Radar device

Abstract

To suppress a decrease in estimation accuracy of an arrival direction of reflected waves in a radar device.SOLUTION: A radar device 1 comprises a transmission antenna 130, a plurality of array antennas, and an angle estimation unit 332. The plurality of array antennas includes: a first antenna set, which is a set of two array antennas arranged with a first distance D1 set so that the angle estimation accuracy characteristic becomes a first estimation accuracy characteristic; and a second antenna set, which is a set of two array antennas arranged with a second distance D2 set so that the estimation accuracy characteristic becomes a second estimation accuracy characteristic different from the first estimation accuracy characteristic. The angle estimation unit estimates the angle using both the first estimation results estimated using the received signal received by the first antenna set and the second estimation results estimated using the received signal received by the second antenna set.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a radar device. [Background technology]

[0002] There is known a technique for estimating an angle indicating the direction of arrival of a reflected wave by utilizing signals received by two array antennas, each of which receives a reflected wave from a target (Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Yan Ma et al. “A Novel ESPRIT-Based Algorithm for DOA Estimation with Distributed Subarray Antenna”, Circuits Syst Signal Process 34, p.2951-2972, 2015 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors have found that angle estimation using two array antennas can result in a decrease in estimation accuracy at specific angles. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms.

[0006] According to one aspect of the present disclosure, there is provided a radar device (1). The radar device includes: a transmitting antenna (130) that transmits a transmission wave (IL) as an electromagnetic wave; a plurality of array antennas (210, 240, 270) that are arranged side by side in a predetermined array direction, each having a plurality of antenna elements (211, 241, 271) linearly arranged at equal intervals along the array direction, and that receive reflected waves (RL) generated when the electromagnetic waves are reflected by a target as reception signals; and an angle estimation unit (332) that estimates an angle indicating the arrival direction of the reflected waves by using the reception signals received by the plurality of array antennas. The antenna includes a first antenna set which is a set of two array antennas arranged at a first distance (D1) spaced apart, and the first distance (D1) is set so that the constant accuracy characteristic is a first estimation accuracy characteristic, and a second antenna set which is a set of two array antennas arranged at a second distance (D2) spaced apart, and the second distance (D2) is set so that the estimation accuracy characteristic is a second estimation accuracy characteristic different from the first estimation accuracy characteristic, and the angle estimation unit estimates the angle using a first estimation result estimated using the received signal received by the first antenna set and a second estimation result estimated using the received signal received by the second antenna set.

[0007] According to this aspect of the radar device, the multiple array antennas include a first antenna set arranged to have a first estimation accuracy characteristic and a second antenna set arranged to have a second estimation accuracy characteristic different from the first estimation accuracy characteristic, and the angle estimator estimates the angle using the first estimation result and the second estimation result. Therefore, by selectively using the first estimation result and the second estimation result, which have different estimation accuracy characteristics, it is possible to suppress a decrease in estimation accuracy in angle estimation. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a diagram showing the positional relationship between a vehicle equipped with a radar device and other vehicles; [Figure 2]FIG. 1 is a block diagram showing a schematic configuration of a radar device. [Figure 3] FIG. 1 is an explanatory diagram showing a schematic configuration of an array antenna. [Figure 4] FIG. 10 is an explanatory diagram showing the estimation accuracy characteristics of the first estimation result. [Figure 5] FIG. 10 is an explanatory diagram showing the estimation accuracy characteristics of the second estimation result. [Figure 6] 10 is a flowchart showing the procedure of an angle estimation process. DETAILED DESCRIPTION OF THE INVENTION

[0009] A. Implementation: A-1.Device configuration: As shown in FIG. 1, a radar device 1 according to the embodiment is mounted on a host vehicle M1. The radar device 1 is installed, for example, in the front grill of the host vehicle M1. The radar device 1 detects a target present in a forward direction of the host vehicle M1. In this embodiment, the target is another vehicle M2. More specifically, the radar device 1 emits electromagnetic waves as transmission waves IL. The transmission waves IL are reflected by a target outside the host vehicle M1 and become reflected waves RL. The radar device 1 detects the direction in which the target exists relative to the host vehicle M1 based on an angle indicating the arrival direction of the reflected waves RL. Note that the radar device 1 may detect targets present in any direction around the host vehicle M1, not limited to the forward direction of the host vehicle M1.

