Vehicle-mounted radar system

Abstract

To provide an on-vehicle radar device capable of preventing low-accuracy three-dimensional object information from being provided to other devices.SOLUTION: An on-vehicle radar device 1 is configured to obtain a stationary reflection point information set SIS consisting of stationary reflection point information SI related to each reflection point that is stationary around the own vehicle in the reflection points of the radio waves on the basis of the physical quantities of the radio waves radiated and the radio waves received by a transmission / reception device, and, if the similarity SIM between the first stationary reflection point information set acquired at the first time point before the time point at which an ignition switch transitions from the ON state to the OFF state after the own vehicle stops and the second stationary reflection point information set acquired at the second time point after the time point at which the ignition switch transitions from the OFF state back to the ON state but before the own vehicle starts moving is less than or equal to a threshold value SIMth, does not provide three-dimensional object information to other devices until a prescribed condition is satisfied after the own vehicle starts moving.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an in-vehicle radar device that acquires information on a three-dimensional object existing around a host vehicle.

Background Art

[0002] An in-vehicle radar device that acquires information on a three-dimensional object existing around a host vehicle has been proposed (see, for example, Patent Document 1 below). This in-vehicle radar device (hereinafter referred to as the "conventional device") includes a transmission / reception device and a processor. The transmission / reception device emits radio waves (radio waves in the millimeter wave band) into a predetermined area centered on a radar beam axis extending from the host vehicle in a predetermined direction, and receives the radio waves reflected by a three-dimensional object located within the predetermined area. The processor acquires three-dimensional object information representing the position, speed, etc. of the three-dimensional object with respect to the host vehicle based on physical quantities related to the emitted radio waves and the received radio waves (reflected waves). This three-dimensional object information is provided to, for example, a driving support device. The driving support device executes various driving support controls (such as adaptive cruise control (ACC), lane tracing assistant (LTA), etc.) based on the three-dimensional object information.

[0003] Further, in a situation where the host vehicle is traveling straight, the processor acquires, among the reflection points of the radio waves, the direction (the angle θ between the straight line passing through one end (the end point on the host vehicle side) of the radar beam axis and the reflection point and the radar beam axis) of a reflection point that is stationary around the host vehicle (stationary reflection point), the distance d between one end of the radar beam axis and the stationary reflection point, and the relative speed Vs (the rate of change of the distance d). The processor calculates the deviation amount of the actual radar beam axis from the designed radar beam axis (hereinafter referred to as the "axis deviation amount") based on the speed Vh of the host vehicle, the angle θ, and the relative speed Vs. The processor corrects the three-dimensional object information based on the acquired axis deviation amount. The processor provides the corrected three-dimensional object information to the driving support device.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Patent Publication No. 2002-228749 [Overview of the Initiative]

[0005] The conventional device described above detects the amount of misalignment based on speed Vh, angle θ, and relative speed Vs. Therefore, it is not possible to obtain the amount of misalignment when the vehicle is stationary (parked). However, there is a risk that the radar beam axis may be displaced (increase or decrease in misalignment) due to some factor while the vehicle is stationary. The processor of the conventional device described above cannot update the amount of misalignment from the time the vehicle starts moving until the vehicle is moving straight. Even if the radar beam axis is displaced while the vehicle is stationary (parked), this displacement of the radar beam axis is not reflected in the amount of misalignment immediately after the vehicle starts moving. In this case, the accuracy of the 3D object information may be low due to the low accuracy of the amount of misalignment. If such low-accuracy 3D object information is provided from the conventional device to the driver assistance system, and driver assistance is performed based on this 3D object information, the safety of the vehicle may be reduced.

[0006] One of the objectives of the present invention is to provide an in-vehicle radar device that can suppress the provision of low-accuracy three-dimensional object information to other devices.

