bp mono (q), f Tx (q)) is generated and angle measurement processing is performed, where, for example, q=1,2.

[0178] The qth virtual receiving array correlation vector h q (f bp mono (q), f Tx As shown in equation (14), the qth virtual receiving array correlation vector h(q) includes Nt(q) × Na(q) elements, which is the product of the number of transmitting antennas Nt(q) and the number of receiving antennas Na(q). q (f bp mono (q), f Tx (q)) is used for angle measurement processing based on the phase difference between the transmitting and receiving antennas 202 with respect to the reflected wave signal from the target. Here, z is an integer between 1 and Na(q).

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[0179] In equation (14), h cal[b] is an array correction value for correcting the phase deviation and amplitude deviation between the transmitting array antennas and the receiving array antennas, where b is an integer between 1 and (Nt(q) × Na(q)).

[0180] The first angle measuring unit 212 of the q-th radar unit 10 calculates, for example, the q-th virtual receiving array correlation vector h q (f bp mono (q), f Tx (q)), the angle measurement evaluation function P H (θ u , f bp mono (q), f Tx (q)) uis varied within a predetermined angle range to calculate a spatial profile.

[0181] The first angle measuring section 212 may extract a predetermined number of maximum peaks from the calculated spatial profile in descending order, and output the azimuth direction of the maximum peak as an angle measurement value (for example, a positioning output).

[0182] There are various methods for angle measurement algorithms (beamformer method, Capon, MUSIC, etc.). For example, the estimation method using an array antenna disclosed in Non-Patent Document 5 may be used. For example, if the number of virtual receiving antennas is Nt×Na and they are equally spaced d H When the antennas are arranged linearly, the beamformer method can be expressed as in the following equation (15): In addition to the beamformer method, methods such as Capon and MUSIC can also be applied in the same way.

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[0183] In equation (15), the superscript H is the Hermitian transpose operator. Also, in equation (15), a(θ u ) is the azimuth direction θ at the center frequency fc of the radar transmission signal u λ is a column vector with Nt×Na elements as expressed by equation (16). In equation (16), λ is the center frequency f c is the wavelength of the radar transmission signal (e.g., a chirp signal) when c It is.

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[0184] In addition, the azimuth direction θ u is a vector that is changed at a predetermined azimuth interval β1 within the azimuth range in which the direction of arrival estimation is performed.

[0185] By the above operation, the first angle measuring unit 212 of the q-th radar unit 10 outputs, for example, a distance index f bp mono (q), and the separation index information f of the DDM signal Tx The first angle measuring unit 212 may output the arrival direction estimation value in (q) to the integrating unit 30. In addition, the first angle measuring unit 212 may further output a distance index f bp mono , the separation index information of the DDM signal f Tx You may output (q).

[0186] Also, the distance index f bp mono (q) may be converted into distance information using equation (1) and output.

[0187] Also, the distance index f bp mono The Doppler frequency of the target in (q) may be output. Since the amount of DS given by the DS unit 102 during transmission is known for each transmitting antenna 103, the first angle measuring unit 212 may output the Doppler frequency of the target based on the separation index information of the DDM signal.

[0188] [Example of operation of second angle measuring unit 212] The second angle measuring unit 212 of the q-th radar unit 10 receives, for example, information input from the second separation unit 211 (for example, a distance index f bp mul (q), and the separation index information f of the DDM signal Tx Based on (qe), an angle measurement process is performed for the second reflected wave signal in the BMS configuration. Here, for example, when q=1, qe=2, and when q=2, qe=1.

[0189] The second angle measuring unit 212, for example, measures the distance index f bp mul (q) and the separation index information f of the DDM signal Tx Based on (qe), the output of the second DA unit 209 is extracted, and the q-th receiving array correlation matrix H q (fbp mul (q), f Tx The second angle measurement unit 212 generates, for example, a distance index f bp mul If the distance indicated by (q) is deemed to be a nearby target, nearby target angle measurement processing is performed, and if it is deemed to be a distant target, distant target angle measurement processing is performed.

[0190] The qth receiving array correlation matrix H q (f bp mul (q), f Tx As shown in equation (17), the qth receiving array correlation matrix H q (f bp mul (q), f Tx (qe)) estimates the direction of the reflected wave signal from the target based on the phase difference between the transmitting and receiving antennas 202. Here, z=1 to Na(q).

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[0191] In equation (17), h cal[b] is an array correction value for correcting the phase deviation and amplitude deviation between the transmitting array antennas and the receiving array antennas, where b is an integer between 1 and (Nt(qe) × Na(q)).

[0192] <Nearby target measurement angle processing> Distance index f bp mul When the distance indicated by (q) is regarded as a nearby target, the second angle measuring unit 212 calculates the qeth receiving array correlation matrix H q (f bp mul (q), f Tx Based on the received signal (qe), a nearby target angle measurement process is performed to estimate the direction of transmission (DOD) and direction of reception (DOA).

[0193] The second angle measurement unit 212 of the qth radar unit 10 may output, for example, a direction of transmission azimuth (DOD) as an angle measurement estimate value (for example, positioning output) to the integrating unit 30. Also, the second angle measurement unit 212 of the qth radar unit 10 may output, for example, a direction of reception azimuth (DOA) as an angle measurement estimate value (for example, positioning output) to the integrating unit 30.

[0194] The second angle measuring unit 212 of the q-th radar unit 10 is, for example, a DOD angle measurement evaluation function P TxH (θ u , f bp mul (q), f Tx (qe)) u The second angle measuring section 212 may calculate a spatial profile by varying within a predetermined angle range. The second angle measuring section 212 may extract a predetermined number of maximum peak directions in the calculated spatial profile in descending order, and output the DOD of the maximum peak to the integrating section 30 as an angle measurement estimate (for example, a positioning output).

[0195] In addition, the DOD angle measurement evaluation function P TxH,q (θ u , f bp mul (q), f Tx Various angle measurement estimation algorithms may be used for (qe). For example, the angle measurement process may be the angle measurement process in the BMS configuration described in Non-Patent Document 2 or 6. Also, the estimation method using an array antenna disclosed in Non-Patent Document 5 may be used. For example, the beamformer method can be expressed as in the following equation (18). In addition to the beamformer method, methods such as Capon and MUSIC can be similarly applied. In the following equation (18), the superscript H is a Hermitian transpose operator.

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[0196] In formula (18), a Tx(qe) (θ u ) is the azimuth direction θ of the transmitting antenna in the qe radar unit 10 at the center frequency fcu 1 shows the transmitting array direction vector for the arriving waves of

[0197] In addition, the second angle measuring unit 212 of the q-th radar unit 10 calculates, for example, a DOA angle measuring evaluation function P RxH,q (θ u , f bp mul (q), f Tx (qe)) Rx The second angle measuring section 212 may vary the angle within a predetermined angle range to calculate a spatial profile. The second angle measuring section 212 may extract a predetermined number of maximum peak directions in the calculated spatial profile in descending order, and output the DOA of the maximum peak to the integrating section 30 as a direction estimation value (for example, a positioning output).

[0198] The DOA measurement evaluation function P RxH,q (θ u , f bp mul (q), f Tx Various angle measurement estimation algorithms may be used for (qe). For example, the beamformer method can be expressed as the following equation (19).

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[0199] In formula (19), a Rx(q) (θ u ) is the azimuth direction θ of the receiving antenna in the qth radar unit 10 at the center frequency fc u The receiving array direction vector for the arriving wave of θ u is a vector that is changed at a predetermined azimuth interval β1 within the azimuth range in which direction estimation is performed.

[0200] <Distant target measurement angle processing> Distance index f bp mul When the distance indicated by (q) is regarded as a distant target, the second angle measuring unit 212 calculates the qth receiving array correlation matrix H q (f bp mul(q), f Tx Based on the above, the qth virtual receiving array correlation vector h q BMS (f bp mul (q), f Tx (qe)) is generated and angle measurement processing is performed. Here, Vec[H] is an operator that generates one column vector by sequentially concatenating each column vector of matrix H in the column direction, and Nt(qe)×Na(q) order column vectors are generated by the following equation (20). In addition, when q=1, qe=2, and when q=2, qe=1.

number

[0201] The second angle measuring unit 212 of the q-th radar unit 10 is, for example, a q-th virtual receiving array correlation vector h q BMS (f bp mul (q), f Tx (qe)) to obtain the BMS configuration angle measurement evaluation function P H BMS (θ u , f bp mul , f Tx (qe)) u is varied within a predetermined angle range to calculate a spatial profile. The second angle measuring unit 212 may, for example, extract a predetermined number of maximum peaks from the calculated spatial profile in descending order, and output the azimuth direction of the maximum peak as an angle measurement value (for example, positioning output). Note that various methods (beamformer method, Capon, MUSIC, etc.) may be used as the angle measurement algorithm.

[0202] For example, the number of q-th virtual receiving antennas in the BMS configuration is Nt(qe) × Na(q), and the antennas are equally spaced d H When the MSs are arranged in a line, the MS configuration angle measurement evaluation function using the beamformer method can be expressed as the following equation (21).

[0203] In equation (21), the superscript H is the Hermitian transpose operator. BMS,q (θ u ) is the azimuth direction θ at the center frequency fc of the radar transmission signal u q represents the direction vector of the qth virtual receiving antenna in the BMS configuration for the incoming wave of , and is a column vector having elements Nt(qe) × Na(q) as expressed in equation (22). In equation (22), λ is the center frequency f c is the wavelength of the radar transmission signal (e.g., a chirp signal) when c In addition, the azimuth direction θ u is a vector that is changed at a predetermined azimuth interval β1 within the azimuth range in which the direction of arrival estimation is performed.

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[0204] Although the first and second angle measuring units 212 have been described as calculating the azimuth direction as the angle measurement estimate, the present invention is not limited to this example, and it is also possible to estimate the elevation direction or estimate the azimuth direction and elevation angle by using MIMO antennas arranged in a rectangular lattice. For example, the second angle measuring unit 212 may calculate the azimuth and elevation angle as the angle measurement estimate, and output the calculated angle as the positioning output.

[0205] By the above operation, the second angle measuring unit 212 of the q-th radar unit 10 outputs, for example, a distance index f bp mul If the distance indicated by (q) can be considered as 1) a nearby target, the separation index information f Tx (qe) may output the estimated value of the direction of origin (DOD) and the estimated value of the direction of origin (DOA). Also, 2) if the target can be considered to be a distant target, the direction of origin (DOD) and the direction of origin (DOA) are assumed to be equal, and the BMS-configured angle measurement evaluation function P H,q BMS (θ u , f bpmul (q), f Tx (qe)) may be output.

[0206] The second angle measuring unit 212 further outputs f bp mul (q), Separation index information of DDM signal f Tx You may output (qe).

[0207] Also, the distance index f bp mul (q) may be converted into distance information using equation (2) and output.

[0208] Since the amount of DS given by the DS unit 102 during transmission by the qe-th radar unit 10 is known for each transmission antenna 103 of the qe-th radar unit 10, the second angle measuring unit 212 calculates the separation index information f of the DDM signal. Tx The Doppler frequency of the target may be output based on (qe).

[0209] Here, in the radar device 1, the positions of the first radar unit 10 and the second radar unit 10 are known in advance. For example, the positions of the first radar unit 10 and the second radar unit 10 are set as focal points, and the sum of the distances from the two focal points is the distance index f bp mul The target may exist on an elliptical curve that is the distance for the BMS indicated by (q). Furthermore, since the direction of transmission (DOD) of the qe-th radar unit 10 and the direction of reception (DOA) of the q-th radar unit 10 are estimated, the second angle measurement unit 212 can determine the target position using the angle measurement result. The second angle measurement unit 212 may use, for example, the estimation result of the target position in such a BMS-configured radar as the positioning output.

[0210] In addition, if there is no intersection of two straight lines based on DOD and DOA on the above-mentioned elliptical curve, the second angle measurement unit 212 may determine that it is a target-directed wave, and since there is a high possibility that the target positioning result is incorrect, it may not output the positioning result as the positioning output, or may output the result determined to be a target-directed wave while outputting the positioning result as the positioning output.

[0211] Incidentally, such discrimination of target indirect waves may be processed in the subsequent integration unit 30.

[0212] Moreover, since a method for estimating a target position in a radar having a BMS is described in, for example, Non-Patent Document 6, a detailed description of the estimation method will be omitted.

[0213] An example of the operation of second angle measuring section 212 has been described above.

[0214] [Example of operation of integration unit 30] In FIG. 4, the integration unit 30 integrates the positioning outputs of the first angle measurement unit 212 and the second angle measurement unit 212 from the first radar unit 10, and the positioning outputs of the first angle measurement unit 212 and the second angle measurement unit 212 from the second radar unit 10, to locate the target.

[0215] The integration unit 30 performs a process of discriminating the indirect wave from the target object based on the output of the second angle measuring unit 212 in each radar unit 10.

