Radar device

Abstract

A control unit of this radar device acquires temperature information related to the internal temperature of an accommodation unit. The control unit acquires, for a plurality of reflectors: a phase error in at least one of between different transmission circuits and between reception circuits, said phase error being based on a comparison result for reflection object information relating to the same reflection object in reception signals of virtual antennas in at least Ns + Nr −1 sets of specific-direction overlap pairs; and a phase error based on a comparison result in a specific-direction non-overlap pair. The control unit estimates that an out-of-range reflection object, which is a reflection object for which the phase error based on the comparison result in the specific-direction overlap pairs is within an allowable error range allowed in accordance with temperature information and for which the phase error based on the comparison result in the specific-direction non-overlap pair is outside the allowable error range, is a virtual image.

Description

radar equipment CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Patent Application No. 2024-123718 filed in Japan on July 30, 2024, and the contents of the original application are incorporated by reference in their entirety.

[0002] This disclosure relates to radar technology.

[0003] Patent Literature 1 discloses a method for determining an abnormality in a radar device. The radar device is provided inside a bumper of a vehicle and includes a transmission processing unit that transmits a transmission wave from the inside of the bumper to the outside. The radar device includes a reception processing unit that receives object reflected waves formed when the transmission wave is reflected by an object around the vehicle, bumper reflected waves formed when the transmission wave is reflected by the bumper, and a transmission / reception leak caused by the transmission wave, and detects the object using the object reflected waves. The radar device includes a bumper determination unit that detects a first reception level of a first reception wave including the bumper reflected waves and the transmission / reception leak, compares the first reception level with a threshold, and determines that an abnormality has occurred in the bumper if the first reception level is greater than the threshold.

[0004] Japanese Patent Application Laid-Open No. 2017-215236

[0005] However, in the radar device, abnormalities other than the bumper abnormality and the transmission / reception leak described in Patent Document 1 may occur. Specifically, the radar device may detect a virtual image due to multipath. Patent Document 1 does not disclose a method for distinguishing such a virtual image from a real image.

[0006] An object of the present disclosure is to provide a radar device capable of distinguishing between virtual images.

[0007] The technical means of the present disclosure for solving the problems will be described below. Note that the claims and the reference symbols in parentheses in this section indicate the correspondence with the specific means described in the embodiments described later in detail, and do not limit the technical scope of the present disclosure.

[0008] a control unit that outputs sensing data correlated with the received signals; wherein Ns and Nr are integers equal to or greater than 1, and wherein at least one of the plurality of transmitting antennas and the plurality of receiving antennas is arranged at uneven intervals to virtually form a plurality of virtual antennas that are assumed for each transmitting antenna in accordance with a phase difference between the received signals between the receiving antennas; and wherein a pair of virtual antennas whose assumed virtual positions overlap among the plurality of virtual antennas are arranged such that, with respect to a mismatched pair, where the combinations of the transmitting circuits and the receiving circuits corresponding to the virtual antennas do not match, when a group of mismatched pairs whose combination patterns of the transmitting circuits and the receiving circuits do not overlap each other is assumed, at least Ns+Nr-2 mismatched pairs are included in the group; and are arranged so that the group includes at least one different wiring length pair, which is a pair of virtual antennas whose virtual positions overlap among the plurality of virtual antennas but whose wiring lengths do not match, and so that the total number of belonging pairs, which are pairs of virtual antennas belonging to at least one of the mismatched pairs and different wiring length pairs included in the group, is at least Ns+Nr-1 pairs, and so that the belonging pairs are specific direction overlapping pairs, in which the positions of corresponding transmitting antennas and receiving antennas overlap in a specific direction, and so that at least one specific direction non-overlapping pair, in which at least one of corresponding transmitting antennas and receiving antennas are in a non-overlapping position in the specific direction, is virtually formed, and the control unit acquires temperature information related to the internal temperature of the accommodating unit,The radar device is configured to perform the following: acquire, for a plurality of reflectors, a phase error between at least one of different transmitting circuits and receiving circuits based on a comparison result of reflector information related to the same reflector in received signals between virtual antennas in at least Ns+Nr-1 specific direction overlapping pairs, and a phase error based on the comparison result in specific direction non-overlapping pairs; and estimate that an out-of-range reflector, which is a reflector whose phase error based on the comparison result in the specific direction overlapping pairs is within an allowable error range allowed according to temperature information and whose phase error based on the comparison result in the specific direction non-overlapping pairs is outside the allowable error range, is a virtual image.

[0009] a control unit that outputs sensing data correlated with the received signals; wherein Ns and Nr are integers equal to or greater than 1, and wherein at least one of the plurality of transmitting antennas and the plurality of receiving antennas is arranged at uneven intervals, and a plurality of virtual antennas are virtually formed, which are assumed for each transmitting antenna in accordance with a phase difference of the received signals between the receiving antennas for the plurality of receiving antennas; and wherein a pair of virtual antennas whose assumed virtual positions overlap among the plurality of virtual antennas are arranged such that, assuming a group of mismatched pairs in which the combinations of transmitting circuits and receiving circuits corresponding to the virtual antennas do not overlap, at least Ns+Nr-2 mismatched pairs are included in the group; and for at least Ns+Nr-2 sets of mismatched pairs within the group, the positions of corresponding transmitting antennas and receiving antennas are arranged to form specific direction overlapping pairs in which they overlap in the specific direction, and at least one specific direction non-overlapping pair is virtually formed in which at least one of corresponding transmitting antennas and receiving antennas is in a non-overlapping position in the specific direction, and the control unit: acquires temperature information related to the internal temperature of the containing unit; acquires, for a plurality of reflectors, phase errors between at least one of different transmitting circuits and receiving circuits based on a comparison result of reflector information related to the same reflector in the received signals of the virtual antennas in at least Ns+Nr-2 sets of specific direction overlapping pairs, and phase errors based on the comparison result in the specific direction non-overlapping pairs; and estimates that an out-of-range reflector is a virtual image, which is a reflector for which the phase error based on the comparison result in the specific direction overlapping pair is within an allowable error range allowed according to the temperature information and the phase error based on the comparison result in the specific direction non-overlapping pair is outside the allowable error range;The radar device is configured to perform the above.

[0010] a control unit that outputs sensing data correlated with the received signals, wherein Ns and Nr are integers equal to or greater than 1, and the plurality of transmitting antennas and the plurality of receiving antennas virtually form a plurality of virtual antennas that are assumed for each transmitting antenna in accordance with a phase difference between received signals between the receiving antennas for the plurality of receiving antennas, and the plurality of virtual antennas are pairs of virtual antennas whose assumed virtual positions overlap, and with respect to mismatched pairs, which are pairs in which the combinations of transmitting circuits and receiving circuits corresponding to the virtual antennas do not match, the plurality of virtual antennas are arranged such that, assuming a group of mismatched pairs in which the combination patterns of transmitting circuits and receiving circuits do not overlap, at least Ns+Nr-2 mismatched pairs are included in the group, and for at least Ns+Nr-2 sets of mismatched pairs within the group, the positions of corresponding transmitting antennas and receiving antennas are arranged to form specific direction overlapping pairs in which they overlap in the specific direction, and at least one specific direction non-overlapping pair is virtually formed in which at least one of corresponding transmitting antennas and receiving antennas is in a non-overlapping position in the specific direction, and the control unit: acquires temperature information related to the internal temperature of the containing unit; acquires, for a plurality of reflectors, phase errors between at least one of different transmitting circuits and receiving circuits based on a comparison result of reflector information related to the same reflector in the received signals of the virtual antennas in at least Ns+Nr-2 sets of specific direction overlapping pairs, and phase errors based on the comparison result in the specific direction non-overlapping pairs; and estimates that an out-of-range reflector is a virtual image, which is a reflector for which the phase error based on the comparison result in the specific direction overlapping pair is within an allowable error range allowed according to the temperature information and the phase error based on the comparison result in the specific direction non-overlapping pair is outside the allowable error range;The radar device is configured to perform the above.

[0011] a control unit that outputs sensing data correlated with the received signals, wherein Ns and Nr are integers equal to or greater than 1, and the plurality of transmitting antennas and the plurality of receiving antennas virtually form a plurality of virtual antennas that are assumed for each transmitting antenna in accordance with a phase difference between received signals between the receiving antennas for the plurality of receiving antennas, and the plurality of virtual antennas are pairs of virtual antennas whose assumed virtual positions overlap, and with respect to mismatched pairs, which are pairs in which the combinations of transmitting circuits and receiving circuits corresponding to the virtual antennas do not match, the plurality of virtual antennas are arranged such that, assuming a group of mismatched pairs in which the combination patterns of transmitting circuits and receiving circuits do not overlap, at least Ns+Nr-2 mismatched pairs are included in the group, and are arranged so that the group includes at least one different wiring length pair, which is a pair of virtual antennas whose virtual positions overlap among the plurality of virtual antennas but whose wiring lengths do not match, and so that the total number of belonging pairs, which are pairs of virtual antennas belonging to at least one of the mismatched pairs and different wiring length pairs included in the group, is at least Ns+Nr-1 pairs, and so that the belonging pairs are specific direction overlapping pairs, in which the positions of corresponding transmitting antennas and receiving antennas overlap in a specific direction, and so that at least one specific direction non-overlapping pair, in which at least one of corresponding transmitting antennas and receiving antennas are in a non-overlapping position in the specific direction, is virtually formed, and the control unit acquires temperature information related to the internal temperature of the accommodating unit,The radar device is configured to perform the following: acquire, for a plurality of reflectors, a phase error between at least one of different transmitting circuits and receiving circuits based on a comparison result of reflector information related to the same reflector in received signals between virtual antennas in at least Ns+Nr-1 specific direction overlapping pairs, and a phase error based on the comparison result in specific direction non-overlapping pairs; and estimate that an out-of-range reflector, which is a reflector whose phase error based on the comparison result in the specific direction overlapping pairs is within an allowable error range allowed according to temperature information and whose phase error based on the comparison result in the specific direction non-overlapping pairs is outside the allowable error range, is a virtual image.

[0012] According to these aspects, it is possible to estimate that an out-of-range reflector is a virtual image, where the phase error based on the comparison result of the overlapping pair in the specific direction is within the allowable error range allowed according to the temperature information and the phase error based on the comparison result of the non-overlapping pair in the specific direction is outside the allowable error range. Therefore, when multipath occurs due to a reflector in a specific direction on the outbound or inbound path of a signal, it is possible to identify a virtual image caused by the multipath.

[0013] 1 is a schematic diagram showing a basic configuration of a radar device according to a first embodiment. FIG. 1 is a schematic diagram showing an example of a combination of a transmitting circuit and a transmitting antenna, and a receiving circuit and a receiving antenna according to the first embodiment. FIG. 2 is a schematic diagram showing an example of an arrangement of a transmitting antenna and a receiving antenna according to the first embodiment. FIG. 3 is a schematic diagram showing a virtual antenna assumed in the first embodiment. FIG. 4 is a block diagram showing a functional configuration of a control unit according to the first embodiment. FIG. 5 is a flowchart showing a control flow according to the first embodiment. FIG. 6 is a flowchart showing a continuation of the control flow. FIG. 7 is a flowchart showing a continuation of the control flow. FIG. 8 is a graph showing an example of a relationship between a wiring length difference and a phase error. FIG. 9 is a graph showing an example of a relationship between a parameter related to a phase error and temperature. FIG. 10 is a table showing an example of a set of virtual antennas used in compensation processing. FIG. 11 is a graph showing a relationship between a phase error between transmitting circuits and temperature. FIG. 12 is a graph showing a relationship between a phase error between receiving circuits and temperature. FIG. 13 is a diagram for explaining phase errors due to multipath. FIG. 14 is a diagram for explaining phase errors due to abnormalities in the transmission and reception environment. FIG. 15 is a graph showing an example of a phase error between transmitting circuits when all detected peaks are real images. FIG. 16 is a graph showing an example of a phase error between transmitting circuits when some of the detected peaks are virtual images. 1 is a graph illustrating a phase error between transmission circuits when there is an abnormality in the transmission and reception environment. FIG. 2 is a graph illustrating a phase difference depending on the acquisition means when a failure occurs. FIG. 3 is a graph illustrating a phase difference depending on the acquisition means when there is an attachment. FIG. 4 is a schematic diagram showing an example of a usage environment of a radar device. FIG. 5 is a schematic diagram for explaining a phase difference that occurs when a signal arrives directly. FIG. 6 is a schematic diagram for explaining a phase difference that occurs when a signal is reflected by a road surface. FIG. 7 is a schematic diagram for explaining a relative phase angle when a signal arrives directly on an outbound path. FIG. 8 is a schematic diagram for explaining a relative phase angle when a signal arrives directly on an inbound path. FIG. 9 is a schematic diagram for explaining the relative phase angle of each virtual antenna in a direct path. FIG. 10 is a schematic diagram for explaining the relative phase angle of the inbound path in an inbound reflection path. FIG. 11 is a schematic diagram for explaining the relative phase angle of each virtual antenna in an inbound reflection path. FIG. 12 is a schematic diagram for explaining the relative phase angle of the outbound path in an outbound reflection path.FIG. 10 is a schematic diagram for explaining the relative phase angle of each virtual antenna in an outward reflection path. FIG. 11 is a graph for explaining the phase difference between a pair of virtual antennas caused by mismatched paths in the vertical direction. FIG. 12 is a graph for explaining the phase difference between a pair of virtual antennas caused by mismatched paths in the horizontal direction. FIG. 13 is a schematic diagram showing an example of the arrangement of transmitting antennas and receiving antennas in a second embodiment. FIG. 14 is a schematic diagram showing virtual antennas assumed in the second embodiment. FIG. 15 is a table showing an example of a set of virtual antennas used in compensation processing.

