Radar reflector device, calibration device and method for checking and calibrating radar sensor in motor vehicle

Abstract

A radar reflector device (20) for checking and calibrating a radar sensor (6) in a motor vehicle (4), comprising: a support device (21) configured to support the radar reflector device (20) on the ground (3); and a radar reflector arm (28) mounted on the support device (21) such that it is pivotable about a pivot axis. A radar reflector (32) is arranged on the radar reflector arm (28). According to the invention, at least one optical reflector target (36) is provided on the pivotable radar reflector arm (28), or an encoder (30) is provided on the support device (21), which encoder can determine the rotational position of the radar reflector arm (28) relative to the support device (21).

Description

Technical Field

[0001] This invention relates to a radar reflector device, a calibration device, and a method for inspecting and calibrating radar sensors in motor vehicles. Background Technology

[0002] Modern motor vehicles are typically equipped with driver assistance systems, which in particular include at least one radar sensor.

[0003] It is generally necessary to check whether the functionality of the radar sensor is affected by the vehicle's placement in front of the sensor and in areas that attenuate radar radiation. This is especially important after repairing areas where radar sensors are installed at the rear of a vehicle; the repair work must be checked to ensure it did not damage the sensor's functionality. Furthermore, the radar sensor's calibration must be checked and recalibrated if necessary.

[0004] The systems known to date for checking radar sensor functionality and recalibrating them when necessary are not optimally suited for radar sensors mounted at vehicle corners. Furthermore, these systems typically only allow checking radar sensor functionality at a fixed, preset angle relative to the vehicle's longitudinal axis of travel. Summary of the Invention

[0005] Therefore, the object of the present invention is to provide an improved apparatus and an improved method for inspecting and calibrating radar sensors in motor vehicles, which in particular enable the inspection of radar sensors located at corners of motor vehicles over a wider angular range and recalibration as needed.

[0006] A radar reflector device according to the present invention for checking the function of radar sensors in a motor vehicle and calibrating radar sensors includes: a support device configured to support the radar reflector device on the ground; and a radar reflector arm disposed on the support device such that it is pivotable about a pivot axis. At least one radar reflector is provided on the pivotable radar reflector arm. An optical reflector target is also provided on the pivotable radar reflector arm, which enables the determination of the position of the radar reflector arm; and / or an encoder is provided on the support device, which enables the determination of the rotational position of the radar reflector arm relative to the support device.

[0007] The present invention also includes a system for checking the functionality of radar sensors in a motor vehicle and calibrating radar sensors. The system according to the invention includes: a radar reflector device according to the invention, and a calibration device having at least one optical image recording device and an evaluation device. The image recording device enables the acquisition of images of a reflector target and / or at least one supporting target. The evaluation device is configured to determine the position of the radar reflector device and / or the position of the radar reflector from the images acquired by the image recording device.

[0008] The present invention also includes a method for inspecting the functionality of a radar sensor in a motor vehicle using a radar reflector device according to the invention, wherein the method comprises: positioning the radar reflector device at a predetermined position on the motor vehicle; pivoting a radar reflector arm with the radar reflector, and during the pivoting of the radar reflector arm: determining the current position of the radar reflector by means of a reflector target or by means of an encoder; capturing the radar reflector with the radar sensor to be inspected and thereby determining the current position of the radar reflector; and comparing the position of the radar reflector determined by means of the reflector target or the encoder with the position of the radar reflector determined by the radar sensor.

[0009] The present invention also includes a method for inspecting the function of a radar sensor in a motor vehicle using a system according to the invention, wherein the method comprises: positioning the motor vehicle with the radar sensor to be measured in front of a calibration device; determining the position and orientation of the motor vehicle, particularly the longitudinal driving axis, by means of the calibration device; positioning a radar reflector device according to the invention below the radar sensor to be inspected, particularly below the antenna of the radar sensor to be inspected; optically capturing an optical support target mounted on a support device using at least one image recording device, thereby determining the position of the radar reflector device relative to the motor vehicle, and correcting the position of the radar reflector device if necessary; manually pivoting a radar reflector arm with the radar reflector; and during the pivoting of the radar reflector arm: determining the current position of the radar reflector by means of an encoder, or optically capturing an optical reflector target mounted on the radar reflector arm using the calibration device and thereby determining the current position of the radar reflector; capturing the radar reflector with the radar sensor to be measured and thereby determining the current position of the radar reflector; and comparing the position of the radar reflector determined by means of an encoder or by optically capturing the reflector target with the position of the radar reflector determined by the radar sensor.

[0010] By using the pivoting radar reflector according to the present invention, the functionality of the radar sensor can be checked over a wide angular range and calibrated as needed.