[0216] For example, when the first radar unit 10 receives a reflected wave signal (e.g., a second reflected wave signal) corresponding to a radar transmission signal (e.g., a second transmission signal) transmitted from the second radar unit 10, the integrating unit 30 determines whether the second reflected wave signal is a direct wave from a target (or whether the second reflected wave signal is a target direct wave or an indirect target wave) based on the second reflected wave signal, based on the DOD of the second transmission signal transmitted from the second radar unit 10, the DOA of the second reflected wave signal received by the first radar unit 10, and the distance between the first radar unit 10 and a target (a target from which the second transmission signal is reflected). Note that the integrating unit 30 may also determine whether the second reflected wave signal is a target direct wave or an indirect target wave in a similar manner when the second radar unit 10 receives a reflected wave signal (e.g., a first reflected wave signal) corresponding to a radar transmission signal (e.g., a first transmission signal) transmitted from the first radar unit 10.

[0217] For example, the positions of the first radar unit 10 and the second radar unit 10 are set as focal points, and the sum of the distances from the two focal points is the distance index f bp mul If there is no intersection of two straight lines based on the direction of transmission (DOD) of the qe-th radar unit 10 output from the second angle measuring unit 212 in the q-th radar unit 10 and the direction of reception (DOA) of the q-th radar unit 10 on the elliptical curve that is the distance for the BMS indicated by (q), it may be determined that the wave is a target-directed wave. In this case, since there is a high possibility that the target positioning result is incorrect, for example, the integrating unit 30 may not output the positioning result as the positioning output, or may output the result determined as a target-directed wave while outputting the positioning result as the positioning output.

[0218] When the indirect wave is determined as a target-directed wave in this way, the integrating unit 30 may perform processing by excluding the positioning output determined as a target-directed wave from the positioning of the target. Alternatively, when a target with a large width, such as a wall or a vehicle, exists, the integrating unit 30 may estimate and output the target position when the indirect wave is regarded as a reflected wave from a target with a large width. Alternatively, when a road surface exists, the integrating unit 30 may estimate and output the target position when the indirect wave is regarded as a road surface reflected wave.

[0219] The same applies to the case where the second angle measuring section 212 outputs a result determined as an indirect target wave in the positioning output.

[0220] Also, for example, the integrating unit 30 may determine the type of target based on the coincidence between the positioning result of the second angle measuring unit 212 of the first radar unit 10 and the positioning result of the second angle measuring unit 212 of the second radar unit 10, which are positioning results of the BMS configuration. For example, the integrating unit 30 may utilize the fact that the coincidence is high for a pole (metal pillar) and low for a target with a large width such as a wall.

[0221] Furthermore, for example, when the detection areas overlap in the positioning output of the first angle measuring unit 212 of the first radar unit 10 and the positioning output of the first angle measuring unit 212 of the second radar unit 10, which are positioning results of the MNS configuration, the integrating unit 30 may output components with high consistency between the two estimation results. For example, the integrating unit 30 may not output components with low consistency between the two estimation results.

[0222] By performing the above-mentioned operations, the integrating unit 30 can remove target indirect waves or multipath reflections that cause false images.

[0223] The integrator 30 may output the positioning output (or the positioning result) to, for example, a vehicle control device (such as an ECU) in the case of an on-vehicle radar, or to an infrastructure control device in the case of an infrastructure radar, both not shown.

[0224] [Radar 10 antenna layout example] Next, an example of the arrangement of the transmitting antenna 103 and the receiving antenna 202 in the first radar unit 10 and the second radar unit 10, and an example of the operation of the angle measuring unit 212 when the antenna arrangement example is used will be described.

[0225] In the following description, the transmitting antenna 103 and the receiving antenna 202 in the first radar unit 10 and the second radar unit 10 will be collectively referred to as a "MIMO antenna."

[0226] In the following description, each antenna constituting the MIMO antenna may be a subarray configuration in which a plurality of antenna elements (e.g., planar patch antennas) are arranged vertically and horizontally, or may be a subarray configuration consisting of a plurality of planar patch antennas that satisfy a desired beam width. Alternatively, the MIMO antenna may be a subarray configuration in which planar patch antennas are arranged in either the vertical or horizontal direction. The more planar patch antennas that constitute the subarray in the horizontal (or vertical) direction, the sharper the directional beam in the horizontal (or vertical) direction can be formed.

[0227] In addition, the Nt(q) transmitting antennas 103 in the q-th radar unit 10 are denoted as Tx(q)#1, ~, #Nt(q), and the Na(q) receiving antennas 202 are denoted as Rx(q)#1, ~, #Na(q), where q is, for example, 1 or 2.

[0228] Below, as examples of MIMO antenna arrangements, MIMO antenna arrangements A, B, and C will be described. With these MIMO antenna arrangements, the radar device 1 can improve radar detection performance by reducing erroneous determinations of indirect waves from targets. Also, the MIMO antenna arrangements A, B, and C are antenna arrangements that expand the aperture length of the virtual receiving antenna when measuring angle with the MNS configuration and when measuring far-field angle with the BMS configuration, and can improve angle measurement performance when measuring angle with the MNS configuration and when measuring far-field angle with the BMS configuration.

[0229] The same holds true even if the first radar unit 10 and the second radar unit 10 described in the arrangement conditions for each MIMO antenna arrangement A, B, and C are replaced (e.g., swapped) with the second radar unit 10 and the first radar unit 10, respectively.

[0230] [MIMO antenna arrangement A] The MIMO antenna arrangement in the first radar unit 10 and the second radar unit 10 satisfies, for example, the following arrangement condition A.

[0231] <Placement condition A> A-1) The minimum antenna spacing MinAS(Tx(1)) among the antenna spacings (e.g., adjacent antenna spacing) of the multiple transmitting antennas 103 of the first radar unit 10 and the minimum antenna spacing MinAS(Rx(2)) among the antenna spacings of the multiple receiving antennas 202 of the second radar unit 10 each include a spacing Da that is equal to or greater than 0.5 wavelengths and less than 1 wavelength. For example, MinAS(Tx(1))<λ, MinAS(Rx(2))<λ. Here, Da may be the maximum value of MinAS(Tx(1)) and MinAS(Rx(2)). Furthermore, the minimum antenna spacing MinAS(Rx(1)) of the multiple receiving antennas 202 of the first radar unit 10 and the minimum antenna spacing MinAS(Tx(2)) of the multiple transmitting antennas 103 of the second radar unit 10 are wider than the spacing Da. For example, MinAS(Rx(1))>Da, MinAS(Tx(2))>Da.

[0232] A-2) The receiving antenna interval of the first radar unit 10 includes an interval wider than the aperture length ApTx(1) of the transmitting antenna of the first radar unit 10, and The transmitting antenna interval of the second radar unit 10 includes an interval wider than the aperture length ApRx(2) of the receiving antenna of the second radar unit 10.

[0233] A-3) The receiving antenna interval of the second radar unit 10 includes an interval wider than the aperture length ApTx(1) of the transmitting antenna of the first radar unit 10, or The transmitting antenna interval of the first radar unit 10 includes an interval wider than the aperture length ApRx(2) of the receiving antenna of the second radar unit 10.

[0234] Here, the arrangement condition A-1 has a grating suppression effect when measuring the angle in the BMS configuration and measuring the nearby target. For example, the radar device 1 can measure the DOD and DOA without a grating. In addition, when the target distance is satisfied and there is no intersection of two straight lines based on the DOD and DOA on an ellipse with the transmitting antenna positions of the first radar unit 10 and the second radar unit 10 (for example, the transmitting antenna positions of the first transmitting antennas Tx(1)#1 and Tx(2)#1) as the focal points, the radar device 1 can determine that the received reflected wave signal is a target-indirect wave and does not output an erroneous positioning result, so that it is possible to remove the target-indirect wave.

[0235] The arrangement condition A-1 is a condition under which the MIMO antenna arrangements in the first radar unit 10 and the second radar unit 10 are not the same (or the BMS configuration is asymmetric). For example, when the number of transmitting antennas and the number of receiving antennas are relatively small (for example, below a threshold), the degree of freedom of antenna arrangement between radars in the BMS configuration can be increased. This makes it possible to further expand the antenna aperture length compared to when the MIMO antenna arrangements in the first radar unit 10 and the second radar unit 10 are the same, and improves the target angle measurement accuracy and angle measurement resolution when measuring nearby targets in the BMS configuration.

[0236] Furthermore, by adding at least one of the arrangement conditions A-2 and A-3 in addition to the arrangement condition A-1, the aperture length of the virtual receiving array in the MNS configuration can be expanded, and the target angle measurement accuracy and angle measurement resolution in the MNS configuration can be improved.

[0237] In addition, the arrangement condition A-3 has the effect of expanding the aperture length of the virtual receiving array when measuring the angle in the BMS configuration, which improves the target angle measurement accuracy and angle measurement resolution when measuring the distant target in the BMS configuration.

[0238] In the following, as an example of a MIMO antenna arrangement in the first radar unit 10 and the second radar unit 10 that satisfies the arrangement condition A, an arrangement example in which the number of transmitting antennas Nt(1) = Nt(2) = 2 and the number of receiving antennas Na(1) = Na(2) = 3 is shown in FIG. 7.

[0239] In FIG. 7, the minimum antenna spacing MinAS(Tx(1)) of the transmitting antennas of the first radar unit 10 is the spacing (also called the pitch) between Tx(1)#1 and Tx(1)#2, which is 0.5 wavelengths (=0.5λ=Da). Also, in FIG. 7, the minimum antenna spacing MinAS(Rx(2)) of the receiving antennas of the second radar unit 10 is the spacing between Rx(2)#2 and Rx(2)#3, which is 0.5 wavelengths (=0.5λ=Da). Therefore, MinAS(Tx(1))<λ, MinAS(Rx(2))<λ are satisfied. Also, in FIG. 7, for example, the minimum antenna spacing MinAS(Rx(1)) of the receiving antennas of the first radar unit 10 is the spacing between Rx(1)#1 and Rx(1)#2, which is 1 wavelength (λ). Also, in Fig. 7, the minimum antenna spacing MinAS(Tx(2)) of the transmitting antennas of the second radar unit 10 is the spacing between Tx(2)#1 and Tx(2)#2, which is two wavelengths (2λ). Therefore, MinAS(Rx(1))>Da, MinAS(Tx(2))>Da. From the above, the MIMO antenna arrangement shown in Fig. 7 satisfies the arrangement condition A-1.

[0240] Furthermore, the receiving antenna spacing of the first radar unit 10 includes a spacing (for example, the spacing λ between Rx(1)#1 and Rx(1)#2) that is wider than the aperture length ApTx(1)(=0.5λ) of the transmitting antenna of the first radar unit 10, and the transmitting antenna spacing of the second radar unit 10 includes a spacing (the spacing 2λ between Tx(2)#1 and Tx(2)#2) that is wider than the aperture length ApRx(2)(=1.5λ) of the receiving antenna of the second radar unit 10. From the above, the MIMO antenna arrangement shown in FIG. 7 satisfies arrangement condition A-2.

[0241] The receiving antenna spacing of the second radar unit 10 includes a spacing (spacing λ between Rx(2)#1 and Rx(2)#2) that is wider than the aperture length ApTx(1) (=0.5λ) of the transmitting antenna of the first radar unit 10. From the above, the MIMO antenna arrangement shown in FIG. 7 satisfies arrangement condition A-3.

[0242] The MIMO antenna arrangement shown in FIG.

[0243] For example, from the MIMO antenna arrangement in the q-th radar unit 10, the arrangement VA of the virtual receiving antenna (or the MIMO virtual antenna) in the MNS configuration in the q-th radar unit 10 is MN(q) #1~VA MN(q) #(Na(q)×Nt(q)) is constructed.

[0244] In addition, from the arrangement of transmitting antennas in the qe-th radar unit 10 and the arrangement of receiving antennas in the q-th radar unit 10, the arrangement VA of the virtual receiving antennas (or MIMO virtual antennas) for distant targets in the BMS configuration in the q-th radar unit 10 is calculated. BM(q) #1~VA BM(q) #(Na(q)×Nt(qe)) is constructed.

[0245] Here, the arrangement of the virtual receiving antenna (virtual receiving array) in the qth radar unit 10 in the MNS configuration may be expressed, for example, as in the following equation (23) based on the position of the transmitting antenna (e.g., the position of the feed point) and the position of the receiving antenna (e.g., the position of the feed point) in the MNS configuration.

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[0246] Here, the position coordinates of the transmitting antenna (for example, Tx(q)#n) of the qth radar unit 10 are expressed as (X Tx(q)#n ,Y Tx(q)#n ) (e.g., n=1,~, Nt(q)), and the position coordinates of the receiving antenna (e.g., Rx(q)#z) are (X Rx(q)#z ,Y Rx(q)_#z ) (for example, z=1,~,Na(q)) and a virtual antenna VA constituting a virtual receiving array antenna is MN(q) #b's position coordinates are (X VMN(q)#b ,Y VMN(q)#b ) (for example, b = 1, ~, Nt(q) × Na(q)).

[0247] In addition, in the formula (23), for example, VA MN(q) #1 is expressed as the position reference (0,0) of the virtual receiving array. Tx(q)#n represents the horizontal position coordinate, and YTx(q)#n represents the vertical position coordinate, but is not limited to this. Here, mod(x,y) is a remainder operator that outputs the remainder when integer x is divided by integer y. ceil(x) is an operator that outputs the smallest integer equal to or greater than the argument x.