[0014] Hereinafter, multiple embodiments of the present disclosure will be described with reference to the drawings. Note that corresponding components in each embodiment are designated by the same reference numerals, and redundant description may be omitted. Furthermore, when only a portion of the configuration is described in each embodiment, the configuration of another previously described embodiment may be applied to the remaining portions of the configuration. Furthermore, in addition to the combinations of configurations explicitly stated in the description of each embodiment, configurations of multiple embodiments may be partially combined together even if not explicitly stated, provided that there is no particular problem with the combination.

[0015] 1 to 33 , a radar device 1 is mounted on a moving object such as a vehicle. The radar device 1 transmits a transmission signal, receives the transmission signal reflected by an object as a received signal, and detects, as sensing data, the distance to a target that is the object that reflected the transmission signal, the relative speed with respect to the target, the direction of the target, and the like.

[0016] The sensing data output from the radar device 1 is input to an in-vehicle ECU (Electronic Control Unit) via an in-vehicle network such as a Control Area Network (CAN) (registered trademark) or Ethernet (registered trademark). The in-vehicle ECU executes various processes for autonomous driving of the vehicle and advanced driving assistance based on the acquired sensing data of each target.

[0017] The processes based on the sensing data include, for example, collision avoidance processing, warning processing, etc. The collision avoidance processing is a process of controlling the vehicle to avoid collision with the target by controlling the brake system, steering system, etc. based on the sensing data of each target. The warning processing is a process of warning the driver of the possibility of collision with the target based on the sensing data of each target.

[0018] 1 , the radar device 1 of this embodiment includes an oscillator 2, multiple transmission circuits 3, multiple transmission antennas TX, multiple reception antennas RX, multiple reception circuits 4, a temperature sensor 5, a control unit 6, and a housing unit 7. The radar device 1 is a so-called MIMO (Multiple-Input-Multiple-Output) radar that transmits transmission signals from multiple transmission antennas TX to artificially increase the number of reception antennas RX beyond the actual number.

[0019] The oscillator 2 receives a control signal from the control unit 6 and generates a modulated signal modulated in response to the control signal. The modulated signal is, for example, a so-called chirp signal whose frequency changes over time. The modulated signal is distributed and output to each channel of the transmitting circuit 3 and the receiving circuit 4. In the following, the modulated signal output from the oscillator 2 to the transmitting circuit 3 is referred to as a transmission signal. Also, the modulated signal output from the oscillator 2 to the receiving circuit 4 is referred to as a local signal.

[0020] The transmission circuit 3 and the reception circuit 4 are each mainly composed of a semiconductor integrated circuit device such as an MMIC (Monolithic Microwave Integrated Circuit). The transmission circuit 3 is connected to a transmission antenna TX via wiring and outputs a transmission signal to the transmission antenna TX. If the number of transmission circuits 3 mounted on one radar device 1 is Ns, Ns is an integer equal to or greater than 2. The transmission circuit 3 includes amplifiers 30 in the same number as the connected transmission antennas TX. The amplifiers 30 amplify the transmission signal output from the oscillator 2 and output it to the corresponding transmission antenna TX.

[0021] The transmitting antenna TX converts an electrical signal, as a transmission signal, supplied from the oscillator 2 into a radio wave signal and transmits it to the outside world. The transmitting antenna TX is configured to include at least one antenna element. For example, the transmitting antenna TX is a patch antenna having multiple flat antenna elements. The antenna elements are arranged on the surface opposite to the ground plane of a dielectric substrate having a ground plane on one surface, so as to face the ground plane. The multiple antenna elements are connected, for example, in series, by a feeder line that supplies the electrical signal.

[0022] The receiving antenna RX receives, as a received signal, a radio wave signal including a transmission signal reflected by a target in the external environment as a reflecting object. The receiving antenna RX is connected to a corresponding receiving circuit 4. The arrangement of the transmitting antenna TX and the receiving antenna RX will be described later.

[0023] The receiving antenna RX converts the received signal as a radio wave signal into an electrical signal and outputs it to the corresponding receiving circuit 4. The receiving antenna RX is, for example, a patch antenna in the same manner as the transmitting antenna TX, in which at least one antenna element is connected in series by a feeder line.

[0024] The receiving circuit 4 is connected to the receiving antenna RX by wiring and acquires the received signal received by the receiving antenna RX. If the number of receiving circuits 4 mounted on one radar device 1 is Nr, Nr is an integer equal to or greater than 2. The receiving circuit 4 includes amplifiers 40 and signal mixers 41, the number of which is the same as the number of connected receiving antennas RX.

[0025] The amplifier 40 amplifies the received signal received by the receiving antenna and outputs it to the signal mixer 41. The signal mixer 41 generates a beat signal by mixing the local signal from the oscillator 2 with the received signal. The generated beat signal becomes an interference signal that represents the frequency difference between the received signal and the local signal. The beat signal is output to the control unit 6 as signal data correlated with the received signal, with high-frequency components that deviate from the frequency difference between the received signal and the local signal filtered out by a low-pass filter (not shown).

[0026] The temperature sensor 5 detects the internal temperature of the housing unit 7 in the radar device 1. The temperature sensor 5 includes, for example, a thermistor and outputs temperature information corresponding to the resistance value of the thermistor. The temperature sensor 5 detects the temperature information of each transmitting circuit 3 and receiving circuit 4 as the internal temperature and outputs it to the control unit 6.

[0027] The accommodation unit 7 is a housing that accommodates 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 accommodation unit 7 includes a radome 7a and a case body 7b. The radome 7a is mainly formed of a transparent material that allows millimeter-wave band radio waves to pass through. The radome 7a is attached to the case body 7b so as to cover the antennas TX and RX. The radome 7a protects the antennas TX and RX while allowing radio waves to pass through, enabling the antennas TX and RX to send and receive signals. The case body 7b, together with the radome 7a, defines an accommodation space that accommodates the components of the radar device 1 described above.

[0028] The control unit 6 is a control unit including at least one dedicated computer. The dedicated computer constituting the control unit 6 may be, for example, an ECU (Electronic Control Unit) specialized for controlling the radar device 1. The dedicated computer constituting the control unit 6 has at least one memory 6a and one processor 6b. The memory 6a is at least one type of non-transitory tangible storage medium, such as a semiconductor memory, a magnetic medium, or an optical medium, that non-temporarily stores computer-readable programs, data, and the like. Here, "storage" may refer to accumulation in which data is retained even when the sensor system is turned off, or may refer to temporary storage in which data is erased when the sensor system is turned off.

[0029] The processor 6b may include at least one of a central processing unit (CPU), a graphics processing unit (GPU), a reduced instruction set computer (RISC)-CPU, a data flow processor (DFP), and a graph streaming processor (GSP) as a core. Alternatively, the processor 6b may be at least one of a digital circuit and an analog circuit. Here, the digital circuit is at least one of an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a system on a chip (SOC), a programmable gate array (PGA), and a complex programmable logic device (CPLD). Such a digital circuit may also have a memory 6a that stores a program.

[0030] The control unit 6 processes the beat signals output from the receiver circuits 4 to perform angle measurement processing to calculate the angle of a reflecting object relative to the radar device 1. The radar device 1 ensures relatively high angular resolution by using a MIMO system to pseudo-ensure that the number of receiver antennas RX is greater than the actual number. In addition, the control unit 6 ensures relatively high angle measurement accuracy by performing compensation processing to compensate for signal phase differences and amplitude differences that occur between different transmitter circuits 3 and different receiver circuits 4.

[0031] For the above compensation process, the transmitting antennas TX and receiving antennas RX are mounted in a specified arrangement. The arrangement of the transmitting antennas TX and receiving antennas RX will be described below with reference to specific examples shown in Figures 2 to 4.

[0032] With multiple transmitting antennas TX and multiple receiving antennas RX, multiple virtual antennas V corresponding to the phase differences of the received signals between the receiving antennas RX are assumed for each transmitting antenna TX. 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.

[0033] The transmitting antennas TX and receiving antennas RX are arranged to form pairs that are combinations of virtual antennas V whose virtual positions overlap. The transmitting antennas TX and receiving antennas RX are arranged to form pairs (mismatched pairs) in which the combinations of the transmitting circuits 3 and receiving circuits 4 do not match between the virtual antennas V. Assuming a group (non-overlapping group) of mismatched pairs in which the combination patterns of the transmitting circuits 3 and receiving circuits 4 do not overlap with each other, the transmitting antennas TX and receiving antennas RX are arranged so that at least Ns+Nr-2 mismatched pairs are included in the non-overlapping group. Furthermore, the transmitting antennas TX and receiving antennas RX are arranged so that for at least Ns+Nr-2 mismatched pairs included in the non-overlapping group, the corresponding transmitting antennas TX and receiving antennas RX are positioned to overlap in a specific direction.

[0034] As an example, assume that the radar device 1 is equipped with four transmitting antennas TX and six receiving antennas RX. Furthermore, in this example, the number of transmitting circuits 3 is Ns = 2, and the number of receiving circuits 4 is Nr = 2. In this case, as shown in FIG. 2 , the number of channels in one transmitting circuit 3 is at least two. The number of channels in one receiving circuit 4 is at least three. Hereinafter, one of the transmitting circuits 3 is referred to as a first transmitting circuit 3_1, and the other as a second transmitting circuit 3_2. Furthermore, one of the receiving circuits 4 is referred to as a first receiving circuit 4_1, and the other as a 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. The second transmitting circuit 3_2 and the second receiving circuit 4_2 are mounted on the same second circuit chip C2.

[0035] Furthermore, in the radar device 1 of this embodiment, at least one transmitting antenna TX has a wiring length different from that of the other transmitting antennas TX. In the example shown in FIG. 2 , the wiring Wt2 of the transmitting antenna TX1_2 connected to the first transmitting circuit 3_1 is longer than the wiring Wt1 of the other transmitting antenna TX. Furthermore, the wiring lengths of the respective wirings Wr of the receiving antenna RX are all substantially the same. Furthermore, the transmitting antenna TX and the receiving antenna RX are arranged so that the difference in wiring length between the virtual antennas V in the belonging group, which will be described later, falls within the allowable difference range.

[0036] In the following, the four transmitting antennas TX and six receiving antennas RX may be distinguished by assigning different reference symbols to them. Specifically, the two transmitting antennas TX connected to the first transmitting circuit 3_1 are referred to as transmitting antennas TX1_1 and TX1_2, and the two transmitting antennas TX connected to the second transmitting circuit 3_2 are referred to as transmitting antennas TX2_1 and TX2_2. The three receiving antennas RX connected to the first receiving circuit 4_1 are referred to 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 referred to as receiving antennas RX2_1, RX2_2, and RX2_3.

[0037] When antennas with different wiring lengths exist, the transmitting antennas TX and receiving antennas RX are arranged so as to include at least one different wiring length pair, which is a pair of virtual antennas whose virtual positions overlap and whose wiring lengths do not match. Furthermore, the transmitting antennas TX and receiving antennas RX are arranged so that the total number of belonging pairs, which are pairs of virtual antennas V belonging to at least one of the mismatched pairs and different wiring length pairs in the non-overlapping group described above, is at least Ns + Nr - 1 pairs. In this embodiment, the transmitting antennas TX and receiving antennas RX are arranged two-dimensionally at equal intervals.

[0038] In the example shown in Fig. 3, the transmitting antennas TX1_1 and TX2_1 are arranged side by side in this order in the X direction, with a gap of 2d between them. In other words, the transmitting antennas TX1_1 and TX2_1 are arranged so that their positions overlap in the Y direction, which is orthogonal to the X direction. The Y direction is an example of a "specific direction." The Y direction is, for example, the vertical direction, and the X direction is, for example, the horizontal direction.

[0039] Furthermore, the transmitting antennas TX1_2, TX1_2 are also arranged side by side in this order from one side to the other in the X direction, with a gap of 2d between them, and are arranged so as to overlap in the Y direction. Furthermore, the transmitting antennas TX1_1, TX1_2 are arranged side by side with a gap of 2d between them in the Y direction. Similarly, the transmitting antennas TX2_1, TX2_2 are arranged side by side with a gap of 2d between them in the Y direction. That is, the transmitting antennas TX1_2, TX2_2 are arranged parallel to the transmitting antennas TX1_1, TX2_1, with a gap of 2d between them.

[0040] Furthermore, the receiving antennas RX1_1, RX1_2, and RX2_1 are arranged in this order from one side to the other in the X direction, with a distance d between them. That is, the receiving antennas RX1_1, RX1_2, and RX2_1 are arranged so that their positions overlap in the Y direction. The receiving antennas RX2_2, RX1_3, and RX2_3 are arranged in this order from one side to the other in the X direction, with a distance d between them, and so that their positions overlap in the Y direction.

[0041] Furthermore, the row of receiving antennas RX1_1, RX1_2, and RX2_1 and the row of receiving antennas RX2_2, RX2_3, and RX1_3 are arranged with a gap of 2d in the Y direction. Under this arrangement, the receiving antennas RX1_1 and RX2_2 are arranged so that their positions overlap in the X direction. Furthermore, the receiving antennas RX1_2 and RX1_3 are also arranged so that their positions overlap in the X direction. Similarly, the receiving antennas RX2_1 and RX2_3 are also arranged so that their positions overlap in the X direction.

