Radar device

Abstract

The present disclosure addresses the problem of providing a radar device capable of discriminating between multiple channels and failures. A transmission antenna (TX) and a reception antenna (RX) of a radar device (1) are configured such that among a set of groups of virtual antennas (V) that overlap at a virtual position and that combinations of a transmission circuit (3) and a reception circuit (4) do not match, at least Ns + Nr-2 groups of unique groups in which combinations of the transmission circuit (3) and the reception circuit (4) do not overlap with other groups. At least one group of different wiring length groups in which virtual positions overlap and wiring lengths are different are included, and the total number of groups belonging to the specific group and / or the different wiring length groups is at least Ns + Nr-1. The control unit (6) diagnoses that the out-of-range reflectors are virtual images caused by multiple channels when the number of out-of-range reflectors, which are reflectors that have acquired errors that exceed an allowable error range permissible according to the temperature information, is within an allowable upper limit number, and diagnoses that the out-of-range reflectors are virtual images caused by multiple channels when the number of out-of-range reflectors exceeds the allowable upper limit number. At least one of the transmission circuit (3) and the reception circuit (4) is diagnosed to be malfunctioning.

Description

[0001] Cross-reference of related applications

[0002] This application is based on Japanese Patent Application No. 2023-89681, filed on May 31, 2023, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] This disclosure relates to a radar technology. Background Technology

[0004] Patent Document 1 discloses a method for determining anomalies in a radar device. The radar device includes a transmission processing unit disposed inside the bumper of a vehicle, which transmits transmission waves from the inside of the bumper to the outside. The radar device also includes a reception processing unit that receives object reflection waves (reflected by objects around the vehicle), bumper reflection waves (reflected by the bumper), and transmission / reception leakage waves caused by the transmission waves, and uses the object reflection waves to detect objects. The radar device further includes a bumper determination unit that detects a first reception level of a first received wave containing the bumper reflection wave and the transmission / reception leakage waves, compares the first reception level with a threshold, and determines that the bumper is abnormal if the first reception level is greater than the threshold.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent document 1: Japanese Patent Application Publication No. 2017-215236.

[0008] However, in radar devices, anomalies other than the bumper malfunction and transmission / reception leakage mentioned in Patent Document 1 can also occur. Specifically, there are concerns about anomalies such as multi-channel malfunctions or radar device failures in radar devices. Patent Document 1 does not disclose a method for identifying such anomalies. Summary of the Invention

[0009] The subject of this disclosure is to provide a radar device capable of identifying multiple channels and malfunctions.

[0010] The following describes the technical means of this disclosure used to solve the problem. Furthermore, the symbols in parentheses within the scope of the patent claim indicate a correspondence with the specific technical means described in the embodiments described below, and are not intended to limit the technical scope of this disclosure.

[0011] The radar device of the first aspect of this disclosure comprises:

[0012] Multiple transmitting antennas and multiple receiving antennas;

[0013] Ns are transmitting circuits, each connected to a transmitting antenna and outputting a transmitting signal;

[0014] Nr receiving circuits, each connected to a receiving antenna, acquire the received signal;

[0015] Control unit, which processes received signals; and

[0016] The housing unit houses the transmitting antenna, the receiving antenna, the transmitting circuit, the receiving circuit, and the control unit.

[0017] Ns and Nr are integers greater than or equal to 2.

[0018] At least one of the multiple transmitting antennas and multiple receiving antennas is configured with unequal intervals.

[0019] Multiple transmit antennas and multiple receive antennas are configured as follows:

[0020] Among groups of virtual antennas assumed for each transmitting antenna based on the phase difference of the received signals between receiving antennas, a unique group comprises at least Ns + Nr - 2 groups of virtual antennas whose virtual positions overlap and whose combinations of transmitting and receiving circuits are inconsistent, where the virtual antennas are groups of virtual antennas whose combinations of transmitting and receiving circuits do not overlap with those of other groups.

[0021] It includes at least one group of different wiring lengths, which is a group of virtual antennas with overlapping virtual locations and inconsistent wiring lengths.

[0022] Furthermore, the total number of groups must be at least Ns + Nr - 1, and these groups must be virtual antennas belonging to at least one of the specific group and the different wiring length group.

[0023] The control unit has:

[0024] An error acquisition unit, based on a comparison of reflector information about the same reflector in the received signals of the virtual antennas in at least Ns+Nr-1 groups, acquires errors of at least one of phase and amplitude between different transmitting circuits and between receiving circuits for multiple reflectors.

[0025] Temperature acquisition unit, which acquires temperature information related to the internal temperature of the containment unit; and

[0026] The diagnostic unit diagnoses the extra-range reflectors as virtual images when the number of extra-range reflectors is within the permissible upper limit, and diagnoses the extra-range reflectors as faulty in at least one of the transmitting circuit and receiving circuit when the number of extra-range reflectors exceeds the permissible upper limit. The extra-range reflectors are reflectors that have acquired an error exceeding the permissible error range based on temperature information.

[0027] The radar device of the second aspect of this disclosure comprises:

[0028] Multiple transmitting antennas and multiple receiving antennas configured at equal intervals;

[0029] Ns are transmitting circuits, each connected to a transmitting antenna and outputting a transmitting signal;

[0030] Nr receiving circuits, each connected to a receiving antenna, acquire the received signal;

[0031] Control unit, which processes received signals; and

[0032] The housing unit houses the transmitting antenna, the receiving antenna, the transmitting circuit, the receiving circuit, and the control unit.

[0033] Ns and Nr are integers greater than or equal to 2.

[0034] Multiple transmit antennas and multiple receive antennas are configured as follows:

[0035] Among groups of virtual antennas assumed for each transmitting antenna based on the phase difference of the received signals between receiving antennas, a unique group comprises at least Ns + Nr - 2 groups of virtual antennas whose virtual positions overlap and whose combinations of transmitting and receiving circuits are inconsistent, where the virtual antennas are groups of virtual antennas whose combinations of transmitting and receiving circuits do not overlap with those of other groups.

[0036] It includes at least one group of different wiring lengths, which is a group of virtual antennas with overlapping virtual locations and inconsistent wiring lengths.

[0037] Furthermore, the total number of groups is at least Ns + Nr - 1, and these groups belong to virtual antennas that are either specific groups or groups with different wiring lengths.

[0038] The control unit has:

[0039] An error acquisition unit, based on a comparison of reflector information about the same reflector in the received signals of the virtual antennas in at least Ns+Nr-1 groups, acquires errors of at least one of phase and amplitude between different transmitting circuits and between receiving circuits for multiple reflectors.

[0040] Temperature acquisition unit, which acquires temperature information related to the internal temperature of the containment unit; and

[0041] The diagnostic unit diagnoses the extra-range reflectors as virtual images when the number of extra-range reflectors is within the permissible upper limit, and diagnoses the extra-range reflectors as faulty in at least one of the transmitting circuit and receiving circuit when the number of extra-range reflectors exceeds the permissible upper limit. The extra-range reflectors are reflectors that have acquired an error exceeding the permissible error range based on temperature information.

[0042] The third aspect of this disclosure is a radar device comprising:

[0043] Multiple transmitting antennas and multiple receiving antennas;

[0044] Ns are transmitting circuits, each connected to a transmitting antenna and outputting a transmitting signal;

[0045] Nr receiving circuits, each connected to a receiving antenna, acquire the received signal;

[0046] Control unit, which processes received signals, and

[0047] The housing unit houses the transmitting antenna, the receiving antenna, the transmitting circuit, the receiving circuit, and the control unit.

[0048] Ns and Nr are integers greater than or equal to 2.

[0049] At least one of the multiple transmitting antennas and multiple receiving antennas is configured with unequal intervals.

[0050] Among groups of virtual antennas assumed for each transmitting antenna based on the phase difference of the received signals between receiving antennas, and within a set of virtual antenna groups where virtual positions overlap and the combinations of transmitting and receiving circuits are inconsistent, the multiple transmitting antennas and multiple receiving antennas comprise a unique group of at least Ns + Nr - 2 groups. This unique group is a group of virtual antennas whose combinations of transmitting and receiving circuits do not overlap with other groups.

[0051] The control unit has:

[0052] An error acquisition unit, based on a comparison of reflector information about the same reflector in the received signals of the virtual antennas in at least Ns+Nr-2 unique groups, acquires errors of at least one of phase and amplitude between different transmitting circuits and between receiving circuits for multiple reflectors.

[0053] Temperature acquisition unit, which acquires temperature information related to the internal temperature of the containment unit; and

[0054] The diagnostic unit diagnoses the extra-range reflectors as virtual images when the number of extra-range reflectors is within the permissible upper limit, and diagnoses the extra-range reflectors as faulty in at least one of the transmitting circuit and receiving circuit when the number of extra-range reflectors exceeds the permissible upper limit. The extra-range reflectors are reflectors that have acquired an error exceeding the permissible error range based on temperature information.

[0055] The fourth aspect of this disclosure is a radar device comprising:

[0056] Multiple transmitting antennas and multiple receiving antennas configured at equal intervals;

[0057] Ns are transmitting circuits, each connected to a transmitting antenna and outputting a transmitting signal;

[0058] Nr receiving circuits, each connected to a receiving antenna, acquire the received signal;

[0059] Control unit, which processes received signals, and

[0060] The housing unit houses the transmitting antenna, the receiving antenna, the transmitting circuit, the receiving circuit, and the control unit.

[0061] Ns and Nr are integers greater than or equal to 2.

[0062] Among groups of virtual antennas assumed for each transmitting antenna based on the phase difference of the received signals between receiving antennas, and within a set of virtual antenna groups where virtual positions overlap and the combinations of transmitting and receiving circuits are inconsistent, the multiple transmitting antennas and multiple receiving antennas comprise a unique group of at least Ns + Nr - 2 groups. This unique group is a group of virtual antennas whose combinations of transmitting and receiving circuits do not overlap with other groups.

[0063] The control unit has:

[0064] An error acquisition unit, based on a comparison of reflector information about the same reflector in the received signals of the virtual antennas in at least Ns+Nr-2 unique groups, acquires errors of at least one of phase and amplitude between different transmitting circuits and between receiving circuits for multiple reflectors.

[0065] Temperature acquisition unit, which acquires temperature information related to the internal temperature of the containment unit; and

[0066] The diagnostic unit diagnoses the extra-range reflectors as virtual images when the number of extra-range reflectors is within the permissible upper limit, and diagnoses the extra-range reflectors as faulty in at least one of the transmitting circuit and receiving circuit when the number of extra-range reflectors exceeds the permissible upper limit. The extra-range reflectors are reflectors that have acquired an error exceeding the permissible error range based on temperature information.

[0067] Based on these methods, if the number of reflectors with errors exceeding the permissible error range based on temperature information (i.e., reflectors outside the range) is within the permissible upper limit, it can be diagnosed that the reflectors outside the range are virtual images. If the number of reflectors outside the range exceeds the permissible upper limit, it can be diagnosed that at least one of the transmitting and receiving circuits is faulty. Therefore, multi-channel faults can be identified. Attached Figure Description

[0068] Figure 1 This is a schematic diagram showing the basic structure of the radar device in the first embodiment.

[0069] Figure 2 This is a schematic diagram illustrating an example of the combination of the transmitting circuit and transmitting antenna, and the receiving circuit and receiving antenna in the first embodiment.

[0070] Figure 3 This is a schematic diagram illustrating an example of the configuration of the transmitting antenna and the receiving antenna in the first embodiment.

[0071] Figure 4 This is a schematic diagram illustrating the hypothetical virtual antenna in the first embodiment.

[0072] Figure 5 This is a block diagram illustrating the functional structure of the control unit according to the first embodiment.

[0073] Figure 6 This is a flowchart illustrating the control flow according to the first embodiment.

[0074] Figure 7 It is a flowchart representing the subsequent steps of the control flow.

[0075] Figure 8 It is a flowchart representing the subsequent steps of the control flow.

[0076] Figure 9 This is a chart illustrating an example of the relationship between wiring length difference and phase error.

[0077] Figure 10 This is a graph illustrating an example of the relationship between parameters associated with phase error and temperature.

[0078] Figure 11 This is a table representing an example of a group of virtual antennas used in the compensation process.

[0079] Figure 12 It is a graph showing the relationship between phase error between transmitting circuits and temperature.

[0080] Figure 13 It is a graph showing the relationship between phase error and temperature between receiving circuits.

[0081] Figure 14 This is a diagram used to illustrate the phase error caused by multiple channels.

[0082] Figure 15 This is a diagram used to illustrate phase errors caused by abnormalities in the transmitting and receiving environment.