[0010] 2, the radar device 1 includes a transmitting unit 100, a receiving unit 200, and a processing unit 300. The radar device 1 is a millimeter-wave radar. In the embodiment, the radar device 1 is an FMCW (Frequency Modulated Continuous Wave) radar.

[0011] The transmitter 100 includes an oscillator 110, a distributor 120, and a transmitting antenna 130. The oscillator 110 is, for example, a voltage-controlled oscillator (VCO). When a triangular wave voltage signal is input from the transmission / reception control unit 320 of the processing unit 300, the oscillator 110 outputs a frequency-modulated high-frequency signal as a transmission signal. The transmission signal output by the oscillator 110 includes an uplink section in which the frequency increases over time, and a downlink section in which the frequency decreases over time.

[0012] The distributor 120 distributes the transmission signal supplied from the oscillator 110 to the transmitting antenna 130 and the first mixer 220, the second mixer 250, and the third mixer 280 of the receiving unit 200. The transmitting antenna 130 radiates the transmission signal supplied from the oscillator 110 via the distributor 120 to the outside of the vehicle M1 as an electromagnetic wave.

[0013] The receiving unit 200 includes a first array antenna 210, a first mixer 220, a first A / D (Analog-to-Digital) conversion unit 230, a second array antenna 240, a second mixer 250, a second A / D conversion unit 260, a third array antenna 270, a third mixer 280, and a third A / D conversion unit 290. In this way, the radar device 1 of this embodiment includes a plurality of array antennas.

[0014] 3, the first array antenna 210 is an equally-spaced linear array antenna configured with K antenna elements 211 arranged at equal intervals in a straight line along a predetermined array direction with a distance d between each other, where K is an integer equal to or greater than 2. The K antenna elements 211 correspond to the first to Kth channels, respectively.

[0015] In this embodiment, the distance d is equal to half the wavelength of the transmission wave IL. Note that the distance d does not need to be exactly the same as the half wavelength of the transmission wave IL, as long as it can be considered to be equal to the half wavelength of the transmission wave IL taking into consideration design errors, variations, and the like.

[0016] The first array antenna 210 receives reflected waves RL reflected by a target as received signals, and outputs the received signals to the first mixer 220 .

[0017] 1 mixes the transmission signal distributed by the distributor 120 with the reception signal input from each antenna element 211, and outputs a beat signal. Since a triangular wave is used as the carrier wave in the radar device 1, the first mixer 220 generates and outputs a beat signal in each of the uplink and downlink sections. The beat signal output by the first mixer 220 is supplied to the first A / D conversion unit 230.

[0018] The first A / D conversion section 230 samples and quantizes the beat signal at a sampling frequency to convert it into a digital signal. The converted digital signal is supplied to the processing section 300.

[0019] 3, the second array antenna 240 is an equally-spaced linear array antenna configured such that K antenna elements 241 are equally spaced apart in a straight line along a predetermined array direction at a distance d from each other, similar to the first array antenna 210. K is an integer equal to or greater than 2. The K antenna elements 241 correspond to the first to Kth channels, respectively.

[0020] The first array antenna 210 and the second array antenna 240 are arranged at a distance D1 from each other along the arrangement direction of the antenna elements 211 and 241. More specifically, the first array antenna 210 and the second array antenna 240 are arranged such that the distance between the antenna element 211 closest to the second array antenna 240 among the multiple antenna elements 211 constituting the first array antenna 210 and the antenna element 241 closest to the first array antenna 210 among the multiple antenna elements 241 constituting the second array antenna 240 is distance D1. In this embodiment, distance D1 is set to 400 times the half wavelength of the transmission wave IL. Distance D1 corresponds to the "first distance" in this disclosure. In the following description, the set of the first array antenna 210 and the second array antenna 240 will also be referred to as the "first antenna set."

[0021] The second array antenna 240 receives the reflected wave RL reflected by the target as a received signal, and outputs the received signal to the second mixer 250.

[0022] 2 is similar to the configuration of the first mixer 220, and therefore its description will be omitted. Also, the configuration of the second A / D conversion section 260 is similar to the configuration of the first A / D conversion section 230, and therefore its description will be omitted.

[0023] 3, the third array antenna 270 is an equally-spaced linear array antenna configured such that K antenna elements 271 are arranged at equal intervals in a straight line along a predetermined arrangement direction with a distance d between each other, similar to the first array antenna 210. K is an integer equal to or greater than 2. The K antenna elements 271 correspond to the first to Kth channels, respectively.