[0007] To solve the above problems, the in-vehicle radar device (1) of the present invention is: A transmitting and receiving device (10) that emits radio waves into a predetermined area (A) centered on a radar beam axis (AX) extending in a predetermined direction from the vehicle, and receives radio waves reflected by a three-dimensional object located within the predetermined area, A processor (20) that acquires three-dimensional object information relating to a three-dimensional object located within a predetermined area based on physical quantities relating to the emitted radio waves and the received radio waves, It is equipped with. The aforementioned processor, Based on the aforementioned physical quantities, it is possible to obtain a set of stationary reflection point information consisting of stationary reflection point information (SI) for each stationary reflection point (SP) among the reflection points of the radio waves that are stationary around the vehicle. The system is configured such that, if the similarity (SIM) between the first static reflection point information set (SIS1), acquired at a first time point before the ignition switch transitions from the ON state to the OFF state after the vehicle has stopped, and the second static reflection point information set (SIS2), acquired at a second time point after the ignition switch transitions from the OFF state back to the ON state but before the vehicle starts moving, is less than or equal to a threshold (SIMth), the system will not provide the three-dimensional object information to other devices until a predetermined condition is met.

[0008] The processor of the vehicle radar system according to the present invention obtains the similarity between a first set of stationary reflection point information acquired before the vehicle's ignition switch transitions to the off state and a second set of stationary reflection point information acquired after the ignition switch transitions to the on state. If the similarity is relatively low (below a threshold), it is highly likely that the radar beam axis has been displaced while parked. In this case, the processor does not provide the three-dimensional object information to other devices (e.g., driver assistance devices) until predetermined conditions (conditions for determining that highly accurate three-dimensional object information has been obtained) are met. In other words, according to the present invention, it is possible to suppress the provision of low-accuracy three-dimensional object information to other devices.

[0009] In an in-vehicle radar device according to one aspect of the present invention, The aforementioned processor, Prior to the aforementioned first time point, the deviation of the actual position and attitude of the radar beam axis from the design-standard position and attitude of the radar beam axis relative to the vehicle body is obtained. If the similarity exceeds the threshold, the three-dimensional object information is corrected based on the deviation amount, and the corrected three-dimensional object information is provided to other devices when the vehicle starts moving.

[0010] If the similarity is relatively high (exceeds the threshold), it is highly likely that the radar beam axis has not shifted during parking. In other words, the deviation amount acquired before parking is equivalent to the deviation amount at the time the vehicle starts moving. Therefore, the processor corrects the 3D information based on the deviation amount acquired before parking and provides the corrected 3D information to other devices at the time the vehicle starts moving. In other words, in this case, highly accurate 3D information is provided to other devices at the time the vehicle starts moving.

[0011] In an in-vehicle radar device according to one aspect of the present invention, The aforementioned processor, During the period in which the vehicle is in motion, the deviation amount is acquired based on information regarding the vehicle's behavior and information regarding the reflection point.

[0012] As is well known, the deviation amount can be acquired using a predetermined calibration device while the vehicle is stationary, but this operation is complicated. According to this embodiment, the deviation amount is automatically acquired while the vehicle is in motion, so the complicated operation described above is unnecessary.

[0013] In an in-vehicle radar device according to one aspect of the present invention, The processor, when the similarity is below the threshold, controls the vehicle's notification device to provide the driver with information indicating that the radar beam axis has been displaced.

[0014] According to this, the operator or repair person can be prompted to correct the mounting position and orientation of the transmitting and receiving device, or to manually obtain the amount of shaft misalignment (for example, by obtaining the amount of shaft misalignment using a predetermined calibration device).

[0015] In another embodiment of the present invention, in an in-vehicle radar device, The aforementioned physical quantity includes the intensity of radio waves received by the transmitting and receiving device.

[0016] The reflectivity of radio waves correlates with the material that constitutes the surface of a three-dimensional object. According to the present invention, information regarding a three-dimensional object (such as the type of the three-dimensional object, the boundary of adjacent three-dimensional objects, etc.) can be detected with higher precision based on the intensity of the reflected wave.

Brief Description of the Drawings

[0017] [Figure 1] FIG. 1 is a block diagram of an in-vehicle radar device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view showing an example of a method for obtaining the amount of shaft misalignment under the situation where the host vehicle is moving straight. [Figure 3] FIG. 3 is a flowchart of a program for obtaining the amount of shaft misalignment during the period when the host vehicle is moving straight. [Figure 4] FIG. 4 is a flowchart of a program for obtaining a stationary reflection point information set when the host vehicle stops. [Figure 5] FIG. 5 is a flowchart of a program for detecting whether the radar beam axis has been displaced during parking. [Figure 6] FIG. 6 is a flowchart of a program for determining whether to provide three-dimensional object information to another device.