[0083] Figure 16 It is a graph used to illustrate the phase angle detected by each virtual antenna in the case of a real image peak.

[0084] Figure 17 It is a graph used to illustrate the phase angle detected by each virtual antenna in the case of virtual image peak.

[0085] Figure 18 This is a graph illustrating the phase error between transmitting circuits when all detected peak values ​​are real images.

[0086] Figure 19 This is a graph illustrating the phase error between transmitting circuits when a portion of the detected peak is a virtual image.

[0087] Figure 20 This is a graph illustrating the phase error between transmitting circuits under abnormal transmitting and receiving conditions.

[0088] Figure 21 This is a graph illustrating the phase difference corresponding to the acquisition method in the event of a fault.

[0089] Figure 22 This is a chart illustrating the phase difference of the acquisition method corresponding to the presence of attached objects.

[0090] Figure 23 This is a schematic diagram illustrating an example of the configuration of the transmitting antenna and the receiving antenna in the second embodiment.

[0091] Figure 24 This is a schematic diagram illustrating the hypothetical virtual antenna in the second embodiment.

[0092] Figure 25 This is a schematic diagram illustrating an example of the configuration of the transmitting antenna and the receiving antenna in the third embodiment.

[0093] Figure 26 This is a schematic diagram illustrating the hypothetical virtual antenna in the third embodiment.

[0094] Figure 27 This is a table representing an example of a group of virtual antennas used in the compensation process.

[0095] Figure 28 This is a schematic diagram illustrating an example of the combination of the transmitting circuit and transmitting antenna, and the receiving circuit and receiving antenna in the fourth embodiment.

[0096] Figure 29 This is a schematic diagram illustrating an example of the configuration of the transmitting antenna and the receiving antenna in the fourth embodiment.

[0097] Figure 30 This is a schematic diagram illustrating the hypothetical virtual antenna in the fourth embodiment.

[0098] Figure 31 This is a graph showing the relative wiring lengths of the hypothetical virtual antennas in the fourth embodiment.

[0099] Figure 32 This is a table showing an example of a group of virtual antennas used for compensation processing in the fifth embodiment. Detailed Implementation

[0100] Hereinafter, several embodiments of the present disclosure will be described based on the accompanying drawings. Furthermore, in each embodiment, corresponding constituent elements may sometimes be labeled with the same symbols, and repeated descriptions may be omitted. Additionally, where only a portion of the structure is described in each embodiment, the structures of other previously described embodiments can be applied to the other parts of that structure. Moreover, in addition to combinations of structures explicitly shown in the descriptions of each embodiment, structures of multiple embodiments can be partially combined with each other, even if not explicitly shown, provided there are no particular obstacles to such combinations.

[0101] (First Implementation)

[0102] Regarding the first embodiment of this disclosure, using Figures 1 to 22 The radar device 1 is mounted on a moving body, such as a vehicle. The radar device 1 transmits a transmission signal and receives the transmission signal reflected by an object as a received signal. It also detects target information such as the distance to the object reflecting the transmission signal (i.e., the target object), the relative speed with the target object, and the target object's orientation.

[0103] Target information output from radar device 1 is input to the vehicle ECU (Electronic Control Unit) via in-vehicle networks such as CAN (Control Area Network) and Ethernet (registered trademark). Based on the acquired target information, the vehicle ECU performs various processes for autonomous driving and advanced driver assistance systems.

[0104] Object-based information processing includes collision avoidance processing and warning processing. Collision avoidance processing uses object information to control the vehicle by controlling the braking system, steering system, etc., to avoid collisions with the target objects. Warning processing uses object information to warn the driver of the possibility of a collision with the target objects.

[0105] like Figure 1 As shown in the basic structure, the radar device 1 of this embodiment includes: an oscillator 2, multiple transmitting circuits 3, multiple transmitting antennas TX, multiple receiving antennas RX, multiple receiving circuits 4, a temperature sensor 5, a control unit 6, and a housing unit 7. The radar device 1 is a radar that virtually increases the number of receiving antennas RX beyond the actual number by transmitting signals from multiple transmitting antennas TX, which is called MIMO (Multiple-Input-Multiple-Output) radar.

[0106] Oscillator 2 receives a control signal from control unit 6 and generates a modulated signal based on the control signal. The modulated signal is, for example, a chirped signal whose frequency varies with time. The modulated signal is distributed and output to the respective channels of transmitting circuit 3 and receiving circuit 4. Hereinafter, the modulated signal output from oscillator 2 to transmitting circuit 3 will be used as the transmitted signal. Additionally, the modulated signal output from oscillator 2 to receiving circuit 4 will be used as the local signal.

[0107] The transmitting circuit 3 and the receiving circuit 4 are both constructed primarily of semiconductor integrated circuit devices such as MMICs (Monolithic Microwave Integrated Circuits). The transmitting circuit 3 is connected to the transmitting antenna TX and outputs a transmitted signal to the transmitting antenna TX. If the number of transmitting circuits 3 mounted on a radar device 1 is Ns, then Ns is an integer greater than or equal to 2. The transmitting circuit 3 has an amplifier 30 with the same number of connected transmitting antennas TX. The amplifier 30 amplifies the transmitted signal output from the oscillator 2 and outputs it to its corresponding transmitting antenna TX.

[0108] The transmitting antenna TX converts the electrical signal supplied from oscillator 2, which serves as the transmission signal, into a radio wave signal and transmits it to the outside. The transmitting antenna TX is configured to include at least one antenna element. For example, the transmitting antenna TX is a patch antenna with multiple antenna elements in a planar shape. Antenna elements are arranged opposite to the ground plane on the surface of a conductive substrate on one side of the substrate. Multiple antenna elements are connected in series, for example, via power supply lines that supply electrical signals.

[0109] The receiving antenna RX receives the radio wave signal, including the transmitted signal reflected by the target object (which is a reflector in the external environment), as the received signal. The receiving antenna RX is connected to the corresponding receiving circuit 4. The configuration of the transmitting antenna TX and the receiving antenna RX will be described later.

[0110] The receiving antenna RX converts the received signal, which is a radio wave signal, into an electrical signal and outputs it to the corresponding receiving circuit 4. The receiving antenna RX, for example, is configured as a patch antenna consisting of at least one antenna element connected in series by a power supply line, similar to the transmitting antenna TX.

[0111] The receiving circuit 4 is connected to the receiving antenna RX and acquires the received signal received by the receiving antenna RX. If the number of receiving circuits 4 mounted on a radar device 1 is Nr, then Nr is an integer greater than or equal to 2. The receiving circuit 4 includes an amplifier 40 and a signal mixing unit 41, the same number as the number of connected receiving antennas RX.

[0112] Amplifier 40 amplifies the received signal received by the receiving antenna and outputs it to signal mixing unit 41. Signal mixing unit 41 generates a beat frequency signal, which is a mixture of the local signal from oscillator 2 and the received signal. The generated beat frequency signal is an interference signal representing the frequency difference between the received signal and the local signal. After the beat frequency signal has been filtered by a low-pass filter (not shown) to remove high-frequency components that deviate from the frequency difference between the received signal and the local signal, it is output to control unit 6 as signal data related to the received signal.

[0113] Temperature sensor 5 detects the temperature inside radar device 1. Temperature sensor 5 may include a thermistor and outputs temperature information corresponding to the thermistor's resistance value. Temperature sensor 5 detects the temperature information of each transmitting circuit 3 and receiving circuit 4 and outputs it to control unit 6.

[0114] The housing unit 7 is a housing that houses the transmitting antenna TX, the receiving antenna RX, the oscillator 2, the transmitting circuit 3, the receiving circuit 4, the temperature sensor 5, and the control unit 6. The housing unit 7 includes an antenna radome 7a and a housing 7b. The antenna radome 7a is formed primarily of a transmissive material that allows millimeter-wave radio waves to pass through. The antenna radome 7a is mounted on the housing 7b to cover the antennas TX and RX. The antenna radome 7a protects the antennas TX and RX and enables the transmission and reception of signals from the antennas TX and RX by utilizing the transmission of radio waves. The housing 7b and the antenna radome 7a together form a housing space that accommodates the constituent elements of the radar device 1 described above.

[0115] Control unit 6 is configured to include at least one dedicated computer. The dedicated computer constituting control unit 6 may be, for example, an ECU (Electronic Control Unit) dedicated to the control of radar device 1.

[0116] Each dedicated computer constituting the control unit 6 has at least one memory 6a and a processor 6b. The memory 6a is, for example, at least one of semiconductor memory, magnetic media, and optical media, a non-transitory tangible storage medium that non-transitorily stores computer-readable programs and data. This storage can refer to storage that retains data even when the sensor system is turned on or off, or it can be temporary storage where data is deleted when the sensor system is turned on or off.

[0117] The processor 6b may include, for example, at least one of the following as its core: CPU (Central Processing Unit), GPU (Graphics Processing Unit), RISC (Reduced Instruction Set Computer) – CPU, DFP (Data Flow Processor), and GSP (Graphics Streaming Processor). Alternatively, the processor 6b may also be at least one of digital circuitry and analog circuitry. Digital circuitry here refers to, for example, at least one of the following: ASIC (Application Specific Integrated Circuit), FPGA (Field Programmable Gate Array), SOC (System on a Chip), PGA (Programmable Gate Array), and CPLD (Complex Programmable Logic Device). Furthermore, such digital circuitry may have a memory 6a storing the program.

[0118] The control unit 6 performs angle measurement processing to calculate the angle of the reflector relative to the radar device 1 by processing multiple beat frequency signals output from multiple receiving circuits 4. The radar device 1 virtually ensures that the number of receiving antennas RX is greater than the actual number by using MIMO, thereby ensuring relatively high angular resolution. In addition, the control unit 6 ensures relatively high angle measurement accuracy by performing compensation processing to compensate for the phase difference and amplitude difference of the signals generated between different transmitting circuits 3 and different receiving circuits 4.

[0119] For compensation purposes, each transmitting antenna (TX) and receiving antenna (RX) is installed according to the specified configuration. See below for reference. Figures 2-4 The specific example shown illustrates the configuration of the transmitting antenna TX and the receiving antenna RX.

[0120] The system comprises multiple transmitting antennas TX and multiple receiving antennas RX. For each receiving antenna RX, multiple virtual antennas V are assumed to correspond to the phase difference of the received signals between the receiving antennas RX, with each transmitting antenna TX representing a phase difference. The virtual position of each virtual antenna V is defined by the relative position of the corresponding transmitting antenna TX with respect to the other transmitting antennas TX and the relative position of the corresponding receiving antenna RX with respect to the other receiving antennas RX.

[0121] The transmitting antenna TX and receiving antenna RX are configured such that the number of unique groups is at least Ns + Nr - 2 groups. Here, a unique group is a group of virtual antennas V whose virtual positions overlap between the assumed virtual antenna V groups for each transmitting antenna TX. Furthermore, a unique group is a group of virtual antennas V whose combinations of transmitting circuit 3 and receiving circuit 4 do not overlap with other groups within the set of virtual antenna groups where the combinations of transmitting circuit 3 and receiving circuit 4 are inconsistent.

[0122] As an example, assume a radar device 1 equipped with four transmitting antennas TX and six receiving antennas RX. Furthermore, in this example, assume the number of transmitting circuits 3 is Ns = 2 and the number of receiving circuits 4 is Nr = 2. In this case, such as Figure 2 As shown, the number of channels in a transmitting circuit 3 is at least 2, and the number of channels in a receiving circuit 4 is at least 3. Hereinafter, one of the transmitting circuits 3 will be designated as the first transmitting circuit 3_1, and the other as the second transmitting circuit 3_2. Similarly, one of the receiving circuits 4 will be designated as the first receiving circuit 4_1, and the other as the second receiving circuit 4_2. In this embodiment, each circuit is mounted on a plurality of circuit chips C. Specifically, the first transmitting circuit 3_1 and the first receiving circuit 4_1 are mounted on the same first circuit chip C1. Furthermore, the second transmitting circuit 3_2 and the second receiving circuit 4_2 are mounted on the same second circuit chip C2.

[0123] Furthermore, in the radar device 1 of this embodiment, the wiring length of at least one transmitting antenna TX is different from the wiring lengths of the other transmitting antennas TX. Figure 2 In the example shown, the wiring length of the transmitting antenna TX1_2 connected to the first transmitting circuit 3_1 is set to be longer than the wiring length of the wiring Wt1 of the other transmitting antennas TX. Alternatively, the wiring lengths of each wiring Wr of the receiving antenna RX are set to be substantially the same. Moreover, the transmitting antenna TX and the receiving antenna RX are configured such that the difference in wiring length between the virtual antennas in the group described later is within an allowable range.