[0248] In addition, the arrangement of the virtual receiving antenna (virtual receiving array) for a distant target in the BMS configuration of the qth radar unit 10 is determined based on, for example, the position of the transmitting antenna (for example, the position of the power feed point) and the position of the receiving antenna (for example, the position of the power feed point) in the BMS configuration. For example, the position coordinates of the transmitting antenna (for example, Tx(qe)#n) in the qeth radar unit 10 are (X Tx(qe)#n ,Y Tx(qe)#n ) (for example, n=1, . . ., Nt(qe)), and the position coordinates of the receiving antenna (for example, Rx(q)#z) in the qth radar unit 10 are represented as (X Rx(q)#z ,Y Rx(q)#z ) (for example, z=1,~,Na(q)), the virtual antenna VA constituting the virtual receiving array antenna is BM(q) #b's position coordinates (X VBM(q)#b ,Y VBM(q)#b ) (for example, b = 1, ~, Nt(qe) × Na(q)) may be expressed as in equation (24).

number

[0249] 8(a) and (b) show examples of arrangements of virtual receiving antennas in the MNS configuration and the BMS configuration in each radar unit 10 configured with the MIMO antenna arrangement shown in FIG.

[0250] For example, the arrangement (X Tx(1)#1 ,Y Tx(1)#1 )=(0,0),(X Tx(1)#2 ,Y Tx(1)#2 )=(0.5λ, 0), and the arrangement of the receiving antennas Rx#1 to Rx#3 (X Rx(1)#1 ,Y Rx(1)#1 )=(ax,ay),(X Rx(1)#2 ,YRx(1)#2 )=(ax+λ,ay),(X Rx(1)#3 ,Y Rx(1)#3 In the case where ax + 2λ, ay) = (ax + 2λ, ay), the position coordinates of the virtual antenna constituting the virtual receiving antenna in the MNS configuration are calculated by equation (23). Here, ax and ay are arbitrary constants. For example, the virtual antenna VA MN(1) #1~VA MN(1) As shown in FIG. 8(a), the position coordinates of #6 are (X VMN(1)#1 ,Y VMN(1)#1 )=(0,0), (X VMN(1)#4 ,Y VMN(1)#4 )=(0.5λ, 0), (X VMN(1)#2 ,Y VMN(1)#2 )=(λ, 0), (X VMN(1)#5 ,Y VMN(1)#5 )= (1.5λ, 0), (X VMN(1)#3 ,Y VMN(1)#3 )=(2λ, 0), (X VMN(1)#6 ,Y VMN(1)#6 )=(2.5λ, 0).

[0251] As shown in FIG. 8B, the virtual receiving antenna VA BM(q) #1~VA BM(q) The position coordinates of #6 are calculated in the same manner using equation (24).

[0252] For example, the first angle measuring unit 212 of the q-th radar unit 10 described above is f bp mono (q) and the separation index information f of the DDM signal Tx Based on (q), the output from the first DA unit 209 is extracted, and the q-th virtual receiving array correlation vector h q (f bp mono (q), f Tx (q)) is generated and angle measurement processing is performed (the same applies to MIMO antenna arrangements B and C described later). Here, the b-th virtual antenna VA MN(q) The received signal by #b is expressed as the virtual receiving array correlation vector h q (f bpmono (q), f Tx The first angle measurement unit 212 performs angle measurement processing using a direction vector generated based on the arrangement of the MIMO virtual receiving antennas shown in (a) of FIG. 8 as the direction vector of the qth virtual receiving antenna in the MNS configuration.

[0253] For example, the second angle measuring unit 212 of the q-th radar unit 10 described above is f bp mul (q) and the separation index information f of the DDM signal Tx Based on (qe), the output of the second DA unit 209 is extracted, and the q-th receiving array correlation matrix H q (f bp mul (q), f Tx (qe)) is generated and used to perform angle measurement processing for nearby targets in the BMS configuration. Here, the qth receiving array correlation matrix H q (f bp mul (q), f Tx The elements in the zth row and ndmth column of the transmitting antenna Tx(qe)#ndm correspond to the received signal of the receiving antenna Rx(q)#z for the transmitting antenna Tx(qe)#ndm (the same applies to the MIMO antenna arrangements B and C described later). Tx(qe) (θ u ) based on the arrangement of transmitting antennas in the first radar unit 10 (for example, the arrangement of transmitting antennas in FIG. 7), and performs angle measurement processing of the transmission azimuth direction (DOD). Rx(q) (θ u ), a vector generated based on the receiving antenna arrangement in the qth radar unit 10 (for example, the receiving antenna arrangement in FIG. 7) is used to perform angle measurement processing of the receiving azimuth direction (DOA).

[0254] In addition, in the angle measurement process of the nearby target in the BMS configuration, the b-th virtual antenna VA BM The received signal by #b is expressed as the virtual receiving array correlation vector h qBMS (f bp mono , f Tx 8(q)) (The same applies to MIMO antenna arrangements B and C described later.) In addition, the second angle measurement unit 212 performs angle measurement processing using a direction vector generated based on the arrangement of the MIMO virtual receiving antennas shown in FIG. 8(b) as the direction vector of the qth virtual receiving antenna in the BMS configuration.

[0255] [MIMO antenna arrangement B] In the MIMO antenna arrangement B, in the first radar unit 10 and the second radar unit 10, the number of transmitting antennas Nt(q) ≧ 3 and the number of receiving antennas Na(q) ≧ 3. The MIMO antenna arrangement in the first radar unit 10 and the second radar unit 10 satisfies, for example, the following arrangement condition B.

[0256] <Placement condition B> A placement that satisfies placement condition B is a placement in which the number of transmitting antennas Nt(q) ≧3 and the number of receiving antennas Na(q) ≧3, and also satisfies the following condition.

[0257] B-1) The minimum antenna spacing MinAS(Tx(1)) among the multiple transmitting antennas 103 of the first radar unit 10 and the minimum antenna spacing MinAS(Rx(2)) among the multiple receiving antennas 202 of the second radar unit 10 each include a spacing Da that is 0.5 or more and less than one wavelength. For example, MinAS(Tx(1))<λ, MinAS(Rx(2))<λ. Furthermore, the minimum antenna spacing MinAS(Rx(1)) among the antenna spacings of the multiple receiving antennas 202 of the first radar unit 10 and the minimum antenna spacing MinAS(Tx(2)) among the antenna spacings of the multiple transmitting antennas 103 of the second radar unit 10 each include a spacing Da that is 0.5 or more and less than one wavelength. For example, MinAS(Rx(1))<λ, MinAS(Tx(2))<λ.

[0258] B-2) The spacing between the receiving antennas of each radar unit 10 includes a spacing wider than the aperture length ApTx(1) of the transmitting antenna, or the spacing between the transmitting antennas of each radar unit 10 includes a spacing wider than the aperture length ApRx(2) of the receiving antenna.

[0259] Here, the arrangement condition B-1 has a grating suppression effect when measuring the angle in the BMS configuration and measuring the nearby target. For example, the radar device 1 can measure the DOD and DOA without a grating. Furthermore, when the target distance is satisfied and there is no intersection of two straight lines based on the DOD and DOA on an ellipse with the transmitting antenna positions of the first radar unit 10 and the second radar unit 10 (for example, the transmitting antenna positions of the first transmitting antennas Tx(1)#1 and Tx(2)#1) as the focal points, the radar device 1 can determine that the target is an indirect wave and does not output an erroneous positioning result, so that it is possible to remove the indirect wave.

[0260] The arrangement condition B-1 is a condition that can be satisfied even when the MIMO antenna arrangements in the first radar unit 10 and the second radar unit 10 are the same (or a condition under which the BMS configuration is symmetrical). For example, when the number of transmitting antennas and the number of receiving antennas are three or more, the effect of expanding the antenna aperture length can be obtained, and the target angle measurement accuracy and angle measurement resolution can be improved when measuring nearby targets in the BMS configuration. In addition, by making the MIMO antenna arrangements in the first radar unit 10 and the second radar unit 10 the same, the effect of reducing the radar manufacturing costs can also be obtained.

[0261] Furthermore, by adding the arrangement condition B-2 in addition to the arrangement condition B-1, the aperture length of the virtual receiving array in the MNS configuration can be enlarged, and the target angle measurement accuracy and angle measurement resolution in the MNS configuration can be improved. For example, in the arrangement condition B-2, the antenna spacing of the multiple receiving antennas 202 of the first radar unit 10 may include a spacing wider than the aperture length of the multiple transmitting antennas 103 of the first radar unit 10, or the antenna spacing of the multiple transmitting antennas 103 of the second radar unit 10 may include a spacing wider than the aperture length of the receiving antennas 202 of the second radar unit 10. This allows the aperture length of the MIMO virtual antenna to be enlarged when measuring nearby targets in the MNS configuration, and the target angle measurement accuracy and angle measurement resolution can be improved.

[0262] Moreover, the arrangement condition B-2 has an effect of expanding the aperture length of the virtual receiving array when measuring the distance target in the angle measurement in the BMS configuration. This can improve the target angle measurement accuracy and angle measurement resolution when measuring the distance target in the BMS configuration. For example, in the arrangement condition B-2, the antenna spacing of the multiple receiving antennas 202 of the second radar unit 10 may include a spacing wider than the aperture length of the multiple transmitting antennas 103 of the first radar unit 10, or the antenna spacing of the multiple transmitting antennas 103 of the first radar unit 10 may include a spacing wider than the aperture length of the multiple receiving antennas 202 of the second radar unit 10. This can expand the aperture length of the MIMO virtual antenna when measuring the distance target in the BMS configuration, and can improve the target angle measurement accuracy and angle measurement resolution.

[0263] In the following, as an example of a MIMO antenna arrangement in the first radar unit 10 and the second radar unit 10 that satisfies arrangement condition B, an arrangement example in which the number of transmitting antennas Nt(1) = Nt(2) = 3 and the number of receiving antennas Na(1) = Na(2) = 3 is shown in FIG. 9.

[0264] In FIG. 9, the minimum antenna spacing MinAS(Tx(1)) of the transmitting antennas of the first radar unit 10 is the spacing between Tx(1)#1 and Tx(1)#2, and is 0.5 wavelengths (=0.5λ). Also, in FIG. 9, the minimum antenna spacing MinAS(Rx(2)) of the receiving antennas of the second radar unit 10 is the spacing between Rx(2)#1 and Rx(2)#2, and is 0.5 wavelengths (=0.5λ). Therefore, MinAS(Tx(1))<λ, MinAS(Rx(2))<λ are satisfied. Also, in FIG. 9, for example, the minimum antenna spacing MinAS(Rx(1)) of the receiving antennas of the first radar unit 10 is the spacing between Rx(1)#1 and Rx(1)#2, and is 0.5 wavelengths (0.5λ). Also, in Fig. 9, the minimum antenna spacing MinAS(Tx(2)) in the transmitting antennas of the second radar unit 10 is the spacing between Tx(2)#1 and Tx(2)#2, and is 0.5 wavelengths (0.5λ). Therefore, MinAS(Rx(1)) < λ, MinAS(Tx(2)) < λ. From the above, the MIMO antenna arrangement shown in Fig. 9 satisfies the arrangement condition B-1.

[0265] Furthermore, the receiving antenna spacing of the first radar unit 10 includes a spacing (for example, the spacing between Rx(1)#2 and Rx(1)#3, 2λ) that is wider than the aperture length ApTx(1)(=1.5λ) of the transmitting antenna of the first radar unit 10, and the receiving antenna spacing of the second radar unit 10 includes a spacing (the spacing between Rx(2)#2 and Rx(2)#3, 2λ) that is wider than the aperture length ApTx(2)(=1.5λ) of the transmitting antenna of the second radar unit 10. From the above, the MIMO antenna arrangement shown in FIG. 9 satisfies arrangement condition B-2.

[0266] The MIMO antenna arrangement shown in FIG.

[0267] For example, from the MIMO antenna arrangement in the first radar unit 10 and the second radar unit 10, the arrangement VA of the virtual receiving antenna (or the MIMO virtual antenna) in the MNS configuration is MN(1) #1~VA MN(1) #9 and VA MN(2) #1~VA MN(2) #9 is configured.

[0268] In addition, the arrangement VA of the virtual receiving antenna (or MIMO virtual antenna) for a distant target in the BMS configuration in the qth radar unit 10 is BM(q) #1~VA BM(q) #9 is constructed. q=1, 2.

[0269] The arrangement of virtual receiving antennas in the MNS configuration and the BMS configuration configured by the MIMO antenna arrangement shown in FIG. 9 is the same, for example, as shown in FIG.

[0270] For example, the first angle measurement unit 212 of the above-mentioned qth radar unit 10 performs angle measurement processing using a direction vector generated based on the arrangement of the MIMO virtual receiving antennas shown in Figure 10 as the direction vector of the qth virtual receiving antenna in the MNS configuration.

[0271] For example, the second angle measuring unit 212 of the q-th radar unit 10 described above measures the transmitting array direction vector a Tx(qe) (θ u ) is generated based on the arrangement of transmitting antennas in the first radar unit 10 (for example, the arrangement of transmitting antennas in FIG. 9). The second angle measuring unit 212 performs angle measuring processing of the transmitting azimuth direction (DOD) using a vector generated based on the arrangement of transmitting antennas in the first radar unit 10 (for example, the arrangement of transmitting antennas in FIG. 9). Rx(q) (θ u ), a vector generated based on the receiving antenna arrangement in the qth radar unit 10 (for example, the receiving antenna arrangement in FIG. 9) is used to perform angle measurement processing of the receiving azimuth direction (DOA).