Modes for Carrying Out the Invention

[0018] (Schematic) An in-vehicle radar device 1 according to an embodiment of the present invention is mounted on a vehicle V1 (host vehicle) having an automatic driving function. The in-vehicle radar device 1 acquires information (solid object information) regarding a solid object OB located within a predetermined region A centered on a predetermined radar beam axis AX extending forward of the host vehicle. The solid object information is provided to other devices mounted on the host vehicle. The solid object information is provided to, for example, an ECU of a driving support device, and the ECU can execute various driving supports based on the solid object information. Further, the in-vehicle radar device 1 has a function (axis deviation correction function) of acquiring a deviation amount (hereinafter referred to as "axis deviation amount ΔAX") of the actual position and orientation of the radar beam axis AX from a reference axis BA (designed position and orientation of the radar beam axis AX), and correcting the solid object information based on the axis deviation amount ΔAX.

[0019] (Specific Configuration) As shown in FIG. 1, the in-vehicle radar device 1 includes a transmission / reception device 10 and a signal processing device 20.

[0020] The transmission / reception device 10 includes a synthesizer, a transmission antenna, and a reception antenna. The synthesizer generates and outputs a modulated wave signal. The transmission antenna and the reception antenna are arranged at the center of the front surface of the host vehicle (for example, the back side of the emblem). The transmission antenna radiates the modulated wave signal output from the synthesizer as a radio wave to a substantially conical region A extending forward of the host vehicle. The reception antenna receives a radio wave (reflected wave) reflected by a solid object located within the region A. The reception antenna provides a signal representing the received reflected wave to the signal processing device 20.

[0021] The frequency of this radio wave belongs to the millimeter wave band. In the following explanation, the central axis of region A will be referred to as the "radar beam axis AX". At the vehicle's production plant, the transceiver 10 is mounted on the vehicle such that the apex of region A (one end of the radar beam axis AX) coincides with the center of the front of the vehicle (hereinafter referred to as the "origin O") and is parallel (horizontal) to the longitudinal direction of the vehicle (i.e., it matches the design position and orientation). Due to vibrations, shocks, etc. that occur during driving after the vehicle is shipped from the production plant, the deviation of the actual position and orientation of the radar beam axis AX from the design position and orientation (reference axis BA) fluctuates.

[0022] The signal processing unit 20 includes a microcomputer equipped with a CPU 20a, ROM 20b (flash ROM), RAM 20c, timer 20d, etc. The signal processing unit 20 is connected to other ECUs (for example, ECUs that perform driver assistance functions such as ACC and LTA (hereinafter referred to as "driver assistance ECUs")) in the vehicle via a communication line (or bus) such as CAN.

[0023] Furthermore, the signal processing device 20 is connected to the speed sensor S1 and the steering angle sensor S2 via a communication line. The signal processing device 20 acquires the vehicle's speed Vh and steering angle SA from the speed sensor S1 and the steering angle sensor S2, respectively. The signal processing device 20 is also connected to the ignition switch device S3 via a communication line. The signal processing device 20 acquires the on / off state of the ignition switch from the ignition switch device S3. The signal processing device 20 may also acquire the speed Vh, steering angle SA, and the on / off state of the ignition switch from the driver assistance ECU.

[0024] (Operation) The signal processing device 20 acquires information about each reflection point P (reflection point information PI) based on information (physical quantities related to radio waves) consisting of the time from when the transmitting / receiving device 10 emits radio waves (transmitted waves) until it receives the reflected waves, the phase difference between the transmitted waves and the reflected waves, the intensity (attenuation level) of the reflected waves, the wavelength of the reflected waves, and the frequency spectrum of the composite wave of the transmitted and reflected waves. Each reflection point information PI is three-dimensional information consisting of the angle θ between the radar beam axis AX and the line passing through one end of the radar beam axis AX and the reflection point P, the distance d between one end of the radar beam axis AX and the reflection point P, and the relative velocity Vs (rate of change of distance d).