[0124] In the following sections, different symbols are sometimes used to distinguish the four transmitting antennas TX and the six receiving antennas RX. Specifically, the two transmitting antennas TX connected to the first transmitting circuit 3_1 are designated as transmitting antennas TX1_1 and TX1_2, and the two transmitting antennas TX connected to the second transmitting circuit 3_2 are designated as transmitting antennas TX2_1 and TX2_2. Furthermore, the three receiving antennas RX connected to the first receiving circuit 4_1 are designated as receiving antennas RX1_1, RX1_2, and RX1_3, and the three receiving antennas RX connected to the second receiving circuit 4_2 are designated as receiving antennas RX2_1, RX2_2, and RX2_3.

[0125] exist Figure 3 In the example shown, the transmitting antennas TX1_1, TX1_2, TX2_1, and TX2_2 are arranged sequentially from one side to the other in the X direction, which serves as the reference direction, with a spacing of 2d. Furthermore, the receiving antennas RX1_1, RX1_2, RX2_1, RX2_2, RX2_3, and RX1_3 are arranged sequentially from one side to the other in the X direction with a spacing of d.

[0126] When antennas with different wiring lengths are present, the transmitting antenna TX and receiving antenna RX are configured such that the number of unique groups is at least Ns + Nr - 2 groups, i.e., 2 groups. In this embodiment, the transmitting antenna TX and receiving antenna RX are configured at equal intervals and in a one-dimensional arrangement. Here, one-dimensional arrangement means that they are arranged along a reference direction.

[0127] For each of the transmitting antennas TX1_1, TX1_2, TX2_1, and TX2_2, we assume 6 virtual antennas V, which are the number of receiving antennas RX. Therefore, we assume a total of 24 virtual antennas V.

[0128] Hereinafter, the multiple virtual antennas V assumed for transmitting antenna TX1_1 will be designated as virtual antennas V1, V2, V3, V4, V5, and V6 from one side to the other. Similarly, the multiple virtual antennas V assumed for transmitting antenna TX1_2 will be designated as virtual antennas V7, V8, V9, V10, V11, and V12 from one side to the other. Furthermore, the group of virtual antennas V assumed for transmitting antenna TX2_1 will be designated as virtual antennas V13, V14, V15, V16, V17, and V18 from one side to the other. Finally, the group of virtual antennas V assumed for transmitting antenna TX2_2 will be designated as virtual antennas V19, V20, V21, V22, V23, and V24 from one side to the other.

[0129] Since adjacent transmit antennas TX are configured with a spacing of 2d between them, the multiple virtual antennas V assumed for a particular transmit antenna TX have the following virtual positions: these virtual positions are offset by 2d from the multiple virtual antennas V assumed for adjacent transmit antennas TX. The receive antennas RX are configured with a spacing of d, therefore, as... Figure 4 As shown, there are 16 groups of virtual antennas V with overlapping virtual positions. Furthermore, in Figure 4 In the diagram, for ease of observation, the virtual positions of the multiple virtual antennas V for each transmitting antenna TX are offset in the vertical direction on the paper. In reality, the multiple virtual antennas V are assumed to be at their respective virtual positions along a virtual line VL extending along the reference direction (X direction). That is, in Figure 4In the diagram, virtual antennas V that are at the same position in the left-right direction on the paper form a group of virtual antennas V with overlapping virtual positions. Hereinafter, using the notation assigned to each individual virtual antenna V, the specific group of virtual antennas V with overlapping virtual positions is represented as (Vn, Vm) (n and m are natural numbers).

[0130] Specifically, (V3,V7), (V4,V8), (V5,V9), (V5,V13), (V6,V10), (V6,V14), (V9,V13), (V10,V14), (V11,V15), (V11,V19), (V12,V16), (V12,V20), (V15,V16), (V16,V20), (V17,V21), and (V18,V22) respectively become groups of virtual antennas V with overlapping virtual positions.

[0131] In the above groups, the virtual antenna V group, which is the set of groups where the combinations of transmitting circuit 3 and receiving circuit 4 are inconsistent with each other in the virtual antenna V, consists of 14 groups excluding (V6, V10) and (V18, V22). In this virtual antenna V group, the number of groups where the combinations of transmitting circuit 3 and receiving circuit 4 do not overlap with other groups is 6, satisfying the condition of at least Ns + Nr - 2 groups. As an example of 6 groups, the groups (V3, V7), (V9, V13), (V11, V15), (V11, V19), (V12, V16), and (V17, V21) can be assumed.

[0132] Furthermore, the transmitting antenna TX and the receiving antenna RX are configured to include at least one group of different wiring lengths. The different wiring length groups are groups of virtual antennas V whose virtual locations overlap and whose wiring lengths are inconsistent. Moreover, the transmitting antenna TX and the receiving antenna RX are configured such that the total number of groups of virtual antennas V belonging to at least one of the aforementioned specific group and the different wiring length group is at least Ns + Nr - 1.

[0133] In one example of the above 6 groups, there are groups with different wiring lengths. That is, 5 of these 6 groups, excluding (V17, V21), are groups with different wiring lengths, satisfying the condition that at least one group is different. Therefore, the total number of groups is 6, satisfying the condition that at least Ns + Nr - 1 groups are different.

[0134] Furthermore, in the compensation process, the group of virtual antennas V assumed can also be a group other than those mentioned above, as long as it does not overlap with the combination of transmitting circuit 3 and receiving circuit 4 of other groups. For example, the combinations of transmitting circuit 3 and receiving circuit 4 of (V4,V8) and (V5,V9) overlap with (V3,V7), but do not overlap with other groups. Therefore, assuming (V4,V8) or (V5,V9) as one of the 6 groups is equivalent to assuming (V3,V7).

[0135] Furthermore, as long as the control unit 6 ensures that the virtual antenna V group that does not overlap with the combination of the transmitting circuit 3 and receiving circuit 4 of other groups is at least Ns + Nr - 2 groups, it can also add groups that overlap with the combination of the transmitting circuit 3 and receiving circuit 4 of these groups as groups for use in compensation processing.

[0136] In order to control the radar device 1, which includes the above-mentioned compensation processing, the processor 6b executes multiple commands contained in the control program stored in the memory 6a. Thus, the control unit 6 constructs a functional unit for controlling the radar device 1. Specifically, as... Figure 5 As shown, the control unit 6 comprises a signal generation unit 60, an AD conversion unit 61, a Fourier transform unit 62, an extraction unit 63, a compensation unit 64, a temperature detection unit 65, a diagnostic unit 66, and an angle acquisition unit 67 as functional units.

[0137] Through the functions of processor 6b, the control unit 6 controls the radar device 1 according to the radar control method. Figures 6-8 The control flow shown is executed. This control flow is repeated during vehicle startup. Furthermore, each "S" in this control flow represents a step executed by multiple commands contained in the control program.

[0138] First of all, Figure 6 In S10, the signal generation unit 60 outputs a transmission signal from the oscillator 2. In the next S20, the AD conversion unit 61 acquires a beat frequency signal from the receiving circuit 4 corresponding to the received signal reflected by the target object and received by the receiving antenna RX from the transmission antenna TX. In S30, the AD conversion unit 61 converts the beat frequency signal into a digital signal by sampling it at predetermined time intervals using an A / D conversion process. In the next S40, the Fourier transform unit 62 performs an FFT (Fast Fourier Transform) on each chirp of the A / D converted beat frequency signal. Thus, the Fourier transform unit 62 acquires a frequency spectrum (range spectrum) with peak values ​​at positions corresponding to the distance to the target object for each chirp. The range spectrum represents the signal strength of each range bin corresponding to the range resolution.

[0139] Then, the Fourier transform unit 62 performs FFT processing on the range spectrum. That is, the Fourier transform unit 62 performs a second FFT processing on the waveforms in the range bins obtained from the first FFT processing of multiple chirps, arranged in a time sequence. Thus, for each velocity bin, a frequency spectrum (velocity spectrum) with peaks at positions corresponding to the relative velocity with respect to the target is obtained. Through the above two-dimensional FFT, the Fourier transform unit 62 acquires two-dimensional information (RV mapping) with peaks at positions corresponding to the distance to the target and the relative velocity of the target. The information about these acquired peaks is an example of "reflector information".

[0140] Next, in S50, the extraction unit 63 extracts the peak value from the RV mapping. In the following S60, the extraction unit 63 acquires the intensity of the extracted peak value. Then, in S70, the extraction unit 63 determines whether the extracted peak value is valid. For example, if the intensity of the peak value is within the allowable intensity range, the extraction unit 63 determines that the peak value is valid. Here, the allowable intensity range is the range where the intensity is above or greater than a specified threshold. If a valid peak value is determined to exist, the process proceeds to S80.

[0141] In S80, the compensation unit 64 obtains the phase error between the transmitting circuits 3, between the receiving circuits 4, and the difference in wiring length corresponding to the virtual antenna V based on the phase of the effective peak value in each virtual channel. Here, the wiring length of the virtual antenna V refers to the total wiring length from the transmitting antenna TX corresponding to the virtual antenna V to the transmitting circuit 3 and from the corresponding receiving antenna RX to the receiving circuit 4. Here, since only wiring Wt2 is longer than wiring Wt1, and all wiring Wr of the receiving antenna RX are substantially the same length, the wiring length of the virtual antenna V assumed for the transmitting antenna TX1_2 is longer than the wiring length of the virtual antenna V assumed for the transmitting antennas TX other than the transmitting antenna TX1_2.

[0142] Generally speaking, such as Figure 9 As shown, the phase error of each virtual antenna V based on the wiring length difference increases linearly with respect to the wiring length difference relative to the reference wiring length Lo (e.g., the shortest wiring length). That is, the phase error relative to the wiring length difference is the value obtained by multiplying the wiring length difference by the parameter K. Therefore, as Figure 9 As shown, in the case of assuming a graph of phase error relative to the wiring length difference, parameter K corresponds to the slope of the graph. That is, if the wiring length of the virtual antenna V assumed for the transmitting antenna TX1_2 in this embodiment is LA, then parameter K can be calculated from the wiring length difference LA - Lo. In this case, the reference wiring length Lo is the wiring length of the virtual antenna V assumed for the transmitting antenna TX other than the transmitting antenna TX1_2 at room temperature.

[0143] Furthermore, parameter K is a parameter corresponding to the value obtained by multiplying the linear expansion coefficient of the wiring by the temperature of the wiring. Since the linear expansion coefficient of an object is independent of temperature, parameter K is a temperature parameter that varies with temperature. Figure 10 As shown, parameter K increases linearly with increasing temperature.

[0144] In the phase compensation process, the compensation unit 64 defines a linear equation based on the phase difference of the peak value in the beat frequency signal for each of the virtual antennas V belonging to a group of Ns+Nr-1 or higher. In this linear equation, the relative phase error between the transmitting circuit 3 and the receiving circuit 4, as well as the relative phase error corresponding to the difference in wiring length, are defined as unknowns. The compensation unit 64 obtains the solution of this linear equation as the relative phase error. The beat frequency signal is a signal associated with the received signal; therefore, the phase difference of the peak value in the beat frequency signal is an example of the comparison result of the received signals of the virtual antennas V with each other.

[0145] The acquisition of relative phase error is detailed below. In the following explanation, the phase at the peak of the beat frequency signal corresponding to the virtual antenna Vn is denoted as θ. Vn (n is a natural number). Additionally, the difference in wiring length in the hypothetical virtual antennas V for the transmitting antenna TXa_b and the receiving antenna RXc_d is denoted as L. abij (a, b, i, j are natural numbers). In the following explanations, for simplicity, such as... Figure 11 As shown, groups (V3,V7), (V9,V13), and (V11,V15) are used as the group. If the cause is the difference in wiring length L... abij Let the phase error be e abij So in Figure 11 In the example shown, the phase difference θ of the peaks related to (V3, V7) V3 -θ V7 It can be defined by the relationship shown in formula (1). Additionally, the phase difference θ of the peaks associated with (V9, V13) V9 -θ V13 It can be defined by the relationship shown in formula (2). Furthermore, the peak phase difference θ associated with (V11,V15) V11 -θ V15 It can be defined by the relationship shown in formula (3).