[0011] This method allows for the inspection of whether the radar sensor's functionality is excessively obstructed by a cover or bumper positioned in front of it. For example, the radar sensor's function might be impaired if the paint layer in the area in front of the sensor is too thick or if inappropriate paint is used, excessively hindering the sensor's transmission and detection of radar radiation. This inspection can be performed at the vehicle manufacturer's office or in a repair shop, especially after repairs to the area in front of the radar sensor on the vehicle.

[0012] Pivoting radar reflectors, in particular, enable the inspection and, if necessary, calibration of radar sensors that are positioned at the corners of a vehicle and emit radar radiation not only forward or backward and to the sides.

[0013] In one implementation, the radar reflector arm can pivot in a plane substantially parallel to the ground of the test field. This allows for particularly good and reliable inspection of the radar sensor and calibration when necessary.

[0014] In one embodiment, the radar reflector device is equipped with a motor configured to pivot the radar reflector arm about a pivot axis. The motor can be configured to pivot the radar reflector arm continuously or incrementally.

[0015] For example, the motor can be configured to pivot the radar reflector arm in steps of up to 0.2°.

[0016] The motor can be configured to pivot the radar reflector arm in a range of at least -65° to +65°, particularly in a range of at least -75° to +75°, or in a range of at least -90° to +90°.

[0017] In one embodiment, the radar reflector device does not have a motor. In this embodiment, the radar reflector arm is designed to be manually pivotable. The motorless construction of the radar reflector device results in a lightweight design, eliminates the need for a motor, and allows for inexpensive manufacturing.

[0018] In one embodiment, the radar reflector device has a fixing device that allows the radar reflector arm to be secured in a desired position. This fixing device can be configured, for example, as a clamping device.

[0019] In one embodiment, the support device has three support elements with feet extending radially outward from the central region of the support device. These three support elements allow the radar reflector device to be reliably and with low vibration supported on the test field ground.

[0020] In one embodiment, the radar reflector arm is pivotally mounted in the central region of the support device. The radar reflector arm can be pivotally mounted in the central region of the support device, in particular, by means of a rotary bearing (which may include, for example, a sliding bearing or a ball bearing).

[0021] In one embodiment, an optical support target is provided on each of at least two support elements. In another embodiment, particularly, an optical support target is provided on each of three support elements. By providing two or three support targets on the support device, the position of the support device on the test field can be determined with greater accuracy, especially when the ground of the test field is not perfectly horizontal.

[0022] If there are two or more support targets at the support device, the location of the radar reflector device can be reliably determined by optically capturing the support targets even if one or more of the optical support targets are not visible (e.g., due to obstruction by a vehicle).

[0023] In one embodiment, the calibration device is configured to determine the position and orientation of a motor vehicle positioned in front of the calibration device based on an image captured by at least one image recording device.

[0024] In one embodiment, the optical image recording device of the calibration apparatus includes at least two cameras and / or at least one stereo camera, enabling the optical image recording device to capture three-dimensional images of the vehicle so as to determine the positions of the support target and the reflector target in three-dimensional space.

[0025] In one embodiment, the system is configured to compare the strength of a radar signal reflected by a radar reflector and detected by a radar sensor with a preset target strength, and determine, based on the comparison, whether the radar signal is excessively attenuated by an area of ​​the vehicle positioned in front of the radar sensor (e.g., a bumper).

[0026] In one embodiment, the method includes positioning a radar reflector device below a vehicle such that the pivot axis of the radar reflector arm is located directly below the radar sensor, particularly directly below the radar sensor antenna.

[0027] The preset positions of the radar reflector device for checking and calibrating radar sensors can be stored in or input into the calibration device. The calibration device can then be configured to monitor the correct position of the calibration device based on images captured by an image recording device of at least one supporting target mounted on a support device. In this way, it can be ensured that the checking of the radar sensor, and, if necessary, the calibration, is performed with the radar reflector device accurately positioned. This improves the reliability and quality of the checking and, if necessary, calibration of the radar reflector device.

[0028] In one embodiment, the method includes pivoting a radar reflector arm, on which the radar reflector is mounted, continuously from a starting position, i.e. without intermediate stops, to an ending position.

[0029] In one embodiment, the method includes pivoting a radar reflector arm with a radar reflector to multiple positions and holding it there.

[0030] The method may include pivoting the radar reflector arm in steps of up to 0.2°. The method may particularly include pivoting the radar reflector arm within a range of at least -65° to +65°, especially within a range of at least -75° to +75°, or within a range of at least -90° to +90°.