[0024] The first array antenna 210 and the third array antenna 270 are arranged at a distance D2 from each other along the arrangement direction of the antenna elements 211 and 271. More specifically, the first array antenna 210 and the third array antenna 270 are arranged such that the distance between the antenna element 211 closest to the third array antenna 270 among the multiple antenna elements 211 constituting the first array antenna 210 and the antenna element 271 closest to the first array antenna 210 among the multiple antenna elements 271 constituting the third array antenna 270 is the distance D2. In this embodiment, the distance D2 is set to 300 times the half wavelength of the transmission wave IL. The distance D2 corresponds to the "second distance" in this disclosure. In the following description, the set of the first array antenna 210 and the third array antenna 270 will also be referred to as the "second antenna set."

[0025] In this embodiment, distance D2 is set so that the ratio of distance D1 to distance D2 falls within the range of 1.3+n to 1.5+n (n is an integer equal to or greater than 0). As described above, in this embodiment, distance D1 is set to 400 times the half wavelength of the transmission wave IL, and distance D2 is set to 300 times the half wavelength of the transmission wave IL. That is, in this embodiment, the ratio of distance D1 to distance D2 is approximately 1.33, which falls within the range of 1.3 to 1.5. By setting distance D2 in this manner, it is possible to appropriately differentiate the estimation accuracy characteristics of a first estimation result and a second estimation result, which will be described later. By selectively using the first estimation result and the second estimation result, it is possible to suppress a decrease in estimation accuracy. In this embodiment, by conducting experiments and simulations in advance, it has been determined that when the ratio of distance D1 to distance D2 falls within the range of "1.3+n to 1.5+n (n is an integer greater than or equal to 0)", the estimation accuracy characteristics of the first estimation result can be appropriately differentiated from the estimation accuracy characteristics of the second estimation result.

[0026] The third array antenna 270 receives the reflected wave RL reflected by the target as a received signal, and outputs the received signal to the third mixer 280.

[0027] 2 is similar to the configuration of first mixer 220, and therefore its description will be omitted. Also, the configuration of third A / D conversion section 290 is similar to the configuration of first A / D conversion section 230, and therefore its description will be omitted.

[0028] The processing unit 300 includes a storage unit 310, a transmission / reception control unit 320, and a signal processing unit 330. The processing unit 300 is configured by a computer including a CPU (Central Processing Unit), a memory, etc. The storage unit 310 stores various programs and data executed in the radar device 1. The transmission / reception control unit 320 controls the transmission unit 100 and the reception unit 200.

[0029] The signal processing unit 330 periodically executes a series of signal processing steps. The signal processing unit 330 functions as a frequency processing unit 331 and an angle estimation unit 332. The frequency processing unit 331 performs frequency conversion on each of the digital signals input from the first A / D conversion unit 230, the second A / D conversion unit 260, and the third A / D conversion unit 290, for example, by FFT (Fast Fourier Transform), and calculates a beat frequency. The frequency processing unit 331 outputs the calculated beat frequency to the angle estimation unit 332.

[0030] The angle estimation unit 332 estimates an angle indicating the arrival direction of the reflected wave RL based on the beat frequency. In this embodiment, the angle estimation unit 332 estimates the angle indicating the arrival direction of the reflected wave RL using ESPRIT (Estimation of Signal Parameter via Rotational Invariance Technique) as a calculation algorithm. In this embodiment, the angle estimation unit 332 executes a first estimation process using a beat frequency based on the received signal received by the first antenna set, and a second estimation process using a beat frequency based on the received signal received by the second antenna set.

[0031] The estimation accuracy characteristics of the first estimation process will be described with reference to FIG. 4. In the following description, the estimation accuracy characteristics of the first estimation process will also be referred to as "first estimation accuracy characteristics." In FIG. 4, the vertical axis represents the detection rate, and the horizontal axis represents the target angle. FIG. 4 illustrates the estimation accuracy characteristics when the target angle is in the angle range of 0° to 1°. In target detection involving two targets, the "target angle" refers to the angle between the direction of arrival of the reflected wave RL from the first target and the direction of arrival of the reflected wave RL from the second target. The "detection rate" refers to the ratio of the number of times that an appropriate angle estimation is performed in a predetermined number of angle estimation trials for each target angle. In this embodiment, an appropriate angle estimation is determined when the angle estimation result falls within an angle range equal to the target angle centered on the target angle. For example, in angle estimation where the target angle is 0.4°, the angle estimation result falls within an angle range of 0.4°±0.2°.