[0146] [Formula 1]

[0147]

[0148] [Formula 2]

[0149]

[0150] [Formula 3]

[0151]

[0152] Furthermore, in the above formula, Θ a Θ b Θ c These are caused by the phase error of the target object. Furthermore, e tx1 This refers to the phase error of the signal generated by the first transmitting circuit 3_1. Additionally, e tx2 This refers to the phase error of the signal generated in the second transmitting circuit 3_2. rx1 It is the phase error of the signal generated by the first receiving circuit 4_1. rx2 It is the phase error of the signal generated by the second receiving circuit 4_2.

[0153] Here, in phase compensation, only the relative phase error between transmitting circuits 3 and the relative phase error between receiving circuits 4 need to be considered. Therefore, the relative phase error of the second transmitting circuit 3_2 relative to the first transmitting circuit 3_1 and the relative phase error of the second receiving circuit 4_2 relative to the first receiving circuit 4_1 are considered. In this case, it is possible to set e tx1 e rx1 =0. Here, if the phase error e abij Replace with L abij ·K, then the above formulas (1) to (3) can be transformed into the following formulas (4) to (6).

[0154] [Formula 4]

[0155]

[0156] [Formula 5]

[0157]

[0158] [Formula 6]

[0159]

[0160] If they are converted into matrix form, the phase difference of each group and the relative phase error satisfy the relationship shown in the following formula (7).

[0161] [Formula 7]

[0162]

[0163] Here, the term on the left side of formula (7) is the phase difference vector Y3 between the overlapping virtual antennas V. The first term on the right side of formula (7) is the coefficient matrix A3. The second term is the phase error vector X3. The phase difference vector Y3 in formula (7) can be calculated from the phase of the peak value in each beat frequency signal. The coefficient matrix A3 is a constant matrix defined by the combination of the transmitting circuit 3, receiving circuit 4, and wiring length difference of each group of virtual antennas V. Therefore, formula (7) can be used as a formula with e tx2 e rx2 The simultaneous equations with K as unknowns are used to solve the problem. That is, the compensation part 64 obtains e as the solution to formula (7). tx2 e rx2 K represents the relative phase error of the second transmitting circuit 3_2 relative to the first transmitting circuit 3_1, the relative phase error of the second receiving circuit 4_2 relative to the first receiving circuit 4_1, and the relative phase error corresponding to the difference in wiring length. The compensation unit 64 is an example of an "error acquisition unit," and the relative phase error is an example of "error information."

[0164] In the following S90, the compensation unit 64 obtains the amplitude error between the transmitting circuit 3 and the receiving circuit 4, and the amplitude error corresponding to the difference in wiring length, based on the amplitude of the effective peak value in each virtual antenna V.

[0165] In the amplitude compensation process, similarly to the phase compensation process, the compensation unit 64 defines a linear equation for the amplitude difference of the peak value of the beat frequency signal for each of the virtual antennas V belonging to the same group (Ns+Nr-1 or higher), with the amplitude error between the transmitting circuit 3 and the receiving circuit 4 as unknowns. The compensation unit 64 obtains the solution to this linear equation as the relative amplitude error. The amplitude difference of the peak value in the beat frequency signal is an example of the comparison result of the received signals of the virtual antennas V with each other.

[0166] Similar to the phase error, the amplitude error caused by the difference in wiring length relative to the reference wiring length Lo increases linearly with respect to the difference in wiring length relative to the reference wiring length. The amount of increase in amplitude error corresponding to the difference in wiring length varies with temperature. That is, the amplitude error caused by the difference in wiring length is the value obtained by multiplying the difference in wiring length by the temperature parameter α.

[0167] In the following description, the same group of virtual antennas V as described in the phase compensation process is used in the amplitude compensation process. In the following description, the amplitude at the peak of the beat frequency signal corresponding to the virtual antenna Vn is denoted as A. Vn (n is a natural number). If the cause is the difference in wiring length L... abij The amplitude error is set as G. abij Then the amplitude difference A of the peak values ​​associated with (V3,V7) V3 -A V7The amplitude difference A of the peak values ​​associated with (V9, V13) can be defined by the relationship shown in formula (8). V9 -A V13 The amplitude difference A of the peak values ​​associated with (V11,V15) can be defined by the relationship shown in formula (9). V11 -A V15 The relationship can be defined by the formula (10).

[0168] [Formula 8]

[0169]

[0170] [Formula 9]

[0171]

[0172] [Formula 10]

[0173]

[0174] Here, if the amplitude error G is... abij Replace with L abij ·α, then the above formulas (8) to (10) can be transformed into the following formulas (11) to (13).

[0175] [Formula 11]

[0176]

[0177] [Formula 12]

[0178]

[0179] [Formula 13]

[0180]

[0181] Here, if formulas (11) to (13) are converted into matrix form, the amplitude difference and relative amplitude error of each group satisfy the relationship shown in the following formula (14).

[0182] [Formula 14]

[0183]

[0184] Here, the term on the left side of formula (14) is the amplitude difference vector Y4 between the overlapping virtual antennas V. The first term on the right side of formula (14) is the coefficient matrix A4. The second term is the amplitude error vector X2. The amplitude difference vector Y4 can be calculated from the peak amplitude of each beat frequency signal. The coefficient matrix A4 is a constant matrix defined by the combination of the transmitting circuit 3, receiving circuit 4, and wiring length of each group of virtual antennas V. That is, the compensation unit 64 obtains G as the solution to formula (14). tx2 G rx2 α represents the relative amplitude error of the second transmitting circuit 3_2 relative to the first transmitting circuit 3_1, the relative amplitude error of the second receiving circuit 4_2 relative to the first receiving circuit 4_1, and the relative amplitude error based on the wiring length. After processing in S90, this process proceeds to... Figure 7 The S160.

[0185] On the other hand, if it is determined in S70 that there is no valid peak value, the process proceeds to S100. In S100, the compensation unit 64 obtains the temperature of each transmitting circuit 3 and each receiving circuit 4 from the temperature sensor 5. Then, in S110, the compensation unit 64 reads a correction table from the memory 6a regarding the phase error and amplitude error between the transmitting circuits 3 based on the temperature.

[0186] Next, in S120, the compensation unit 64 obtains the relative phase error between the transmitting circuit 3 and the receiving circuit 4 by comparing the acquired temperature with a calibration table. Then, in S130, the compensation unit 64 obtains the relative amplitude error between the transmitting circuit 3 and the receiving circuit 4 by comparing the acquired temperature with a calibration table. After the processing in S130, in S140, the compensation unit 64 compensates for the relative phase error between the transmitting circuit 3 and the receiving circuit 4. Furthermore, in S150, the compensation unit 64 compensates for the relative amplitude error between the transmitting circuit 3 and the receiving circuit 4. Afterwards, this process proceeds to... Figure 8 The S320.

[0187] Enter Figure 7 In S160, the temperature detection unit 65 acquires temperature information from the temperature sensor 5. The temperature detection unit 65 is an example of a "temperature acquisition unit". Next, in S170, the diagnostic unit 66 acquires the permissible range of the phase error corresponding to the temperature information, i.e., the permissible error range. For example, the diagnostic unit 66 acquires the permissible error range for the transmission phase error, which is one of the transmission phase error and the reception phase error. The permissible error range is the range of transmission phase errors that are allowed to occur when the radar device 1, without any adverse conditions, receives a non-multi-channel reflected wave. The permissible error range is, for example, the range of transmission phase errors that are above or above the lower threshold and below or less than the upper threshold.

[0188] Figure 12 The correlation shown applies to the relative phase error between the temperature information and the transmitting circuit 3. Similarly, Figure 13 The correlation shown applies to the relative phase error between the temperature information and the receiving circuit 4. Therefore, the diagnostic unit 66 can define the range of phase error that occurs between circuits 3 and 4 based on the temperature information as an allowable error range. For example, the diagnostic unit 66 defines the allowable error range based on their correlation, which is stored in advance in a storage medium such as memory 6a in the form of a formula or table. As the formula for the correlation, for example, based on... Figure 12 , 13 The regression equation is inferred from the relevant data shown.

[0189] The permissible error range is defined as the range of phase error assumed for the peak value (real image peak) of the path-consistent signal under normal transmission and reception conditions. In this case, such as Figure 16 As shown, the phase difference of the same peak value between virtual antennas V overlapping at virtual locations is relatively small. In the case of multiple channels, the phase changes correspondingly with the path length, therefore, as... Figure 17 As shown, the phase difference of the peaks in the group of virtual antennas V increases, and the phase error exceeds the allowable error range.

[0190] Then, in S180, the diagnostic unit 66 determines whether there is an out-of-range peak among the multiple peaks. This out-of-range peak is the peak where the calculated transmission phase error is outside the allowable error range. If there is no out-of-range peak, it can be presumed that the reflector detected as the peak is a real image Ir. On the other hand, if there is an out-of-range peak, it can be presumed that the reflector detected as the peak may be a virtual image Iv caused by multiple channels. Each peak corresponds to a reflector of the reflected signal, so the number of peaks is equivalent to the number of reflectors. That is, an out-of-range peak is an example of an "out-of-range reflector".

[0191] That is, such as Figure 14 As shown, in the case of a reflector that is a real image Ir, the path of the transmitted signal from the transmitting antenna TX to the target is substantially the same as the path of the reflected signal reflected by the reflector and received by the receiving antenna RX. Therefore, the phase error calculated based on this peak value is within the allowable error range. On the other hand, in the case of multi-channel generation, the path of the transmitted signal from the transmitting antenna TX to the target is not the same as the path of the reflected signal reflected by the reflector and received by the receiving antenna RX. In this case, the peak value of the virtual image Iv caused by multi-channel generation changes phase with the difference between the paths of the signals before and after reflection.

[0192] In S180, when it is determined that there are no out-of-range peaks, i.e. Figure 18As shown, when all peak values ​​are within the tolerance range, this process proceeds to S190. Furthermore, the tolerance range is determined by... Figure 18 The range is shown by the solid line in the chart. In S190, the diagnostic unit 66 estimates all peak values ​​as real images Ir. On the other hand, when an out-of-range peak value is determined in S180, the process proceeds to S200.

[0193] In S200, the diagnostic unit 66 determines whether the number of out-of-range peaks exceeds the allowable upper limit. Here, the allowable upper limit is the number of virtual image peaks permitted under normal transmission and reception conditions. Under normal transmission and reception conditions, such as... Figure 19 As shown, only peak values ​​that actually originate from multiple channels (virtual image peaks) become out-of-range peaks. However, under abnormal transmission and reception conditions, even real image peaks can become out-of-range peaks.

[0194] Here, the abnormal transmission and reception environment includes, for example, a fault in at least one of the transmitting circuit 3 and the receiving circuit 4, and an environment caused by signal obstruction due to attachments to the radome 7a. In the case of a fault, the signal processed by circuits 3 and 4 may be phase-shifted due to the fault. Alternatively, in the case of attachments, the signal strength of the received signal is reduced because the attachments cover the antenna TX and RX. As a result, the SN ratio is insufficient, and the phase deviation of the signal may increase. For these reasons, in an abnormal transmission and reception environment, such as... Figure 15 As shown, the real image peak can also become an out-of-range peak. In this case, as... Figure 20 As shown, the number of out-of-range peaks is greater than in a normal transmission and reception environment. Therefore, the diagnostic unit 66 can determine whether the transmission and reception environment is normal or abnormal by judging whether the number of out-of-range peaks exceeds the allowable upper limit.

[0195] In S210, the diagnostic unit 66 resets the fault counter and attachment counter (described later) up to the previous cycle. On the other hand, when the number of out-of-range peaks is determined to exceed the allowable upper limit, this process proceeds to S220.

[0196] In S220, for the phase difference between the virtual antennas V with overlapping virtual positions, the diagnostic unit 66 determines whether the phase difference obtained in the phase compensation process and the phase difference obtained by a method other than the phase compensation process are outside the allowable difference range. The phase difference obtained in the phase compensation process is the difference between the phases of the received signals obtained from each virtual antenna V with overlapping virtual positions, calculated for the same peak value. The allowable difference range is the range of phase differences that are allowed under normal transmission and reception conditions, which is above or above the lower threshold of the phase difference, and below or less than the upper threshold. Alternatively, the method other than the compensation process is, for example, the phase difference calculated by the assembled self-diagnostic (BIST: Built-In Self-Test) function. The phase difference obtained by a method other than the phase compensation process is, for example, the phase difference obtained from the internal signals in the radar device 1, such as test signals, without performing transmission and reception of external signals, and corresponding to each channel of the circuits 3 and 4 corresponding to the virtual antennas V.