[0042] The number of virtual antennas V is assumed to be the same as the number of receiving antennas RX, that is, six, for each of the transmitting antennas TX1_1, TX1_2, TX2_1, and TX2_2. Therefore, a total of 24 virtual antennas V are virtually formed.

[0043] Here, for the transmitting antenna TX1_1, the virtual antennas V assumed for the receiving antennas RX1_1, RX1_2, RX2_1, RX2_2, RX2_3, and RX1_3 are designated as virtual antennas V1, V2, V3, V4, V5, and V6, in that order. Furthermore, for the transmitting antenna TX1_2, the virtual antennas V assumed for each receiving antenna RX are designated as virtual antennas V7, V8, V9, V10, V11, and V12, in the order of the receiving antennas RX. Similarly, the virtual antennas V assumed for the transmitting antenna TX2_1 are designated as virtual antennas V13, V14, V15, V16, V17, and V18, in the same order. Similarly, the virtual antennas V assumed for the transmitting antenna TX2_2 are designated as virtual antennas V19, V20, V21, V22, V23, and V24, in the same order.

[0044] In this embodiment, the transmitting antenna TX and the receiving antenna RX are arranged so that three or more virtual antennas V are virtually formed in the Y direction. In angle detection, in order to increase the maximum detection angle without angle ambiguity while increasing the angular resolution, it is necessary to narrow the minimum antenna spacing and widen the antenna aperture width. When the number of virtual antennas V is two, the minimum antenna spacing and the antenna aperture width are essentially the same, and therefore they cannot be designed independently. For example, if the maximum detection angle is prioritized, the antenna aperture width becomes smaller and the angular resolution decreases. On the other hand, if the angular resolution is prioritized, the maximum detection angle becomes narrower. Therefore, by arranging the antennas so that three or more virtual antennas V are virtually formed, the minimum antenna spacing and the antenna aperture width can be designed independently.

[0045] Fig. 4 shows a virtual arrangement of virtual antennas V assumed in the arrangement of Fig. 3. Adjacent transmitting antennas TX in the X direction are arranged at an interval of 2d. Therefore, a group of virtual antennas V assumed for a specific transmitting antenna TX is at a virtual position relatively shifted by 2d from a group of virtual antennas V assumed for an adjacent transmitting antenna TX in the X direction. Furthermore, adjacent transmitting antennas TX in the Y direction are arranged at an interval of 2d. Therefore, a group of virtual antennas V assumed for a specific transmitting antenna TX is at a virtual position relatively shifted by 2d from a group of virtual antennas V assumed for an adjacent transmitting antenna TX in the Y direction.

[0046] In FIG. 4, the virtual positions of the multiple virtual antennas V for each transmitting antenna TX are illustrated shifted in the vertical direction of the page. In reality, virtual antennas V1 to V3 and virtual antennas V13 to V15 are virtually formed at virtual positions on a virtual line VL1 extending in the X direction. Virtual antennas V4 to V9 and virtual antennas V16 to V21 are virtually formed at virtual positions on a virtual line VL2. Virtual antennas V10 to V12 and virtual antennas V22 to V24 are virtually formed at virtual positions on a virtual line VL3. Virtual line VL2 is a virtual line extending parallel to virtual line VL1 at a distance 2d from virtual line VL1. Virtual line VL3 is a virtual line extending parallel to virtual line VL2 at a distance 2d from virtual line VL2.

[0047] In the following, a specific set of virtual antennas V with overlapping virtual positions will be expressed as (Vn, Vm) using the symbols assigned to each individual virtual antenna V (n and m are natural numbers).

[0048] As shown in FIG. 4, in this arrangement, (V3, V13), (V4, V7), (V5, V8), (V6, V9), (V6, V16), (V6, V19), (V9, V16), (V9, V19), (V12, V22), (V16, V19), (V17, V20), and (V18, V21) are pairs of virtual antennas V with overlapping virtual positions.

[0049] Among these pairs, there are eight mismatched pairs in which the combinations of the transmitting circuits 3 and receiving circuits 4 corresponding to the virtual antennas V do not match among the virtual antennas V. Specifically, the mismatched pairs are (V3, V13), (V4, V7), (V6, V16), (V6, V19), (V9, V16), (V9, V19), (V12, V22), and (V16, V19).

[0050] For example, for the pair (V3, V13), the virtual antenna V3 corresponds to the combination of the transmitter circuit 3_1 and the receiver circuit 4_2. The virtual antenna V13 corresponds to the combination of the transmitter circuit 3_2 and the receiver circuit 4_1. Therefore, the combination of the virtual antenna V13 and the combination of the virtual antenna V3 are mismatched. Similarly, for the pair (V6, V16), the virtual antenna V6 corresponds to the combination of the transmitter circuit 3_1 and the receiver circuit 4_2. The virtual antenna V16 corresponds to the combination of the transmitter circuit 3_2 and the receiver circuit 4_2. This pair shares the receiver circuit 4_2, but the transmitter circuits 3_1 and 3_2 are different. Therefore, this pair is a mismatched pair in terms of the combination of the circuits 3 and 4. Similarly, the pairs (V4, V7), (V6, V19), (V9, V16), (V9, V19), (V12, V22), and (V16, V19) are also mismatched pairs.

[0051] Among these, (V3, V13), (V6, V19), and (V9, V19) are combination patterns of the transmitter circuit 3 and the receiver circuit 4 that overlap. Specifically, the circuits 3 and 4 corresponding to (V3, V13) are combination patterns of the transmitter circuit 3_1 and the receiver circuit 4_2, and the transmitter circuit 3_2 and the receiver circuit 4_1. Similarly, (V6, V19) and (V9, V19) are combination patterns that overlap. Similarly, the circuits 3 and 4 corresponding to (V6, V16) are combination patterns of the transmitter circuit 3_1 and the receiver circuit 4_2, and the transmitter circuit 3_2 and the receiver circuit 4_2, and this pattern overlaps with (V9, V16) and (V12, V22).

[0052] Here, from among the eight mismatched pairs, a non-overlapping group is assumed, which is a group of mismatched pairs whose combination patterns of the transmitting circuits 3 and the receiving circuits 4 do not overlap with each other. The assumed non-overlapping group is a group of nine different combinations consisting of one of (V3, V13), (V6, V19), and (V9, V19), one of (V6, V16), (V9, V16), and (V12, V22), (V4, V7), and (V16, V19).

[0053] Of these mismatched pairs, (V4, V7), (V6, V19), (V9, V16), and (V16, V19) are vertically non-overlapping pairs in which at least one of the corresponding transmitting antennas TX and receiving antennas RX does not overlap in the Y direction. For example, with respect to (V4, V7), the antennas TX and RX corresponding to virtual antenna V4 are transmitting antenna TX1_1 and receiving antenna 2_2. On the other hand, the antennas TX and RX corresponding to virtual antenna V7 are transmitting antenna TX1_2 and receiving antenna 1_1. The transmitting antennas TX1_1 and TX1_2 are spaced apart 2d in the Y direction, so their Y direction positions do not overlap. Similarly, the receiving antennas RX2_2 and RX1_1 do not overlap in the Y direction positions. Similarly, for (V6, V19), (V9, V16), and (V16, V19), the transmitting antennas TX and the receiving antennas RX are not arranged to overlap in the Y direction. Among all pairs with overlapping virtual positions, the vertically non-overlapping pairs are the four pairs mentioned above, as well as (V5, V8), (V6, V9), (V17, V20), and (V18, V21). Vertically non-overlapping pairs are an example of a "specific direction non-overlapping pair."

[0054] On the other hand, among the mismatched pairs, (V3, V13), (V9, V19), (V6, V16), and (V12, V22) are vertically overlapping pairs in which the corresponding transmitting antennas TX and the corresponding receiving antennas RX are overlapped in the Y direction. For example, with respect to (V3, V13), the antennas TX and RX corresponding to virtual antenna V3 are transmitting antenna TX1_1 and receiving antenna 2_1. On the other hand, the antennas TX and RX corresponding to virtual antenna V13 are transmitting antenna TX2_1 and receiving antenna 1_1. Since transmitting antennas TX1_1 and TX12_1 are arranged side by side in the X direction, their Y direction positions overlap. Similarly, receiving antennas RX2_1 and RX1_1 also overlap in the Y direction. The same is true for (V9, V19), (V6, V16), and (V12, V22). Of all the pairs of overlapping virtual positions, only the four pairs are vertically overlapping pairs. Vertically overlapping pairs are an example of "specific direction overlapping pairs."

[0055] Among the pairs of overlapping virtual positions, there are six horizontally overlapping pairs in which corresponding transmitting antennas TX and receiving antennas RX are arranged in overlapping positions in the X direction. Specifically, (V4, V7), (V5, V8), (V6, V9), (V16, V19), (V17, V20), and (V18, V21) are horizontally overlapping pairs. For example, with respect to (V4, V7), the antennas TX and RX corresponding to virtual antenna V4 are transmitting antenna TX1_1 and receiving antenna RX2_2. On the other hand, the antennas TX and RX corresponding to virtual antenna V7 are transmitting antenna TX1_2 and receiving antenna RX1_1. The transmitting antennas TX1_1 and TX1_2 overlap in the X direction. Similarly, the receiving antennas RX2_2 and RX1_1 overlap in the X direction. Pairs other than those described above are horizontally non-overlapping pairs in which at least one of the corresponding transmitting antennas TX and corresponding receiving antennas RX is not arranged to overlap in the X direction. A horizontally overlapping pair is an example of an "orthogonal overlapping pair." A horizontally non-overlapping pair is an example of an "orthogonal non-overlapping pair."

[0056] As a result, there are four non-overlapping groups formed by mismatched pairs in which corresponding transmitting antennas TX and corresponding receiving antennas RX are overlapped in the Y direction. Each group is formed by one of (V3, V13) and (V9, V19), and one of (V6, V16) and (V12, V22). Each of these four groups is formed by two mismatched pairs. The number of these two pairs satisfies the condition that it is equal to or greater than Ns + Nr - 2 pairs.

[0057] Furthermore, among the pairs of overlapping virtual positions, (V4, V7), (V5, V8), (V9, V16), (V9, V19), and (V12, V22) are pairs of different wiring lengths. That is, the arrangement of the antennas TX and RX in this embodiment is an arrangement in which there is at least one pair of different wiring lengths.

[0058] Therefore, the arrangement of the antennas TX and RX in this embodiment is an arrangement that allows for at least Ns+Nr-1 pairs, i.e., three pairs to be associated. Examples of the three pairs to be associated include (V3, V13), (V6, V16), and (V9, V19). The reception processing unit 62 compensates for errors between the transmission circuits 3 and the reception circuits 4 based on the reception results for these at least three pairs to be associated.

[0059] The control unit 6 may additionally use, as pairs to be used for compensation processing, mismatched pairs in which the combination of the transmitter circuit 3 and the receiver circuit 4 overlaps. In other words, as long as there are secured at least Ns+Nr-2 mismatched pairs in which the combination of the transmitter circuit 3 and the receiver circuit 4 does not overlap with other pairs, the pairs to be additionally used are not limited to mismatched pairs.

[0060] To control the radar device 1, including the compensation process described above, the processor 6b executes a plurality of instructions contained in a control program stored in the memory 6a. In this way, the control unit 6 implements a functional section for controlling the radar device 1. Specifically, as shown in FIG. 5, the control unit 6 implements a transmission processing section 61 and a reception processing section 62 as functional sections.

[0061] The radar control method in which the control unit 6 controls the radar device 1 using the functions of the processor 6b is executed according to the control flows shown in Figures 6 to 9. This control flow is executed repeatedly while the vehicle is running. Note that each "S" in this control flow represents a plurality of steps executed by a plurality of commands included in the control program.

[0062] First, in S10 of FIG. 6 , the transmission processing unit 61 causes the oscillator 2 to output a transmission signal. Subsequently, in S20, the reception processing unit 62 acquires, from the receiving circuit 4, a beat signal corresponding to a received signal received by the receiving antenna RX after the transmission signal transmitted to the outside from the transmitting antenna TX is reflected by a target. Subsequently, in S30, the reception processing unit 62 converts the beat signal into a digital signal by A / D conversion processing, which samples the beat signal at predetermined time intervals. Subsequently, in S40, the reception processing unit 62 performs FFT (Fast Fourier Transform) processing for each chirp of the A / D converted beat signal. As a result, the reception processing unit 62 acquires, for each chirp, a frequency spectrum (distance spectrum) showing a peak at a frequency position corresponding to the distance to the target. The distance spectrum is data indicating the signal strength for each distance bin according to the distance resolution.

[0063] The reception processing unit 62 then performs FFT processing on the distance spectrum. That is, the reception processing unit 62 performs a second FFT processing on a waveform in which the phases at the distance bins obtained by the first FFT processing for multiple chirps are arranged in time series. As a result, a frequency spectrum (velocity spectrum) showing peaks at positions corresponding to the relative velocity from the target is obtained for each velocity bin. By performing the above two-dimensional FFT, the reception processing unit 62 acquires two-dimensional information (RV map) showing peaks at positions corresponding to the distance to the target and the relative velocity of the target. The information about the peaks acquired in this manner is an example of "reflector information."

[0064] Next, in S50, the reception processing unit 62 extracts a peak from the RV map. Subsequently, in S60, the reception processing unit 62 acquires the intensity of the extracted peak. Then, in S70, the reception processing unit 62 determines whether the extracted peak is valid. For example, the reception processing unit 62 determines that the peak is valid if the intensity of the peak is within an allowable intensity range. Here, the allowable intensity range is a range in which the intensity is equal to or greater than a predetermined threshold. If it is determined that a valid peak exists, the flow proceeds to S80.