[0272] Moreover, the second angle measuring unit 212 performs angle measuring processing on the direction vector of the qth virtual receiving antenna in the BMS configuration, using a direction vector generated based on the arrangement of the MIMO virtual receiving antennas in FIG.

[0273] [MIMO antenna arrangement C] The MIMO antenna arrangement in the first radar unit 10 and the second radar unit 10 satisfies, for example, the following arrangement condition C.

[0274] <Placement condition C> C-1) The minimum antenna spacing MinAS(Tx(1)) among the multiple transmitting antennas 103 of the first radar unit 10 and the minimum antenna spacing MinAS(Rx(2)) among the multiple receiving antennas 202 of the second radar unit 10 are one wavelength or more and are different from each other (not an integer multiple relationship). For example, MinAS(Tx(1)) ≧ λ, MinAS(Rx(2)) ≧ λ, and MinAS(Tx(1)) ≠ MinAS(Rx(2)). Furthermore, the minimum antenna spacing MinAS(Rx(1)) among the antenna spacings of the multiple receiving antennas 202 of the first radar unit 10 and the minimum antenna spacing MinAS(Tx(2)) among the antenna spacings of the multiple transmitting antennas 103 of the second radar unit 10 are one wavelength or more and are different from each other (are not in an integer multiple relationship), and at least one of the minimum antenna spacings of the transmitting antennas or the minimum antenna spacings of the receiving antennas between the radar units 10 is different. For example, MinAS(Rx(1)) ≧ λ, MinAS(Tx(2)) ≧ λ, and at least one of MinAS(Rx(1)) ≠ MinAS(Rx(2)) or MinAS(Tx(1)) ≠ MinAS(Tx(2)) is satisfied.

[0275] C-2) The transmission antenna spacing and the reception antenna spacing of the first radar unit 10 are determined by the absolute value SD MN1 The second radar unit 10 includes a transmission antenna interval and a reception antenna interval that are equal to or larger than 0.5 wavelengths and equal to or smaller than 0.8 wavelengths, and the transmission antenna interval and the reception antenna interval of the second radar unit 10 include an absolute value SD MN2 The interval where is equal to or greater than 0.5 wavelengths and equal to or less than 0.8 wavelengths is included.

[0276] C-3) The transmission antenna interval of the first radar unit 10 and the reception antenna interval of the second radar unit 10 are determined by the absolute value SD of the difference between the transmission antenna interval of the first radar unit 10 and the reception antenna interval of the second radar unit 10. BM12The transmission antenna spacing of the second radar unit 10 and the receiving antenna spacing of the first radar unit 10 include a spacing that is equal to or greater than 0.5 wavelengths and equal to or less than 0.8 wavelengths, and the absolute value SD of the difference between the transmission antenna spacing of the second radar unit 10 and the receiving antenna spacing of the first radar unit 10 is BM21 The interval where is equal to or greater than 0.5 wavelengths and equal to or less than 0.8 wavelengths is included.

[0277] Here, in measuring angles in a BMS configuration, the radar device 1 selects and determines a DOD / DOA that is on an ellipse (e.g., on an ellipse with the transmitting antenna positions of the first transmitting antennas Tx(1)#1 and Tx(2)#1 as its focal point) that satisfies the target distance from among combinations of peak directions (e.g., peak directions including gratings) in the DOD / DOA when positioning a nearby target. In this case, for example, the DOD or DOA of the indirect wave from the target may coincide with the grating direction due to the interval between the transmitting antennas of the first radar unit 10 or the interval between the receiving antennas of the second radar unit 10. Even in this case, by satisfying the arrangement condition C-1, the interval between the transmitting antennas of the second radar unit 10 or the interval between the receiving antennas of the first radar unit 10 is different from the interval between the transmitting antennas in the first radar unit 10 and the interval between the receiving antennas in the second radar unit 10, so that the DOD or DOA of the indirect wave from the target does not match the grating direction of the interval between the transmitting antennas of the second radar unit 10 or the interval between the receiving antennas of the first radar unit 10. Therefore, when measuring nearby targets in the BMS configuration in the first radar unit 10 or the second radar unit 10, the subsequent integrating unit 30 can detect and remove the indirect wave from the target.

[0278] For example, the integration unit 30 determines whether the first reflected wave signal and the second reflected wave signal are direct waves from a target (or whether they are direct waves from the target or indirect waves from the target) based on a comparison between a positioning result (e.g., DOD and DOA) using a reflected wave signal (e.g., a first reflected wave signal) corresponding to a transmission signal transmitted from the second radar unit 10 and received at the first radar unit 10, and a positioning result (e.g., DOD and DOA) using a reflected wave signal (e.g., a second reflected wave signal) corresponding to a transmission signal transmitted from the first radar unit 10 and received at the second radar unit 10. As described above, the antenna arrangement is asymmetric between the first radar section 10 and the second radar section 10, and therefore the grating direction for the signal transmitted from the first radar section 10 to the second radar section 10 constituting the BMS is different from the grating direction for the signal transmitted from the second radar section 10 to the first radar section 10 constituting the BMS. This enables the radar device 1 to detect and remove indirect waves from targets based on a comparison of the positioning results in each BMS configuration.

[0279] The arrangement condition C-1 is a condition under which the MIMO antenna arrangements in the first radar unit 10 and the second radar unit 10 are not the same (or the BMS configuration is asymmetric). For example, when the number of transmitting antennas and the number of receiving antennas are relatively small (for example, below a threshold), the degree of freedom of antenna arrangement between radars in the BMS configuration can be increased. This makes it possible to further expand the antenna aperture length compared to when the MIMO antenna arrangements in the first radar unit 10 and the second radar unit 10 are the same, and improves the target angle measurement accuracy and angle measurement resolution when measuring nearby targets in the BMS configuration.

[0280] Furthermore, by satisfying arrangement condition C-2, the virtual receiving antenna spacing includes the absolute value of the difference between the transmitting antenna spacing and the receiving antenna spacing. Therefore, according to equation (23), the virtual receiving antenna spacing includes spacing of 0.5 to 0.8 wavelengths. This makes it possible to suppress grating lobes while expanding the aperture length of the virtual receiving array in the MNS configuration, thereby improving the target angle measurement accuracy and angle measurement resolution in the MNS configuration.

[0281] Similarly, by satisfying the arrangement condition C-3, the virtual receiving antenna spacing when measuring distant targets in the BMS configuration includes spacing of 0.5 to 0.8 wavelengths according to formula (24). This makes it possible to suppress grating lobes while expanding the aperture length of the virtual receiving array in the BMS configuration, thereby improving the target angle measurement accuracy and angle measurement resolution in the BMS configuration.

[0282] In addition, SD MN1 , S.D. MN2 , S.D. BM12 and S.D. BM21 For example, the SD may be set according to the viewing angle of the radar device 1, and grating lobes within the viewing angle can be suppressed. For example, when the transmitting and receiving antennas are arranged in the horizontal direction, and the viewing angle in the horizontal direction is a wide viewing angle in the range of about ±70 degrees to ±90 degrees, MN1 , S.D. MN2 , S.D. BM12 and S.D. BM21 Alternatively, when the horizontal viewing angle is narrow, in the range of about ±20 degrees to ±40 degrees, the intervals may be set to be wider, for example, SD MN1 , S.D. MN2 , S.D. BM12 and S.D. BM21 and may be set to about 0.7λ, where λ represents the wavelength of the carrier frequency of the radar transmission signal. For example, when a chirp signal is used as the radar transmission signal, λ is the wavelength of the center frequency in the frequency sweep band of the chirp signal.

[0283] In the following, as an example of a MIMO antenna arrangement in the first radar unit 10 and the second radar unit 10 that satisfies the arrangement condition C, an arrangement example in which the number of transmitting antennas Nt(1) = Nt(2) = 2 and the number of receiving antennas Na(1) = Na(2) = 3 is shown in FIG. 11.

[0284] 11, the minimum antenna spacing between the transmitting and receiving antennas of the first radar unit 10 is MinAS(Tx(1))=λ, MinAS(Rx(1))=1.6λ, and the minimum antenna spacing between the transmitting and receiving antennas of the second radar unit 10 is MinAS(Tx(2))=2.1λ, MinAS(Rx(2))=1.6λ. Therefore, since MinAS(Tx(1)) ≠ MinAS(Tx(2)), the arrangement condition C-1 is satisfied.

[0285] The absolute value SD of the difference between the transmission antenna interval and the reception antenna interval in the first radar unit 10 MN1 is 0.6λ, and the absolute value of the difference between the transmitting antenna spacing and the receiving antenna spacing in the second radar unit 10, SD MN2 is 0.5λ, and an interval in which the difference value is equal to or greater than 0.5 wavelengths and is 0.8 wavelengths is included, so that the arrangement condition C-2 is satisfied.

[0286] The absolute value of the difference between the transmission antenna interval of the first radar unit 10 and the reception antenna interval of the second radar unit 10, SD BM12 is 0.6λ, and the absolute value of the difference between the transmission antenna spacing of the second radar unit 10 and the reception antenna spacing of the first radar unit 10, SD BM21 is 0.5λ, and both include intervals in which the difference value is 0.5 or more and 0.8 wavelengths or less, so that the arrangement condition C-3 is satisfied.

[0287] The MIMO antenna arrangement shown in FIG.

[0288] For example, from the MIMO antenna arrangement in the first radar unit 10 and the second radar unit 10, the arrangement VA of the virtual receiving antenna (or the MIMO virtual antenna) in the MNS configuration is MN(q) #1~VA MN(q) #6 is configured.

[0289] In addition, the arrangement VA of the virtual receiving antenna (or MIMO virtual antenna) for a distant target in the BMS configuration in the qth radar unit 10 is BM(q) #1~VA BM(q) #6 is constructed. q=1 or 2.

[0290] 12(a) and 12(b) show examples of arrangements of virtual receiving antennas in the MNS configuration and the BMS configuration formed by the MIMO antenna arrangement of FIG.

[0291] For example, the first angle measurement unit 212 of the above-mentioned qth radar unit 10 performs angle measurement processing using a direction vector generated based on the arrangement of the MIMO virtual receiving antennas shown in (a) of Figure 12 as the direction vector of the qth virtual receiving antenna in the MNS configuration.

[0292] For example, the second angle measuring unit 212 of the q-th radar unit 10 described above measures the transmitting array direction vector a Tx(qe) (θ u 11) in the second radar unit 10. The second angle measuring unit 212 performs angle measurement processing of the transmission azimuth direction (DOD) using a vector generated based on the arrangement of the transmitting antennas in the second radar unit 10 (for example, the arrangement of the transmitting antennas in FIG. 11). Rx(q) (θ u 11) in the qth radar unit 10, a vector is generated based on the arrangement of receiving antennas in the qth radar unit 10 (for example, the arrangement of receiving antennas in FIG. 11) to measure the angle of the receiving azimuth (DOA).

[0293] In addition, the second angle measurement unit 212 can perform angle measurement processing using a direction vector generated based on the arrangement of the MIMO virtual receiving antennas shown in (b) of Figure 12 as the direction vector of the qth virtual receiving antenna in the BMS configuration.

[0294] The above describes examples of MIMO antenna arrangements.

[0295] As described above, in this embodiment, the radar device 1 can remove the indirect target wave from the nearby target in the BMS configuration, and can improve the angle measurement performance in the MNS configuration and the BMS configuration. Therefore, according to this embodiment, the radar device 1 can detect the target efficiently.

[0296] (Variation 1) The MIMO antenna arrangement may be an arrangement in which the following condition A-4 is further added to the above-mentioned arrangement condition A.

[0297] A-4) The antenna spacing of the multiple transmitting antennas 103 of the second radar unit 10 and the antenna spacing of the multiple receiving antennas 202 of the first radar unit 10 are determined by the absolute value SD of the difference between the transmitting antenna spacing of the second radar unit 10 and the receiving antenna spacing of the first radar unit 10. BM21 The interval where is equal to or greater than 0.5 wavelengths and equal to or less than 0.8 wavelengths is included.

[0298] By satisfying the arrangement condition A-4, the virtual receiving antenna spacing when measuring distant targets in the BMS configuration includes spacing of 0.5 to 0.8 wavelengths according to formula (24). This makes it possible to suppress grating lobes while expanding the aperture length of the virtual receiving array in the BMS configuration, thereby improving the target angle measurement accuracy and angle measurement resolution in the BMS configuration.

[0299] In the following, as an example of a MIMO antenna arrangement in the first radar unit 10 and the second radar unit 10 that satisfies the arrangement conditions A-1 to A-4, an arrangement example in which the number of transmitting antennas Nt(1) = Nt(2) = 2 and the number of receiving antennas Na(1) = Na(2) = 3 is shown in FIG. 13.

[0300] FIG. 13 shows an example of an arrangement similar to the example of the MIMO antenna arrangement shown in FIG. 7, in which the distance between the receiving antennas Rx(1)#1 and Rx(1)#2 of the first radar unit 10 is changed from λ to 1.5λ, but otherwise the arrangement is the same as that shown in FIG. 7. The MIMO antenna arrangement shown in FIG. 13 satisfies the arrangement conditions A-1, A-2, and A-3, as in FIG. 7. Also, as shown in FIG. 13, the distance between Rx(1)#1 and Rx(1)#2 is 1.5λ, and the distance between Tx(2)#1 and Tx(2)#2 is 2λ, so the absolute value SD of the difference between these distances BM21 is 0.5 wavelength, which satisfies the arrangement condition A-4.