[0197] Here, when the anomaly in the transmission and reception environment is caused by a fault in circuits 3 and 4, the phase difference obtained by methods other than compensation processing is also outside the permissible range. On the other hand, when the anomaly in the transmission and reception environment is caused by attachments, the phase difference obtained by methods other than compensation processing is within the permissible range. Therefore, as... Figure 21 As shown, in the case of a group of virtual antennas V where the phase difference obtained during the compensation process and the phase difference obtained by methods other than the compensation process are both outside the allowable difference range, it can be presumed that the abnormality in the transmission and reception environment is caused by a fault in circuits 3 and 4. Furthermore, Figure 21 The permissible range of difference is represented by the solid line in the chart. On the other hand, as... Figure 22 As shown, in the case of a group of virtual antennas V whose phase differences obtained without compensation processing and whose phase differences obtained by methods other than compensation processing are both outside the allowable difference range, it can be presumed that the abnormality of the transmission and reception environment is caused by attachments. Furthermore, even if there are groups of virtual antennas V whose phase differences obtained without compensation processing and whose phase differences obtained by methods other than compensation processing are both outside the allowable difference range, but the number of such groups is within the upper limit, the diagnostic unit 66 can presumably determine that the abnormality of the transmission and reception environment is caused by attachments. In other words, the upper limit can be 0 groups or 1 group of abnormalities.

[0198] In S220, if it is determined that the phase difference caused by BIST is outside the allowable tolerance range, the process proceeds to S230, where the diagnostic unit 66 uses a fault counter for fault diagnosis to perform a count. Conversely, if it is determined that the phase error caused by BIST is within the allowable tolerance range, the process proceeds to S240. In S240, the diagnostic unit 66 uses an attachment counter to perform a count. The attachment counter is used for attachment diagnosis of attachments attached to the radome 7a.

[0199] Enter Figure 8 In step S250, the diagnostic unit 66 determines whether the adhesion counter is above a threshold. If it is determined that the adhesion counter is above the threshold, the process proceeds to step S260. In step S260, the diagnostic unit 66 outputs an adhesion notification. The diagnostic unit 66 may output the adhesion notification to, for example, other ECUs installed in the vehicle. Alternatively, the diagnostic unit 66 may output the adhesion notification to a central external device of the vehicle.

[0200] On the other hand, when it is determined that the attachment counter is less than the threshold, the process proceeds to S270. In S270, the diagnostic unit 66 determines whether the fault counter is above the threshold. When it is determined that the attachment counter is above the threshold, the process proceeds to S280. In S280, the diagnostic unit 66 outputs a fault notification. The diagnostic unit 66 can output a fault notification to, for example, other ECUs installed in the vehicle. Alternatively, the diagnostic unit 66 can output a fault notification to a central device outside the vehicle.

[0201] On the other hand, when the fault counter is determined to be less than the threshold, this process proceeds to S290. In S290, the diagnostic unit 66 presumes that the out-of-range peak is caused by the virtual image Iv, i.e., caused by multiple channels.

[0202] In S300, the compensation unit 64 performs phase compensation on the peak value of the presumed real image Ir. For example, the compensation unit 64 stores the acquired relative phase error in the memory 6a as compensation data for acquiring the relative angle described later. Furthermore, in S310, the compensation unit 64 performs compensation by storing the relative amplitude error between the transmitting circuit 3 and the receiving circuit 4 in the memory 6a as compensation data.

[0203] Enter Figure 8In S320, the angle acquisition unit 67 acquires the relative angle of the reflector based on the phase information of the peak value that is presumed to be a real image Ir and has been compensated. Specifically, the angle acquisition unit 67 acquires the phase difference between the virtual antennas V by performing FFT processing on multiple peak values ​​extracted from the beat frequency signals of the received signals based on the compensated virtual antennas V. The phase difference between the virtual antennas V is related to the relative angle of the target object, so the angle acquisition unit 67 acquires the relative angle by converting the acquired phase difference into a relative angle. At this time, the angle acquisition unit 67 acquires the relative angle after compensating the phase difference between the transmitting circuit 3 and the receiving circuit 4 by using compensation data.

[0204] According to this first embodiment, when the number of reflective objects with errors exceeding the allowable error range based on temperature information (i.e., out-of-range peaks) is within the allowable upper limit, it can be diagnosed that the out-of-range peaks are virtual images Iv. When the number of out-of-range peaks exceeds the allowable upper limit, it can diagnose a fault in at least one of the transmitting circuit and the receiving circuit. Therefore, the radar device 1 can distinguish between multiple channels and faults.

[0205] (Second Implementation)

[0206] like Figure 23 , 24 As shown, the second embodiment is a variation of the first embodiment. In the second embodiment, the transmitting antenna TX is configured in a two-dimensional manner. That is, the transmitting antenna TX is configured at equal intervals in two reference directions.

[0207] In the second embodiment, the number of transmitting antennas TX and receiving antennas RX are the same as in the first embodiment. Furthermore, the number of transmitting circuits 3 and receiving circuits 4 are also the same as in the first embodiment.

[0208] exist Figure 23 In the example shown, transmitting antennas TX1_1 and TX2_1 are arranged sequentially from one side to the other in the X direction with a spacing of 2d. Furthermore, transmitting antennas TX1_2 and TX1_2 are arranged sequentially from one side to the other in the Y direction, which is orthogonal to the X direction, with a spacing of s. Additionally, transmitting antennas TX2_1 and TX2_2 are arranged sequentially from one side to the other in the Y direction with a spacing of s. That is, transmitting antennas TX1_2 and TX2_2 are arranged parallel to transmitting antennas TX1_1 and TX2_1, separated by a 2d spacing.

[0209] Furthermore, the receiving antennas RX1_1, RX1_2, RX2_1, RX2_2, RX2_3, and RX1_3 are arranged sequentially from one side to the other in the X direction with intervals d. Since the number of each antenna TX and RX is the same as in the first embodiment, in the second embodiment, as... Figure 24As shown, it is also assumed that there are a total of 24 virtual antennas V.

[0210] Adjacent transmitting antennas TX in the X direction are arranged with a spacing of 2d between them. Therefore, the column of the assumed virtual antenna V for a particular transmitting antenna TX is a virtual position that is offset by 2d relative to the column of the assumed virtual antenna V for the adjacent transmitting antennas TX in the X direction. Similarly, adjacent transmitting antennas TX in the Y direction are arranged with a spacing of s between them. Therefore, the column of the assumed virtual antenna V for a particular transmitting antenna TX is a virtual position that is offset by s relative to the column of the assumed virtual antenna V for the adjacent transmitting antennas TX in the Y direction.

[0211] In addition, Figure 24 In, also with Figure 4 Similarly, the virtual positions of the multiple virtual antennas V for each transmitting antenna TX are offset in the vertical direction on the paper. In practice, the multiple virtual antennas V assumed for transmitting antennas TX1_1 and TX2_1 are assumed to have their own virtual positions on a virtual line VL1 extending along the X direction. Furthermore, the multiple virtual antennas V assumed for transmitting antennas TX1_2 and TX2_2 are assumed to have their own virtual positions on a virtual line VL2 extending along the X direction. Moreover, the columns of virtual antennas V on virtual line VL1 and the columns of virtual antennas V on virtual line VL2 are separated by a distance s in the Y direction.

[0212] Therefore, as Figure 24 As shown, a group of virtual antennas V with overlapping virtual positions can be assumed between multiple virtual antennas V assumed for transmitting antenna TX1_1 and multiple virtual antennas V assumed for transmitting antenna TX2_1. Specifically, (V3,V13), (V4,V14), (V5,V15), and (V6,V16) form a group of virtual antennas V with overlapping virtual positions.

[0213] Similarly, a group of virtual antennas V with overlapping virtual positions can be assumed between the multiple virtual antennas V assumed for transmitting antenna TX1_2 and the multiple virtual antennas V assumed for transmitting antenna TX2_2. Specifically, (V9,V19), (V10,V20), (V11,V21), and (V12,V22) become a group of virtual antennas V with overlapping virtual positions.

[0214] The above groups constitute a set of combinations of transmitting circuit 3 and receiving circuit 4 that do not overlap with each other in the virtual antenna V. Within this set, the number of combinations of transmitting circuit 3 and receiving circuit 4 that do not overlap with other groups is 3, satisfying the condition of at least Ns + Nr - 2 groups.

[0215] As one example of three groups, we can assume groups (V3,V13), (V5,V15), and (V6,V16). Furthermore, as another example of three groups, we can assume groups (V9,V19), (V11,V21), and (V12,V22).

[0216] Furthermore, although the combinations of transmitting circuit 3 and receiving circuit 4 (V4,V14), (V9,V19), (V10,V20), and (V3,V13) are repeated, they are not repeated with other groups. Therefore, assuming (V4,V14), (V9,V19), or (V10,V20) as one of the three groups is equivalent to assuming (V3,V13). Similarly, assuming (V11,V21) as one of the three groups is equivalent to assuming (V5,V15), and assuming (V12,V22) as one of the three groups is equivalent to assuming (V6,V16).

[0217] Furthermore, among the special groups mentioned above, groups (V9, V19), (V11, V21), and (V12, V22) are also groups with different wiring lengths. Therefore, the condition that there are more than one group of different wiring lengths is also satisfied.

[0218] The above states that at least three groups belong to either the unique group or the different wiring length groups, satisfying the condition of at least Ns + Nr - 1 groups. For example, (V9, V19), (V11, V21), and (V12, V22) can be assumed as the belonging groups of these three groups. Furthermore, one or two of the belonging groups (V9, V19), (V11, V21), and (V12, V22) can be exchanged with the groups described above that have an equivalent relationship.

[0219] (Third implementation method)

[0220] like Figures 25-27 As shown, the third embodiment is a variation of the first embodiment. In the radar device 1 of the third embodiment, the number of transmitting antennas TX and receiving antennas RX, and the number of transmitting circuits 3 and receiving circuits 4 are the same as in the first embodiment. Furthermore, the combination of transmitting antenna TX with transmitting circuit 3, and the combination of receiving antenna RX with receiving circuit 4 are also different. Figure 2 The same as shown.

[0221] In this embodiment, the transmitting antennas TX are configured at unequal intervals. Figure 25In the example shown, transmitting antennas TX1_1, TX1_2, TX2_1, and TX2_2 are arranged sequentially from one side to the other in the X direction, which serves as the reference direction. Transmitting antennas TX1_1 and TX1_2 are arranged with a 6d interval between them. Transmitting antennas TX1_2 and TX2_1 are arranged with a 3d interval between them. Furthermore, transmitting antennas TX2_1 and TX2_2 are arranged with a 6d interval between them.

[0222] Furthermore, the receiving antennas RX1_1, RX1_2, RX2_1, RX2_2, RX2_3, and RX1_3 are arranged sequentially from one side to the other in the reference direction with an interval of d.

[0223] For each of the transmitting antennas TX1_1, TX1_2, TX2_1, and TX2_2, a virtual antenna V is assumed to be the number of receiving antennas RX, i.e., 6 virtual antennas V. Therefore, in this embodiment, a total of 24 virtual antennas V are assumed.

[0224] Here, the multiple virtual antennas V assumed for transmitting antenna TX1_1 are designated as virtual antennas V1, V2, V3, V4, V5, and V6 from one side to the other. The multiple virtual antennas V assumed for transmitting antenna TX1_2 are designated as virtual antennas V7, V8, V9, V10, V11, and V12 from one side to the other. The group of virtual antennas V assumed for transmitting antenna TX2_1 is designated as virtual antennas V13, V14, V15, V16, V17, and V18 from one side to the other. The group of virtual antennas V assumed for transmitting antenna TX2_2 is designated as virtual antennas V19, V20, V21, V22, V23, and V24 from one side to the other.

[0225] Since the transmitting antennas TX1_1 and TX1_2 are arranged with a 6d interval between them, the virtual antenna group V assumed for transmitting antenna TX1_1 becomes a virtual position offset by 6d from the virtual antenna group V assumed for transmitting antenna TX1_2. Furthermore, since the transmitting antennas TX1_2 and TX2_1 are arranged with a 3d interval between them, the virtual antenna group V assumed for transmitting antenna TX1_2 becomes a virtual position offset by 3d from the virtual antenna group V assumed for transmitting antenna TX2_1. Moreover, since the transmitting antennas TX2_1 and TX2_2 are arranged with a 6d interval between them, the virtual antenna group V assumed for transmitting antenna TX2_1 becomes a virtual position offset by 6d from the virtual antenna group V assumed for transmitting antenna TX2_2.