[0065] In S80, the reception processing unit 62 acquires a phase error corresponding to the difference in wiring length between the transmission circuits 3, between the reception circuits 4, and for the virtual antenna V, based on the phase of the effective peak in each virtual channel. Here, the wiring length of the virtual antenna V refers to the sum of the wiring length from the transmission antenna TX corresponding to the virtual antenna V to the transmission circuit 3 and the wiring length from the corresponding reception antenna RX to the reception circuit 4. Here, only the wiring Wt2 is longer than the wiring Wt1, and all of the wiring Wr of the reception antenna RX are substantially the same length, so the wiring length of the virtual antenna V assumed for the transmission antenna TX1_2 is longer than the wiring lengths of the virtual antennas V assumed for the transmission antennas TX other than the transmission antenna TX1_2.

[0066] Generally, as shown in FIG. 10 , the phase error due to the wiring length difference for each virtual antenna V increases linearly according to the wiring length difference relative to a reference wiring length Lo (e.g., the shortest wiring length). That is, the phase error relative to the wiring length difference is a value obtained by multiplying the wiring length difference by a parameter K. Therefore, as shown in FIG. 11 , when a graph of the phase error relative to the wiring length difference is assumed, the parameter K corresponds to the slope of the graph. That is, when the wiring length LA of the virtual antenna V assumed for the transmitting antenna TX1_2 in this embodiment is taken as LA, the parameter K can be calculated from the wiring length difference LA-Lo. In this case, the reference wiring length Lo is the wiring length at room temperature of the virtual antenna V assumed for the transmitting antennas TX other than the transmitting antenna TX1_2.

[0067] The parameter K corresponds to the product of the linear expansion coefficient of the wiring and the temperature of the wiring. Since the linear expansion coefficient of an object does not depend on temperature, the parameter K is a temperature parameter that changes depending on temperature. As shown in Figure 11, the parameter K increases linearly as the temperature increases.

[0068] In the phase compensation process, the reception processing unit 62 defines a linear equation based on the phase difference of the peaks in the beat signal for each of the Ns+Nr-1 or more sets of virtual antennas V in the belonging set. In this linear equation, the relative phase error between the transmission circuits 3 and the reception circuits 4, and the relative phase error corresponding to the difference in wiring length, are defined as unknowns. The reception processing unit 62 obtains the solution of this linear equation as the relative phase error. Because the beat signal is a signal correlated with the reception signal, the phase difference of the peaks in the beat signal is an example of the result of comparing the reception signals between the virtual antennas V.

[0069] The acquisition of the relative phase error will be described in detail below. In the following description, the phase at the peak of the beat signal corresponding to the virtual antenna Vn is defined as θ Ｖｎ (n is a natural number). The difference in wiring length in the virtual antenna V assumed for the pair of the transmitting antenna TXa_b and the receiving antenna RXc_d is expressed as L ａｂｉｊ (a, b, i, j are natural numbers). In the following explanation, for simplicity, three pairs, (V3, V13), (V6, V16), and (V9, V19), as shown in FIG. 12, are used as belonging pairs. Of these three pairs, (V3, V13) and (V6, V16) are mismatched pairs. And (V9, V19) is a different wiring length pair.

[0070] Wiring length difference L ａｂｉｊ The phase error caused by ａｂｉｊ In the example shown in FIG. 12, the phase difference θ of the peak for (V3, V13) is Ｖ３ -θ Ｖ１３ can be defined by the relationship shown in Equation (1). Also, the phase difference θ of the peaks related to (V6, V16) Ｖ６９ -θ Ｖ１６ can be defined by the relationship shown in Equation (2). Furthermore, the phase difference θ of the peaks related to (V9, V19) Ｖ９ -θ Ｖ１９ can be defined by the relationship shown in equation (3).

[0071] In the above formula, Θ ａ , Θ ｂ, Θ ｃ are the target-induced phase errors, and e ｔｘ１ is the phase error of the signal generated in the first transmission circuit 3_1. ｔｘ２ is the phase error of the signal generated in the second transmission circuit 3_2. ｒｘ１ is the phase error of the signal generated in the first receiving circuit 4_1. ｒｘ２ is the phase error of the signal generated in the second receiving circuit 4_2.

[0072] Here, in the phase compensation, it is sufficient to take into consideration the relative phase error between the transmission circuits 3 and the relative phase error between the reception circuits 4. Therefore, the relative phase error of the second transmission circuit 3_2 relative to the first transmission circuit 3_1 and the relative phase error of the second reception circuit 4_2 relative to the first reception circuit 4_1 are taken into consideration. In this case, e ｔｘ１ , e ｒｘ１ = 0, where the phase error e ａｂｉｊ To, L ａｂｉｊ When substituted with K, the above formulas (1) to (3) can be transformed into the following formulas (4) to (6).

[0073] When this is converted into a matrix format, the phase difference and relative phase error of each pair satisfy the relationship expressed by the following equation (7).

[0074] Here, the term on the left side of Equation (7) is a phase difference vector Y3 between overlapping virtual antennas V. The first term on the right side of Equation (7) is a coefficient matrix A3. The second term of Equation (7) is a phase difference vector Y3, which can be calculated from the phase of the peak in each beat 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 pair of virtual antennas V. Therefore, Equation (7) can be expressed as e ｔｘ２ , e ｒｘ２ , K as unknowns. That is, the reception processing unit 62 calculates e as a solution of the equation (7). ｔｘ２ , e ｒｘ２, K are acquired as the relative phase error of the second transmission circuit 3_2 with respect to the first transmission circuit 3_1, the relative phase error of the second reception circuit 4_2 with respect to the first reception circuit 4_1, and the relative phase error according to the wiring length difference. The reception processing unit 62 is an example of an "error acquisition unit," and the relative phase error is an example of "error information."

[0075] In the next step S90, the reception processing unit 62 obtains, based on the amplitude of the effective peak in each virtual antenna V, the amplitude error between the transmission circuits 3 and the reception circuits 4, and the amplitude error according to the difference in wiring length.

[0076] In the amplitude compensation process, similar to the phase compensation process, the reception processing unit 62 defines a linear equation based on the amplitude difference of the peaks of the beat signal for each of the Ns+Nr-1 or more belonging sets of virtual antennas V, with the amplitude error between the transmission circuits 3 and the reception circuits 4 being the unknowns. The reception processing unit 62 obtains the solution of this linear equation as the relative amplitude error. This amplitude difference of the peaks of the beat signal is an example of the result of comparing the reception signals between the virtual antennas V.

[0077] The amplitude error due to the difference in wiring length from the reference wiring length Lo increases linearly with the difference in wiring length from the reference wiring length, similar to the phase error. The increase in the amplitude error due to the difference in wiring length changes with temperature. In other words, the amplitude error due to the difference in wiring length is the value obtained by multiplying the difference in wiring length by the parameter α.

[0078] In the following description, it is assumed that the same set of virtual antennas V as in the above-described phase compensation process is also used in the amplitude compensation process. In the following description, the amplitude at the peak of the beat signal corresponding to the virtual antenna Vn is denoted as A Ｖｎ (n is a natural number) The difference in wiring length L ａｂｉｊ The amplitude error caused by G ａｂｉｊ Then, the amplitude difference A of the peak for (V3, V13) Ｖ３ -A Ｖ１３ is the amplitude difference A of the peaks related to equation (8), (V6, V16) Ｖ６ -A Ｖ１６ is the amplitude difference A of the peaks related to equation (9), (V9, V19) Ｖ９ -A Ｖ１９can be defined by the relationship shown in Equation (10).

[0079] Here, the amplitude error G ａｂｉｊ To, L ａｂｉｊ When substituted with α, the above formulas (8) to (10) can be transformed into the following formulas (11) to (13).

[0080] When equations (11) to (13) are converted into a matrix format, the amplitude difference and relative amplitude error of each pair satisfy the relationship expressed by the following equation (14).

[0081] Here, the term on the left side of Equation (14) is an amplitude difference vector Y4 between the overlapping virtual antennas V. The first term on the right side of Equation (14) is a coefficient matrix A4, and the second term is an amplitude error vector X2. The amplitude difference vector Y4 can be calculated from the peak amplitude of each beat signal. The coefficient matrix A4 is a constant matrix defined by the combination of the transmission circuit 3, the reception circuit 4, and the wiring length of each pair of virtual antennas V. That is, the reception processing unit 62 calculates G as a solution of Equation (14). ｔｘ２ , G ｒｘ２ , α are acquired as the relative amplitude error of the second transmission circuit 3_2 with respect to the first transmission circuit 3_1, the relative amplitude error of the second reception circuit 4_2 with respect to the first reception circuit 4_1, and the relative amplitude error due to the wiring length. After the process of S90, the flow proceeds to S160 in FIG.

[0082] On the other hand, if it is determined in S70 that no valid peak exists, the flow proceeds to S100. In S100, the reception processing unit 62 acquires the temperatures of each transmission circuit 3 and each reception circuit 4 from the temperature sensor 5. Then, in S110, the reception processing unit 62 reads from the memory 6a a correction table for the phase error and amplitude error between the transmission circuits 3 according to the temperature.

[0083] Next, in S120, the reception processing unit 62 compares the acquired temperature with the correction table to obtain the relative phase error between the transmission circuits 3 and between the reception circuits 4. Then, in S130, the reception processing unit 62 compares the acquired temperature with the correction table to obtain the relative amplitude error between the transmission circuits 3 and between the reception circuits 4. After the processing of S130, in S140, the reception processing unit 62 compensates for the relative phase error between the transmission circuits 3 and between the reception circuits 4. Furthermore, in S150, the reception processing unit 62 compensates for the relative amplitude error between the transmission circuits 3 and between the reception circuits 4. Thereafter, the flow proceeds to S320 in FIG. 9 .

[0084] Returning to FIG. 7 , in S160, the reception processing unit 62 acquires temperature information from the temperature sensor 5. The reception processing unit 62 is an example of a "temperature acquisition unit." In the following S170, the reception processing unit 62 acquires an allowable error range, which is an allowable range for a phase error according to the temperature information. For example, the reception processing unit 62 acquires an allowable error range for the transmission phase error out of the transmission phase error and the reception phase error. The allowable error range is an error range that is allowable as a transmission phase error that can occur when a non-multipath reflected wave is received by a fault-free radar device 1. The allowable error range is, for example, a range of transmission phase error that is equal to or exceeds a lower threshold and equal to or exceeds an upper threshold.

[0085] A correlation is established between the temperature information and the relative phase error between the transmitting circuit 3, as shown in FIG. 13 . Similarly, a correlation is established between the temperature information and the relative phase error between the receiving circuit 4, as shown in FIG. 14 . Therefore, the receiving processing unit 62 can define the range of phase error that may occur between the circuits 3 and 4 depending on the temperature information as an allowable error range. For example, the receiving processing unit 62 defines the allowable error range based on these correlations that are stored in advance in a storage medium such as the memory 6 a in the form of a relational equation or a table. As the correlation equation, for example, a regression equation estimated from correlation data as shown in FIGS. 13 and 14 may be stored.

[0086] The allowable error range is defined as the range of the phase error expected for the peak due to the real image Ir of the target under a normal transmission / reception environment, i.e., the real image peak. The real image peak is a peak due to a signal transmitted and received via a direct path from the radar device 1 to the target and from the target to the radar device 1.

[0087] On the other hand, ghosts caused by signals transmitted and received via a mismatched path, in which the signal paths between the radar device 1 and the target are mismatched, i.e., peaks of a virtual image Iv (virtual image peaks) may be detected. The phase difference between peaks for the same target between virtual antennas V with overlapping virtual positions in the mismatched path may be relatively large compared to the case of a direct path. In this case, the phase error of the circuits 3 and 4 obtained from the phase difference due to the mismatched path will also fall outside the allowable error range expected to be obtained from the phase difference due to the direct path.

[0088] In S180, the reception processing unit 62 determines whether there is a peak where the transmission phase error obtained from the phase difference between the vertical non-overlapping pairs is outside the allowable error range and the transmission phase error obtained from the phase difference between the vertical overlapping pairs is within the allowable error range. In this way, the reception processing unit 62 determines whether the peak is a virtual peak transmitted and received by mismatched paths in the vertical direction.

[0089] If it is determined that a peak that satisfies the above conditions is present, the flow proceeds to S185. In S185, the reception processing unit 62 estimates that the peak is a false peak caused by a mismatched path in the vertical direction. The reception processing unit 62 stores the estimation result in the memory 6a or the like.

[0090] In S190, the reception processing unit 62 determines whether there is a peak where the transmission phase error obtained from the phase difference in the horizontal non-overlapping pair is outside the allowable error range and the transmission phase error obtained from the phase difference in the horizontal overlapping pair is within the allowable error range. In this way, the reception processing unit 62 determines whether the peak is a false peak transmitted and received by a mismatched path in the horizontal direction.

[0091] If it is determined that a peak that satisfies the above conditions is present, the flow proceeds to S195. In S195, the reception processing unit 62 estimates that the relevant peak is a false peak caused by a mismatched path in the horizontal direction. The reception processing unit 62 stores the estimation result in the memory 6a or the like, as in the case of the vertical direction.

[0092] Through the processes of S180 to S195, the reception processing unit 62 distinguishes between virtual image peaks caused by mismatched paths in the vertical direction and virtual image peaks caused by path mismatched paths in the horizontal direction from among the multiple peaks.