[0031] The pivot position of the radar reflector can be preset, for example, by the manufacturer of the radar sensor to be inspected or the manufacturer of the driver assistance system.

[0032] The manufacturer of the radar sensor or driver assistance system to be inspected can also preset whether the radar reflector arm should pivot continuously or pivot with intermediate stops in order to inspect the radar sensor.

[0033] In one embodiment, the method includes comparing the strength of a radar signal reflected by a radar reflector and detected by a radar sensor with a preset target strength, and determining, based on the comparison, whether the radar signal is excessively attenuated by an area of ​​the vehicle positioned in front of the radar sensor (e.g., a bumper). Attached Figure Description

[0034] Figure 1 A perspective view shows a test field used for inspecting and calibrating radar sensors installed in motor vehicles.

[0035] Figure 2 An enlarged perspective view of a radar reflector device according to an embodiment of the present invention is shown.

[0036] Figure 3 A radar reflector device according to the invention is shown in top view, which is arranged below a radar sensor located in the central area at the front of a motor vehicle.

[0037] Figure 4 A radar reflector device according to the invention is shown in top view, which is arranged below a radar sensor located at the left front corner of a motor vehicle. Detailed Implementation

[0038] An embodiment of the present invention will now be described with reference to the accompanying drawings.

[0039] Figure 1The test field 2, used for inspecting and calibrating the radar sensor 6 installed in the motor vehicle 4, is shown in perspective schematic diagram.

[0040] A vehicle 4 equipped with radar sensor 6 is positioned in front of calibration device 8. Calibration device 8 is specifically configured for calibrating sensors of driver assistance systems and includes at least one image recording device 10 configured to capture images of the vehicle 4 positioned in front of calibration device 8.

[0041] The calibration device 8 includes at least two image recording devices (cameras) 10 or at least one stereo camera to capture three-dimensional images of the motor vehicle 4.

[0042] The calibration device 8 also includes an evaluation device 12, which is configured to evaluate images captured by at least one image recording device 10.

[0043] Between the vehicle 4 and the calibration device 8, a radar reflector device 20 according to the invention is arranged on the ground 3 of the test field 2.

[0044] Figure 2 An enlarged perspective view of the radar reflector device 20 according to the present invention is shown.

[0045] The radar reflector device 20 includes a support device 21 configured to support the radar reflector device 20 on the ground 3. The support device 21 includes three support elements 22 that extend radially outward from a central region 24 of the support device 21. Each support element 22 has a foot 26 at its outer end.

[0046] The radar reflector device 20 also includes a radar reflector arm 28, which is pivotally mounted on the central region 24.

[0047] The radar reflector arm 28 has a first arm segment 28a that extends substantially parallel to the ground 3 of the test field.

[0048] In addition, the radar reflector arm 28 has a second arm segment 28b that extends orthogonally from one end of the first arm segment 28a, such that the second arm segment 28b is substantially perpendicular to the orientation of the ground 3 of the test field 2.

[0049] A radar reflector is provided at the upper end of the second arm segment 27b away from the ground 3 of the test field 2. The radar reflector is configured to reflect radar radiation emitted by the radar sensor 6.

[0050] The radar reflector arm 28 can pivot in a plane substantially parallel to the ground orientation of the test field.

[0051] A motor 25 can be installed between the support device 21 and the radar reflector arm 28 to pivot the radar reflector arm 28. The radar reflector arm 28 can also be configured to pivot manually.

[0052] An optical support target 34 may be provided on at least one of the three support elements 22, and the optical support target may be optically captured by at least one image recording device 10 of the calibration device. The support target 34 may also be provided on two or three support elements 22.

[0053] An encoder 30 may be provided between the support device 21 and the radar reflector arm 28, which enables the determination of the current rotational or angular position of the radar reflector arm 28 relative to the support device 21.

[0054] Alternatively or additionally to the encoder 30, an optical reflector target 36 may be provided on the radar reflector arm 28, which can be optically captured by at least one image recording device 10 of the calibration device 10. In the embodiment shown in the figures, the reflector target 36 is mounted on the second arm segment 28b of the radar reflector arm 28.

[0055] To inspect the radar sensor 6 installed in the vehicle 4 and recalibrate it if necessary, the vehicle 4, with the radar sensor 6 to be measured, is positioned in front of the calibration device 8, such as... Figure 1 As shown.

[0056] An image of the motor vehicle 4 can be captured using at least one image recording device 10 disposed in the calibration device 8. The position and orientation of the motor vehicle 4 in front of the calibration device 8 can be determined from the captured image, especially the longitudinal driving axis.

[0057] Therefore, if necessary, optical measuring plates (Messtafeln) can be installed on two or four wheels of the vehicle 4.

