JP2011117800A - Device for inspecting onboard radar and method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for inspecting an onboard radar and a method therefor which can make a driver to easily inspect deviation of the direction of transmission or reception of the onboard radar and operation thereof at a gas station or in a multistory parking space. <P>SOLUTION: There are provided the device for inspecting the onboard radar and the method therefor, wherein the relative directions of a retroreflector 2 and the onboard radars 12 and 13 are changed by a vehicle turntable 8 which turns the vehicle 1 around, to inspect operations of the onboard radars attached respectively to a plurality of places out of the front, the rear, obliquely front places on the right and the left, obliquely rear places on the right and the left and lateral places on the right and the left of the vehicle. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an in-vehicle radar inspection apparatus and method for inspecting an in-vehicle UWB radar or millimeter wave radar.

  In recent years, on-vehicle radar technology has been developed, and accordingly, vehicles equipped with radar have become widespread. There are two types of in-vehicle radars: millimeter wave radar for forward tracking and UWB radar for approaching vehicle warning and parking assistance. The on-board radar detects obstacles and prompts warnings in advance to prevent traffic accidents, reduce damage in the event of a collision, and support driving by drivers such as parking assistance and driving following the vehicle. There is expected. Since the in-vehicle radar is mainly mounted inside the bumper or the front grille, it is likely to receive an impact from the outside, and the function of the radar may be impaired or the transmission or reception direction may be shifted. The deviation in the transmission or reception direction of the antenna caused by an impact or the like does not correctly radiate the radar signal in the direction of the vehicle center axis, so that the standard of the front direction is different and an error occurs in the detected direction.

  In the millimeter wave radars that have become widespread these days, if the transmission or reception direction of the antenna does not indicate the correct direction, it is possible to follow the vehicle in the adjacent lane, causing an accident. It must face in the direction of the central axis. In addition, UWB radar, which is expected to become popular in the future, enables detection with higher accuracy than conventional radar technology. A radar system using a UWB radar detects various obstacles such as vehicles and humans over a wide angle at a short distance, and mainly aims to support safe driving. Applications include rear collision warning and parking assistance for rear monitoring, blind spot assistance and lane change assistance for radars at an angle, and side impact mitigation for side monitoring radars. Each radar system is considered to be affected by external impacts like the millimeter wave radar, and the operation of each radar needs to be inspected. Such misdetection due to a shift in transmission / reception direction or a failure may cause a traffic accident, and thus inspection is required to maintain normal operation of the in-vehicle radar system.

  In the conventional on-vehicle radar aim adjustment inspection device and the aim adjustment inspection method (Japanese Patent Application Laid-Open No. 2004-69658-Patent Document 1), a method of performing on-vehicle radar aim adjustment using laser light is described. A mechanism for attaching the mirror jig to the radar is required. In another transmission direction deviation detection device (Japanese Patent Laid-Open No. 2000-329853-Patent Document 2), it is described that a deviation in the transmission direction of a laser radar is detected using a laser reflector. The method for measuring the relative position is not described. Further, a test simulator for a collision prevention radar system (Japanese Patent Laid-Open No. 2001-517301-Patent Document 3) provides means for testing an operation of a high frequency unit for testing a millimeter wave radar in a factory. It was complicated, including a wave transceiver, and could not be used for simple inspection.

  Conventionally, a radar antenna alignment inspection apparatus for irradiating a radar in the vehicle central axis direction has been proposed as a positioning system and positioning method in Japanese Patent Laid-Open No. 2005-331353 (Patent Document 4). The normal direction of the beam axis 21 of the millimeter wave radar 20 is specified based on a planar image captured by the imaging device 25 from above the vehicle 1, and the normal direction of the beam axis 21 and the incident surface 22 of the target 23 are orthogonal to each other. As described above, a method is described in which the target 23 is moved and rotated along the rail 25 by the moving unit 24 and compared, and the beam shaft 21 is positioned. A radar inspection apparatus and method for irradiating diagonally forward, diagonally rearward, and laterally left and right are not known.

JP 2004-69658 A JP 2000-329853 A JP 2001-517301 A JP-A-2005-331353

  The present invention has been made in view of the above-described problems of the prior art, and an in-vehicle radar inspection device and a method for enabling a driver to easily inspect the transmission and reception direction deviation and operation of the in-vehicle radar in a gas station, a multi-story parking lot, and the like. It aims to provide a method.