[0025] When the vehicle's ignition switch is ON, the signal processing device 20 acquires a set of reflection point information PIS, which consists of multiple reflection point information PI corresponding to each reflection point P. Based on the reflection point information set PIS, the signal processing device 20 sequentially acquires three-dimensional object information (type of object, position, speed, etc.) which is information about three-dimensional objects located around the vehicle. Furthermore, as described below, while the vehicle is in motion, the signal processing device 20 sequentially acquires the axle misalignment amount ΔAX and corrects the three-dimensional object information based on the axle misalignment amount ΔAX. The signal processing device 20 then provides the corrected three-dimensional object information to other devices such as the driver assistance ECU.

[0026] Next, the axis misalignment correction function of the on-board radar device 1 will be described. The on-board radar device 1, while the vehicle is in motion, sequentially acquires (updates) the axis misalignment amount ΔAX, similar to the device in Patent Document 1. That is, when the vehicle's ignition switch is ON, the signal processing device 20 acquires the speed Vh and steering angle SA from the speed sensor S1 and steering angle sensor S2 at predetermined intervals. The signal processing device 20 determines that the vehicle is moving in a straight line when the speed Vh exceeds the threshold Vhth and the steering angle SA is less than or equal to the threshold SAth. In this case, the signal processing device 20 identifies a stationary reflection point P (hereinafter referred to as "stationary reflection point SP") relative to the ground based on the reflection point information set PIS. Next, the signal processing device 20 calculates the amount of axial misalignment ΔAX based on the direction of each stationary reflection point SP (the angle θ between the radar beam axis AX and the line passing through one end of the radar beam axis AX and the stationary reflection point SP, and the radar beam axis AX) and the relative velocity Vs (the rate of change of the distance d between one end of the radar beam axis AX and the stationary reflection point SP), as described below.

[0027] For example, the signal processing device 20 acquires the axial misalignment amount ΔAX (angle deviation in a plan view) as shown below. Figure 2(A) shows a situation where the stationary reflection point SP is located diagonally to the right and in front of the vehicle, and the radar beam axis AX coincides with the reference axis BA. In this example, the following equation (1) holds true. Vs = Vh × cosθ 1 ···(1) On the other hand, Figure 2(B) shows a situation where the stationary reflection point SP is in the same position as in Figure 2(A), and the radar beam axis AX is tilted diagonally forward to the left. As shown in the figure, even if the radar beam axis AX is deviated from the reference axis BA, the relative velocity Vs obtained based on the physical quantities related to radio waves is the same as when the radar beam axis AX coincides with the reference axis BA (Figure 2(A)). That is, in the example shown in Figure 2(B), the angle θ2 is greater than the angle θ1, but the relative velocity Vs is the same as in the example shown in Figure 2(A). Therefore, the following equation (2) holds. Vh×cos(θ2−ΔAX)=Vs (2) Based on equation (2), the axial displacement ΔAX is obtained (see equation (3) below). ΔAX=θ2−ArcCos(Vs / Vh) ···(3)

[0028] In the examples shown in Figures 2(A) and 2(B), one end of the radar beam axis AX coincides with the origin O. The signal processing device 20 can acquire the deviation of the radar beam axis AX from the origin O using the same method as conventional devices. Alternatively, the signal processing device 20 may acquire the axial deviation amount ΔAX using, for example, the method disclosed in Japanese Patent Application Publication No. 2018-54315.

[0029] Next, we will explain the function for detecting whether the radar beam axis AX has shifted during the period when the vehicle is stationary (parked). When the signal processing device 20 detects that the speed Vh is "0", it stores (writes to ROM 10b) the latest axis displacement amount ΔAX acquired before the first time point. Furthermore, at the first time point, the signal processing device 20 acquires information (hereinafter referred to as "stationary reflection point information SI") regarding multiple stationary reflection points SP whose distance d from the vehicle exceeds a threshold dth (for example, 50 centimeters). The signal processing device 20 then stores this stationary reflection point information SI as a stationary reflection point information set SIS1.

[0030] Subsequently, when the signal processing device 20 detects that the vehicle's ignition switch has transitioned to the off state and then back to the on state, it acquires a set of stationary reflection point information SIS2 at that second time point, which consists of stationary reflection point information SI relating to multiple stationary reflection points SP whose distance d from the vehicle exceeds a threshold dth (for example, 50 centimeters).