[0093] After a negative determination is made in S190 or after processing in S195, the flow proceeds to S200 in FIG. 8 . In S200, the reception processing unit 62 determines whether the number of peaks for which both the transmission phase error obtained from the phase difference in the vertical non-overlapping pair and the transmission phase error obtained from the phase difference in the horizontal non-overlapping pair are outside the allowable error range exceeds the allowable upper limit. Here, the allowable upper limit is the number of virtual peaks that are allowable under a normal transmission / reception environment. Under a normal transmission / reception environment, as shown in FIG. 15 , only peaks (virtual peaks) that are substantially derived from mismatched paths are out-of-range peaks. Therefore, under a normal transmission / reception environment, it is possible to determine that out-of-range peaks are virtual peaks and that peaks within the allowable error range are real peaks, as shown in FIGS. 17 and 18 . However, under an abnormal transmission / reception environment, even real peaks may be out-of-range peaks.

[0094] Here, an abnormal transmission / reception environment includes, for example, an environment in which at least one of the following occurs: a failure in at least one of the transmission circuit 3 and the reception circuit 4, or signal interference due to attachments to the radome 7a. In the event of a failure, the signals processed by the circuits 3 and 4 may be out of phase due to the influence of the failure. Furthermore, if attachments adhere to the antennas TX and RX, the attachments may cover the antennas TX and RX, reducing the signal strength of the received signal. This may result in an insufficient signal-to-noise ratio and increased signal phase variation. Due to these factors, in an abnormal transmission / reception environment, real image peaks may also become out-of-range peaks, as shown in FIG. 16 . In this case, as shown in FIG. 19 , the number of out-of-range peaks will be greater than in a normal transmission / reception environment. Therefore, the reception processing unit 62 can determine whether the transmission / reception environment is normal or abnormal by determining whether the number of out-of-range peaks exceeds the allowable upper limit.

[0095] If it is determined that the number of peaks outside the allowable error range is within the allowable upper limit, the flow proceeds to S210. In S210, the reception processing unit 62 resets the fault counter and the attachment counter (described below) that had been counted up to the previous cycle. In the following S211, the reception processing unit 62 determines whether there are peaks for which the phase differences of both the vertical overlapping pair and the horizontal overlapping pair are outside the allowable error range. The reception processing unit 62 may determine whether the number of peaks that meet the condition in S200 is one or more.

[0096] If it is determined that a corresponding peak exists, the flow proceeds to S212. In S212, the reception processing unit 62 estimates that the corresponding peak is an artifact caused by transmission and reception on mismatched paths in both the vertical and horizontal directions, and stores the estimation result in the memory 6a, etc. After processing S212, the flow proceeds to S250.

[0097] On the other hand, if it is determined in S200 that the number of peaks outside the allowable range exceeds the upper limit of allowable number, the flow proceeds to S220.

[0098] In S220, the reception processing unit 62 determines whether the phase error acquired in the phase compensation process based on the phase difference between the virtual antennas V in S80 and the phase error acquired by a method other than the phase compensation process are both outside the allowable error range. For example, the reception processing unit 62 determines whether the method other than the compensation process for the phase error between the transmission circuits 3 is a phase error calculated by, for example, a built-in self-test (BIST) function of each of the circuits 3, 4, etc. The phase difference acquired by a method other than the phase compensation process is, for example, a phase error acquired corresponding to each channel of the circuits 3, 4 corresponding to the virtual antenna V, which is acquired in response to an internal signal in the radar device 1, such as a test signal, which does not transmit or receive a signal to or from the outside.

[0099] Here, if the abnormality in the transmission / reception environment is due to a failure of circuits 3 and 4, the phase error calculated by a method other than the phase compensation process will also be outside the allowable error range. On the other hand, if the abnormality in the transmission / reception environment is due to an attachment, the phase error calculated by a method other than the phase compensation process will be within the allowable error range. Therefore, as shown in FIG. 20 , if there is a pair of phase errors in which the phase error calculated by the phase compensation process and the phase error calculated by a method other than the phase compensation process are both outside the allowable error range, it can be assumed that the abnormality in the transmission / reception environment is due to a failure of circuits 3 and 4. Note that the allowable error range in FIG. 20 is the range indicated by the solid line in the graph. Also, in FIG. 20 and FIG. 21 described below, circles indicate phase errors calculated by the phase compensation process, and triangles indicate phase errors calculated by BIST.

[0100] On the other hand, as shown in Figure 21, if there is no pair of virtual antennas V for which the phase error acquired by the compensation process and the phase error acquired by a method other than the compensation process are both outside the allowable error range, it can be assumed that the abnormality in the transmission and reception environment is due to an attached object. Note that even if there are pairs for which the phase errors described above are outside the allowable error range, the reception processing unit 62 may assume that the abnormality in the transmission and reception environment is due to an attached object if the number of pairs is within the upper limit. The upper limit number may be 0 pairs or 1 pair or more.

[0101] If it is determined in S220 that the phase error determined by the BIST is outside the allowable error range, the flow proceeds to S230, where the reception processing unit 62 counts up a fault counter, which is a counter for fault diagnosis. On the other hand, if it is determined that the phase error determined by the BIST is within the allowable error range, the flow proceeds to S240. In S240, the reception processing unit 62 counts up an attachment counter. The attachment counter is a counter for diagnosing attachment of attachments to the radome 7a.

[0102] In S250 of FIG. 9 , the reception processing unit 62 determines whether the object counter is equal to or greater than the threshold value. If it is determined that the object counter is equal to or greater than the threshold value, the flow proceeds to S260. In S260, the reception processing unit 62 outputs an object notification. The reception processing unit 62 may output the object notification to, for example, another ECU mounted on the vehicle. Alternatively, the reception processing unit 62 may output the object notification to a center external to the vehicle.

[0103] On the other hand, if it is determined that the adhesion counter is less than the threshold value, the flow proceeds to S270. In S270, the reception processing unit 62 determines whether the malfunction counter is equal to or greater than the threshold value. If it is determined that the malfunction counter is equal to or greater than the threshold value, the flow proceeds to S280. In S280, the reception processing unit 62 outputs a malfunction notification. The reception processing unit 62 may output the malfunction notification to, for example, another ECU installed in the vehicle. Alternatively, the reception processing unit 62 may output the malfunction notification to a center external to the vehicle.

[0104] On the other hand, if it is determined that the failure counter is less than the threshold value, the flow proceeds to S290. In S290, the reception processing unit 62 estimates that the out-of-range peak is due to a virtual image Iv, i.e., due to multipath.

[0105] In S300, the reception processing unit 62 performs phase compensation on the peak estimated to be the real image Ir. For example, the reception processing unit 62 performs phase compensation by removing a relative phase error from the phase of the real image peak in the Doppler spectrum corresponding to the signal transmitted through at least one of the second transmission circuit 3_2 and the second reception circuit 4_2. Alternatively, the reception processing unit 62 may simply store the acquired relative phase error in the memory 6a as compensation data to be used when acquiring the relative angle, which will be described later. Furthermore, in S310, the reception processing unit 62 performs amplitude compensation on the peak estimated to be the real image Ir. The reception processing unit 62 may perform phase compensation by removing a relative phase error from the phase of the real image peak, as in the phase compensation, or may perform amplitude compensation by storing the relative amplitude error in the memory 6a as compensation data.

[0106] In S320, the reception processing unit 62 acquires the relative angle of the reflecting object based on the phase information of the compensated peak estimated as the real image Ir. Specifically, the reception processing unit 62 performs FFT processing on a waveform in which the phases of the peaks in the integrated spectrum obtained by integrating the compensated Doppler spectra corresponding to each virtual antenna V are aligned. As a result, the reception processing unit 62 acquires an angular spectrum showing peaks at positions corresponding to the relative angle with respect to the target. The reception processing unit 62 acquires the relative angle by extracting the peaks of the angular spectrum.

[0107] Then, in S190, the reception processing unit 62 outputs the sensing data to the in-vehicle ECU, etc. The sensing data includes, for example, at least one of the target distance, speed, and relative angle.

[0108] According to this, it is possible to estimate that an out-of-range reflector, which is a reflector whose phase error based on the comparison result of a specific direction overlapping pair is within the allowable error range allowed according to the temperature information and whose phase error based on the comparison result of a specific direction non-overlapping pair is outside the allowable error range, is a virtual image Iv. Therefore, when multipath occurs at a reflector in a specific direction on the outbound or inbound path of a signal, it is possible to identify the virtual image Iv caused by the multipath.

[0109] Here, the reduction of the influence of mismatched paths in the phase compensation process and the discrimination of false peaks due to mismatched paths will be described in detail. For example, assume that the radar device 1 is used on a road as shown in Fig. 22. The signal path between a signal transmission / reception point Pa of the radar device 1 and a specific reflection point Pb of a certain target may become a path mismatched path, in which the outbound and return paths do not match.

[0110] One specific path mismatch is a return reflection path in which a signal travels directly from the transmission / reception point Pa to the reflection point Pb on the outbound path, and is reflected at a specific reflection point Pc on the road surface on the return path before reaching the transmission / reception point Pa. Another specific path mismatch is a return reflection path in which a signal travels directly from the transmission / reception point Pa to the reflection point Pc on the outbound path, and is reflected at the reflection point Pc on the outbound path before reaching the reflection point Pb, and is then directed from the reflection point Pb to the transmission / reception point Pa on the return path.

[0111] Here, as shown in Figures 23 and 24, a relative phase angle shift occurs between signals received at each virtual antenna V depending on the Y-direction positions of the transmitting antenna TX and receiving antenna RX corresponding to the virtual antenna V. For example, assume that a signal from the transmitting antenna TX reaches directly from the transmitting / receiving point Pa to the reflecting point Pb on the outbound path. If the distance between the transmitting / receiving point Pa and the reflecting point Pb is sufficiently large, the relative angle θ of the reflecting point Pb with respect to each transmitting antenna TX can be considered to be equal. If this relative angle is θ, a phase angle shift of 2d sin θ occurs between signals between transmitting antennas TX that are 2d apart in the Y-direction. Similarly, when a signal reaches directly from the reflecting point Pb to the transmitting / receiving point Pa on the return path, a phase angle shift of the same magnitude occurs between receiving antennas RX that are 2d apart in the Y-direction.

[0112] Also, consider the case where, on the outbound path, a signal from a transmitting antenna TX travels from a transmitting / receiving point Pa and is reflected at a reflection point Pc on the road surface before reaching a reflection point Pb. If the relative angle of reflection point Pb with respect to each transmitting antenna TX is φ, a phase angle shift of 2d sin φ occurs between the signals between transmitting antennas TX that are separated by 2d in the Y direction. Similarly, when, on the return path, a signal travels from reflection point Pb to reflection point Pc and reaches the transmitting / receiving point Pa, a phase angle shift of the same magnitude occurs between receiving antennas RX that are separated by 2d in the Y direction.

[0113] As a result, when at least one of the transmitting antenna TX and the receiving antenna RX is shifted from the reference position in the Y direction, the phase angle of the received signal of the virtual antenna V is shifted compared to the virtual antenna V formed by the transmitting antenna TX and the receiving antenna RX at the reference position in the Y direction.

[0114] For example, in the case of a direct path in which a signal travels directly between a transmitting / receiving point Pa and a reflecting point Pb on both the outbound and return paths, if the transmitting antenna TX1_1 is set as the reference position (i.e., phase angle 0) for the transmitting antenna TX, the phase angle shift shown in Fig. 25 occurs on the outbound path of the signal transmitted from each of the transmitting antennas TX2_1, TX2_2, and TX1_2. Also, if the receiving antennas RX1_1, RX1_2, and RX2_1 are set as the reference positions for the receiving antenna RX, the phase angle shift shown in Fig. 26 occurs on the return path of the signal received by the receiving antennas RX2_2, RX1_3, and RX2_3.

[0115] That is, for each virtual antenna V, a relative phase angle occurs between the received signals, which is the sum of the phase angle shift on the outbound path due to the Y-direction position of the corresponding transmitting antenna TX and the phase angle shift on the return path due to the Y-direction position of the receiving antenna RX.

[0116] In the case of a direct path, as shown in Figure 27, the relative phase angles are the same for virtual antennas V whose virtual positions overlap. Therefore, when the phase difference is calculated for the peak of the same target for virtual antennas V whose virtual positions overlap, the relative phase angles are canceled out regardless of the arrangement of the corresponding antennas TX and RX. Therefore, there is no substantial effect on the compensation process for the phase error between circuits 3 and 4. Note that even when the signal passes through a path that reflects at reflection point Pc on both the outbound and inbound paths, the relative phase angles are the same for virtual antennas V whose virtual positions overlap.

[0117] On the other hand, when mismatched paths occur, the relative phase angles of vertically non-overlapping pairs are not canceled out. For example, in the case of a return path reflection path, for the receiving antenna RX, as shown in Figure 28, a phase angle shift of -2d sin φ with respect to the receiving antennas RX1_1, RX1_2, and RX2_1 occurs on the return path of the signal received by the receiving antennas RX2_2, RX1_3, and RX2_3. Note that the phase angle occurring on the outgoing path of the signal is the same as in Figure 25.

[0118] Therefore, as shown in Figure 29, the relative phase angles of the vertical non-overlapping pairs do not match. As an example, for (V4, V7), the relative phase angle of virtual antenna V4 is -2d sin φ, and the relative phase angle of virtual antenna V7 is 2d sin θ. Therefore, when the phase difference of (V4, V7) is taken, the difference between these relative phase angles remains.

[0119] On the other hand, for vertically overlapping pairs, the relative phase angles are canceled out in the peak phase difference even in the return reflection path. As an example, for (V3, V13), the relative phase angles of virtual antennas V3 and V13 are both 0. Therefore, even if the peak phase difference is taken for the vertically overlapping pair, the influence of the relative phase angle due to the return reflection path does not substantially occur.