[0301] 14(a) and 14(b) show examples of arrangements of virtual receiving antennas in the MNS configuration and the BMS configuration in each radar unit 10 configured with the MIMO antenna arrangement shown in FIG.

[0302] For example, from the MIMO antenna arrangement in the radar unit 10 and the second radar unit 10 shown in FIG. 13, the arrangement VA of the virtual receiving antenna (or the MIMO virtual antenna) in the MNS configuration is as shown in FIG. 14(a). MN(1) #1~VA MN(1) #6 and VA MN(2) #1~VA MN(2) #6 is configured.

[0303] In addition, as shown in FIG. 14(b), the arrangement VA of the virtual receiving antenna (or MIMO virtual antenna) for the distant target in the BMS configuration is BM(q) #1~VA BM(q) #6 is constructed. q=1, 2.

[0304] For example, in the first radar unit 10 shown in FIG. 8B, the virtual receiving antenna arrangement VA for a distant target in the BMS configuration is BM(1) #1~VA BM(1) In the case of #6, there is no spacing narrower than one wavelength, and the spacing is such that it is difficult to suppress grating lobes. On the other hand, the MIMO antenna layout shown in FIG. 13, which satisfies the layout condition A-4, is the layout VA of the virtual receiving antenna for a distant target in the BMS configuration in the first radar unit 10 shown in FIG. 14(b). BM(1) #1~VA BM(1) #6 includes an interval of 0.5 wavelengths narrower than one wavelength, and the aperture of the virtual receiving antenna is expanded from 4λ in Fig. 8(b) to 4.5λ. By satisfying placement condition A-4 in this way, it becomes possible to suppress grating lobes while expanding the aperture length of the virtual receiving array in the BMS configuration, and it is possible to improve the target angle measurement accuracy and angle measurement resolution in the BMS configuration.

[0305] (Variation 2) The MIMO antenna arrangement may be an arrangement in which the following condition B-3 is further added to the above-mentioned arrangement condition B.

[0306] B-3) The transmission antenna interval of the second radar unit 10 and the reception antenna interval of the first radar unit 10 are determined by the absolute value SD BM21 includes the interval of 0.5 to 0.8 wavelengths.

[0307] By satisfying the arrangement condition B-3, the virtual receiving antenna spacing when measuring distant targets in the BMS configuration includes spacing of 0.5 to 0.8 wavelengths according to equation (24). This makes it possible to suppress grating lobes while expanding the aperture length of the virtual receiving array in the BMS configuration, thereby improving the target angle measurement accuracy and angle measurement resolution in the BMS configuration.

[0308] (Variation 3) In the above-mentioned example of arrangement satisfying the arrangement conditions A, B, and C, an example has been described in which an arrangement in a one-dimensional direction (for example, the horizontal direction) is shown and the angle measuring unit 212 measures the angle in the azimuth direction, but the present invention is not limited to this.

[0309] For example, each of the arrangement examples may be an arrangement in the vertical direction, in which case the angle measuring unit 212 can measure the elevation angle.

[0310] Furthermore, for example, the following two-dimensional arrangement condition (Ya, Yb, or Yc) may be added to each of the arrangement conditions A, B, and C, so that the MIMO antennas are arranged two-dimensionally (for example, horizontally and vertically). The two-dimensional arrangement of the MIMO antennas enables the angle measurement unit 212 to measure the elevation angle in addition to the azimuth direction. This allows the radar device 1 to detect the three-dimensional coordinates of the target. Here, Y may be any one of A, B, or C.

[0311] Furthermore, for example, a MIMO antenna arrangement that satisfies the following two-dimensional arrangement condition (Ya, Yb or Yc) together with the arrangement condition X has, in addition to the effect obtained by the arrangement that satisfies the arrangement condition X, a grating suppression effect in a direction different from the arrangement direction that satisfies the arrangement condition X (for example, a direction perpendicular to the arrangement direction) during nearby target positioning in a BMS configuration.

[0312] In the following arrangement conditions, X and Y are either arrangement condition A, B, or C, and X and Y may be different combinations.

[0313] <2D arrangement condition X-Ya> In addition to satisfying the placement condition X in a one-dimensional direction (eg, the horizontal direction), the placement condition Y-1 is satisfied in an orthogonal direction (eg, the vertical direction).

[0314] <2D arrangement condition X-Yb> In addition to satisfying the placement condition X in a one-dimensional direction (eg, the horizontal direction), the placement conditions Y-1 and Y-2 are satisfied in an orthogonal direction (eg, the vertical direction).

[0315] <2D arrangement condition X-Yc> In addition to satisfying placement condition X in a one-dimensional direction (e.g., the horizontal direction), placement conditions Y-1, Y-2, and Y-3 are satisfied in an orthogonal direction (e.g., the vertical direction) (except when Y is placement condition B).

[0316] For example, when the arrangement direction that satisfies the arrangement condition X is the horizontal direction, there is a grating suppression effect in the direction of the MIMO antenna arrangement that satisfies the two-dimensional arrangement condition (Ya, Yb or Yc) (for example, a direction perpendicular to the horizontal direction).

[0317] Furthermore, when the target distance is satisfied and there is no intersection of two straight lines based on the two-dimensional DOD and two-dimensional DOA on an ellipsoid having its focus at the transmitting antenna positions of the first radar unit 10 and the second radar unit 10 (for example, the transmitting antenna positions of the first transmitting antennas Tx(1) #1 and Tx(2) #1), the radar device 1 can determine that the corresponding reflected wave is an indirect wave from the target and does not output an erroneous positioning result, thereby making it possible to remove the indirect wave from the target.

[0318] Furthermore, a MIMO antenna arrangement that satisfies the two-dimensional arrangement condition (Yb or Yc) together with the arrangement condition X can increase the aperture length of the virtual receiving array in the MNS configuration in a direction different from the arrangement direction that satisfies the arrangement condition X (for example, a direction perpendicular to the arrangement direction), in addition to the effect obtained by the arrangement that satisfies the arrangement condition X, thereby improving the target angle measurement accuracy and angle measurement resolution in the MNS configuration. Furthermore, for example, a MIMO antenna arrangement that satisfies the two-dimensional arrangement condition (Yc) also has the effect of increasing the aperture length of the virtual receiving array when measuring angles in the BMS configuration, thereby improving the target angle measurement accuracy and angle measurement resolution when measuring distant targets in the BMS configuration.

[0319] In addition, in each arrangement condition, the same holds true even if the first radar section 10 and the second radar section 10 are replaced (switched) with the second radar section 10 and the first radar section 10, respectively. Moreover, the same holds true even if the first radar section 10 and the second radar section 10 in arrangement condition X are replaced (switched) with the second radar section 10 and the first radar section 10, respectively, in arrangement condition Y.

[0320] Below, we show an example of a MIMO antenna arrangement that satisfies the two-dimensional arrangement conditions.

[0321] For example, the arrangement of the virtual receiving antenna in the qth radar unit 10 in the MNS configuration can be shown using equation (23) based on the position of the transmitting antenna (e.g., the position of the feed point) and the position of the receiving antenna (e.g., the position of the feed point) in the MNS configuration (not shown). Similarly, the arrangement of the virtual receiving antenna for a distant target in the qth radar unit 10 in the BMS configuration can be shown using equation (24) based on the position of the transmitting antenna (e.g., the position of the feed point) and the position of the receiving antenna (e.g., the position of the feed point) in the BMS configuration (not shown).

[0322] Fig. 15 shows an example of an arrangement in which MIMO antennas in the first radar unit 10 and the second radar unit 10 are added in the vertical direction (e.g., the vertical direction in Fig. 15) to a MIMO antenna arrangement (e.g., the arrangement shown in Fig. 7) that satisfies arrangement condition A in the horizontal direction (e.g., the horizontal direction in Fig. 15) so as to satisfy two-dimensional arrangement condition A-Ac. In the example of Fig. 15, the number of transmitting antennas Nt(1) = Nt(2) = 4, and the number of receiving antennas Na(1) = Na(2) = 4.

[0323] The following describes the arrangement portion added in the vertical direction in FIG.

[0324] Minimum antenna spacing MinAS in the vertical direction of the transmitting antennas of the first radar unit 10 V (Tx(1)) is the distance between Tx(1)#1 and Tx(1)#3, which is 0.5 wavelengths (=0.5λ=Da), and is the minimum antenna distance MinAS in the vertical direction of the receiving antenna of the second radar unit 10. V (Rx(2)) is the distance between Rx(2)#3 and Rx(2)#4, which is 0.5 wavelengths (=0.5λ=Da). Therefore, MinAS V (Tx(1))<λ, MinAS V (Rx(2))<λ.

[0325] In addition, the minimum antenna spacing MinAS in the vertical direction of the receiving antenna of the first radar unit 10 V(Rx(1)) is, for example, the distance between Rx(1)#3 and Rx(1)#4, which is two wavelengths (2λ), and is the minimum antenna distance MinAS in the vertical direction of the transmission antenna of the second radar unit 10. V (Tx(2)) is, for example, the interval between Tx(2)#1 and Tx(2)#3, which is one wavelength (λ). V (Rx(1))>Da, MinAS V (Tx(2))>Da.

[0326] From the above, in the MIMO antenna arrangement shown in FIG. 15, the vertical arrangement portion satisfies the arrangement condition A-1.

[0327] Moreover, the vertical receiving antenna spacing of the first radar unit 10 includes a spacing (for example, a spacing of 2λ between Rx(1)#3 and Rx(1)#4) that is wider than the aperture length ApTxV(1)(=1.5λ) of the vertical transmitting antenna of the first radar unit 10. Moreover, the vertical transmitting antenna spacing of the second radar unit 10 includes a spacing (for example, a spacing λ between Tx(2)#1 and Tx(2)#3) that is wider than the aperture length ApRxV(2)(=0.5λ) of the vertical receiving antenna of the second radar unit 10. From the above, in the MIMO antenna arrangement shown in FIG. 15, the vertical arrangement portion satisfies arrangement condition A-2.

[0328] Furthermore, the spacing between the transmitting antennas in the vertical direction of the first radar unit 10 includes a spacing (spacing λ between Tx(1) #3 and Tx(1) #4) that is wider than the aperture length ApRxV(2) (=0.5λ) of the receiving antennas in the vertical direction of the second radar unit 10. From the above, in the MIMO antenna arrangement shown in Fig. 15, the vertical arrangement portion satisfies arrangement condition A-3.

[0329] 15 satisfies the two-dimensional arrangement conditions A-Ac. With such an arrangement, the above-mentioned effects can be obtained.

[0330] Note that FIG. 15 shows an example of an arrangement in which one vertical column satisfies the two-dimensional arrangement condition A-Ac, but is not limited to this. For example, as shown in FIG. 16, an arrangement in which multiple vertical columns satisfy the two-dimensional arrangement condition A-Ac may be used.

[0331] Furthermore, similar to the two-dimensional arrangement conditions A-Ac shown in FIGS. 15 and 16, non-limiting examples of the present disclosure are also applicable to other two-dimensional arrangement conditions.

[0332] Fig. 17 shows an example of an arrangement in which MIMO antennas in the first radar unit 10 and the second radar unit 10 are added in the vertical direction (e.g., the vertical direction in Fig. 17) to a MIMO antenna arrangement (e.g., the arrangement shown in Fig. 7) that satisfies arrangement condition A in the horizontal direction (e.g., the horizontal direction in Fig. 17) so as to satisfy two-dimensional arrangement condition A-Ab. In the example of Fig. 17, the number of transmitting antennas Nt(1) = Nt(2) = 3, and the number of receiving antennas Na(1) = Na(2) = 4.

[0333] The following describes the arrangement portion added in the vertical direction in FIG.

[0334] Minimum antenna spacing MinAS in the vertical direction of the transmitting antennas of the second radar unit 10 V (Tx(2)) is the distance between Tx(2)#1 and Tx(2)#3, which is 0.5 wavelengths (=Da), and is the minimum antenna distance MinAS in the vertical direction of the receiving antenna of the first radar unit 10. V (Rx(1)) is the distance between Rx(1)#3 and Rx(2)#4, which is 0.5 wavelengths (=Da). Therefore, MinAS V (Tx(2))<λ, MinAS V (Rx(1))<λ.

[0335] In addition, the minimum antenna spacing MinAS in the vertical direction of the receiving antenna of the second radar unit 10 V (Rx(2)) is, for example, the distance between Rx(2)#3 and Rx(2)#4, which is one wavelength (λ), and is the minimum antenna distance MinAS in the vertical direction of the receiving antenna of the first radar unit 10. V(Tx(1)) is, for example, the interval between Tx(1)#1 and Tx(1)#3, which is 1.5 wavelengths (1.5λ). V (Rx(2))>Da, MinAS V (Tx(1))>Da.

[0336] From the above, in the MIMO antenna arrangement shown in FIG. 17, the vertical arrangement portion satisfies the arrangement condition A-1.