[0032] In Fig. 4, the angle range of the target angle where the detection rate is 0.8 or more is indicated by hatching. As shown in Fig. 4, the angle range where the detection rate is 0.8 or more and the angle range where the detection rate is less than 0.8 alternate in the angle range of the target angle from 0° to 1°. The inventors have found that the angle range where the detection rate is 0.8 or more and the angle range where the detection rate is less than 0.8 vary depending on the beam pattern of each array antenna and the positional relationship between the two array antennas. In the first estimation accuracy characteristic of this embodiment, the detection rate is less than 0.8 in the angle ranges of 0.1° or less, 0.2° to 0.3°, around 0.5°, and around 0.8°.

[0033] Next, the estimation accuracy characteristics of the second estimation process will be described with reference to FIG. 5. In the following description, the estimation accuracy characteristics of the second estimation process will also be referred to as "second estimation accuracy characteristics." In FIG. 5, the vertical axis represents the detection rate, and the horizontal axis represents the target angle. As in FIG. 4, FIG. 5 shows the estimation accuracy characteristics in the angle range of the target angle from 0° to 1°. In FIG. 5, the angle range of the target angle where the detection rate is 0.8 or higher is indicated by hatching. As shown in FIG. 5, in the second estimation accuracy characteristics, the detection rate is less than 0.8 in the angle ranges of 0.1° or less, 0.3° to 0.4°, and around 0.7°. As such, the angle range where the detection rate is less than 0.8 in the first estimation process and the angle range where the detection rate is less than 0.8 in the second estimation process are different from each other.

[0034] A-2. Angle estimation process: The angle estimation unit 332 executes the angle estimation process shown in Fig. 6 at a predetermined cycle. In step S2, the angle estimation unit 332 executes the first estimation process using a beat frequency based on the signal received by the first radar set, and obtains a first estimation result for the target angle.

[0035] In step S4, the angle estimation unit 332 determines whether high resolution is required. In this embodiment, the angle estimation unit 332 determines that high resolution is required when the first estimation result is less than 1°.

[0036] If it is determined that high resolution is required (step S4: Yes), in step S6, the angle estimation unit 332 performs a second estimation process using the beat frequency based on the received signal received by the second radar set, and obtains a second estimation result for the target angle.

[0037] In step S8, the angle estimation unit 332 selects an appropriate estimation result from the first estimation result and the second estimation result according to the respective estimation accuracy characteristics. For example, if the first estimation result is "0.5°," which is included in the angle range with a low detection rate according to the first estimation accuracy characteristics, the angle estimation unit 332 selects the second estimation result. That is, generally, the angle estimation unit 332 estimates the angle indicating the arrival direction of the reflected wave RL by referring to the estimation result with a detection rate of 0.8 or higher for the target angle among the first estimation result and the second estimation result, which have different angle ranges with a detection rate of less than 0.8 as described above. As described above, in this embodiment, the angle estimation unit 332 selectively selects one of the first estimation result and the second estimation result to perform angle estimation. This allows the appropriate estimation result to be selected according to the estimation accuracy characteristics, thereby preventing a decrease in the estimation accuracy of the arrival direction. In addition, if the detection rate for the target angle is 0.8 or higher in either the first estimation result or the second estimation result, the angle estimation unit 332 may perform angle estimation by referring to one of the predetermined estimation results.

[0038] If it is determined in step S4 that high resolution is not required (step S4: No), the angle estimation unit 332 adopts the first estimation result and ends the angle estimation process. Since the first estimation result is adopted when high resolution is not required, there is no need to further perform angle estimation based on the signal received by the second radar set, and it is possible to prevent the time required for angle estimation from becoming long.

[0039] The radar device 1 of the embodiment described above includes a first antenna set arranged to have a first estimation accuracy characteristic and a second antenna set arranged to have a second estimation accuracy characteristic different from the first estimation accuracy characteristic, and the angle estimation unit 332 estimates the angle using the first estimation result and the second estimation result. Therefore, by selectively using the first estimation result and the second estimation result, which have different estimation accuracy characteristics, it is possible to suppress a decrease in estimation accuracy in angle estimation.