  One feature of the present invention is that the relative direction of the retro-reflector and the in-vehicle radar is changed by a vehicle turntable that rotates the vehicle, and the front, rear, left and right diagonal front, left and right diagonal rear, and left and right side of the vehicle, respectively. The in-vehicle radar inspection apparatus and the method for inspecting the operation of the in-vehicle radar attached at a plurality of locations.

  Another feature of the present invention is that the relative direction between the retro-reflector and the in-vehicle radar is changed by rotating the retro-reflector around the vehicle stopped at a predetermined position. An in-vehicle radar inspection apparatus and method for inspecting the operation of an in-vehicle radar attached to a plurality of locations in the front, left and right diagonally rear and left and right sides.

  In the above-mentioned invention, it is provided with a notification device, and the inspection of the on-vehicle radar is started at each of a plurality of positions of the front of the vehicle, the rear, the left and right diagonal front, the left and right diagonal rear and the left and right sides for the driver. In addition, the fact that the operation is judged to be normal or abnormal can be notified by text display, sound, video, or a combination thereof.

  Moreover, in the said invention, a 2 surface corner reflector, a 3 surface corner reflector, or a Luneberg lens can be utilized as a retroreflector.

  According to the vehicle-mounted radar inspection apparatus and method of the present invention, the vehicle-mounted radars installed at a plurality of locations in the vehicle front direction, the rear, the left and right diagonally forward, the left and right diagonally rear, or the left and right sides are separated by a single retroreflector. In addition, the single retro-reflector can be easily inspected with a scan that makes one relative rotation around the vehicle.

The block diagram of the vehicle-mounted radar inspection apparatus of the 1st Embodiment of this invention. The block diagram of the vehicle-mounted radar inspection apparatus of the 2nd Embodiment of this invention. The block diagram of the vehicle-mounted radar inspection apparatus of the 3rd Embodiment of this invention. The block diagram of the vehicle-mounted radar inspection apparatus of the 4th Embodiment of this invention. Explanatory drawing of the center axis detection method of the vehicle in the 3rd, 4th embodiment of this invention. The block diagram of a prior art example.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
As shown in FIG. 1, the vehicle 1 is provided with UWB radars 12 for confirming safe driving and safe driving on the front left and right and rear left and right respectively. For this purpose, a millimeter wave radar 13 is installed.

  The on-vehicle radar inspection apparatus for the radar-equipped vehicle 1 includes a turntable 8 that rotates the vehicle 1 mounted thereon, a single retroreflector 2 that is installed at a close position outside the periphery of the turntable 8, An informing device 3 that informs the driver in the vehicle 1 to start the inspection of the in-vehicle radars 12 and 13 and to determine whether the operation is normal or abnormal by text display, voice, video, or a combination thereof. And a control device 4 that controls the rotation of the turntable 8 and the operation of the notification device 3.

  The retro-reflector 2 is installed at the height of the bumper or front grill of the vehicle 1 where the on-vehicle radars 12 and 13 are installed. The retro-reflector 2 functions to reflect radio waves, electromagnetic waves, and light incident thereon in a direction opposite to the direction in which it is incident, for example, a two-sided corner reflector, a three-sided corner reflector, or a Luneberg. Use a lens.

  The notification device 3 informs the driver of the completion of the rotation of the vehicle 1, the start of inspection of the in-vehicle radar, and whether the operation of the in-vehicle radar is normal or abnormal by text display, voice, or both. Has a function to inform. In the case of voice, a speaker installed at a location that can be heard by the driver of the vehicle 1 is used, and in the case of character display, a display or an electric bulletin board installed at a location that is also visible to the driver is used. Then, when the vehicle 1 is moved onto the stopped turntable 8, and the turntable 8 is rotated to adjust the direction of the vehicle 1 to the normal inspection start direction, in order to notify the completion of the movement of the vehicle 1, For example, a notification or display such as “An object that reflects radio waves in the front direction has been installed” is displayed. In order to notify the start of the inspection of the in-vehicle radar, for example, a notification or display such as “Start inspection of the in-vehicle radar. Turn on the radar.” If you want to determine whether the in-vehicle radar is operating normally or abnormally, for example, “Are there any warnings or indications indicating that there are obstacles in the forward direction? The in-vehicle radar is operating correctly. If there is no alarm or display, the in-vehicle radar may not be operating properly. Please contact your dealer or repair shop. ” Further, when the turntable 8 makes one rotation and the vehicle 1 has moved to the initial position, for example, a notification or display such as “The inspection of the in-vehicle radar is completed” is performed.