[0337] Furthermore, the vertical receiving antenna spacing of the second radar unit 10 includes a spacing (for example, spacing λ between Rx(2)#3 and Rx(2)#4) that is wider than the aperture length ApTxV(2)(=0.5λ) of the vertical transmitting antenna of the second radar unit 10, and the vertical transmitting antenna spacing of the first radar unit 10 includes a spacing (spacing 1.5λ between Tx(2)#1 and Tx(2)#3) that is wider than the aperture length ApRxV(1)(=0.5λ) of the vertical receiving antenna of the first radar unit 10. From the above, in the MIMO antenna arrangement shown in FIG. 17, the vertical arrangement portion satisfies arrangement condition A-2.

[0338] Moreover, the vertical transmitting antenna spacing of the second radar unit 10 does not include a spacing wider than the aperture length ApRxV(1) (=0.5λ) of the vertical receiving antenna of the first radar unit 10. Moreover, the vertical receiving antenna spacing of the first radar unit 10 does not include a spacing wider than the aperture length ApTxV(2) (=0.5λ) of the vertical transmitting antenna of the second radar unit 10. For the above reasons, in the MIMO antenna arrangement shown in FIG. 17, the vertical arrangement portion does not satisfy arrangement condition A-3.

[0339] 17 satisfies the two-dimensional arrangement condition A-Ab. With such an arrangement, the effects of the above-mentioned two-dimensional arrangement condition A-Ab can be obtained.

[0340] 15 to 17, a case has been described in which the MIMO antennas added vertically to the MIMO antenna arrangement shown in FIG. 7 are arranged so that their horizontal positions match (so that they are lined up vertically); however, this is not limited to this, and the MIMO antennas may be arranged so that their horizontal positions differ (for example, diagonally upward or diagonally downward).

[0341] For example, Fig. 18 shows an example of an arrangement in which the horizontal positions of the MIMO antennas added in the vertical direction shown in Fig. 17 are offset to be different. For example, in Fig. 18, Tx(1)#3 is arranged with a 1.5λ offset from the horizontal position of Tx(1)#1, and Rx(1)#4 is arranged with a 0.5λ offset from the horizontal position of Rx(1)#3. Also, Tx(2)#3 is arranged with a 0.5λ offset from the horizontal position of Tx(2)#1, and Rx(2)#4 is arranged with a λ offset from the horizontal position of Rx(2)#3.

[0342] In the MIMO antenna arrangement shown in Fig. 18, the vertical arrangement relationship is the same as that in Fig. 17, the two-dimensional arrangement condition A-Ab is satisfied, and the above-mentioned effects can be obtained. Note that the non-limiting examples of the present disclosure can be similarly applied to other two-dimensional arrangement conditions.

[0343] Fig. 19 shows an example of an arrangement in which a MIMO antenna in the qth radar unit 10 is added in the vertical direction to the MIMO antenna arrangement shown in Fig. 9 which satisfies the arrangement condition B, so as to satisfy the two-dimensional arrangement condition B-Bb. For example, in Fig. 19, the number of transmitting antennas Nt(1) = Nt(2) = 5, and the number of receiving antennas Na(1) = Na(2) = 5. Note that the MIMO antenna arrangements of the first radar unit 10 and the second radar unit 10 are the same, and q in Fig. 19 is q = 1 for the first radar unit 10, and q = 2 for the second radar unit 10.

[0344] The following describes the arrangement portion added in the vertical direction in FIG.

[0345] In FIG. 19, the minimum antenna spacing MinAS in the vertical direction of the transmission antenna of the first radar unit 10 V (Tx(1)) is the interval between Tx(1)#1 and Tx(1)#4, which is 0.5 wavelengths (=0.5λ), and is the minimum antenna interval MinAS in the vertical direction of the receiving antenna of the second radar unit 10. V (Rx(2)) is the distance between Rx(2)#3 and Rx(2)#4, which is 0.5 wavelengths (=0.5λ). Therefore, MinAS V (Tx(1))<λ, MinAS V (Rx(2))<λ.

[0346] In addition, the minimum antenna spacing MinAS in the vertical direction of the receiving antenna of the first radar unit 10 V (Rx(1)) is, for example, the distance between Rx(1)#3 and Rx(1)#4, which is 0.5 wavelengths (0.5λ), and is the minimum antenna distance MinAS in the vertical direction of the transmission antenna of the second radar unit 10. V (Tx(2)) is, for example, the interval between Tx(2)#1 and Tx(2)#4, which is 0.5 wavelengths (0.5λ). V (Rx(1)) < λ, MinAS V (Tx(2)) < λ.

[0347] As described above, in the MIMO antenna arrangement shown in FIG. 19, the vertical arrangement portion satisfies arrangement condition B-1.

[0348] Also, the vertical receiving antenna spacing of the qth radar unit 10 includes a spacing (for example, a spacing of 2λ between Rx(q)#4 and Rx(q)#5) wider than the aperture length ApTxV(q) (=1.5λ) of the transmitting antenna of the qth radar unit 10 (where q=0 and 1). From the above, in the MIMO antenna arrangement shown in Fig. 19, the vertical arrangement portion satisfies arrangement condition B-2.

[0349] As a result, in the MIMO antenna arrangement shown in Fig. 19, the vertical arrangement portion satisfies arrangement condition B. The MIMO antenna arrangement shown in Fig. 19 satisfies two-dimensional arrangement condition B-Bc. With such an arrangement, the effect of the above-mentioned two-dimensional arrangement condition B-Bc can be obtained.

[0350] Fig. 20 shows an example of an arrangement in which a MIMO antenna in the qth radar unit 10 is added in the vertical direction to satisfy two-dimensional arrangement condition C-Cc to the MIMO antenna arrangement shown in Fig. 11 which satisfies arrangement condition C. For example, in Fig. 20, the number of transmitting antennas Nt(1) = Nt(2) = 3, and the number of receiving antennas Na(1) = Na(2) = 4.

[0351] The following describes the arrangement portion added in the vertical direction in FIG.

[0352] In FIG. 20, the minimum antenna spacing MinAS in the vertical direction of the transmitting and receiving antennas of the first radar unit 10 V (Tx(1))=1.6λ, MinAS V (Rx(1))=λ, and the minimum antenna spacing MinAS V (Tx(2))=1.6λ, MinAS V (Rx(2))=2.1λ. Therefore, MinAS V (Rx(1)) ≠ MinAS V Since it is (Rx(2)), it satisfies the placement condition C-1.

[0353] In addition, in the transmission and reception antenna spacing of the first radar unit 10 and the second radar unit 10, the absolute value SD of the difference between the transmission antenna spacing and the reception antenna spacing in the vertical direction of the first radar unit 10 MN1 is 0.6λ, and the absolute value of the difference between the transmission antenna spacing and the reception antenna spacing of the second radar unit 10 in the vertical direction, SD MN2 is 0.5λ, and includes an interval where the difference is 0.5 to 0.8 wavelengths, so that the arrangement condition C-2 is satisfied.

[0354] The absolute value of the difference between the vertical spacing between the transmitting antennas of the first radar unit 10 and the vertical spacing between the receiving antennas of the second radar unit 10 is SD BM12 is 0.5λ, and the absolute value SD of the difference between the vertical spacing of the transmitting antennas of the second radar unit 10 and the vertical spacing of the receiving antennas of the first radar unit 10 is BM21 is 0.6λ, and both include intervals of 0.5 to 0.8 wavelengths, so that the arrangement condition C-3 is satisfied.

[0355] As a result, in the MIMO antenna arrangement shown in Fig. 20, the vertical arrangement portion satisfies the arrangement condition C. The MIMO antenna arrangement shown in Fig. 20 satisfies the two-dimensional arrangement condition C-Cc. With such an arrangement, the effects of the above-mentioned two-dimensional arrangement condition C-Cc can be obtained.

[0356] 20, an example of an arrangement in which one vertical column satisfies the two-dimensional arrangement condition C-Cc has been described, but the present invention is not limited to this. For example, as shown in FIG. 21, an arrangement in which multiple vertical columns satisfy the two-dimensional arrangement condition C-Cc may be used.

[0357] In addition, in Figures 20 and 21, an example is shown in which the horizontal positions of the MIMO antennas arranged (or added) in the vertical direction are aligned so as to match (align vertically), but this is not limited to this, and the MIMO antennas may be arranged so that their horizontal positions are different (for example, diagonally upward or diagonally downward).

[0358] (Variation 4) In the above embodiment, a BMS configuration (e.g., two radar units 10) including the first radar unit 10 and the second radar unit 10 has been described, but the number of radar units 10 constituting the radar device 1 is not limited to two. For example, the BMS configuration may include three or more radar units 10, and the same effects as those of the above embodiment can be obtained.

[0359] For example, when three radar units 10 (for example, the first to third radar units 10) are used and the above embodiment is applied, the operation is as follows.

[0360] For example, the control unit 304 outputs a transmission switching control signal to the transmission unit 100 (SW unit 101) of each radar unit 10 so that the transmission signal transmitted from the first radar unit 10, the transmission signal transmitted from the second radar unit 10, and the transmission signal transmitted from the third radar unit 10 are alternately switched in a time division manner for each transmission period Tr.

[0361] The receiving unit 200 of each radar unit 10 includes three DA units 209, a CFAR unit 210, and an angle measurement unit 212 so as to receive reflected wave signals corresponding to the transmission signals of each radar unit 10 transmitted in a time-division manner, and receives and processes the reflected waves corresponding to the transmission signals from each radar unit 10 individually, and outputs the reflected waves to the integrating unit 30. The operation of each unit is similar to that of the above-described embodiment, and similar effects can be obtained.

[0362] In the above, an example in which two or more radar units 10 are switched in a time division manner to transmit a transmission signal has been described, but the present invention is not limited thereto, and the radar device 1 may simultaneously multiplex and transmit transmission signals from the multiple radar units 10 using other multiplex transmission methods such as Doppler multiplexing or code division multiplexing. Alternatively, the radar device 1 may transmit transmission signals from two or more radar units 10 by combining multiple simultaneous multiplex transmission methods, such as a combination of time division transmission and Doppler multiplexing. For example, the radar device 1 may perform simultaneous multiplex transmission such as Doppler multiplexing from two of the multiple radar units 10, and transmit signals by switching the combination of the simultaneously multiplexed radar units 10 in a time division manner. Even in a configuration of three or more radar units 10, the same effects as those of the non-limiting examples of the present disclosure can be obtained.

[0363] (Variation 5) In addition, the MIMO antenna arrangement described in this embodiment may be arranged upside down, inverted left and right, or diagonally when mounted on a vehicle, etc., and the same effects as those of the non-limiting examples of the present disclosure can be obtained. In addition, in the MIMO antenna arrangement described in this embodiment, the transmitting antennas and the receiving antennas may be interchanged.

[0364] An embodiment of the present disclosure has been described above.

[0365] [Other embodiments] In the above-mentioned embodiments, the configuration using a chirp signal as TxSig has been described, but a signal other than the chirp signal may be used. For example, TxSig may be a pulse compression wave such as a coded pulse signal. When a coded pulse signal is used for TxSig, the mixer unit 204 of the receiving radio unit 203 converts a high-frequency received signal into a baseband signal, and by using a correlator (not shown) that correlates with the coded pulse signal to be transmitted instead of the beat analysis unit 208, the subsequent processing can be performed in the same manner as the processing according to the above-mentioned embodiments, and the same effects can be obtained.

[0366] In the radar device according to the embodiment of the present disclosure, the transmitter and the receiver may be disposed separately in physically separate locations. Also, in the receiver according to the embodiment of the present disclosure, the angle measuring unit and other components may be disposed separately in physically separate locations.

[0367] In addition, in one embodiment of the present disclosure, for example, the number of transmitting antennas, the number of receiving antennas, the number of DDMs, the number of radar units, the DDM interval, and a parameter related to the DDM interval (for example, δ q ), parameters related to the transmission period (e.g., N sw ), antenna spacing, and antenna aperture length are merely examples, and the parameters are not limited to these values.

[0368] Although not shown, the radar device according to an embodiment of the present disclosure includes, for example, a central processing unit (CPU), a storage medium such as a read only memory (ROM) storing a control program, and a working memory such as a random access memory (RAM). In this case, the functions of each of the above-mentioned units are realized by the CPU executing the control program. However, the hardware configuration of the radar device is not limited to this example. For example, each functional unit of the radar device may be realized as an integrated circuit (IC). Each functional unit may be individually implemented as a single chip, or may be implemented as a single chip that includes some or all of the functional units.

[0369] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present disclosure is not limited to such examples. It is clear that a person skilled in the art can come up with various modified or amended examples within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present disclosure. In addition, the components in the above embodiments may be arbitrarily combined within the scope of the disclosure.

[0370] In addition, the notation "... part" in the above-mentioned embodiments may be replaced with other notations such as "... circuitry", "... assembly", "... device", "... unit", or "... module".

[0371] In each of the above embodiments, the present disclosure has been described as an example configured using hardware, but the present disclosure can also be realized by software in cooperation with hardware.

[0372] Moreover, each functional block used in the description of each of the above embodiments is typically realized as an LSI, which is an integrated circuit. The integrated circuit may control each functional block used in the description of the above embodiments and may have input terminals and output terminals. These may be individually integrated into one chip, or may be integrated into one chip that includes some or all of them. Here, the term LSI is used, but depending on the degree of integration, it may also be called an IC, a system LSI, a super LSI, or an ultra LSI.