[0031] The signal processing device 20 calculates the similarity SIM between the stationary reflection point information set SIS1 and the stationary reflection point information set SIS2. Specifically, the signal processing device 20 calculates the cosine similarity for all combinations of each stationary reflection point information SI constituting the stationary reflection point information set SIS1 and each stationary reflection point information SI constituting the stationary reflection point information set SIS2, and obtains the sum of these cosine similarities as the similarity SIM. If the similarity SIM is less than or equal to the threshold SIMth, the signal processing device 20 determines that the radar beam axis AX was displaced (the axis misalignment amount ΔAX changed) between the first and second time points (while parked). In this case, the signal processing device 20 does not provide the 3D object information to the driving assistance system until the third time point when the vehicle can move straight and update the axis misalignment amount ΔAX. Therefore, driving assistance is prohibited during this period (the time period spanning from the second to the third time point). On the other hand, if the similarity SIM exceeds the threshold SIMth, the signal processing device 20 determines that the radar beam axis AX has not been displaced (the axis misalignment amount ΔAX has not changed) between the first and second time points (while parked). In this case, at the second time point, the signal processing device 20 acquires the three-dimensional object information and corrects the three-dimensional object information based on the stored axis misalignment amount ΔAX. The signal processing device 20 then provides the corrected three-dimensional object information to the driving assistance system. Therefore, driving assistance is performed immediately after the ignition switch is turned ON (second time point). The threshold SIMth corresponds to the lower limit of the similarity SIM at which driving assistance can be safely performed, and this lower limit is determined experimentally.

[0032] Next, referring to Figures 3 to 6, we will describe programs PR1 to PR4, which are executed by the CPU 20a (hereinafter simply referred to as "CPU") to realize the above-mentioned transmission support function. The CPU executes each program in parallel. When the CPU finishes executing each program, it starts executing each program again. A flag F is used in these programs. Flag F indicates whether or not 3D object information can be provided to the driver assistance system. When flag F is "0", the CPU cannot provide 3D object information to the driver assistance system. When flag F is "1", the CPU can provide 3D object information to the driver assistance system. At the time the vehicle is shipped from the production plant, flag F is set to "1".

[0033] (Program PR1) The CPU starts executing program PR1 from step 100 and proceeds to step 101.

[0034] In step 101, the CPU determines whether the vehicle's speed Vh exceeds the threshold Vhth. If the CPU determines that the speed Vh exceeds the threshold Vhth (101: Yes), it proceeds to step 102. On the other hand, if the CPU does not determine that the speed Vh exceeds the threshold Vhth (101: No), it proceeds to step 106 and terminates the execution of program PR1.

[0035] In step 102, the CPU determines whether the steering angle SA is less than or equal to the threshold SAth. If it determines that the steering angle SA is less than or equal to the threshold SAth (i.e., the vehicle is moving straight) (102: Yes), the process proceeds to step 103. On the other hand, if the CPU does not determine that the steering angle SA is less than or equal to the threshold SAth (102: No), the process proceeds to step 106 and the execution of program PR1 ends.

[0036] In step 103, the CPU obtains the axial misalignment amount ΔAX. Next, the CPU proceeds to step 104.

[0037] In step 104, the CPU stores the axial misalignment amount ΔAX in ROM 20b. Next, the CPU proceeds to step 105.

[0038] In step 105, the CPU sets flag F to "1". Next, the CPU proceeds to step 106 and terminates the execution of program PR1. If flag F was "1" when the CPU started step 105, the CPU proceeds to step 106 with flag F still set to "1".

[0039] (Program PR2) The CPU starts executing program PR2 from step 200 and proceeds to step 201.

[0040] In step 201, the CPU determines whether the vehicle's speed Vh is "0". If the CPU determines that the speed Vh is "0" (i.e., the vehicle is stopped) (201: Yes), it proceeds to step 202. On the other hand, if the CPU does not determine that the speed Vh is "0" (201: No), it returns to step 201.

[0041] In step 202, the CPU acquires the stationary reflection point information set SIS1. Next, the CPU proceeds to step 203.