[0226] Therefore, in such an antenna TX, RX configuration, such as Figure 26 As shown, there are 3 groups of virtual antennas V with overlapping virtual positions. Additionally, in Figure 26In the diagram, the virtual positions of the multiple virtual antennas V for each transmitting antenna TX are also recorded offset from the vertical direction on the paper. In fact, the virtual positions of multiple virtual antennas V are assumed on a virtual line VL extending along the reference direction (X direction). Specifically, (V10, V13), (V11, V14), and (V12, V15) become groups of virtual antennas V with overlapping virtual positions.

[0227] like Figure 26 and Figure 27 As shown, the above three groups are sets of combinations of transmitting circuit 3 and receiving circuit 4 that are inconsistent with each other in the virtual antenna V. Furthermore, these three groups are sets of combinations of transmitting circuit 3 and receiving circuit 4 that do not overlap. Therefore, in this antenna configuration, the number of unique groups is three, satisfying the condition of at least Ns + Nr - 2 groups.

[0228] Furthermore, these three groups represent different wiring length groups. Specifically, the wiring lengths of virtual antennas V10, V11, and V12 are longer than those of virtual antennas V13, V14, and V15. Therefore, in this antenna configuration, there are three groups with different wiring lengths, satisfying the condition of at least one group. Moreover, based on the above, in this antenna configuration, there are three groups, satisfying the condition of at least Ns + Nr - 1 groups.

[0229] (Fourth Implementation)

[0230] like Figures 28-31 As shown, the fourth embodiment is a variation of the first embodiment. In the second embodiment, the transmitting antenna TX and the receiving antenna RX are configured in a two-dimensional configuration, and the transmitting antenna TX is configured at unequal intervals.

[0231] As an example of this embodiment, assume a radar device 1 equipped with 12 transmitting antennas TX and 16 receiving antennas RX. Here, the number of transmitting circuits 3 is set to Ns = 4, and the number of receiving circuits 4 is set to Nr = 4. In this case, as... Figure 28 As shown, the number of channels in a transmitting circuit 3 is at least 3, and the number of channels in a receiving circuit 4 is at least 4. Hereinafter, the four transmitting circuits 3 are sometimes distinguished as first transmitting circuit 3_1, second transmitting circuit 3_2, third transmitting circuit 3_3, and fourth transmitting circuit 3_4. Similarly, the four receiving circuits 4 are sometimes distinguished as first receiving circuit 4_1, second receiving circuit 4_2, third receiving circuit 4_3, and fourth receiving circuit 4_4.

[0232] In this embodiment, each circuit is also mounted on multiple circuit chips C. Specifically, the first transmitting circuit 3_1 and the first receiving circuit 4_1 are mounted on the same first circuit chip C1. Furthermore, the second transmitting circuit 3_2 and the second receiving circuit 4_2 are mounted on the same second circuit chip C2. In addition, the third transmitting circuit 3_3 and the third receiving circuit 4_3 are mounted on the same third circuit chip C3. Moreover, the fourth transmitting circuit 3_4 and the fourth receiving circuit 4_4 are mounted on the same fourth circuit chip C4. Furthermore, the wiring lengths of each wiring Wt between the transmitting antenna TX and the corresponding transmitting circuit 3, and the wiring lengths of each wiring Wr between the receiving antenna RX and the corresponding receiving circuit 4, are defined as follows: the wiring length of each assumed virtual antenna V becomes... Figure 31 The relative relationships are shown in the diagram. That is, at least one of the wiring lengths from each transmitting circuit 3 to each transmitting antenna TX and from each receiving antenna RX to each receiving circuit 4 is defined as follows: the wiring length of the corresponding virtual antenna V becomes... Figure 31 The relative relationships shown.

[0233] Furthermore, similar to the first embodiment, the 12 transmitting antennas TX and 16 receiving antennas RX are sometimes distinguished by different symbols. Specifically, the three transmitting antennas TX connected to the first transmitting circuit 3_1 are designated as transmitting antennas TX4, TX5, and TX6, and the three transmitting antennas TX connected to the second transmitting circuit 3_2 are designated as transmitting antennas TX1, TX2, and TX3. Moreover, the three transmitting antennas TX connected to the third transmitting circuit 3_3 are designated as transmitting antennas TX7, TX8, and TX9, and the three transmitting antennas TX connected to the fourth transmitting circuit 3_4 are designated as transmitting antennas TX10, TX11, and TX12.

[0234] In addition, sometimes the four receiving antennas RX connected to the first receiving circuit 4_1 are designated as receiving antennas RX5, RX6, RX7, and RX8, and the four receiving antennas RX connected to the second receiving circuit 4_2 are designated as receiving antennas RX1, RX2, RX3, and RX4. Moreover, sometimes the four receiving antennas RX connected to the third receiving circuit 4_3 are designated as receiving antennas RX9, RX10, RX11, and RX12, and the four receiving antennas RX connected to the fourth receiving circuit 4_4 are designated as receiving antennas RX13, RX14, RX15, and RX16.

[0235] The above describes a two-dimensional configuration of the transmitting antenna TX and the receiving antenna RX. For example... Figure 29As shown, multiple transmit antennas TX are arranged in four columns along the X direction and separated in the Y direction. In these four columns along the X direction, two transmit antennas TX are each arranged in the first, second, and fourth columns from the origin. Furthermore, in the third column from the origin, six transmit antennas TX are arranged. Here, the interval of one scale division in the X direction is defined as d, and the interval of one scale division in the Y direction is defined as s. Transmit antennas TX12, TX10, and TX9 are arranged at equal intervals of d. Additionally, transmit antennas TX5, TX4, and TX3 are also arranged at equal intervals of d. On the other hand, transmit antenna TX9 is arranged at a interval of 20d with respect to transmit antenna TX5. That is, in this third column, the transmit antennas TX are arranged at unequal intervals in the X direction.

[0236] Furthermore, the multiple receiving antennas RX are arranged in two columns along the X direction, but separated in the Y direction. Each of these two columns along the X direction contains eight receiving antennas TX. In each column, these receiving antennas RX are arranged at equal intervals along the X direction. Moreover, in the two columns along the X direction, the first column from the origin is configured to be positioned in the same Y direction as the first column of transmitting antennas TX from the origin. Additionally, in the two columns along the X direction, the second column from the origin is configured to be positioned in the same Y direction as the fourth column of transmitting antennas TX from the origin.

[0237] For each of the 12 transmit antennas TX, 16 virtual antennas V are assumed to correspond to the number of receive antennas RX. Therefore, in this embodiment, a total of 192 virtual antennas V are assumed. Specifically, using... Figure 30 The configuration shown assumes 192 virtual antennas V.

[0238] Hereinafter, the virtual antenna V corresponding to a specific receiving antenna RXb (where a and b are natural numbers) among the 16 assumed virtual antennas V for a specific transmitting antenna TXa will be denoted as Vc (c = (a-1)×16+b). Furthermore, in Figure 30 In order to avoid complicating things, the "V" is omitted.

[0239] like Figure 30As shown, there are 24 groups of virtual antennas V with overlapping virtual positions. Among them, there are 13 unique groups where the combination of transmitting circuit 3 and receiving circuit 4 does not overlap with other groups. For example, (V2,V85), (V9,V88), (V10,V93), (V12,V97), (V16,V86), (V60,V129), (V64,V133), (V76,V145), (V80,V149), (V95,V97), (V98,V165), (V105,V168), and (V106,V173) can be assumed to be unique groups. The compensation unit 64, described later, performs compensation processing based on the received signals that can be acquired through at least 6 of these groups of virtual antennas V.

[0240] Furthermore, similar to the first embodiment, the group of virtual antennas V assumed in the compensation process can be any group whose combination of transmitting circuit 3 and receiving circuit 4 does not overlap with other groups, or it can be assumed to be a group other than those mentioned above. For example, the combinations of transmitting circuit 3 and receiving circuit 4 in (V3, V86) and (V4, V87) overlap with (V2, V85), but do not overlap with other groups. Therefore, assuming (V3, V86) or (V4, V87) as one of the 13 groups is equivalent to assuming (V2, V85).

[0241] Here, since Ns=4 and Nr=4, in the processing of S80 and S90, the control unit 6 further calculates the phase error and amplitude error between the transmitting circuits 3, the phase error and amplitude error between the receiving circuits 4, and the phase error and amplitude error corresponding to the difference in wiring length, based on the beat frequency signals of at least 7 groups in the group.

[0242] Furthermore, when the number of antennas (TX and RX) is relatively large, as described above, the configuration of antennas (TX and RX) can be determined using a genetic algorithm. For example, as evaluation criteria for the characteristics of the current generation generated by the genetic algorithm, overlap efficiency, rank, wiring efficiency, FOV, and separation angle can be listed. Overlap efficiency is a parameter obtained by dividing the total rank by the number of channels reduced due to overlap of virtual positions; a high overlap efficiency is preferred. Rank is a pre-determined parameter. Wiring efficiency is a parameter corresponding to the dispersion of antenna coordinates input to the same circuit; a low wiring efficiency is preferred. FOV is a parameter corresponding to the spacing between antennas; a low FOV is preferred. Separation angle is a parameter corresponding to the aperture length; a high separation angle is preferred.

[0243] (Fifth Implementation)

[0244] The fifth embodiment is a variation of the first embodiment. As shown in the fifth embodiment, the wiring Wt and Wr of all transmitting antennas TX and receiving antennas RX can be of equal length.

[0245] The acquisition of relative phase error in the case of equal-length wiring is detailed below. In the following explanation, the phase at the peak of the beat frequency signal corresponding to the virtual antenna Vn is denoted as θ. Vn (n is a natural number). In the following explanation, for the sake of simplicity, such as Figure 32 As shown, only the groups (V9, V13) and (V11, V15) are used as combinations of transmitting circuit 3 and receiving circuit 4 that do not overlap with other groups. Furthermore, as a combination of transmitting circuit 3 and receiving circuit 4 that does not overlap with (V9, V13), the group (V10, V14) is added.

[0246] In this case, the phase difference θ of the peaks related to (V9, V13) V9 -θ V13 The phase difference θ of the peaks related to (V10, V14) can be defined by the relationship shown in formula (15). V10 -θ V14 The phase difference θ of the peaks related to (V11,V15) can be defined by the relationship shown in formula (16). V11 -θ V15 The relationship can be defined by the formula (17).

[0247] [Formula 15]

[0248]

[0249] [Formula 16]

[0250]

[0251] [Formula 17]

[0252]

[0253] Θ a Θ b Θ c These are caused by the phase error of the target object. Furthermore, e tx1 It is the phase error of the signal generated by the first transmitting circuit 3_1, e tx2 This refers to the phase error of the signal generated in the second transmitting circuit 3_2. rx1 It is the phase error of the signal generated by the first receiving circuit 4_1, e rx2 It is the phase error of the signal generated by the second receiving circuit 4_2.

[0254] In phase compensation, it is only necessary to consider the relative phase error between the transmitting circuits 3 and the relative phase error between the receiving circuits 4. Therefore, if we consider the relative phase error of the second transmitting circuit 3_2 relative to the first transmitting circuit 3_1 and the relative phase error of the second receiving circuit 4_2 relative to the first receiving circuit 4_1, then we can assume e tx1 e rx1 =0. Therefore, formulas (15) to (17) can be transformed into the following formulas (18) to (20).

[0255] [Formula 18]

[0256]

[0257] [Formula 19]

[0258]

[0259] [Formula 20]

[0260]

[0261] Here, if formulas (18) to (20) are converted into matrix form, the phase difference and relative phase error of each group satisfy the relationship expressed by the following formula (21).

[0262] [Formula 21]

[0263]

[0264] The term on the left side of formula (21) is the phase difference vector Y1 between the overlapping virtual antennas V. The first term on the right side of formula (21) is the coefficient matrix A1, and the second term is the phase error vector X1. The phase difference vector Y1 in formula (21) can be calculated from the phase of the peak value in each beat frequency signal. In addition, the coefficient matrix A1 is a constant matrix defined by the combination of the transmitting circuit 3 and the receiving circuit 4 of each group of virtual antennas V. Therefore, formula (21) can be used as a formula with e tx2 e rx2 Solve the simultaneous equations for the unknowns. That is, the compensation part obtains e as a solution to formula (21). tx2 e rx2 This refers to the relative phase error of the second transmitting circuit 3_2 relative to the first transmitting circuit 3_1, and the relative phase error of the second receiving circuit 4_2 relative to the first receiving circuit 4_1.

[0265] In the amplitude compensation process, similarly to the phase compensation process, the compensation unit 64 defines a linear equation for the amplitude difference of the peak values ​​of the beat frequency signal for each specific group, with the amplitude error between the transmitting circuit 3 and the receiving circuit 4 as unknowns, and obtains the solution of this linear equation as the relative amplitude error. The amplitude difference of the peak values ​​in the beat frequency signal is an example of the comparison result of the received signals of the virtual antennas V with each other.