[0120] Furthermore, when transmission and reception occur via an outward reflection path, as shown in Figure 30, for the transmitting antenna TX, a phase angle shift of -2d sinφ occurs for the transmitting antennas TX1_1 and TX2_1 on the outward path of the signals transmitted from the transmitting antennas TX1_2 and TX2_2.

[0121] Therefore, in the case of the outbound reflection path, as in the case of the return reflection path, the relative phase angles do not match for vertical non-overlapping pairs, and the relative phase angles match for vertical overlapping pairs (see Figures 31 and 32).

[0122] In this embodiment, the reception processing unit 62 acquires the phase error between the circuits 3 and 4 based on the phase difference between the virtual antennas V of the vertically overlapping pair belonging to the non-overlapping group in the compensation process. Therefore, even if transmission and reception occur via any mismatched path, the influence of the relative phase angle on the acquisition of the phase error between the circuits 3 and 4 is substantially avoided.

[0123] On the other hand, when the phase error between the circuits 3 and 4 is obtained from the phase difference between peaks in a vertical non-overlapping pair, the obtained phase error differs depending on whether the peak is a virtual peak or a real peak. Suppose the phase error obtained from the phase difference between a peak originating from a certain target in a vertical overlapping pair is within the allowable error range, and the phase error of a peak obtained from the phase difference between peaks originating from the same target in a vertical non-overlapping pair is outside the allowable error range. In this case, the peak can be estimated to be a virtual peak caused by mismatched paths in the vertical direction.

[0124] Although the above describes the occurrence of mismatched paths due to road surface reflections, objects other than the road surface (such as the ceiling of a tunnel) that exist in the Y direction relative to the radar device 1 can also be a cause of path mismatched paths.

[0125] Similarly, a signal path mismatch path may occur in the X direction due to a reflecting object present in the X direction of the radar device 1. For example, an installed object such as a guardrail or a tunnel wall may be a cause of a path mismatch path in the X direction.

[0126] The graph in Figure 33 shows the relative phase angle of the virtual antenna V in each pair due to the outward reflection path in the X direction. As shown in Figure 33, the relative phase angles of six horizontal non-overlapping pairs differ due to the mismatched paths in the X direction. Suppose that the phase error obtained from the phase difference of a peak originating from a certain target in a horizontal overlapping pair is within the allowable error range, and the phase error of a peak obtained from the phase difference of a peak originating from the same target in a horizontal non-overlapping pair is outside the allowable error range. In this case, it can be estimated that the peak is a false peak due to the mismatched paths in the horizontal direction.

[0127] Second Embodiment As shown in Figures 34 to 36, the second embodiment is a modified example of the first embodiment. In the radar device 1 of the second 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 those in the first embodiment. The corresponding relationship between the transmitting antennas TX and the transmitting circuits 3 and the corresponding relationship between the receiving antennas RX and the receiving circuits 4 are also the same as those in the first embodiment. In this embodiment, the wiring lengths of the wirings Wt between the transmitting antennas TX and the corresponding transmitting circuits 3 are all substantially the same. The wiring lengths of the wirings Wr between the receiving antennas RX and the corresponding receiving circuits 4 are all substantially the same.

[0128] The arrangement of the four transmitting antennas TX is the same as in the first embodiment. As shown in FIG. 34, the receiving antennas RX1_1, RX1_2, and RX2_1 are arranged in this order from one side to the other in the X direction. Therefore, the receiving antennas RX1_1, RX1_2, and RX2_1 are arranged so that their positions overlap in the Y direction. The receiving antennas RX1_1 and RX1_2 are arranged with a distance d between them. Furthermore, the receiving antennas RX1_2 and RX2_1 are arranged with a distance 2d between them.

[0129] The receiving antennas RX1_3, RX2_2, and RX2_3 are arranged in this order from one side to the other in the X direction. That is, the receiving antennas RX1_3, RX2_2, and RX2_3 are arranged so that their positions in the Y direction overlap. The receiving antennas RX1_1 and RX1_2 are arranged with a distance d between them, and the receiving antennas RX1_2 and RX2_1 are arranged with a distance 2d between them.

[0130] The row of receiving antennas RX1_1, RX1_2, and RX2_1 and the row of receiving antennas RX1_3, RX2_2, and RX2_3 are arranged with a gap of 2d in the Y direction. Under this arrangement, the receiving antennas RX1_1 and RX1_3 are arranged in positions that overlap in the X direction. Furthermore, the receiving antennas RX1_2 and RX2_2 are also arranged so that their positions overlap in the X direction. Similarly, the receiving antennas RX2_1 and RX2_3 are also arranged so that their positions overlap in the X direction.

[0131] For the transmitting antenna TX1_1, the virtual antennas V formed virtually for the receiving antennas RX1_1, RX1_2, RX2_1, RX1_3, RX2_2, and RX2_3 are designated as virtual antennas V1, V2, V3, V4, V5, and V6, in that order. Furthermore, for the transmitting antenna TX1_2, the virtual antennas V formed virtually for each receiving antenna RX are designated as virtual antennas V7, V8, V9, V10, V11, and V12, in the order of the receiving antennas RX. Similarly, the virtual antennas V formed virtually for the transmitting antenna TX2_1 are designated as virtual antennas V13, V14, V15, V16, V17, and V18, in the same order. Similarly, the virtual antennas V assumed for the transmitting antenna TX2_2 are designated as virtual antennas V19, V20, V21, V22, V23, and V24.

[0132] Figure 35 shows a virtual arrangement of virtual antennas V virtually formed in the arrangement of Figure 34. Transmitting antennas TX adjacent to each other in the X direction are arranged with an interval of 2d between them. Therefore, the group of virtual antennas V assumed for a specific transmitting antenna TX is at a virtual position relatively shifted by 2d from the group of virtual antennas V assumed for transmitting antennas TX adjacent to each other in the X direction. Furthermore, transmitting antennas TX adjacent to each other in the Y direction are arranged with an interval of 2d between them. Therefore, the group of virtual antennas V assumed for a specific transmitting antenna TX is at a virtual position relatively shifted by 2d from the group of virtual antennas V assumed for transmitting antennas TX adjacent to each other in the Y direction.

[0133] 35, as in the first embodiment, the virtual positions of the multiple virtual antennas V for each transmitting antenna TX are illustrated shifted in the vertical direction of the paper. In reality, virtual antennas V1 to V3 and virtual antennas V13 to V15 are virtually formed at virtual positions on a virtual line VL1 extending in the X direction. Furthermore, virtual antennas V4 to V9 and virtual antennas V16 to V21 are virtually formed at virtual positions on a virtual line VL2. In addition, virtual antennas V10 to V11 and virtual antennas V22 to V24 are virtually formed at virtual positions on a virtual line VL3.

[0134] As shown in FIG. 35, in this arrangement, the pairs of virtual antennas V with overlapping virtual positions are (V3, V14), (V4, V7), (V5, V8), (V6, V9), (V6, V17), (V6, V20), (V9, V17), (V9, V20), (V12, V23), (V16, V19), (V17, V20), and (V18, V21).

[0135] Among these, seven pairs, (V3, V14), (V5, V8), (V6, V17), (V6, V20), (V9, V17), (V9, V20), and (V12, V23), are mismatched pairs in which the combinations of the transmitter circuits 3 and receiver circuits 4 corresponding to the respective virtual antennas V do not match among the virtual antennas V. For example, for the pair (V3, V14), the combination of the transmitter circuit 3_1 and receiver circuit 4_2 corresponds to the virtual antenna V3. The combination of the transmitter circuit 3_2 and receiver circuit 4_1 corresponds to the virtual antenna V14, which is mismatched with the combination of the virtual antenna V3. Similarly, for the pair (V6, V17), the combination of the transmitter circuit 3_1 and receiver circuit 4_2 corresponds to the virtual antenna V6, and the combination of the transmitter circuit 3_2 and receiver circuit 4_2 corresponds to the virtual antenna V17. In this pair, the receiving circuit 4_2 is common but the transmitting circuits 3_1 and 3_2 are different, so it is a mismatched pair as a combination of the circuits 3 and 4. (V5, V8), (V6, V20), (V9, V17), (V9, V20), (V12, V23), and (V17, V20) are also mismatched pairs.

[0136] Among these, (V3, V14), (V6, V20), and (V9, V20) are combination patterns of the transmitter circuit 3 and the receiver circuit 4 that overlap. Specifically, the circuits 3 and 4 corresponding to (V3, V14) are combination patterns that combine the transmitter circuit 3_1 and the receiver circuit 4_2, and the transmitter circuit 3_2 and the receiver circuit 4_1. Similarly, (V6, V20) and (V9, V20) are combination patterns that overlap. Similarly, the circuits 3 and 4 corresponding to (V6, V17) are combination patterns that combine the transmitter circuit 3_1 and the receiver circuit 4_2, and the transmitter circuit 3_2 and the receiver circuit 4_2, and this pattern overlaps with (V9, V17) and (V12, V23).

[0137] Here, from the seven mismatched pairs, nine non-overlapping groups are assumed, each consisting of one of (V3, V14), (V6, V20), and (V9, V20), one of (V6, V17), (V9, V17), and (V12, V23), and (V5, V8).

[0138] Among these mismatched pairs, (V5, V8), (V6, V20), and (V9, V17) have at least one of the corresponding transmitting antennas TX and receiving antennas RX that are vertically non-overlapping pairs. For example, for (V5, V8), the antennas TX and RX that correspond to virtual antenna V5 are transmitting antenna TX1_1 and receiving antenna 2_2. On the other hand, the antennas TX and RX that correspond to virtual antenna V8 are transmitting antenna TX1_2 and receiving antenna 1_2. The transmitting antennas TX1_1 and TX1_2 do not overlap in the Y direction. The receiving antennas RX2_2 and RX1_2 also do not overlap in the Y direction. Similarly, for (V6, V20) and (V9, V17), the transmitting antennas TX and receiving antennas RX do not overlap in the Y direction.

[0139] On the other hand, (V3, V14), (V6, V17), (V9, V20), and (V12, V23) are vertically overlapping pairs. For example, with respect to (V3, V14), transmitting antenna TX1_1 and receiving antenna 2_1 correspond to virtual antenna V3. On the other hand, transmitting antenna TX2_1 and receiving antenna 1_2 correspond to virtual antenna V14. The transmitting antennas TX1_1 and TX2_1 overlap in the Y direction. Similarly, the receiving antennas RX2_1 and RX1_2 overlap in the Y direction. The same is true for (V6, V17), (V9, V20), and (V12, V23).

[0140] Among the overlapping pairs of virtual positions, there are six horizontal overlapping pairs. The horizontal overlapping pairs are (V4, V7), (V5, V8), (V6, V9), (V16, V19), (V17, V20), and (V18, V21). Pairs other than those mentioned above are horizontal non-overlapping pairs.

[0141] As a result, there are four non-overlapping groups formed by vertically overlapping pairs, each consisting of either (V3, V14) or (V9, V20) and either (V6, V17) or (V12, V23). Because each of these four groups consists of two mismatched pairs, they satisfy the condition of Ns + Nr - 2 or more pairs. The reception processing unit 62 compensates for errors between the transmission circuits 3 and the reception circuits 4 based on the reception results of at least one of (V3, V14) and (V9, V20) and at least one of (V6, V17) and (V12, V23).

[0142] The phase error acquisition process in S80 for the above-described layout and equal-length wiring will now be described in detail. In this process, the pair of virtual antennas V shown in Fig. 36 is used. That is, the reception processing unit 62 additionally uses two pairs of virtual antennas V, (V3, V14) and (V6, V17), which are included in the group, as well as (V9, V20), which is a combination of the transmitter circuit 3 and the receiver circuit 4 that overlaps with (V3, V14).

[0143] In this case, the phase difference θ of the peak for (V3, V14) Ｖ３ -θ Ｖ１４ is the phase difference θ of the peaks related to equation (15), (V6, V17) Ｖ６ -θ Ｖ１７ is the phase difference θ of the peaks related to equation (16), (V9, V20) Ｖ９ -θ Ｖ２０ can be defined by the relationship shown in Equation (17).

[0144] Here, the relative phase error of the second transmission circuit 3_2 with respect to the first transmission circuit 3_1 and the relative phase error of the second reception circuit 4_2 with respect to the first reception circuit 4_1 are obtained, and e ｔｘ１ , e ｒｘ１ = 0. In this case, the formulas (15) to (17) can be transformed into the following formulas (18) to (20).

[0145] When equations (18) to (20) are converted into a matrix format, the phase difference and relative phase error of each pair satisfy the relationship expressed by equation (21) below.

[0146] The above formula (21) is e ｔｘ２ , e ｒｘ２ That is, the reception processing unit 62 can solve the simultaneous equations with e as the solution of the equation (21). ｔｘ２ , e ｒｘ２ are obtained as the relative phase error of the second transmission circuit 3_2 with respect to the first transmission circuit 3_1 and the relative phase error of the second reception circuit 4_2 with respect to the first reception circuit 4_1.

[0147] Next, the amplitude error acquisition process in S90 will be described in detail. In the following amplitude compensation process, the same set of virtual antennas V as in the phase compensation process is used. The peak amplitude difference A for (V3, V14) is Ｖ３ -A Ｖ１４ is the amplitude difference A of the peaks related to equation (22), (V6, V17) Ｖ６ -A Ｖ１７ is the amplitude difference A of the peaks related to equation (23), (V9, V20) Ｖ９ -A Ｖ２０ can be defined by the relationship shown in equation (24).