[0042] In step 203, the CPU stores the stationary reflection point information set SIS1 in ROM 10b. Thus, when the CPU detects that its vehicle has stopped, it acquires the stationary reflection point information set SIS1 and stores it in ROM 10b before the ignition switch transitions to the off state. Next, the CPU proceeds to step 204 and terminates the execution of program PR2.

[0043] (Program PR3) The CPU starts executing program PR3 from step 300 and proceeds to step 301.

[0044] In step 301, the CPU determines whether the vehicle's ignition switch is in the off state. If the CPU determines that the ignition switch is in the off state (301: Yes), it proceeds to step 302. On the other hand, if the CPU does not determine that the ignition switch is in the off state (301: No), it returns to step 301.

[0045] In step 302, the CPU determines whether the vehicle's ignition switch is in the ON position. If the CPU determines that the ignition switch is in the ON position (302: Yes), it proceeds to step 303. On the other hand, if the CPU does not determine that the ignition switch is in the ON position (302: No), it returns to step 302.

[0046] In step 303, the CPU acquires the stationary reflection point information set SIS2. Next, the CPU proceeds to step 304.

[0047] In step 304, the CPU reads the stationary reflection point information set SIS1 from ROM10b and calculates the similarity SIM between the stationary reflection point information set SIS1 and the stationary reflection point information set SIS2. Next, the CPU proceeds to step 305.

[0048] In step 305, the CPU determines whether the similarity SIM is less than or equal to the threshold SIMth. If the CPU determines that the similarity SIM is less than or equal to the threshold SIMth (i.e., the similarity is relatively low) (305: Yes), it proceeds to step 306. On the other hand, if the CPU does not determine that the similarity SIM is less than or equal to the threshold SIMth (305: No), it proceeds to step 307.

[0049] In step 306, the CPU sets flag F to "0". Then, in step 307, the CPU sets flag F to "1". Next, the CPU proceeds to step 308 and terminates the execution of program PR3.

[0050] (Program PR4) The CPU starts executing program PR4 from step 400 and proceeds to step 401.

[0051] In step 401, the CPU acquires three-dimensional object information based on the information (reflection point information set PIS) obtained from the transmitting / receiving device 10. Next, the CPU proceeds to step 402.

[0052] In step 402, the CPU determines whether flag F is "1". Flag F is set to "0" or "1" during the execution of programs PR1 and PR3. If the CPU determines that flag F is "1" (402: Yes), it proceeds to step 403. On the other hand, if the CPU does not determine that flag F is "1" (402: No), it proceeds to step 405.

[0053] In step 403, the CPU reads the axial displacement amount ΔAX from ROM 10b and corrects the 3D object information based on this axial displacement amount ΔAX. Next, the CPU proceeds to step 404.

[0054] In step 404, the CPU provides the 3D object information to the driver assistance system. Next, the CPU proceeds to step 406 and terminates the execution of program PR4. Alternatively, if the CPU proceeds from step 403 to step 405, it proceeds to step 406 without providing the 3D object information to the driver assistance system and terminates the execution of program PR4.

[0055] (effect) The signal processing device 20 of the in-vehicle radar device 1 acquires a similarity SIM between the stationary reflection point information set SIS1 acquired before the vehicle's ignition switch transitions to the off state and the stationary reflection point information set SIS2 acquired after the ignition switch transitions to the on state. If the similarity SIM is relatively low (below the threshold SIMth), it is highly likely that the radar beam axis AX has been displaced while parked. In this case, the signal processing device 20 does not provide the 3D object information to other devices (e.g., driver assistance devices) until a predetermined condition is met (the vehicle moves straight and the axis displacement amount ΔAX is updated). In other words, according to this embodiment, it is possible to suppress the provision of low-accuracy 3D object information to other devices.

[0056] If the similarity SIM is relatively high (exceeding the threshold SIMth), it is highly likely that the radar beam axis AX has not shifted during parking. In other words, the amount of axis misalignment ΔAX acquired before parking is equivalent to the amount of axis misalignment ΔAX at the time the vehicle starts moving. Therefore, the signal processing device 20 corrects the 3D object information based on the amount of axis misalignment ΔAX acquired before parking and provides the corrected 3D object information to other devices at the time the vehicle starts moving. In other words, in this case, highly accurate 3D object information is provided to other devices at the time the vehicle starts moving.