  The control device 4 controls the rotation of the turntable 8, and controls the notification device 3 in each step of inspection to cause the driver to perform the above notification. In addition, when controlling the rotation of the turntable 8, the control device 4 performs a control to rotate the turntable 8 at an appropriate speed without stopping in the present embodiment. However, by the control device 4, the location where the on-vehicle radars 12 and 13 are mounted in the majority of vehicles 1, that is, the position in front of the driver with a rotation angle of 0 °, and about 30 ° counterclockwise. Right diagonally forward position, 90 ° equally right side position, 150 ° diagonally right rear position, 180 ° right rear position, 210 ° diagonal left rear position, 270 ° left side position, 330 The rotary table 8 is temporarily stopped at each of the left diagonally forward positions of °, or at a plurality of selectively set rotational positions, and the operations of the in-vehicle radars 12 and 13 installed at the corresponding positions are stopped. You may make it perform control which makes a driver | operator check.

  Next, an in-vehicle radar inspection method executed by operating the in-vehicle radar inspection apparatus having the above configuration is as follows. The driver is instructed to move the vehicle 1 onto the turntable 8, and the turntable 8 is rotated to adjust the direction of the vehicle 1 to the normal inspection start direction. Then, a notification or display such as “An object that reflects radio waves in the front direction has been installed” is given to notify the driver of the completion of movement of the vehicle 1. Then, for example, the start of inspection of the in-vehicle radar is informed by a notification or display such as “Start inspection of the in-vehicle radar. Turn on the radar.”

  Thereafter, the rotation of the turntable 8 is started by the control device 4, and the rotation of the vehicle 1 thereon is started. Then, a highly probable rotational position where the on-vehicle radars 12 and 13 are installed, a position directly in front of the driver, a right front position, a right side position, a right rear position, a right rear position, a left position The operation of the on-vehicle radar when the oblique rear position, the left side position, and the left oblique front position are directed to the retro-reflector 2, or at each of a plurality of rotation positions set in advance. To get the driver to judge whether the vehicle is normal or abnormal, for example, “Are there any warnings or indications that there are obstacles in the forward direction? Is working properly. If there is no warning or indication, the in-vehicle radar may not be working properly. Please contact your dealer or repair shop. ” The kind of alarm or display.

  When the turntable 8 makes one rotation and the vehicle 1 has moved to the first position, for example, a notification or display such as “The inspection of the in-vehicle radar is completed” is given to notify the completion of the inspection.

  In the inspection of the in-vehicle radars 12 and 13, radio waves are transmitted from the in-vehicle radars 12 and 13, reflected by the retro-reflector 2, and the reflected signals are received by the in-vehicle radars 12 and 13, and the received reflected signals are used. The position of the retroreflector 2 is determined, and the determination result is confirmed by the driver through the user interface of the in-vehicle radars 12 and 13 themselves.

  If the in-vehicle radars 12 and 13 do not detect the retro-reflector 2 or indicate a location different from the retro-reflector 2 even if they can be detected, the in-vehicle radars 12 and 13 have failed. You will be asked to confirm.

  In addition, if it controls to turn the turntable 8 while temporarily stopping at a predetermined rotation position, it can be ensured that the driver can check and check the operation of the on-vehicle radars 12 and 13 slowly and accurately.

  Thus, according to the on-vehicle radar inspection apparatus and method of the present embodiment, the driver can easily check the transmission or reception direction deviation and operation of the on-vehicle radar at a gas station, a multilevel parking lot, or the like.

[Second Embodiment]
An on-vehicle radar inspection apparatus and method according to a second embodiment of the present invention will be described with reference to FIG. In contrast to the first embodiment in which the turntable 8 on which the vehicle 1 is placed is rotated, in the present embodiment, the vehicle 1 is stopped at a predetermined place, and the periphery thereof is set to the retro-reflector 2. This is characterized in that the driver can confirm the operation of the on-vehicle radars 12 and 13 while making the vehicle run by itself.