[0373] The method of integration is not limited to LSI, but may be realized using a dedicated circuit or a general-purpose processor and memory. After LSI manufacture, a field programmable gate array (FPGA) that can be programmed, or a reconfigurable processor that can reconfigure the connections or settings of circuit cells inside the LSI may be used.

[0374] Furthermore, if a new integrated circuit technology that can replace LSI appears due to the progress of semiconductor technology or a derivative technology, it is possible to integrate the functional blocks using that technology. The application of biotechnology is also a possibility.

[0375] <Summary of this disclosure> A radar device according to one non-limiting example of the present disclosure includes a first radar circuit having a plurality of first transmitting antennas and a plurality of first receiving antennas, and a second radar circuit having a plurality of second transmitting antennas and a plurality of second receiving antennas, wherein the plurality of first transmitting antennas transmit first transmission signals having a predetermined center frequency, the plurality of second transmitting antennas transmit second transmission signals having the predetermined center frequency, the plurality of first receiving antennas receive at least one of a first reflected wave signal corresponding to the first transmission signal and a second reflected wave signal corresponding to the second transmission signal, the plurality of second receiving antennas receive at least one of the first reflected wave signal and the second reflected wave signal, and a minimum interval of the plurality of first transmitting antennas in a first direction and a minimum interval of the plurality of second receiving antennas in the first direction are greater than or equal to 0.5 wavelengths and less than 1 wavelength of the first and second transmission signals.

[0376] In one non-limiting embodiment of the present disclosure, in the first direction, the minimum spacing of the multiple first receiving antennas and the minimum spacing of the multiple second transmitting antennas are wider than the minimum spacing of the multiple first transmitting antennas and the minimum spacing of the multiple second receiving antennas.

[0377] In one non-limiting embodiment of the present disclosure, in the first direction, the adjacent antenna spacing of the multiple first receiving antennas includes a spacing wider than an aperture length of the multiple first transmitting antennas, and the adjacent antenna spacing of the multiple second transmitting antennas includes a spacing wider than an aperture length of the multiple second receiving antennas.

[0378] In one non-limiting embodiment of the present disclosure, in the first direction, the spacing between adjacent antennas of the multiple second receiving antennas includes a spacing wider than an aperture length of the multiple first transmitting antennas, or the spacing between adjacent antennas of the multiple first transmitting antennas includes a spacing wider than an aperture length of the multiple second receiving antennas.

[0379] In one non-limiting embodiment of the present disclosure, in the first direction, the adjacent first antenna spacing of the multiple second transmitting antennas and the adjacent second antenna spacing of the multiple first receiving antennas include spacing in which the difference between the first antenna spacing and the second antenna spacing is greater than or equal to 0.5 wavelengths and less than or equal to 0.8 wavelengths of the first and second transmitting signals.

[0380] In one non-limiting embodiment of the present disclosure, there are three or more of each of the plurality of first transmitting antennas and the plurality of second transmitting antennas, there are three or more of each of the plurality of first receiving antennas and the plurality of second receiving antennas, and in the first direction, a minimum spacing between the plurality of first receiving antennas and a minimum spacing between the plurality of second transmitting antennas is greater than or equal to 0.5 wavelengths and less than 1 wavelength of the first and second transmitting signals.

[0381] In one non-limiting embodiment of the present disclosure, in the first direction, the adjacent antenna spacing of the multiple first receiving antennas and the adjacent antenna spacing of the multiple second receiving antennas include a spacing wider than an aperture length of the multiple first transmitting antennas, or the adjacent antenna spacing of the multiple first transmitting antennas and the adjacent antenna spacing of the multiple second transmitting antennas include a spacing wider than an aperture length of the multiple second receiving antennas.

[0382] In one non-limiting embodiment of the present disclosure, in the first direction, the adjacent first antenna spacing of the multiple second transmitting antennas and the adjacent second antenna spacing of the multiple first receiving antennas include spacing in which the difference between the first antenna spacing and the second antenna spacing is greater than or equal to 0.5 wavelengths and less than or equal to 0.8 wavelengths of the first and second transmitting signals.

[0383] In one non-limiting embodiment of the present disclosure, the first radar circuit further includes a control circuit that, when it receives the second reflected wave signal, determines whether the second reflected wave signal is a direct wave from the target based on the second reflected wave signal, based on the transmission azimuth direction of the second transmission signal transmitted from the second radar circuit, the reception azimuth direction of the second reflected wave signal received by the first radar circuit, and the distance between the first radar circuit and the target from which the second transmission signal is reflected.

[0384] A radar device according to one non-limiting example of the present disclosure includes a first radar circuit having a plurality of first transmitting antennas and a plurality of first receiving antennas, and a second radar circuit having a plurality of second transmitting antennas and a plurality of second receiving antennas, wherein the plurality of first transmitting antennas transmit first transmission signals having a predetermined center frequency, the plurality of second transmitting antennas transmit second transmission signals having the predetermined center frequency, the plurality of first receiving antennas receive at least one of a first reflected wave signal corresponding to the first transmission signal and a second reflected wave signal corresponding to the second transmission signal, and the plurality of second receiving antennas receive at least one of the first reflected wave signal and the second reflected wave signal, and in a first direction, a minimum interval between the plurality of first transmitting antennas and a minimum interval between the plurality of second receiving antennas differ from each other by one or more wavelengths of the first and second transmission signals, and a minimum interval between the plurality of first receiving antennas and a minimum interval between the plurality of second transmitting antennas differ from each other by one or more wavelengths of the first and second transmission signals.

[0385] In one non-limiting example of the present disclosure, in the first direction, the adjacent first antenna spacing of the multiple first transmitting antennas and the adjacent second antenna spacing of the multiple first receiving antennas include a spacing in which the difference between the first antenna spacing and the second antenna spacing is greater than or equal to 0.5 wavelengths and less than or equal to 0.8 wavelengths of the first and second transmission signals, and the adjacent third antenna spacing of the multiple second transmitting antennas and the adjacent fourth antenna spacing of the multiple second receiving antennas include a spacing in which the difference between the third antenna spacing and the fourth antenna spacing is greater than or equal to 0.5 wavelengths and less than or equal to 0.8 wavelengths of the first and second transmission signals.

[0386] In one non-limiting example of the present disclosure, in the first direction, the adjacent first antenna spacing of the multiple first transmitting antennas and the adjacent second antenna spacing of the multiple second receiving antennas include spacings in which the difference between the first antenna spacing and the second antenna spacing is greater than or equal to 0.5 wavelengths and less than or equal to 0.8 wavelengths of the first and second transmission signals, and the adjacent third antenna spacing of the multiple second transmitting antennas and the adjacent fourth antenna spacing of the multiple first receiving antennas include spacings in which the difference between the third antenna spacing and the fourth antenna spacing is greater than or equal to 0.5 wavelengths and less than or equal to 0.8 wavelengths of the first and second transmission signals.

[0387] In one non-limiting embodiment of the present disclosure, the first radar circuit receives the second reflected wave signal, and the second radar circuit further includes a control circuit that receives the first reflected wave signal and determines whether the first reflected wave signal and the second reflected wave signal are direct waves from a target based on a comparison between a positioning result using the first reflected wave signal and a positioning result using the second reflected wave signal.

[0388] In one non-limiting embodiment of the present disclosure, a minimum spacing between the first plurality of transmitting antennas and a minimum spacing between the second plurality of transmitting antennas are different from each other, or a minimum spacing between the first plurality of receiving antennas and a minimum spacing between the second plurality of receiving antennas are different from each other.

[0389] In one non-limiting embodiment of the present disclosure, the multiple first transmitting antennas, the multiple first receiving antennas, the multiple second transmitting antennas, and the multiple second receiving antennas are arranged two-dimensionally including the first direction and a second direction different from the first direction, and in the second direction, the minimum spacing between the multiple first transmitting antennas and the minimum spacing between the multiple second receiving antennas is greater than or equal to 0.5 wavelengths and less than 1 wavelength of the first and second transmitting signals, and the minimum spacing between the multiple first receiving antennas and the minimum spacing between the multiple second transmitting antennas is wider than the minimum spacing between the multiple first transmitting antennas and the minimum spacing between the multiple second receiving antennas.

[0390] In one non-limiting embodiment of the present disclosure, in the second direction, the antenna spacing between adjacent ones of the multiple first receiving antennas includes a spacing wider than the aperture length of the multiple first transmitting antennas, and the antenna spacing between adjacent ones of the multiple second transmitting antennas includes a spacing wider than the aperture length of the multiple second receiving antennas.

[0391] In one non-limiting embodiment of the present disclosure, in the second direction, the spacing between adjacent antennas of the multiple second receiving antennas includes a spacing wider than the aperture length of the multiple first transmitting antennas, or the spacing between adjacent antennas of the multiple first transmitting antennas includes a spacing wider than the aperture length of the multiple second receiving antennas.

[0392] In one non-limiting embodiment of the present disclosure, the multiple first transmitting antennas, the multiple first receiving antennas, the multiple second transmitting antennas, and the multiple second receiving antennas are arranged two-dimensionally including the first direction and a second direction different from the first direction, there are three or more of each of the multiple first transmitting antennas and the multiple second transmitting antennas, there are three or more of each of the multiple first receiving antennas and the multiple second receiving antennas, a minimum spacing between the multiple first transmitting antennas in the second direction and a minimum spacing between the multiple second receiving antennas in the first direction are greater than or equal to 0.5 wavelengths and less than 1 wavelength of the first and second transmitting signals, and the minimum spacing between the multiple first receiving antennas and the multiple second transmitting antennas are greater than or equal to 0.5 wavelengths and less than 1 wavelength of the first and second transmitting signals.

[0393] In one non-limiting embodiment of the present disclosure, in the second direction, the adjacent antenna spacing of the multiple first receiving antennas and the adjacent antenna spacing of the multiple second receiving antennas include a spacing wider than an aperture length of the multiple first transmitting antennas, or the adjacent antenna spacing of the multiple first transmitting antennas and the adjacent antenna spacing of the multiple second transmitting antennas include a spacing wider than an aperture length of the multiple second receiving antennas.

[0394] In one non-limiting embodiment of the present disclosure, the multiple first transmitting antennas, the multiple first receiving antennas, the multiple second transmitting antennas, and the multiple second receiving antennas are arranged two-dimensionally including the first direction and a second direction different from the first direction, and in the second direction, a minimum spacing between the multiple first transmitting antennas and a minimum spacing between the multiple second receiving antennas differ from each other by one or more wavelengths of the first and second transmitting signals, and a minimum spacing between the multiple first receiving antennas and a minimum spacing between the multiple second transmitting antennas differ from each other by one or more wavelengths of the first and second transmitting signals.

[0395] In one non-limiting example of the present disclosure, in the second direction, the adjacent first antenna spacing of the multiple first transmitting antennas and the adjacent second antenna spacing of the multiple first receiving antennas include spacings in which the difference between the first antenna spacing and the second antenna spacing is greater than or equal to 0.5 wavelengths and less than or equal to 0.8 wavelengths of the first and second transmission signals, and the adjacent third antenna spacing of the multiple second transmitting antennas and the adjacent fourth antenna spacing of the multiple second receiving antennas include spacings in which the difference between the third antenna spacing and the fourth antenna spacing is greater than or equal to 0.5 wavelengths and less than or equal to 0.8 wavelengths of the first and second transmission signals.

[0396] In one non-limiting example of the present disclosure, in the second direction, the first antenna spacing and the fourth antenna spacing include spacings where the difference between the first antenna spacing and the fourth antenna spacing is greater than or equal to 0.5 wavelengths and less than or equal to 0.8 wavelengths of the first and second transmission signals, and the third antenna spacing and the second antenna spacing include spacings where the difference between the third antenna spacing and the second antenna spacing is greater than or equal to 0.5 wavelengths and less than or equal to 0.8 wavelengths of the first and second transmission signals.

[0397] In a transmission and reception method for a radar device according to one non-limiting embodiment of the present disclosure, a first radar circuit transmits a first transmission signal having a predetermined center frequency using a plurality of first transmitting antennas, a second radar circuit transmits a second transmission signal having the predetermined center frequency using a plurality of second transmitting antennas, the first radar circuit receives at least one of a first reflected wave signal corresponding to the first transmission signal and a second reflected wave signal corresponding to the second transmission signal using a plurality of first receiving antennas, and the second radar circuit receives at least one of the first reflected wave signal and the second reflected wave signal using a plurality of second receiving antennas, wherein a minimum interval between the plurality of first transmitting antennas in a first direction and a minimum interval between the plurality of second receiving antennas in the first direction are greater than or equal to 0.5 wavelengths and less than 1 wavelength of the first and second transmission signals.