[0040] Furthermore, the angle is estimated by referring to the estimation result between the first estimation result and the second estimation result, which has an angle estimation accuracy equal to or higher than a predetermined threshold, so that an appropriate estimation result can be adopted depending on the estimation accuracy characteristics, and a decrease in the estimation accuracy of the arrival direction can be further suppressed.

[0041] Furthermore, by specifying the relationship between distance D1 and distance D2 so that the ratio of the first distance to the second distance falls within the range of 1.3+n to 1.5+n (n is an integer greater than or equal to 0), the first accuracy estimation characteristic and the second estimation accuracy characteristic can be appropriately differentiated, and by using the first estimation result and the second estimation result appropriately, a decrease in estimation accuracy can be suppressed.

[0042] Furthermore, in angle estimation using ESPRIT, it is possible to suppress a decrease in estimation accuracy.

[0043] B. Other Embodiments: (B1) In the above embodiment, the radar device 1 includes three array antennas: the first array antenna 210, the second array antenna 240, and the third array antenna 270. However, the present disclosure is not limited to this. Also, the first array antenna 210 is included in both the first radar set and the second radar set, but the present disclosure is not limited to this. For example, the radar device 1 may further include a fourth array antenna, and the set of the third array antenna 270 and the fourth array antenna may be used as the second radar set. This configuration also achieves the same effects as the above embodiment.

[0044] Furthermore, while the radar device 1 includes two radar sets, a first radar set and a second radar set, the present disclosure is not limited to this. The radar device 1 may also include three or more radar sets with different estimation accuracy characteristics. This configuration also achieves the same effects as the above-described embodiment. In addition, since the number of options for estimation accuracy characteristics can be increased, the possibility that the estimation result will fall in a region with a low detection rate can be reduced, and a decrease in the estimation accuracy of the angle estimation can be further reduced.

[0045] (B2) In the above embodiment, distance D2 is set so that the ratio of distance D1 to distance D2 falls within the range of "1.3+n to 1.5+n (n is an integer equal to or greater than 0)," but the present disclosure is not limited to this. The relationship between distance D1 and distance D2 may be such that one of distances D1 and D2 is not an integer multiple of the other. This configuration also makes it possible to differentiate the estimation accuracy characteristics of the first estimation result from the second estimation accuracy characteristics, as in the above embodiment. By selectively using the first estimation result and the second estimation result, it is possible to prevent a decrease in estimation accuracy.

[0046] (B3) In the above embodiment, the angle estimation unit 332 estimates the angle indicating the arrival direction of the reflected wave RL using ESPRIT as a calculation algorithm, but the present disclosure is not limited to this. The angle estimation unit 332 may estimate the angle indicating the arrival direction of the reflected wave RL using another calculation algorithm, such as MUSIC (Multiple Signal Classification). This configuration also achieves the same effects as the above embodiment.

[0047] (B4) In the above embodiment, the angle estimation unit 332 determines that high resolution is required when the first estimation result is within 1° in step S4 of the angle estimation process, but the present disclosure is not limited to this. For example, the angle estimation unit 332 may determine that high resolution is required when the distance to the target estimated using the beat frequency is equal to or greater than a predetermined threshold. This configuration also achieves the same effects as the above embodiment. Furthermore, the angle estimation unit 332 may always perform angle estimation using the first estimation result and the second estimation result, regardless of whether high resolution is required.

[0048] (B5) In the above embodiment, the angle estimation unit 332 estimates the angle indicating the arrival direction of the reflected wave RL by referring to the estimation result having a detection rate of 0.8 or higher out of the first estimation result and the second estimation result in step S4 of the angle estimation process, but the present disclosure is not limited to this. The angle estimation unit 332 may estimate the angle indicating the arrival direction of the reflected wave RL by referring to the estimation result having a detection rate of 0.8 or higher. The threshold may be set arbitrarily depending on the estimation accuracy required for angle estimation. This embodiment also achieves the same effects as the above embodiment.

[0049] (B6) In the above embodiment, the angle estimation unit 332 performs angle estimation by selectively referring to one of the first estimation result and the second estimation result, but the present disclosure is not limited to this. For example, if the detection rate for the target angle in either the first estimation result or the second estimation result is 0.8 or higher, the angle estimation unit 332 may perform angle estimation by using the result of averaging the first estimation result and the second estimation result.