  As shown in FIG. 2, the in-vehicle radar inspection apparatus according to the present embodiment includes a single retroreflector 2 that moves around the vehicle 1 stopped at a predetermined position, and a reflector that moves the retroreflector 2 in a circle. It is indicated by text display, voice, video or a combination thereof that the mobile device 7 and the driver in the vehicle 1 start checking the on-vehicle radars 12 and 13 and determine whether the operation is normal or abnormal. It is comprised from the alerting | reporting apparatus 3 which alert | reports, and the control apparatus 4 which controls operation | movement of these reflector movement apparatuses 7, and operation | movement of the alerting | reporting apparatus 3. FIG.

  About the retroreflector 2 and the alerting | reporting apparatus 3, it has the structure and function similar to 1st Embodiment. The reflector moving device 7 is controlled by the control device 4 and functions to move the retroreflector 2 around the vehicle 1 at a predetermined speed. As the configuration, for example, a retro-reflector 2 is constructed by laying a ring-shaped rail, placing a self-propelled carriage on the rail, and attaching the retro-reflector 2 to the carriage, thereby allowing the carriage to self-propel on the rail. Can also be configured to move in a circle. Or the structure which attaches the retro-reflector 2 to the circumference part of the rotary plate rotated, or to a rotary ring, and makes the retro-reflector 2 move circularly by rotating a rotary plate or a rotary ring may be sufficient.

  Similarly to the first embodiment, the retro-reflector 2 is also installed at the height of the bumper or front grill of the vehicle 1 on which the in-vehicle radars 12 and 13 are installed.

  The control device 4 controls the reflector moving device 7 to control the circular movement of the retroreflector 2, and controls the notification device 3 to perform the above notification to the driver. Even in the present embodiment, the control device 4 performs control so that the retroreflector 2 rotates once at an appropriate speed without stopping. However, the control device 4 causes the retro-reflector 2 to be mounted in the vehicle 1 where the in-vehicle radars 12 and 13 are mounted, that is, a position in front of the driver with a rotation angle of 0 °, approximately counterclockwise. 30 °, right diagonally forward, 90 °, right right, 150 ° diagonally backward, 180 ° right behind, 210 ° diagonally backward, 270 ° left , The position diagonally to the left of 330 °, or a plurality of rotation positions that are selectively set in advance, and the operations of the on-vehicle radars 12 and 13 installed at the corresponding positions are temporarily stopped. You may make it perform control which makes a driver | operator check.

  The on-vehicle radar inspection method using the on-vehicle radar inspection device of the present embodiment is almost the same as that of the first embodiment. The driver is instructed to move and stop the vehicle 1 to a predetermined inspection position, and adjustment is performed so that the retro-reflector 2 is located at the inspection start position directly in front of the vehicle 1. The subsequent control and inspection methods are the same as those in the first embodiment except that the control device 4 controls the circular movement of the retroreflector 7 by the reflector moving device 7.

  Incidentally, if the retroreflector 7 is controlled to move in a circle while being temporarily stopped at a predetermined rotational position, it is possible to ensure that the driver can check and check the operation of the in-vehicle radars 12 and 13 slowly and accurately.

  Also in the present embodiment, as in the first embodiment, the driver can easily check the transmission and reception direction deviation and operation of the in-vehicle radar at a gas station, a multi-story parking lot, and the like.

[Third Embodiment]
An in-vehicle radar inspection apparatus and method according to a third embodiment of the present invention will be described with reference to FIGS. The feature of the present embodiment is that, with respect to the first embodiment, the vehicle central axis is automatically detected and the retroreflector 2 is positioned at the front of the vehicle on the central axis to check the operation of the millimeter wave radar. The point is that it can be done strictly. Hereinafter, the same reference numerals are used for the elements common to the first embodiment shown in FIG.

  In the present embodiment, an imaging device 5 such as a camera for imaging the vehicle 1 on the turntable 8 is installed at a position above the center of the turntable 8, and the image of the vehicle 1 taken by the image pickup device 5 is shown in FIG. The vehicle center axis is detected by the method shown in FIG. 4 and the control device 4 controls to move the turntable 8 so that the retro-reflector 2 is positioned on the vehicle center axis.