[0398] In a transmission and reception method for a radar device according to one non-limiting embodiment of the present disclosure, a first radar circuit transmits a first transmission signal having a predetermined center frequency using a plurality of first transmitting antennas, a second radar circuit transmits a second transmission signal having the predetermined center frequency using a plurality of second transmitting antennas, the first radar circuit receives at least one of a first reflected wave signal corresponding to the first transmission signal and a second reflected wave signal corresponding to the second transmission signal using a plurality of first receiving antennas, and the second radar circuit receives at least one of the first reflected wave signal and the second reflected wave signal using a plurality of second receiving antennas, wherein in a first direction, a minimum interval between the plurality of first transmitting antennas and a minimum interval between the plurality of second receiving antennas differ from each other by one or more wavelengths of the first and second transmission signals, and the minimum interval between the plurality of first receiving antennas and the minimum interval between the plurality of second transmitting antennas differ from each other by one or more wavelengths of the first and second transmission signals. [Industrial Applicability]

[0399] The present disclosure is suitable for a radar device that detects a wide angle range. [Explanation of symbols]

[0400] 1. Radar equipment 10 Radar section 20,20a Synchronous section 30 Integration Department 100 Transmitter 101 Switch section 102 Doppler shift section 103 Transmitting Antenna 200,200a Receiver 201 System Processing Unit 202 Receiving antenna 203 Receiving Radio Unit 204 Mixer section 205 LPF 206 Analysis Department 207 A / D conversion section 208 Beat Analysis Section 209 Doppler Analysis Unit 210 CFAR Department 211 Separation section 212 Angle measurement section 301 Generation part 302 Modulation signal generator 303 VCO 304 Control Unit

Claims

1. A first radar circuit having multiple first transmitting antennas and multiple first receiving antennas, A second radar circuit having multiple second transmitting antennas and multiple second receiving antennas, It is equipped with, The plurality of first transmitting antennas transmit a first transmitting signal having a predetermined center frequency. The plurality of second transmitting antennas transmit a second transmitting signal having the predetermined center frequency. The plurality of first receiving antennas receive at least one of a first reflected wave signal corresponding to the first transmission signal and a second reflected wave signal corresponding to the second transmission signal. The plurality of second receiving antennas receive at least one of the first reflected wave signal and the second reflected wave signal. In the first direction, The minimum spacing between the plurality of first transmitting antennas and the minimum spacing between the plurality of second receiving antennas differ from each other by one wavelength or more of the first and second transmitting signals. The minimum spacing between the plurality of first receiving antennas and the minimum spacing between the plurality of second transmitting antennas are different from each other by one wavelength or more of the first and second transmitting signals. Radar device.

2. In the first direction, The spacing between adjacent first antennas of the plurality of first transmitting antennas, and the spacing between adjacent second antennas of the plurality of first receiving antennas, include spacings where the difference between the first antenna spacing and the second antenna spacing is 0.5 wavelengths or more and 0.8 wavelengths or less of the first and second transmitting signals. The spacing between adjacent third antennas of the plurality of second transmitting antennas, and the spacing between adjacent fourth antennas of the plurality of second receiving antennas, include spacings where the difference between the third antenna spacing and the fourth antenna spacing is 0.5 wavelengths or more and 0.8 wavelengths or less of the first and second transmitting signals. The radar device according to claim 1.

3. In the first direction, The spacing between adjacent first antennas of the plurality of first transmitting antennas, and the spacing between adjacent second antennas of the plurality of second receiving antennas, include spacings where the difference between the first antenna spacing and the second antenna spacing is 0.5 wavelengths or more and 0.8 wavelengths or less of the first and second transmitting signals. The spacing between adjacent third antennas of the plurality of second transmitting antennas, and the spacing between adjacent fourth antennas of the plurality of first receiving antennas, include spacings where the difference between the third antenna spacing and the fourth antenna spacing is 0.5 wavelengths or more and 0.8 wavelengths or less of the first and second transmitting signals. The radar device according to claim 1.

4. The first radar circuit receives the second reflected wave signal, The second radar circuit receives the first reflected wave signal, The system further comprises a control circuit that determines whether the first reflected wave signal and the second reflected wave signal are direct waves from a target, based on a comparison of the positioning result using the first reflected wave signal and the positioning result using the second reflected wave signal. The radar device according to claim 1.

5. The minimum spacing between the plurality of first transmitting antennas and the minimum spacing between the plurality of second transmitting antennas are different from each other, or The minimum spacing between the plurality of first receiving antennas and the minimum spacing between the plurality of second receiving antennas are different from each other. The radar device according to claim 1.

6. The plurality of first transmitting antennas, the plurality of first receiving antennas, the plurality of second transmitting antennas, and the plurality of second receiving antennas are arranged two-dimensionally, including the first direction and the second direction different from the first direction. In the second direction, The minimum spacing between the plurality of first transmitting antennas and the minimum spacing between the plurality of second receiving antennas is 0.5 wavelengths or more and less than 1 wavelength of the first and second transmitting signals, and The minimum spacing between the plurality of first receiving antennas and the minimum spacing between the plurality of second transmitting antennas are wider than the minimum spacing between the plurality of first transmitting antennas and the minimum spacing between the plurality of second receiving antennas. The radar device according to claim 1.

7. In the second direction, The spacing between adjacent antennas of the plurality of first receiving antennas includes a spacing wider than the aperture length of the plurality of first transmitting antennas, and The spacing between adjacent antennas of the plurality of second transmitting antennas includes a spacing wider than the aperture length of the plurality of second receiving antennas. The radar device according to claim 6.

8. In the second direction, The spacing between adjacent antennas of the plurality of second receiving antennas includes a spacing wider than the aperture length of the plurality of first transmitting antennas, or The spacing between adjacent antennas of the plurality of first transmitting antennas includes a spacing wider than the aperture length of the plurality of second receiving antennas. The radar device according to claim 7.

9. The plurality of first transmitting antennas, the plurality of first receiving antennas, the plurality of second transmitting antennas, and the plurality of second receiving antennas are arranged two-dimensionally, including the first direction and the second direction different from the first direction. Each of the plurality of first transmitting antennas and the plurality of second transmitting antennas consists of three or more units, and each of the plurality of first receiving antennas and the plurality of second receiving antennas consists of three or more units, In the second direction, The minimum spacing between the plurality of first transmitting antennas and the minimum spacing between the plurality of second receiving antennas in the first direction is 0.5 wavelengths or more and less than 1 wavelength of the first and second transmitting signals, and The minimum spacing between the plurality of first receiving antennas and the minimum spacing between the plurality of second transmitting antennas is 0.5 wavelengths or more and less than 1 wavelength of the first and second transmitting signals. The radar device according to claim 1.

10. In the second direction, The spacing between adjacent antennas of the plurality of first receiving antennas and the spacing between adjacent antennas of the plurality of second receiving antennas includes spacing that is wider than the aperture length of the plurality of first transmitting antennas, or The spacing between adjacent first transmitting antennas and the spacing between adjacent second transmitting antennas includes spacing that is wider than the aperture length of the multiple second receiving antennas. The radar device according to claim 9.

11. The plurality of first transmitting antennas, the plurality of first receiving antennas, the plurality of second transmitting antennas, and the plurality of second receiving antennas are arranged two-dimensionally, including the first direction and the second direction different from the first direction. In the second direction, The minimum spacing between the plurality of first transmitting antennas and the minimum spacing between the plurality of second receiving antennas differ from each other by one wavelength or more of the first and second transmitting signals. The minimum spacing between the plurality of first receiving antennas and the minimum spacing between the plurality of second transmitting antennas are different from each other by one wavelength or more of the first and second transmitting signals. The radar device according to claim 1.

12. In the second direction, The spacing between adjacent first antennas of the plurality of first transmitting antennas, and the spacing between adjacent second antennas of the plurality of first receiving antennas, include spacings where the difference between the first antenna spacing and the second antenna spacing is 0.5 wavelengths or more and 0.8 wavelengths or less of the first and second transmitting signals. The spacing between adjacent third antennas of the plurality of second transmitting antennas, and the spacing between adjacent fourth antennas of the plurality of second receiving antennas, include spacings where the difference between the third antenna spacing and the fourth antenna spacing is 0.5 wavelengths or more and 0.8 wavelengths or less of the first and second transmitting signals. The radar device according to claim 11.

13. In the second direction, The first antenna spacing and the fourth antenna spacing include spacings where the difference between the first antenna spacing and the fourth antenna spacing is 0.5 wavelengths or more and 0.8 wavelengths or less of the first and second transmitted signals. The third antenna spacing and the second antenna spacing include spacings where the difference between the third antenna spacing and the second antenna spacing is 0.5 wavelengths or more and 0.8 wavelengths or less of the first and second transmitted signals. The radar device according to claim 12.

14. The first radar circuit transmits a first transmission signal having a predetermined center frequency using a plurality of first transmitting antennas. The second radar circuit transmits a second transmission signal having the predetermined center frequency using a plurality of second transmitting antennas. The first radar circuit uses a plurality of first receiving antennas to receive at least one of a first reflected wave signal corresponding to the first transmitted signal and a second reflected wave signal corresponding to the second transmitted signal. The second radar circuit is a transmission and reception method for a radar device, which uses a plurality of second receiving antennas to receive at least one of the first reflected wave signal and the second reflected wave signal. In the first direction, The minimum spacing between the plurality of first transmitting antennas and the minimum spacing between the plurality of second receiving antennas differ from each other by one wavelength or more of the first and second transmitting signals. The minimum spacing between the plurality of first receiving antennas and the minimum spacing between the plurality of second transmitting antennas are different from each other by one wavelength or more of the first and second transmitting signals. A method for transmitting and receiving data from a radar device.

15. In the first direction, The spacing between adjacent first antennas of the plurality of first transmitting antennas, and the spacing between adjacent second antennas of the plurality of first receiving antennas, include spacings where the difference between the first antenna spacing and the second antenna spacing is 0.5 wavelengths or more and 0.8 wavelengths or less of the first and second transmitting signals. The spacing between adjacent third antennas of the plurality of second transmitting antennas, and the spacing between adjacent fourth antennas of the plurality of second receiving antennas, include spacings where the difference between the third antenna spacing and the fourth antenna spacing is 0.5 wavelengths or more and 0.8 wavelengths or less of the first and second transmitting signals. The method for transmitting and receiving signals in a radar device according to claim 14.

16. In the first direction, The spacing between adjacent first antennas of the plurality of first transmitting antennas, and the spacing between adjacent second antennas of the plurality of second receiving antennas, include spacings where the difference between the first antenna spacing and the second antenna spacing is 0.5 wavelengths or more and 0.8 wavelengths or less of the first and second transmitting signals. The spacing between adjacent third antennas of the plurality of second transmitting antennas, and the spacing between adjacent fourth antennas of the plurality of first receiving antennas, include spacings where the difference between the third antenna spacing and the fourth antenna spacing is 0.5 wavelengths or more and 0.8 wavelengths or less of the first and second transmitting signals. The method for transmitting and receiving signals in a radar device according to claim 14.

17. The first radar circuit receives the second reflected wave signal using the plurality of first receiving antennas, The second radar circuit receives the first reflected wave signal using the plurality of second receiving antennas. Based on a comparison of the positioning result using the first reflected wave signal and the positioning result using the second reflected wave signal, it is determined whether the first reflected wave signal and the second reflected wave signal are direct waves from the target. The method for transmitting and receiving signals in a radar device according to claim 14.

18. The minimum spacing between the plurality of first transmitting antennas and the minimum spacing between the plurality of second transmitting antennas are different from each other, or The minimum spacing between the plurality of first receiving antennas and the minimum spacing between the plurality of second receiving antennas are different from each other. The method for transmitting and receiving signals in a radar device according to claim 14.

19. The plurality of first transmitting antennas, the plurality of first receiving antennas, the plurality of second transmitting antennas, and the plurality of second receiving antennas are arranged in two dimensions including the first direction and a second direction different from the first direction. In the second direction, The minimum spacing between the plurality of first transmitting antennas and the minimum spacing between the plurality of second receiving antennas is 0.5 wavelengths or more and less than 1 wavelength of the first and second transmitting signals, and The minimum spacing between the plurality of first receiving antennas and the minimum spacing between the plurality of second transmitting antennas are wider than the minimum spacing between the plurality of first transmitting antennas and the minimum spacing between the plurality of second receiving antennas. The method for transmitting and receiving signals in a radar device according to claim 14.

20. The plurality of first transmitting antennas, the plurality of first receiving antennas, the plurality of second transmitting antennas, and the plurality of second receiving antennas are arranged in two dimensions including the first direction and the second direction different from the first direction. Each of the plurality of first transmitting antennas and the plurality of second transmitting antennas consists of three or more units, and each of the plurality of first receiving antennas and the plurality of second receiving antennas consists of three or more units, In the second direction, The minimum spacing between the plurality of first transmitting antennas and the minimum spacing between the plurality of second receiving antennas in the first direction is 0.5 wavelengths or more and less than 1 wavelength of the first and second transmitting signals, and The minimum spacing between the plurality of first receiving antennas and the minimum spacing between the plurality of second transmitting antennas is 0.5 wavelengths or more and less than 1 wavelength of the first and second transmitting signals. The method for transmitting and receiving signals in a radar device according to claim 14.

21. The plurality of first transmitting antennas, the plurality of first receiving antennas, the plurality of second transmitting antennas, and the plurality of second receiving antennas are arranged in two dimensions including the first direction and the second direction different from the first direction. In the second direction, The minimum spacing between the plurality of first transmitting antennas and the minimum spacing between the plurality of second receiving antennas differ from each other by one wavelength or more of the first and second transmitting signals. The minimum spacing between the plurality of first receiving antennas and the minimum spacing between the plurality of second transmitting antennas are different from each other by one wavelength or more of the first and second transmitting signals. The method for transmitting and receiving signals in a radar device according to claim 14.

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