[0266] The following describes the case where the same virtual antenna V group as the phase compensation process described above is used in the amplitude compensation process. In this case, the amplitude difference A of the peaks related to (V9, V13) is... V9 -A V13 The amplitude difference A of the peak values ​​related to (V10, V14) can be defined by the relationship shown in formula (22). V10 -A V14 The amplitude difference A of the peak values ​​related to (V11, V15) can be defined by the relationship shown in formula (23). V11 -A V15 The relationship can be defined by the formula (24).

[0267] [Formula 22]

[0268]

[0269] [Formula 23]

[0270]

[0271] [Formula 24]

[0272]

[0273] Furthermore, in the above formula, G a G b G c These are caused by the amplitude error of the target object. Furthermore, G tx1 It is the amplitude error of the signal generated by the first transmitting circuit 3_1, G tx2 It refers to the amplitude error of the signal generated by the second transmitting circuit 3_2. rx1 It is the amplitude error of the signal generated by the first receiving circuit 4_1. G rx2 It is the amplitude error of the signal generated by the second receiving circuit 4_2.

[0274] Here, similar to phase compensation, if we consider the relative amplitude error of the second transmitting circuit 3_2 relative to the first transmitting circuit 3_1, and the relative amplitude error of the second receiving circuit 4_2 relative to the first receiving circuit 4_1, then we can set G... tx1 G rx1=0. Therefore, formulas (22) to (24) can be transformed into the following formulas (25) to (27).

[0275] [Formula 25]

[0276]

[0277] [Formula 26]

[0278]

[0279] [Formula 27]

[0280]

[0281] Here, if formulas (25) to (27) are converted into matrix form, the amplitude difference and relative amplitude error of each group satisfy the relationship expressed by the following formula (28).

[0282] [Formula 28]

[0283]

[0284] The term on the left side of formula (28) is the amplitude difference vector Y2 between the overlapping virtual antennas V. The first term on the right side of formula (28) is the coefficient matrix A2, and the second term is the amplitude error vector X2. The amplitude difference vector Y2 is calculated from the amplitude of the peak value in each beat frequency signal. The coefficient matrix A2 is a constant matrix defined by the combination of the transmitting circuit 3 and the receiving circuit 4 of each group of virtual antennas V. That is, the compensation unit 64 obtains the solution G of formula (28). tx2 G rx2 As the relative amplitude error of the second transmitting circuit 3_2 relative to the first transmitting circuit 3_1, and the relative amplitude error of the second receiving circuit 4_2 relative to the first receiving circuit 4_1.

[0285] (Other implementation methods)

[0286] The above describes several implementation methods, but this disclosure should not be interpreted as limited to these implementation methods. Various implementation methods and combinations can be applied without departing from the spirit of this disclosure.

[0287] In a modified example, if the diagnostic unit 66 determines that the attachment counter is above a threshold, i.e., if attachment is detected, it may perform attachment-related processing in place of the notification processing in S240 or in addition to the notification processing in S240. Specifically, the diagnostic unit 66 may perform a process to activate a heater (not shown) installed on the radar device 1. If the attachment is frost, the frost can be removed by activating the heater. Alternatively, the diagnostic unit 66 may identify the antennas TX and RX affected by the attachment and perform a prohibition process to prevent the received signals in the virtual antenna V associated with those antennas TX and RX from being used for acquiring target information. The diagnostic unit 66 may also first activate the heater and then perform the prohibition process if the attachment is not removed.

[0288] In a modified example, for the relative amplitude error between at least one of the different transmitting circuits 3 and receiving circuits 4, the diagnostic unit 66 can diagnose whether the peak is caused by a virtual image or a fault based on the number of peaks that exceed the allowable error range based on temperature information.

[0289] In a modified example, the temperature detection unit 65 can also acquire temperature information corresponding to the phase information in S160. Specifically, in S160, the temperature detection unit 65 detects the temperature information based on the parameter K calculated in S80. As described above, the parameter K is a temperature parameter that varies with temperature. That is, the temperature detection unit 65 can acquire temperature information based on the phase information calculated in S80. Figure 9 Temperature information is obtained by establishing a correspondence between the value of parameter K and temperature, as shown. This correspondence is pre-stored in a storage medium such as memory 6a. The correspondence is stored, for example, in the form of a function or a table. Alternatively, the temperature detection unit can also obtain temperature information corresponding to the relative amplitude error. The parameter α in the calculation of the relative amplitude error is also a temperature-corresponding value, just like parameter K; therefore, the temperature detection unit 65 can obtain temperature information based on the correlation between parameter α and temperature.

[0290] Furthermore, the temperature information corresponding to the phase information is the temperature associated with the wiring, and therefore is a temperature close to the actual temperature of the wiring. That is, the sensor temperature information and the phase temperature information are essentially inconsistent due to differences in the temperature detection location. In this embodiment, the phase temperature information is generally a temperature lower than the sensor temperature information. For example, if the external temperature of the radar device 1 is equivalent to room temperature, and the sensor temperature information of the normal temperature sensor 5 is around 60°C, the phase temperature information would be a temperature lower than that sensor temperature information, for example, around 40°C.

[0291] In a variation of the fourth embodiment, the transmitting antenna TX and the receiving antenna RX may be configured with unequal intervals.

[0292] In a variation, the dedicated computer constituting control unit 6 may also be a sensor control ECU that comprehensively controls various sensors mounted on the vehicle. The dedicated computer constituting control unit 6 may also be an integrated ECU that integrates the vehicle's driving control. The dedicated computer constituting control unit 6 may also be a determination ECU that determines the driving task in the vehicle's driving control. The dedicated computer constituting control unit 6 may also be a monitoring ECU that monitors the vehicle's driving control. The dedicated computer constituting control unit 6 may also be an evaluation ECU that evaluates the vehicle's driving control.

[0293] The dedicated computer constituting control unit 6 can also be a navigation ECU that navigates the vehicle's driving path. The dedicated computer constituting control unit 6 can also be a positioner ECU that estimates the vehicle's own state variables. The dedicated computer constituting control unit 6 can also be an actuator ECU that controls the vehicle's driving actuators. The dedicated computer constituting control unit can also be an HCU (Hman Machine Interface) Control Unit that controls information prompts within the vehicle. The dedicated computer constituting control unit 6 can also be a computer outside the vehicle, such as an external center or mobile terminal capable of communicating with the vehicle.

[0294] In a variation, the mobile body to which the radar device 1 is applied may be, for example, an autonomous robot capable of carrying goods or collecting information through autonomous or remote driving. Autonomous robots include autonomous vehicles. In addition to the methods described so far, the above-described embodiments and variations can also be implemented as control devices configured to be mounted on a mobile body and having at least one processor 6b and one memory 6a, and implemented as processing circuits (e.g., processing ECUs) or semiconductor devices (e.g., semiconductor chips).

[0295] (The disclosure of technical ideas)

[0296] This specification discloses several technical ideas described in the following list of items. Some items may be described in a multiple dependent form, whereby a preceding item is selectively referenced in a subsequent item. Furthermore, some items may be described in a multiple dependent form, referring to another multiple dependent form. These items described in multiple dependent forms define several technical ideas.

[0297] (Technical Idea 1)

[0298] A radar device comprising:

[0299] Multiple transmit antennas (TX) and multiple receive antennas (RX);

[0300] Ns transmitting circuits (3), which are connected to the transmitting antenna and output transmitting signals;

[0301] Nr receiving circuits (4), which are connected to the receiving antenna and acquire the received signal;

[0302] Control unit (6), which processes the received signal; and

[0303] The housing unit (7) houses the transmitting antenna, the receiving antenna, the transmitting circuit, the receiving circuit, and the control unit.

[0304] The Ns and Nr are both integers greater than or equal to 2.

[0305] At least one of the plurality of transmitting antennas and the plurality of receiving antennas is configured at unequal intervals.

[0306] The plurality of transmitting antennas and the plurality of receiving antennas are configured as follows:

[0307] Among groups of virtual antennas (V) assumed for each of the receiving antennas based on the phase difference of the received signals between the receiving antennas, a unique group comprises at least Ns + Nr - 2 groups of virtual antennas whose virtual positions overlap and whose combinations of transmitting and receiving circuits are inconsistent, where the combinations of transmitting and receiving circuits do not overlap with those of the other groups.

[0308] It includes at least one group of different wiring lengths, which is a group of virtual antennas whose virtual locations overlap and whose wiring lengths are inconsistent.

[0309] Furthermore, the total number of groups is at least Ns + Nr - 1, and these groups belong to the virtual antennas that are at least one of the specific group and the different wiring length group.

[0310] The control unit has:

[0311] Error acquisition unit (64) acquires, based on the comparison results of reflector information about the same reflector in the received signals of the virtual antennas in the at least Ns+Nr-1 group, at least one of the phase and amplitude errors between the transmitting circuits and between the receiving circuits for the plurality of reflectors.

[0312] Temperature acquisition unit (65) acquires temperature information associated with the internal temperature of the containment unit; and

[0313] The diagnostic unit (66) diagnoses that the out-of-range reflectors are virtual images when the number of out-of-range reflectors is within the allowable upper limit, and diagnoses that at least one of the transmitting circuit and the receiving circuit is faulty when the number of out-of-range reflectors exceeds the allowable upper limit. The out-of-range reflectors are reflectors that have acquired an error exceeding the allowable error range based on the temperature information.

[0314] (Technical Idea 2)

[0315] A radar device comprising:

[0316] Multiple transmit antennas (TX) and multiple receive antennas (RX) are configured at equal intervals.

[0317] Ns transmitting circuits (3), which are connected to the transmitting antenna and output transmitting signals;

[0318] Nr receiving circuits (4), which are connected to the receiving antenna and acquire the received signal;

[0319] Control unit (6), which processes the received signal; and

[0320] The housing unit (7) houses the transmitting antenna, the receiving antenna, the transmitting circuit, the receiving circuit, and the control unit.

[0321] The Ns and Nr are both integers greater than or equal to 2.

[0322] The plurality of transmitting antennas and the plurality of receiving antennas are configured as follows:

[0323] Among groups of virtual antennas (V) assumed for each of the receiving antennas based on the phase difference of the received signals between the receiving antennas, a unique group comprises at least Ns + Nr - 2 groups of virtual antennas whose virtual positions overlap and whose combinations of transmitting and receiving circuits are inconsistent, where the combinations of transmitting and receiving circuits do not overlap with those of the other groups.

[0324] It includes at least one group of different wiring lengths, which is a group of virtual antennas whose virtual locations overlap and whose wiring lengths are inconsistent.

[0325] Furthermore, the total number of groups is at least Ns + Nr - 1, and these groups belong to the virtual antennas that are at least one of the specific group and the different wiring length group.

[0326] The control unit has:

[0327] Error acquisition unit (64) acquires, based on the comparison results of reflector information about the same reflector in the received signals of the virtual antennas in the at least Ns+Nr-1 group, at least one of the phase and amplitude errors between the transmitting circuits and between the receiving circuits for the plurality of reflectors.

[0328] Temperature acquisition unit (65) acquires temperature information associated with the internal temperature of the containment unit; and

[0329] The diagnostic unit (66) diagnoses that the out-of-range reflectors are virtual images when the number of out-of-range reflectors is within the allowable upper limit, and diagnoses that at least one of the transmitting circuit and the receiving circuit is faulty when the number of out-of-range reflectors exceeds the allowable upper limit. The out-of-range reflectors are reflectors that have acquired an error exceeding the allowable error range based on the temperature information.

[0330] (Technical Idea 3)

[0331] A radar device comprising:

[0332] Multiple transmit antennas (TX) and multiple receive antennas (RX);

[0333] Ns transmitting circuits (3), which are connected to the transmitting antenna and output transmitting signals;

[0334] Nr receiving circuits (4), which are connected to the receiving antenna and acquire the received signal;

[0335] Control unit (6), which processes the received signal; and

[0336] The housing unit (7) houses the transmitting antenna, the receiving antenna, the transmitting circuit, the receiving circuit, and the control unit.

[0337] The Ns and Nr are both integers greater than or equal to 2.

[0338] At least one of the plurality of transmitting antennas and the plurality of receiving antennas is configured at unequal intervals.