[0148] Here, taking into consideration the relative amplitude error of the second transmission circuit 3_2 with respect to the first transmission circuit 3_1 and the relative amplitude error of the second reception circuit 4_2 with respect to the first reception circuit 4_1, G ｔｘ１ , G ｒｘ１ = 0. Equations (22) to (24) can be transformed into the following equations (25) to (27).

[0149] Here, equations (25) to (27) are converted into a matrix format, and the amplitude difference and relative amplitude error of each pair satisfy the relationship expressed in equation (28) below after conversion.

[0150] The receiving processor 62 receives G as a solution of the equation (28).ｔｘ２ , G ｒｘ２ are obtained as the relative amplitude error of the second transmission circuit 3_2 with respect to the first transmission circuit 3_1 and the relative amplitude error of the second reception circuit 4_2 with respect to the first reception circuit 4_1.

[0151] Furthermore, in the arrangement of this embodiment, vertical overlapping pairs and vertical non-overlapping pairs, as well as horizontal overlapping pairs and horizontal non-overlapping pairs, are virtually formed for the virtual antenna V. Therefore, similar to the first embodiment, the reception processing unit 62 can distinguish between virtual image peaks caused by mismatched paths in the vertical direction and virtual image peaks caused by path mismatched paths in the horizontal direction from among multiple peaks by the processing of S180 to S195.

[0152] (Other Embodiments) Although multiple embodiments have been described above, the present disclosure should not be construed as being limited to those embodiments, and can be applied to various embodiments and combinations within the scope that does not deviate from the gist of the present disclosure.

[0153] In a modified example, when the reception processing unit 62 determines that the object counter is equal to or greater than the threshold value, i.e., when it diagnoses that an object has adhered, it may execute a process to deal with the object instead of or in addition to the notification process of S260. Specifically, the reception processing unit 62 may execute a process to activate a heater (not shown) provided in the radar device 1. If the object is frost, the frost can be removed by activating the heater. Furthermore, the reception processing unit 62 may identify the antennas TX and RX affected by the object and execute a prohibition process to prohibit the use of the received signal from the virtual antenna V associated with the antennas TX and RX for acquiring sensing data. The reception processing unit 62 may first activate the heater and then execute the prohibition process if the object has not been removed.

[0154] In a modified example, the reception processing unit 62 may obtain an allowable error range for the reception phase error out of the transmission phase error and the reception phase error, and detect the illusion peak based on the reception phase error. Furthermore, in a modified example, the reception processing unit 62 may diagnose whether the peak is due to an illusion or a fault, depending on the number of peaks that fall outside the allowable error range allowed according to the temperature information, for the relative amplitude error between at least one of different transmission circuits 3 and reception circuits 4.

[0155] In a modified example, the reception processing unit 62 may acquire temperature information corresponding to the phase information in S160. More specifically, the reception processing unit 62 in S160 detects temperature information based on the parameter K calculated in S80. As described above, the parameter K is a parameter that changes depending on the temperature. That is, the reception processing unit 62 can acquire temperature information from the correspondence relationship between the value of the parameter K and the temperature. This correspondence relationship is stored in advance in a storage medium such as the memory 6a. The correspondence relationship is stored in the form of, for example, a function formula or a table. The temperature detection unit may also acquire temperature information corresponding to the relative amplitude error. Like the parameter K, the parameter α used in calculating the relative amplitude error is also a value corresponding to the temperature, and therefore the reception processing unit 62 can acquire temperature information from the correlation between the parameter α and the temperature.

[0156] Note that the temperature information corresponding to the phase information is a temperature related to the wiring, and is therefore relatively close to the actual temperature of the wiring. In other words, the sensor temperature information and the phase temperature information basically do not match due to differences in the temperature detection locations. In this embodiment, the phase temperature information is basically a lower temperature 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 from a normal temperature sensor 5 is about 60°C, the phase temperature information may be a lower temperature, for example, about 40°C.

[0157] In a modification of the first embodiment, all of the wiring lengths between the transmitting antennas TX and the transmitting circuit 3 may be substantially equal. In a modification of the second embodiment, as shown in FIG. 2, the wiring Wt2 of the transmitting antenna TX1_2 connected to the first transmitting circuit 3_1 may be longer than the wiring Wt1 of the other transmitting antennas TX.

[0158] In a modified example, both the transmitting antennas TX and the receiving antennas RX may be arranged at irregular intervals. Also, in a modified example, in a radar device 1 in which at least one of the transmitting antennas TX and the receiving antennas RX is arranged at irregular intervals, at least one of the wiring lengths may be different from the others.

[0159] In a modified example, the X direction may be vertical and the Y direction may be horizontal, or the Y and X directions may be directions other than vertical and horizontal.

[0160] In a modified example, the dedicated computer constituting the control unit 6 may be a sensor management ECU that comprehensively controls multiple types of sensors mounted on the vehicle. The dedicated computer constituting the control unit 6 may be an integration ECU that integrates vehicle driving control. The dedicated computer constituting the control unit 6 may be a determination ECU that determines driving tasks in vehicle driving control. The dedicated computer constituting the control unit 6 may be a monitoring ECU that monitors vehicle driving control. The dedicated computer constituting the control unit 6 may be an evaluation ECU that evaluates vehicle driving control. The dedicated computer constituting the control unit 6 may be a navigation ECU that navigates the vehicle's driving route.

[0161] The dedicated computer constituting the control unit 6 may be a locator ECU that estimates the vehicle's own state quantity. The dedicated computer constituting the control unit 6 may be an actuator ECU that controls the vehicle's driving actuators. The dedicated computer constituting the control unit may be an HCU (Human Machine Interface (HMI) Control Unit) that controls the presentation of information in the vehicle. The dedicated computer constituting the control unit 6 may be a computer other than the vehicle that constitutes, for example, an external center or mobile terminal that can communicate with the vehicle.

[0162] In a modified example, the mobile body equipped with the radar device 1 may be, for example, an autonomous robot that can transport luggage or collect information by autonomous driving or remote driving. Examples of the autonomous robot include an autonomous vehicle.

[0163] (Disclosure of Technical Ideas) This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be described in a multiple dependent form, with the subsequent clause alternatively referring to the preceding clause. Furthermore, some clauses may be described in a multiple dependent form, with the subsequent clause referring to another multiple dependent clause. These multiple dependent clauses define multiple technical ideas.

[0164] (Technical Idea 1) A radio communication system comprising: a plurality of transmitting antennas (TX) and a plurality of receiving antennas (RX); Ns transmitting circuits (3) connected by wiring to the corresponding transmitting antennas to output transmitting signals; Nr receiving circuits (4) connected by wiring to the corresponding receiving antennas to acquire receiving signals; a housing unit (7) for housing the transmitting circuits and the receiving circuits; and a control unit (6) for outputting sensing data correlated with the receiving signals, wherein Ns and Nr are integers of 2 or more; at least one of the plurality of transmitting antennas and the plurality of receiving antennas is arranged at unequal intervals, and a plurality of virtual antennas (V) are virtually formed for each transmitting antenna according to a phase difference of the receiving signals between the receiving antennas for the plurality of receiving antennas; and for mismatched pairs, which are pairs of virtual antennas among the plurality of virtual antennas whose assumed virtual positions overlap and whose combinations of the transmitting circuit and the receiving circuit corresponding to the virtual antennas do not match among the virtual antennas, the group is arranged so that, assuming a group of mismatched pairs whose combination patterns of the transmitting circuit and the receiving circuit do not overlap with each other, the group includes at least Ns+Nr-2 pairs of mismatched pairs; and for pairs of virtual antennas among the plurality of virtual antennas whose virtual positions overlap and whose wiring lengths do not match, the group is arranged so that the total number of belonging pairs, which are pairs of virtual antennas belonging to at least one of the mismatched pairs and the different wiring length pairs included in the group, is at least Ns+Nr-1 pairs; and for the belonging pairs, the positions of the corresponding transmitting antennas and receiving antennas overlap in a specific direction, forming specific direction overlapping pairs, and the control unit is configured to acquire temperature information related to an internal temperature of the accommodation unit, ...a radar device configured to perform the following operations: acquiring, for a plurality of reflectors, a phase error between at least one of the different transmitting circuits and the receiving circuits based on a comparison result of reflector information regarding the same reflector in the received signals of the virtual antennas in at least Ns+Nr-1 sets of the specific direction overlapping pairs, and the phase error based on the comparison result in the specific direction non-overlapping pairs; and estimating that an out-of-range reflector, which is a reflector for which the phase error based on the comparison result in the specific direction overlapping pairs is within an allowable error range allowed according to the temperature information and the phase error based on the comparison result in the specific direction non-overlapping pairs is outside the allowable error range, is a virtual image.

[0165] (Technical Idea 2) A radio communication system comprising: a plurality of transmitting antennas (TX) and a plurality of receiving antennas (RX); Ns transmitting circuits (3) connected to the corresponding transmitting antennas to output transmitting signals; Nr receiving circuits (4) connected to the corresponding receiving antennas to acquire receiving signals; a housing unit (7) housing the transmitting circuits and the receiving circuits; and a control unit (6) outputting sensing data correlated with the receiving signals, wherein Ns and Nr are integers of 2 or more; at least one of the plurality of transmitting antennas and the plurality of receiving antennas is arranged at unequal intervals, and a plurality of virtual antennas (V) are virtually formed for each transmitting antenna according to a phase difference of the receiving signals between the receiving antennas for the plurality of receiving antennas; and with respect to mismatched pairs, which are pairs of virtual antennas whose assumed virtual positions overlap among the plurality of virtual antennas and whose combinations of the transmitting circuits and the receiving circuits corresponding to the virtual antennas do not match, when a group of the mismatched pairs whose combination patterns of the transmitting circuits and the receiving circuits do not overlap with each other is assumed, the mismatched pairs are arranged so that at least Ns+Nr-2 pairs of the mismatched pairs are included in the group, and for at least Ns+Nr-2 pairs of the mismatched pairs in the group, the mismatched pairs are arranged so that corresponding transmitting antennas and corresponding receiving antennas are arranged to form specific direction overlapping pairs whose positions overlap in a specific direction, and at least one specific direction non-overlapping pair whose corresponding transmitting antennas and / or corresponding receiving antennas are in non-overlapping positions in the specific direction is virtually formed, and the control unit acquires temperature information related to an internal temperature of the containing unit, Acquiring, for a plurality of reflectors, phase errors at least between different transmitting circuits and between different receiving circuits based on a comparison result of reflector information regarding the same reflector in the received signals of the virtual antennas in at least Ns+Nr-2 sets of overlapping pairs in the specific direction, and the phase errors based on the comparison result in the non-overlapping pairs in the specific direction;and estimating that an out-of-range reflector is a virtual image when the phase error based on the comparison result in the specific direction overlapping pair is within an allowable error range that is permissible depending on the temperature information, and when the phase error based on the comparison result in the specific direction non-overlapping pair is outside the allowable error range.

[0166] (Technical Idea 3) A radio communication system comprising: a plurality of transmitting antennas (TX) arranged at equal intervals and a plurality of receiving antennas (RX) arranged at equal intervals; Ns transmitting circuits (3) connected to the corresponding transmitting antennas and outputting transmitting signals; Nr receiving circuits (4) connected to the corresponding receiving antennas and acquiring receiving signals; a housing unit (7) housing the transmitting circuits and the receiving circuits; and a control unit (6) outputting sensing data correlated with the receiving signals, wherein Ns and Nr are each integers of 2 or more, and the plurality of transmitting antennas and the plurality of receiving antennas virtually form a plurality of virtual antennas (V) assumed for each transmitting antenna according to a phase difference of the receiving signals between the receiving antennas for the plurality of receiving antennas, and with respect to mismatched pairs, which are pairs of virtual antennas whose assumed virtual positions overlap among the plurality of virtual antennas and whose combinations of the transmitting circuits and the receiving circuits corresponding to the virtual antennas do not match, when a group of the mismatched pairs whose combination patterns of the transmitting circuits and the receiving circuits do not overlap with each other is assumed, the mismatched pairs are arranged so that at least Ns+Nr-2 pairs of the mismatched pairs are included in the group, and for at least Ns+Nr-2 pairs of the mismatched pairs in the group, the mismatched pairs are arranged so that corresponding transmitting antennas and corresponding receiving antennas are arranged to form specific direction overlapping pairs whose positions overlap in a specific direction, and at least one specific direction non-overlapping pair whose corresponding transmitting antennas and / or corresponding receiving antennas are in non-overlapping positions in the specific direction is virtually formed, and the control unit acquires temperature information related to an internal temperature of the containing unit, Acquiring, for a plurality of reflectors, phase errors at least between different transmitting circuits and between different receiving circuits based on a comparison result of reflector information regarding the same reflector in the received signals of the virtual antennas in at least Ns+Nr-2 sets of overlapping pairs in the specific direction, and the phase errors based on the comparison result in the non-overlapping pairs in the specific direction;and estimating that an out-of-range reflector is a virtual image when the phase error based on the comparison result in the specific direction overlapping pair is within an allowable error range that is permissible depending on the temperature information, and when the phase error based on the comparison result in the specific direction non-overlapping pair is outside the allowable error range.