[0058] Alternatively, the vehicle 4 can be positioned on the test field 2 at a location predetermined by markings constructed on the ground 3 of the test field 2.

[0059] The central region 24 of the radar reflector device 20 according to the invention—in which a pivot axis is constructed—is positioned directly below the radar sensor 6 to be inspected, and in particular directly below the antenna of the radar sensor 6 to be inspected.

[0060] Figure 3 A top view shows the radar reflector device 20 according to the invention, which is arranged below the radar sensor 6 located in the central area at the front of the vehicle 4.

[0061] Figure 4A top view shows the radar reflector device 20 according to the invention, which is arranged below the radar sensor 6 located at the left front corner of the vehicle 4.

[0062] At least one support target 34, which is located on the support device 21 and is not obstructed by the vehicle 4, can be optically captured by at least one image recording device 10 in order to determine the position of the radar reflector device 20 relative to the vehicle 4 from the captured image.

[0063] The position of the radar reflector device 20 determined in this way can be compared with the preset position for the corresponding radar sensor 6, and corrected if necessary, until it matches the preset position.

[0064] Alternatively, the location of the radar reflector device 20 can be preset by markings present on the ground 3 of the test field 2. In this case, the calibration device 8 is not required to position the radar reflector device 20 at the vehicle 4.

[0065] As an alternative, a mechanical positioning aid, such as a pointer, can be provided on the radar reflector device 20. This positioning aid can be positioned at a preset location on the vehicle 4, thereby positioning the radar reflector device 20 at a preset location on the vehicle 4.

[0066] After the radar reflector device 20 is positioned at a preset location on the vehicle 4, the radar sensor 6 to be inspected in the vehicle 4 is activated, and the radar reflector arm 28 with radar reflector 32 will pivot manually or by means of a motor 25 mounted on the radar reflector device 20 around the central region 24 of the radar reflector device 20.

[0067] Here, the radar reflector arm 28 can pivot continuously, i.e. without intermediate stops, or pivot successively to different stationary positions.

[0068] For example, the radar reflector arm 28 can pivot in steps of up to 0.2° within a range of at least -65° to +65°, particularly within a range of at least -75° to +75°, or within a range of at least -90° to +90°.

[0069] During the pivoting of the radar reflector arm 28, at least one optical reflector target 36 disposed on the radar reflector arm 28 can be optically captured by at least one image recording device 10 of the calibration device 8 in order to determine the current position of the radar reflector 32.

[0070] The current position of the radar reflector 32 can also be determined by using an encoder 30 mounted on the support device 21. In this case, the calibration device 8 is not required to determine the current position of the radar reflector 32.

[0071] Simultaneously, during the pivoting motion of the radar reflector arm 28, the radar reflector 32 is acquired using the radar sensor 6 to be inspected. The current position of the radar reflector 32 is also determined based on the information provided by the radar sensor 6.

[0072] Now, the position of the radar reflector 32, determined by the encoder 30 or by optical capture of the optical reflector target 36, is compared with the position of the radar reflector 32 determined by the radar sensor 6. This can be used to determine whether the radar sensor 6 is functioning properly and is correctly calibrated.

[0073] The constant (angular) deviation between the position determined by the encoder 30 or by optical capture of the optical reflector target 36 and the position of the radar reflector 32 determined by the radar sensor 6 can be used to infer the erroneous orientation of the radar sensor 6 that needs correction.

[0074] The dramatic fluctuations in the intensity of the radar signal reflected by radar reflector 32 indicate that the paint layer in front of radar sensor 6 is interfering with radar radiation, for example, due to excessive thickness or defects in the paint layer.

[0075] The attenuation of the radar signal caused by the paint layer can be determined by comparing the intensity of the radar signal reflected by the radar reflector 32, as measured by the radar sensor 6, with the intensity of the target, for example, that can be stored in the evaluation device 12.

[0076] In this way, it can be checked whether the function of radar sensor 6 is excessively obstructed by a cover or bumper located in front of radar sensor 6. For example, the function of radar sensor 6 may be obstructed because the paint layer in the area in front of radar sensor 6 is too thick or improper paint is used, which excessively hinders the radar sensor 6 from emitting and detecting radar radiation. This inspection can be performed at the vehicle manufacturer's office or in a repair shop, especially after repairs have been made to the area in front of radar sensor 6 on vehicle 4.