[0339] Among groups of virtual antennas (V) assumed for each of the plurality of receiving antennas based on the phase difference of the received signals between the receiving antennas, in a set of groups of virtual antennas where the virtual positions overlap and the combinations of the transmitting and receiving circuits are inconsistent, the plurality of transmitting antennas and the plurality of receiving antennas comprise a unique group of at least Ns + Nr - 2 groups, which are groups of virtual antennas whose combinations of the transmitting and receiving circuits do not overlap with other groups.

[0340] The control unit has:

[0341] Error acquisition unit (64) acquires, based on the comparison results of reflector information about the same reflector in the received signals of the virtual antennas in the unique group of at least Ns+Nr-2 groups, at least one of the phase and amplitude errors between the transmitting circuits and between the receiving circuits for multiple reflectors.

[0342] Temperature acquisition unit (65) acquires temperature information associated with the internal temperature of the containment unit; and

[0343] The diagnostic unit (66) diagnoses that the out-of-range reflectors are virtual images when the number of out-of-range reflectors is within the allowable upper limit, and diagnoses that at least one of the transmitting circuit and the receiving circuit is faulty when the number of out-of-range reflectors exceeds the allowable upper limit. The out-of-range reflectors are reflectors that have acquired an error exceeding the allowable error range based on the temperature information.

[0344] (Technical Idea 4)

[0345] A radar device comprising:

[0346] Multiple transmit antennas (TX) and multiple receive antennas (RX) are configured at equal intervals.

[0347] Ns transmitting circuits (3), which are connected to the transmitting antenna and output transmitting signals;

[0348] Nr receiving circuits (4), which are connected to the receiving antenna and acquire the received signal;

[0349] Control unit (6), which processes the received signal; and

[0350] The housing unit (7) houses the transmitting antenna, the receiving antenna, the transmitting circuit, the receiving circuit, and the control unit.

[0351] The Ns and Nr are both integers greater than or equal to 2.

[0352] Among groups of virtual antennas (V) assumed for each of the plurality of receiving antennas based on the phase difference of the received signals between the receiving antennas, in a set of groups of virtual antennas where the virtual positions overlap and the combinations of the transmitting and receiving circuits are inconsistent, the plurality of transmitting antennas and the plurality of receiving antennas comprise a unique group of at least Ns + Nr - 2 groups, which are groups of virtual antennas whose combinations of the transmitting and receiving circuits do not overlap with other groups.

[0353] The control unit has:

[0354] Error acquisition unit (64) acquires, based on the comparison results of reflector information about the same reflector in the received signals of the virtual antennas in the unique group of at least Ns+Nr-2 groups, at least one of the phase and amplitude errors between the transmitting circuits and between the receiving circuits for multiple reflectors.

[0355] Temperature acquisition unit (65) acquires temperature information associated with the internal temperature of the containment unit; and

[0356] The diagnostic unit (66) diagnoses that the out-of-range reflectors are virtual images when the number of out-of-range reflectors is within the allowable upper limit, and diagnoses that at least one of the transmitting circuit and the receiving circuit is faulty when the number of out-of-range reflectors exceeds the allowable upper limit. The out-of-range reflectors are reflectors that have acquired an error exceeding the allowable error range based on the temperature information.

[0357] (Technical Idea 5)

[0358] According to any one of the technical ideas 1 to 4, the radar device described

[0359] The diagnostic unit performs the diagnosis on at least the phase error between the transmitting circuits.

[0360] (Technical Idea 6)

[0361] According to any one of the technical ideas 1 to 5, the radar device described

[0362] The housing unit has an antenna radome (7a) that covers the exterior of the transmitting antenna and the receiving antenna.

[0363] If the phase difference between the virtual antenna groups is within the upper limit and the phase difference based on information other than the comparison result is also outside the allowable difference range, the diagnostic unit stops diagnosing the fault because the number of out-of-range reflectors exceeds the allowable upper limit, and diagnoses the fault as being caused by an attachment material attached to the antenna cover.

[0364] (Technical Idea 7)

[0365] According to the radar device described in Technical Concept 6,

[0366] The diagnostic unit outputs notifications regarding the adhesion of the attached substance and the malfunction.

Claims

1. A radar device, characterized by Possessing: a plurality of transmission antennas (TX) and a plurality of reception antennas (RX); Ns transmission circuits (3) connected to the transmission antennas and outputting transmission signals; Nr reception circuits (4) connected to the reception antennas and acquiring reception signals; a control unit (6) that processes the reception signals; and a housing unit (7) that houses the transmission antennas, the reception antennas, the transmission circuits, the reception circuits, and the control unit, Ns and Nr are each an integer of 2 or more, at least one of the plurality of transmission antennas and the plurality of reception antennas is arranged at unequal intervals, the plurality of transmission antennas and the plurality of reception antennas are arranged so that: in a set of groups of virtual antennas (V) in which virtual positions overlap and combinations of the transmission circuits and the reception circuits are inconsistent, between groups of the virtual antennas assumed per the transmission antennas with respect to phase differences of the reception signals between the reception antennas, there are included at least Ns+Nr-2 groups of unique groups in which the combinations of the transmission circuits and the reception circuits are not repeated from other groups, there are included at least one group of different wiring length groups in which the virtual positions overlap and wiring lengths are inconsistent, and a total number of the groups belonging to at least one of the unique groups and the different wiring length groups is at least Ns+Nr-1 groups, the control unit has: an error acquisition section (64) that acquires, with respect to at least one of phase and amplitude, an error between at least one of the transmission circuits and the reception circuits for a plurality of reflectors, based on a comparison result of reflector information about the same reflector in the reception signals of the virtual antennas with respect to the plurality of reflectors in the at least Ns+Nr-1 groups of the groups belonging to the unique groups and the different wiring length groups; a temperature acquisition section (65) that acquires temperature information associated with an internal temperature of the housing unit; and a diagnosis section (66) that diagnoses that a range-out reflector, which is the reflector for which the error exceeding an allowable error range allowed according to the temperature information is acquired, is a fault in at least one of the transmission circuits and the reception circuits, in a case where a number of the range-out reflectors exceeds an allowable upper limit number, and diagnoses that the range-out reflector is a virtual image, in a case where the number of the range-out reflectors is within the allowable upper limit number. Possessing: a plurality of transmission antennas (TX) and a plurality of reception antennas (RX) arranged at equal intervals; 2. A radar device, characterized by Ns transmission circuits (3) connected to the transmission antennas and outputting transmission signals; Nr reception circuits (4) connected to the reception antennas and acquiring reception signals; a control unit (6) that processes the reception signals; and a housing unit (7) that houses the transmission antennas, the reception antennas, the transmission circuits, the reception circuits, and the control unit, ​ ​ a housing unit (7) that houses the transmission antennas, the reception antennas, the transmission circuits, the reception circuits, and the control unit, Ns and Nr are each an integer of 2 or more, the plurality of transmission antennas and the plurality of reception antennas are configured so that: among groups of virtual antennas (V) assumed per each of the transmission antennas with respect to phase differences of the reception signals between the reception antennas, a set of groups of the virtual antennas in which virtual positions overlap and combinations of the transmission circuits and the reception circuits are not consistent contains at least Ns+Nr-2 groups of unique groups in which the combinations of the transmission circuits and the reception circuits are not repeated from other groups, at least one group of different wiring length groups in which the virtual positions overlap and wiring lengths are not consistent is contained, and a total number of the groups belonging to at least one of the unique groups and the different wiring length groups is at least Ns+Nr-1 groups, the control unit has: an error acquisition unit (64) that acquires errors of at least one of phases and amplitudes between at least one of the transmission circuits and the reception circuits with respect to at least Ns+Nr-1 groups of the groups belonging to the virtual antennas based on comparison results of reflection object information with respect to the same reflection object in the reception signals of the virtual antennas with respect to each other, a temperature acquisition unit (65) that acquires temperature information associated with an internal temperature of the housing unit, and a diagnosis unit (66) that diagnoses that a range-out reflection object is a ghost when a number of the range-out reflection objects is within an allowable upper limit number, diagnoses that at least one of the transmission circuits and the reception circuits is malfunctioning when the number of the range-out reflection objects exceeds the allowable upper limit number, and the range-out reflection object is the reflection object for which the error exceeding an allowable error range according to the temperature information is acquired.

3. A radar device, characterized by provided with: a plurality of transmission antennas (TX) and a plurality of reception antennas (RX); Ns transmission circuits (3) connected to the transmission antennas and outputting transmission signals; Nr reception circuits (4) connected to the reception antennas and acquiring reception signals; a control unit (6) that processes the reception signals; and a housing unit (7) that houses the transmission antennas, the reception antennas, the transmission circuits, the reception circuits, and the control unit, Ns and Nr are each an integer of 2 or more, at least one of the plurality of transmission antennas and the plurality of reception antennas is not configured at equal intervals, ​ In a set of groups of the virtual antennas whose virtual positions overlap and whose combinations of the transmission circuits and the reception circuits are not identical between groups of virtual antennas (V) assumed per the transmission antennas with respect to a plurality of the reception antennas according to phase differences of the reception signals between the reception antennas, the plurality of the transmission antennas and the plurality of the reception antennas include at least Ns+Nr-2 groups of unique groups which are the groups of the virtual antennas whose combinations of the transmission circuits and the reception circuits are not repeated from other groups, the control unit has: an error acquisition section (64) which acquires errors of at least one of phase and amplitude between at least one of the transmission circuits and the reception circuits for a plurality of reflectors based on comparison results of reflector information on the same reflector in the reception signals of the virtual antennas with respect to the plurality of reflectors in the at least Ns+Nr-2 groups of the unique groups of the virtual antennas; a temperature acquisition section (65) which acquires temperature information associated with an internal temperature of the housing unit; and a diagnosis section (66) which diagnoses that the out-of-range reflector is a ghost when a number of the out-of-range reflectors is within an allowable upper limit number, and diagnoses that at least one of the transmission circuits and the reception circuits is malfunctioning when the number of the out-of-range reflectors exceeds the allowable upper limit number, the out-of-range reflector being the reflector for which the error exceeding an allowable error range according to the temperature information is acquired.

4. A radar device, characterized by provided with: a plurality of transmission antennas (TX) arranged at equal intervals and a plurality of reception antennas (RX) arranged at equal intervals; Ns transmission circuits (3) connected to the transmission antennas and outputting transmission signals; Nr reception circuits (4) connected to the reception antennas and acquiring reception signals; a control unit (6) which processes the reception signals; and a housing unit (7) which houses the transmission antennas, the reception antennas, the transmission circuits, the reception circuits, and the control unit, the Ns and the Nr are each an integer of 2 or more, In a set of groups of the virtual antennas whose virtual positions overlap and whose combinations of the transmission circuits and the reception circuits are not identical between groups of virtual antennas (V) assumed per the transmission antennas with respect to a plurality of the reception antennas according to phase differences of the reception signals between the reception antennas, the plurality of the transmission antennas and the plurality of the reception antennas include at least Ns+Nr-2 groups of unique groups which are the groups of the virtual antennas whose combinations of the transmission circuits and the reception circuits are not repeated from other groups, the control unit has: an error acquisition section (64) which acquires errors of at least one of phase and amplitude between at least one of the transmission circuits and the reception circuits for a plurality of reflectors based on comparison results of reflector information on the same reflector in the reception signals of the virtual antennas with respect to the plurality of reflectors in the at least Ns+Nr-2 groups of the unique groups of the virtual antennas; ​ a temperature acquisition section (65) that acquires temperature information associated with an internal temperature of the housing unit; and a diagnosis section (66) that, in a case where the number of out-of-range reflectors is within an upper limit number, diagnoses that the out-of-range reflectors are virtual images, and, in a case where the number of out-of-range reflectors exceeds the upper limit number, diagnoses that at least one of the transmission circuit and the reception circuit is malfunctioning, the out-of-range reflectors being the reflectors for which the error exceeding an allowable error range allowed according to the temperature information is acquired.

5. The radar apparatus according to any one of claims 1 to 4, characterized in that the diagnosis section performs the diagnosis at least on the error of the phase among the transmission circuits.

6. The radar apparatus according to any one of claims 1 to 4, characterized in that the housing unit has a radome (7a) that covers the outside of the transmission antenna and the reception antenna, in a case where the number of groups of the virtual antennas whose phase difference from each other is outside an allowable difference range based on information other than the comparison result is within an upper limit number of groups, the diagnosis section suspends diagnosis that the reason why the number of out-of-range reflectors exceeds the upper limit number is the malfunction, and diagnoses that the reason is attachment of an attached object to the radome.

7. The radar apparatus according to claim 6, characterized in that the diagnosis section outputs a notification about the attachment of the attached object and the malfunction.

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