[0167] (Technical Idea 4) A radio communication system comprising: a plurality of transmitting antennas (TX) arranged at equal intervals and a plurality of receiving antennas (RX) arranged at equal intervals; Ns transmitting circuits (3) connected by wiring to the corresponding transmitting antennas to output transmitting signals; Nr receiving circuits (4) connected by wiring to the corresponding receiving antennas to acquire receiving signals; a housing unit (7) for housing the transmitting circuits and the receiving circuits; and a control unit (6) for outputting sensing data correlated with the receiving signals, wherein Ns and Nr are each integers of 2 or more, and the plurality of transmitting antennas and the plurality of receiving antennas virtually form a plurality of virtual antennas (V) assumed for each transmitting antenna according to a phase difference of the receiving signals between the receiving antennas for the plurality of receiving antennas, and for mismatched pairs, which are pairs of virtual antennas among the plurality of virtual antennas whose assumed virtual positions overlap and whose combinations of the transmitting circuit and the receiving circuit corresponding to the virtual antennas do not match among the virtual antennas, the group is arranged so that, assuming a group of mismatched pairs whose combination patterns of the transmitting circuit and the receiving circuit do not overlap with each other, the group includes at least Ns+Nr-2 pairs of mismatched pairs; and for pairs of virtual antennas among the plurality of virtual antennas whose virtual positions overlap and whose wiring lengths do not match, the group is arranged so that the total number of belonging pairs, which are pairs of virtual antennas belonging to at least one of the mismatched pairs and the different wiring length pairs included in the group, is at least Ns+Nr-1 pairs; and for the belonging pairs, the positions of the corresponding transmitting antennas and receiving antennas overlap in a specific direction, forming specific direction overlapping pairs, and the control unit is configured to acquire temperature information related to an internal temperature of the accommodation unit, ...a radar device configured to perform the following operations: acquiring, for a plurality of reflectors, a phase error between at least one of the different transmitting circuits and the receiving circuits based on a comparison result of reflector information regarding the same reflector in the received signals of the virtual antennas in at least Ns+Nr-1 sets of the specific direction overlapping pairs, and the phase error based on the comparison result in the specific direction non-overlapping pairs; and estimating that an out-of-range reflector, which is a reflector for which the phase error based on the comparison result in the specific direction overlapping pairs is within an allowable error range allowed according to the temperature information and the phase error based on the comparison result in the specific direction non-overlapping pairs is outside the allowable error range, is a virtual image.

[0168] (Technical Concept 5) The radar device according to any one of Technical Concepts 1 to 4, wherein the specific direction is a vertical direction.

[0169] (Technical Concept 6) The radar device according to any one of Technical Concepts 1 to 4, wherein the specific direction is a horizontal direction.

[0170] (Technical Idea 7) The multiple transmitting antennas and the multiple receiving antennas are arranged so that at least one orthogonal non-overlapping pair, which is a pair of virtual antennas in which at least one of the corresponding transmitting antennas and the corresponding receiving antennas are non-overlapping in an orthogonal direction orthogonal to the specific direction, and one orthogonal overlapping pair, which is a pair of virtual antennas in which the corresponding transmitting antennas and the corresponding receiving antennas are overlapping in the orthogonal direction, are formed virtually; and estimating that the out-of-range reflector is a virtual image includes estimating that the reflector in which the phase error based on the comparison result in the orthogonal overlapping pair is within the allowable error range and the phase error based on the comparison result in the orthogonal non-overlapping pair is outside the allowable error range is also the virtual image, according to any one of Technical Ideas 1 to 6.

[0171] (Technical Idea 8) The radar device according to any one of Technical Ideas 1 to 7, wherein the control unit is configured to output sensing data of the reflecting object excluding the virtual image.

Claims

1. A system comprising: a plurality of transmitting antennas (TX) and a plurality of receiving antennas (RX); Ns transmitting circuits (3) connected by wiring to the corresponding transmitting antennas to output transmitting signals; Nr receiving circuits (4) connected by wiring to the corresponding receiving antennas to acquire receiving signals; a housing unit (7) for housing the transmitting circuits and the receiving circuits; and a control unit (6) for outputting sensing data correlated with the receiving signals, wherein Ns and Nr are each an integer of 2 or more; at least one of the plurality of transmitting antennas and the plurality of receiving antennas is arranged at unequal intervals, and a plurality of virtual antennas (V) are virtually formed for each transmitting antenna according to the phase difference of the receiving signals between the receiving antennas for the plurality of receiving antennas; and for mismatched pairs, which are pairs of virtual antennas among the plurality of virtual antennas whose assumed virtual positions overlap and whose combinations of the transmitting circuit and the receiving circuit corresponding to the virtual antennas do not match among the virtual antennas, the group is arranged so that, assuming a group of mismatched pairs whose combination patterns of the transmitting circuit and the receiving circuit do not overlap with each other, the group includes at least Ns+Nr-2 pairs of mismatched pairs; and for pairs of virtual antennas among the plurality of virtual antennas whose virtual positions overlap and whose wiring lengths do not match, the group is arranged so that the total number of belonging pairs, which are pairs of virtual antennas belonging to at least one of the mismatched pairs and the different wiring length pairs included in the group, is at least Ns+Nr-1 pairs; and for the belonging pairs, the positions of the corresponding transmitting antennas and receiving antennas overlap in a specific direction, forming specific direction overlapping pairs, and the control unit is configured to acquire temperature information related to an internal temperature of the accommodation unit, ...a radar device configured to perform the following operations: acquiring, for a plurality of reflectors, a phase error between at least one of the different transmitting circuits and the receiving circuits based on a comparison result of reflector information regarding the same reflector in the received signals of the virtual antennas in at least Ns+Nr-1 sets of the specific direction overlapping pairs, and the phase error based on the comparison result in the specific direction non-overlapping pairs; and estimating that an out-of-range reflector, which is a reflector for which the phase error based on the comparison result in the specific direction overlapping pairs is within an allowable error range allowed according to the temperature information and the phase error based on the comparison result in the specific direction non-overlapping pairs is outside the allowable error range, is a virtual image.

2. A radio communication system comprising: a plurality of transmitting antennas (TX) and a plurality of receiving antennas (RX); Ns transmitting circuits (3) connected to the corresponding transmitting antennas and outputting transmitting signals; Nr receiving circuits (4) connected to the corresponding receiving antennas and acquiring receiving signals; a housing unit (7) housing the transmitting circuits and the receiving circuits; and a control unit (6) outputting sensing data correlated with the receiving signals, wherein Ns and Nr are integers of 2 or more; at least one of the plurality of transmitting antennas and the plurality of receiving antennas is arranged at unequal intervals, and a plurality of virtual antennas (V) are virtually formed for each of the transmitting antennas according to the phase difference of the receiving signals between the receiving antennas; and with respect to mismatched pairs, which are pairs of virtual antennas whose assumed virtual positions overlap among the plurality of virtual antennas and whose combinations of the transmitting circuits and the receiving circuits corresponding to the virtual antennas do not match, when a group of the mismatched pairs whose combination patterns of the transmitting circuits and the receiving circuits do not overlap with each other is assumed, the mismatched pairs are arranged so that at least Ns+Nr-2 pairs of the mismatched pairs are included in the group, and for at least Ns+Nr-2 pairs of the mismatched pairs in the group, the mismatched pairs are arranged so that corresponding transmitting antennas and corresponding receiving antennas are arranged to form specific direction overlapping pairs whose positions overlap in a specific direction, and at least one specific direction non-overlapping pair whose corresponding transmitting antennas and / or corresponding receiving antennas are in non-overlapping positions in the specific direction is virtually formed, and the control unit acquires temperature information related to an internal temperature of the containing unit, Acquiring, for a plurality of reflectors, phase errors at least between different transmitting circuits and between different receiving circuits based on a comparison result of reflector information regarding the same reflector in the received signals of the virtual antennas in at least Ns+Nr-2 sets of overlapping pairs in the specific direction, and the phase errors based on the comparison result in the non-overlapping pairs in the specific direction;and estimating that an out-of-range reflector is a virtual image when the phase error based on the comparison result in the specific direction overlapping pair is within an allowable error range that is permissible depending on the temperature information, and when the phase error based on the comparison result in the specific direction non-overlapping pair is outside the allowable error range.

3. A radio communication system comprising: a plurality of transmitting antennas (TX) arranged at equal intervals and a plurality of receiving antennas (RX) arranged at equal intervals; Ns transmitting circuits (3) connected to the corresponding transmitting antennas and outputting transmitted signals; Nr receiving circuits (4) connected to the corresponding receiving antennas and acquiring received signals; a housing unit (7) housing the transmitting circuits and the receiving circuits; and a control unit (6) outputting sensing data correlated with the received signals, wherein Ns and Nr are each integers of 2 or greater; and the plurality of transmitting antennas and the plurality of receiving antennas virtually form a plurality of virtual antennas (V) assumed for each transmitting antenna according to the phase difference of the received signals between the receiving antennas for the plurality of receiving antennas; and with respect to mismatched pairs, which are pairs of virtual antennas whose assumed virtual positions overlap among the plurality of virtual antennas and whose combinations of the transmitting circuits and the receiving circuits corresponding to the virtual antennas do not match, when a group of the mismatched pairs whose combination patterns of the transmitting circuits and the receiving circuits do not overlap with each other is assumed, the mismatched pairs are arranged so that at least Ns+Nr-2 pairs of the mismatched pairs are included in the group, and for at least Ns+Nr-2 pairs of the mismatched pairs in the group, the mismatched pairs are arranged so that corresponding transmitting antennas and corresponding receiving antennas are arranged to form specific direction overlapping pairs whose positions overlap in a specific direction, and at least one specific direction non-overlapping pair whose corresponding transmitting antennas and / or corresponding receiving antennas are in non-overlapping positions in the specific direction is virtually formed, and the control unit acquires temperature information related to an internal temperature of the containing unit, Acquiring, for a plurality of reflectors, phase errors at least between different transmitting circuits and between different receiving circuits based on a comparison result of reflector information regarding the same reflector in the received signals of the virtual antennas in at least Ns+Nr-2 sets of overlapping pairs in the specific direction, and the phase errors based on the comparison result in the non-overlapping pairs in the specific direction;and estimating that an out-of-range reflector is a virtual image when the phase error based on the comparison result in the specific direction overlapping pair is within an allowable error range that is permissible depending on the temperature information, and when the phase error based on the comparison result in the specific direction non-overlapping pair is outside the allowable error range.

4. A radio communication system comprising: a plurality of transmitting antennas (TX) arranged at equal intervals and a plurality of receiving antennas (RX) arranged at equal intervals; Ns transmitting circuits (3) connected by wiring to the corresponding transmitting antennas to output transmitting signals; Nr receiving circuits (4) connected by wiring to the corresponding receiving antennas to acquire receiving signals; a housing unit (7) for housing the transmitting circuits and the receiving circuits; and a control unit (6) for outputting sensing data correlated with the receiving signals, wherein Ns and Nr are each integers of 2 or more; and the plurality of transmitting antennas and the plurality of receiving antennas virtually form a plurality of virtual antennas (V) assumed for each transmitting antenna according to the phase difference of the receiving signals between the receiving antennas for the plurality of receiving antennas; and for mismatched pairs, which are pairs of virtual antennas among the plurality of virtual antennas whose assumed virtual positions overlap and whose combinations of the transmitting circuit and the receiving circuit corresponding to the virtual antennas do not match among the virtual antennas, the group is arranged so that, assuming a group of mismatched pairs whose combination patterns of the transmitting circuit and the receiving circuit do not overlap with each other, the group includes at least Ns+Nr-2 pairs of mismatched pairs; and for pairs of virtual antennas among the plurality of virtual antennas whose virtual positions overlap and whose wiring lengths do not match, the group is arranged so that the total number of belonging pairs, which are pairs of virtual antennas belonging to at least one of the mismatched pairs and the different wiring length pairs included in the group, is at least Ns+Nr-1 pairs; and for the belonging pairs, the positions of the corresponding transmitting antennas and receiving antennas overlap in a specific direction, forming specific direction overlapping pairs, and the control unit is configured to acquire temperature information related to an internal temperature of the accommodation unit, ...a radar device configured to perform the following operations: acquiring, for a plurality of reflectors, a phase error between at least one of the different transmitting circuits and the receiving circuits based on a comparison result of reflector information regarding the same reflector in the received signals of the virtual antennas in at least Ns+Nr-1 sets of the specific direction overlapping pairs, and the phase error based on the comparison result in the specific direction non-overlapping pairs; and estimating that an out-of-range reflector, which is a reflector for which the phase error based on the comparison result in the specific direction overlapping pairs is within an allowable error range allowed according to the temperature information and the phase error based on the comparison result in the specific direction non-overlapping pairs is outside the allowable error range, is a virtual image.

5. A radar device according to any one of claims 1 to 4, wherein the specific direction is a vertical direction.

6. A radar device according to any one of claims 1 to 4, wherein the specific direction is a horizontal direction.

7. The multiple transmitting antennas and the multiple receiving antennas are arranged so that at least one pair of orthogonal non-overlapping pairs, which are pairs of virtual antennas in which at least one of the corresponding transmitting antennas and one of the corresponding receiving antennas are non-overlapping in an orthogonal direction orthogonal to the specific direction, and one orthogonal overlapping pair, which are pairs of virtual antennas in which the corresponding transmitting antennas and one of the corresponding receiving antennas are overlapping in the orthogonal direction, are formed virtually; and estimating that the out-of-range reflector is a virtual image includes estimating that the reflector in which the phase error based on the comparison result in the orthogonal overlapping pair is within the allowable error range and the phase error based on the comparison result in the orthogonal non-overlapping pair is outside the allowable error range is also the virtual image.

8. A radar device according to any one of claims 1 to 4, wherein the control unit is configured to output sensing data of the reflecting object excluding the virtual image.

Images