  Next, an in-vehicle radar inspection method using the in-vehicle radar inspection apparatus of the above embodiment will be described. The rotation position at which the mark placed on the reference line or the reference point on the circumference of the turntable 8 coincides with the retroreflector 2 is set as the reference position, and the control device 4 controls the rotation of the turntable 8 to set the reference position. To stop. Then, the imaging device 5 images the vehicle 1 on the turntable 8 and transmits it to the vehicle center axis detection device 6. As shown in FIG. 5, the vehicle center axis detection device 6 approximates a vehicle 1 imaged from above by a rectangle approximation by image processing, and extracts left and right vehicle long sides 11 from the vehicle 9 approximated by the rectangle. The center line of the left and right vehicle long sides 11 is defined as the vehicle center axis 10. With respect to the front and rear of the vehicle, it is determined in advance that the vehicle 1 is stopped forward on the turntable 8, and for example, in FIG. 5, the lower side of the vehicle central axis 10 is determined as the front. The deviation angle of the vehicle central axis 10 from the retroreflector 2 is determined by drawing a reference line on the turntable 8 or marking a reference point on the circumference so that the vehicle central axis 10 is offset from the reference line or Determine how many times the reference point mark is off.

  If the vehicle center axis 10 is detected by the vehicle center axis detection device 6 in this way, the control device 4 corrects only the detected deviation angle of the vehicle center axis 10 so that the vehicle center axis 10 passes through the retroreflector 2. The inspection start position.

  When the setting of the inspection start position is completed, the in-vehicle radar inspection is executed in the same manner as in the method of the first embodiment.

  According to the third embodiment, in addition to the same operations and effects as the first embodiment, the inspection of the millimeter wave radar 13 mounted at the front center of the normal vehicle 1 can be performed more strictly. Have

[Fourth Embodiment]
An in-vehicle radar inspection apparatus and method according to a fourth embodiment of the present invention will be described with reference to FIGS. The feature of the present embodiment is that, with respect to the second embodiment, the vehicle central axis is automatically detected and the retroreflector 2 is positioned at the front of the vehicle on the central axis to check the operation of the millimeter wave radar 13. Is that it can be done strictly. Hereinafter, the same reference numerals are used for the elements common to the second embodiment shown in FIG.

  In the present embodiment, an imaging device 5 such as a camera that images the vehicle 1 placed in the rotation circle is installed at a position above the center point of the rotation circle of the retroreflector 2, and the imaging device 5 captures an image. Similarly to the third embodiment, the vehicle center axis 10 is detected from the image of the vehicle 1 by the method shown in FIG. 5, and the retroreflector 2 is positioned on the vehicle center axis by the control device 4. Is moved to the inspection start position.

  Next, an in-vehicle radar inspection method using the in-vehicle radar inspection apparatus of the above embodiment will be described. A center line passing through the retro-reflector 2 is set as a reference position. Then, the vehicle 1 is imaged by the imaging device 5 and transmitted to the vehicle center axis detection device 6, and the vehicle center axis 10 is detected by the vehicle center axis detection device 6 by the method shown in FIG. Also in the present embodiment, with respect to the front and rear of the vehicle, an arrangement for stopping the vehicle 1 toward the retro-reflector 2 in advance is made, for example, the lower side of the vehicle central axis 10 is determined to be the front in FIG. Then, a deviation angle of the vehicle center shaft 10 from the retroreflector 2 is determined.

  If the vehicle center axis detection device 6 detects the vehicle center axis 10 in this way, the control device 4 operates the reflector moving device 7 by the deviation angle detected by the vehicle center axis 10 to move the retro reflector 2 in the opposite direction. The inspection center position is set so that the vehicle center shaft 10 passes through the retro-reflector 2.

  When the setting of the inspection start position is completed, the in-vehicle radar inspection is executed in the same manner as in the method of the second embodiment.

  According to the fourth embodiment, in addition to the same operations and effects as the second embodiment, the inspection of the millimeter wave radar 13 mounted at the front center of the normal vehicle 1 can be performed more strictly. Have

  In each of the above embodiments, the number and position of on-vehicle radars are not particularly limited. In addition, the mounted radar can be automatically inspected for the vehicle 1 on which the UWB radar 12 is mounted together with the millimeter wave radar 13 or on the vehicle 1 on which only a plurality of UWB radars 12 are mounted.