[0050] The processing unit 300 and the methods described herein may be implemented by a special-purpose computer configured with a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the processing unit 300 and the methods described herein may be implemented by a special-purpose computer configured with a processor configured with one or more dedicated hardware logic circuits. Alternatively, the processing unit 300 and the methods described herein may be implemented by one or more special-purpose computers configured with a processor and memory programmed to perform one or more functions in combination with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory storage medium.

[0051] The present disclosure is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in each embodiment corresponding to the technical features in the form described in the Summary of the Invention section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted. (Form 1) A radar device (1), a transmitting antenna (130) that transmits a transmission wave (IL) as an electromagnetic wave; a plurality of array antennas (210, 240, 270) each having a plurality of antenna elements (211, 241, 271) linearly arranged at equal intervals along a predetermined arrangement direction, the array antennas being arranged side by side in the arrangement direction, and receiving reflected waves (RL) generated when the electromagnetic waves are reflected by a target as reception signals; an angle estimation unit (332) that estimates an angle indicating the direction of arrival of the reflected wave by using the received signals received by the plurality of array antennas; Equipped with the plurality of array antennas include a first antenna set which is a set of two array antennas arranged at a first distance (D1) that is set so that the angle estimation accuracy characteristic is a first estimation accuracy characteristic, and a second antenna set which is a set of two array antennas arranged at a second distance (D2) that is set so that the angle estimation accuracy characteristic is a second estimation accuracy characteristic that is different from the first estimation accuracy characteristic; the angle estimation unit estimates the angle using a first estimation result estimated using the received signals received by the first antenna set and a second estimation result estimated using the received signals received by the second antenna set. Radar equipment. (Form 2) The radar device according to aspect 1, the angle estimation unit estimates the angle by referring to one of the first estimation result and the second estimation result, which has an estimation accuracy of the angle for the target angle that is equal to or greater than a predetermined threshold. Radar equipment. (Form 3) The radar device according to aspect 1 or 2, the first distance and the second distance have a relationship in which one distance is not an integer multiple of the other distance; Radar equipment. (Form 4) The radar device according to aspect 3, a ratio of the first distance to the second distance is in the range of 1.3+n to 1.5+n (n is an integer equal to or greater than 0); Radar equipment. (Form 5) The radar device according to any one of aspects 1 to 4, The angle estimation unit estimates the angle using ESPRIT. Radar equipment. [Explanation of symbols]

[0052] 1... radar device, 130... transmitting antenna, 210... first array antenna, 240... second array antenna, 270... third array antenna, 332... angle estimating unit, D1... distance, D2... distance, IL... transmitted wave, RL... reflected wave

Claims

1. A radar device (1), a transmitting antenna (130) that transmits a transmission wave (IL) as an electromagnetic wave; a plurality of array antennas (210, 240, 270) each having a plurality of antenna elements (211, 241, 271) linearly arranged at equal intervals along a predetermined arrangement direction, the array antennas being arranged side by side in the arrangement direction, and receiving reflected waves (RL) generated when the electromagnetic waves are reflected by a target as reception signals; an angle estimation unit (332) that estimates an angle indicating the direction of arrival of the reflected wave by using the received signals received by the plurality of array antennas; Equipped with the plurality of array antennas include a first antenna set which is a set of two array antennas arranged at a first distance (D1) that is set so that the angle estimation accuracy characteristic is a first estimation accuracy characteristic, and a second antenna set which is a set of two array antennas arranged at a second distance (D2) that is set so that the angle estimation accuracy characteristic is a second estimation accuracy characteristic that is different from the first estimation accuracy characteristic; the angle estimation unit estimates the angle using a first estimation result estimated using the received signals received by the first antenna set and a second estimation result estimated using the received signals received by the second antenna set. Radar equipment.

2. The radar device according to claim 1, the angle estimation unit estimates the angle by referring to one of the first estimation result and the second estimation result, which has an estimation accuracy of the angle for the target angle that is equal to or greater than a predetermined threshold. Radar equipment.

3. 3. The radar device according to claim 1, the first distance and the second distance have a relationship in which one distance is not an integer multiple of the other distance; Radar equipment.

4. The radar device according to claim 3, a ratio of the first distance to the second distance is in the range of 1.3+n to 1.5+n (n is an integer equal to or greater than 0); Radar equipment.

5. 3. The radar device according to claim 1, The angle estimation unit estimates the angle using ESPRIT. Radar equipment.

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