Claims

1. A radar reflector device (20) for inspecting and calibrating a radar sensor (6) in a motor vehicle (4), wherein the radar reflector device (20) comprises: A support device (21) is configured to support the radar reflector device (20) on the ground (3); as well as A radar reflector arm (28) is mounted on the support device (21) such that the radar reflector arm can pivot about a pivot axis. A radar reflector (32) is provided at the radar reflector arm (28). At least one optical reflector target (36) is provided at the pivotable radar reflector arm (28); or An encoder (30) is provided on the support device (21) to determine the rotational position of the radar reflector arm (28) relative to the support device (21).

2. The radar reflector device (20) according to claim 1, having a motor (25) configured to pivot the pivotable radar reflector arm (28).

3. The radar reflector device (20) according to claim 1 or 2, wherein at least one support target (34) is provided on the support device (21), wherein the support device (21) has in particular three support elements (22) extending radially outward from the central region (24) of the support device (21).

4. The radar reflector device (20) according to claim 3, wherein an optical support target (34) is provided at at least one of the support elements (22), wherein, in particular, an optical support target (34) is provided at each of two or three of the support elements (22).

5. A system for inspecting and calibrating radar sensors (6) in a motor vehicle (4), said system comprising: Radar reflector device (20) according to any one of the preceding claims; as well as The calibration device (8) has at least one optical image recording device (10) which enables it to capture images of the reflector target (36) and / or the at least one support target (34); And an evaluation device (12) configured to determine the position of the radar reflector device (20) and / or the position of the radar reflector (32) based on the captured images.

6. The system according to claim 5, wherein the calibration device (8) is configured to determine the position and orientation of a motor vehicle (4) arranged in front of the calibration device (8).

7. The system according to claim 5 or 6, wherein the image recording device (10) comprises at least two cameras and / or at least one stereo camera.

8. The system according to any one of claims 5 to 7, wherein the system is configured to: compare the strength of a radar signal reflected by the radar reflector (32) and detected by the radar sensor (6) with a preset target strength, and determine, based on the comparison, whether the radar signal is excessively attenuated by the area of ​​the motor vehicle (4) arranged in front of the radar sensor (6).

9. A method for inspecting a radar sensor (6) in a motor vehicle (4) using a radar reflector device (20) according to any one of claims 1 to 4, wherein the method comprises: Position the radar reflector device (20) at a predetermined location on the motor vehicle (4); Pivot the radar reflector arm (28) with the radar reflector (32). During the pivoting of the radar reflector arm (28): The current position of the radar reflector (32) is determined by means of a reflector target (36) or by means of an encoder (30); The radar reflector (32) is captured using the radar sensor (6) to be inspected, and the current position of the radar reflector (32) is determined therefrom. as well as The position of the radar reflector (32) determined by the reflector target (36) or the encoder (30) is compared with the position of the radar reflector (32) determined by the radar sensor (6).

10. A method for inspecting a radar sensor (6) in a motor vehicle (4) using a system according to any one of claims 5 to 7, wherein the method comprises: Position the motor vehicle (4) with the radar sensor (6) to be measured in front of the calibration device (8); The position and orientation of the motor vehicle (4) are determined by means of the calibration device (8), especially the longitudinal driving axis; Position the radar reflector device (20) according to any one of claims 1 to 4 below the radar sensor (6) to be inspected; The optical support target (34) set on the support device (21) is optically captured using at least one image recording device (10), thereby determining the position of the radar reflector device (20) relative to the motor vehicle (4), and correcting the position of the radar reflector device (20) if necessary. Pivot the radar reflector arm (28) with the radar reflector (32). During the pivoting of the radar reflector arm (28): The current position of the radar reflector (32) can be determined by means of an encoder (30), or by means of the calibration device (8) to optically capture at least one optical reflector target (36) set on the radar reflector arm (28) and thereby determine the current position of the radar reflector (32). The radar reflector (32) is captured using the radar sensor (6) to be inspected, and the current position of the radar reflector (32) is determined therefrom. as well as The position of the radar reflector (32), determined by means of the encoder (30) or by optical capture of the optical reflector target (36), is compared with the position of the radar reflector (32) determined by the radar sensor (6).

11. The method according to claim 9 or 10, wherein the method comprises continuously pivoting the radar reflector arm (28) with the radar reflector (32).

12. The method according to any one of claims 9 to 11, wherein the method comprises successively pivoting the radar reflector arm (28) with the radar reflector (32) to a plurality of angular positions and holding there temporarily, wherein two adjacent angular positions are particularly spaced up to 0.2° apart.

13. The method according to any one of claims 9 to 12, wherein the method comprises: The intensity of the radar signal reflected by the radar reflector (32) and detected by the radar sensor (6) is compared with the preset target intensity, and it is determined based on the comparison whether the radar signal is excessively attenuated by the area of ​​the motor vehicle (4) arranged in front of the radar sensor (6).

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