DESCRIPTION OF SYMBOLS 1 ... Vehicle 2 ... Retro-reflector 3 ... Notification apparatus 4 ... Control apparatus 5 ... Imaging apparatus 6 ... Vehicle center axis detection apparatus 7 ... Reflector moving apparatus 8 ... Turntable 9 ... Vehicle that approximated a rectangle 10 ... Vehicle center axis 11 ... Vehicle length Side 12 ... UWB radar 13 ... millimeter wave radar

Claims (11)

An in-vehicle radar inspection device for inspecting an in-vehicle radar mounted in a plurality of locations of a vehicle,
A turntable for rotating the vehicle;
A single retroreflector installed outside the rotation circle of the turntable and near the circumference of the rotation circle;
An on-vehicle radar inspection device comprising a turntable drive device that controls rotation of the turntable.   The in-vehicle radar inspection device according to claim 1, further comprising a notification device that notifies an operation confirmation instruction of the on-vehicle radar toward the vehicle by text display, voice, video, or a combination thereof. An imaging device for imaging the vehicle on the turntable;
A vehicle center axis detection device that detects a center axis in the front-rear direction of the vehicle on the turntable from an image captured by the imaging device;
The vehicle center axis detected by the vehicle center axis detection device is positioned at a basic position where it intersects the front of the retroreflector, and the rotation table driving device sets the rotation table at each rotation angle set in advance from the basic position. The on-vehicle radar inspection device according to claim 1, further comprising a rotational position control device that performs rotational position control for stopping the rotation.   The in-vehicle radar inspection apparatus according to claim 1, wherein the retro reflector is a two-surface corner reflector, a three-surface corner reflector, or a Luneberg lens. An in-vehicle radar inspection device for inspecting radars mounted in a plurality of locations of a vehicle,
A single retro-reflector that rotates around the vehicle at a position outside the rotation range of the vehicle at a predetermined location where the inspection vehicle is stopped;
An in-vehicle radar inspection apparatus comprising: a reflector moving device that rotates and moves the retro reflector.   6. The in-vehicle radar inspection apparatus according to claim 5, further comprising an informing device for informing an operation confirmation instruction of the in-vehicle radar toward the vehicle by text display, voice, video, or a combination thereof. An imaging device for imaging the vehicle stopped at the predetermined position;
A vehicle central axis detection device that detects a central axis in the front-rear direction of the vehicle from an image captured by the imaging device;
The center axis of the vehicle detected by the vehicle center axis detecting device is aligned with the basic position intersecting the front of the retro reflector, and the retro reflector by the reflector moving device is set for each rotational movement angle set in advance from the basic position. The in-vehicle radar inspection device according to claim 5, further comprising a reflector position control device that performs reflector position control for stopping the rotational movement of the vehicle.   The in-vehicle radar inspection apparatus according to claim 5, wherein the retro reflector is a two-surface corner reflector, a three-surface corner reflector, or a Luneberg lens. A scanning step of rotating the vehicle or rotating the retro-reflector so that the retro-reflector scans around the vehicle stopped at a predetermined position;
And a notification step for notifying the driver of the start of inspection of the on-vehicle radar and whether the operation is normal or abnormal by text display, voice, video or a combination thereof. In-vehicle radar inspection method. As a step prior to the start of the scanning step,
A vehicle imaging step of imaging the vehicle stopped at the predetermined position from an upper position;
A center axis detection step of detecting the vehicle center axis from the captured image;
A positioning step of moving the retroreflector or the vehicle so that the retroreflector and the center axis of the vehicle overlap,
In the scanning step, the retroreflector is moved or rotated so that the retroreflector stops at the front, rear, left and right diagonal front, left and right diagonal rear and left and right side positions of the vehicle,
In the notification step, the driver starts the inspection of the in-vehicle radar at each position on the front, rear, left and right diagonally front, left and right diagonally rear, and left and right sides of the vehicle, and judges whether the operation is normal or abnormal. The in-vehicle radar inspection method according to claim 9, wherein the information is notified by text display, voice, video, or a combination thereof.   The in-vehicle radar inspection method according to claim 9 or 10, wherein a two-surface corner reflector, a three-surface corner reflector, or a Luneberg lens is used as the retroreflector.

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