[0057] The present invention is not limited to the embodiments described above, and various modifications can be adopted within the scope of the present invention.

[0058] (Variation 1) In the above embodiment, when acquiring the axial misalignment amount ΔAX, the signal processing device 20 determines whether the vehicle is moving in a straight line based on the information acquired from the steering angle sensor S2. Alternatively (or in addition to this), the signal processing device 20 may determine whether the vehicle is moving in a straight line based on information acquired from an acceleration sensor, a yaw rate sensor, or the like.

[0059] (Modification 2) The signal processing device 20 may, based on the similarity SIM, notify the driver if it detects that there is a high probability that the radar beam axis AX has shifted while the vehicle is parked. In this case, the signal processing device 20 will, in principle, not provide the 3D object information to other devices. Subsequently, if predetermined conditions are met, the signal processing device 20 will be able to provide the 3D object information to other devices. For example, the above predetermined conditions are met when the driver or repair person corrects the mounting position and orientation of the transceiver 10 so that the radar beam axis AX aligns with the reference axis BA, and manually sets the flag F to "1" using a predetermined device. Alternatively, for example, the above predetermined conditions are met when the driver or repair person acquires the axis misalignment amount ΔAX using a predetermined calibration device (a radio wave reflector installed in a predetermined position) while the vehicle is parked, and manually sets the flag F to "1" using the same predetermined device.

[0060] (Variation 3) The signal processing device 20 may calculate the displacement amount ΔAXP of the radar beam axis AX that occurred during parking based on the similarity SIM. The signal processing device 20 may then correct the three-dimensional object information by adding the displacement amount ΔAXP to the axis misalignment amount ΔAX acquired before parking, and provide the corrected three-dimensional object information to other devices when the vehicle starts moving. [Explanation of symbols]

[0061] 1... Vehicle-mounted radar device, 10... Transmitter / receiver device, 20... Signal processing device

Claims

1. A transmitting and receiving device that emits radio waves in a predetermined area centered on a radar beam axis extending in a predetermined direction from the vehicle, and receives radio waves reflected by a three-dimensional object located within the predetermined area, A processor that acquires three-dimensional object information relating to a three-dimensional object located within a predetermined area based on physical quantities relating to the emitted radio waves and the received radio waves, An in-vehicle radar system equipped with, The aforementioned processor, Based on the aforementioned physical quantity, it is possible to obtain a set of stationary reflection point information consisting of stationary reflection point information for each of the radio wave reflection points that are stationary around the vehicle. The system is configured such that, if the similarity between the first set of stationary reflection point information acquired at a first time point before the ignition switch transitions from the ON state to the OFF state after the vehicle has stopped, and the second set of stationary reflection point information acquired at a second time point after the ignition switch transitions from the OFF state back to the ON state, but before the vehicle starts moving, is below a threshold, the system will not provide the three-dimensional object information to other devices until a predetermined condition is met. Vehicle-mounted radar system.

2. In the vehicle-mounted radar device according to claim 1, The aforementioned processor, Prior to the aforementioned first time point, the deviation of the actual position and attitude of the radar beam axis from the design-standard position and attitude of the radar beam axis relative to the vehicle body is obtained. If the similarity exceeds the threshold, the three-dimensional object information is corrected based on the deviation amount, and the corrected three-dimensional object information is provided to another device when the vehicle starts moving. Vehicle-mounted radar system.

3. In the vehicle-mounted radar device according to claim 2, The aforementioned processor, The system is configured to acquire the deviation amount based on information regarding the vehicle's behavior and information regarding the reflection point during the period in which the vehicle is in motion. Vehicle-mounted radar system.

4. In the vehicle-mounted radar device according to claim 1, An in-vehicle radar system configured such that, when the similarity is below the threshold, the processor controls a notification device provided by the vehicle to present information to the driver indicating that the radar beam axis has been displaced.

5. In an in-vehicle radar device according to any one of claims 1 to 3, An on-board radar system in which the physical quantity includes the intensity of radio waves received by the transmitting and receiving device.

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