Apparatus, system and method for determining a position of a calibration tool in front of a motor vehicle

Abstract

A mobile device (12) for determining the position of a calibration tool (10) in front of a motor vehicle (2), particularly for preparing to calibrate a vehicle sensor (8) installed in the motor vehicle (2), the mobile device comprising: a bracket (14); a measuring plate (18); and at least one camera (20). The measuring plate (18) and the at least one camera (20) are mounted relative to each other at the bracket (14) in a pre-given fixed spatial relationship.

Description

Technical Field

[0001] The present invention relates to an apparatus, system, and method for determining the position of a calibration tool in front of a motor vehicle, particularly for preparing a vehicle sensor installed in a motor vehicle for calibration. Background Technology

[0002] Modern motor vehicles often have a range of vehicle sensors that assist the driver in recognizing the surrounding environment. Examples include cameras, radar systems, lidar systems, and distance sensors, which are typically used in conjunction with driver assistance systems. These sensors are usually calibrated with a more or less oriented detection area to ensure proper functioning. Calibration can be performed not only during final assembly or shortly before vehicle delivery, but also after vehicle repairs or maintenance, where recalibration of the sensors may be necessary.

[0003] To calibrate vehicle sensors, a calibration tool is positioned in front of the vehicle and within the field of view of the corresponding vehicle sensor, serving as a reference object.

[0004] In the calibration process, the reference object must be placed very precisely in order to obtain reproducible and accurate results. Because motor vehicles move on their own wheels before calibration and therefore never stop precisely in the same position, re-performing the precise placement of the reference object for each vehicle is complex and costly.

[0005] Therefore, the objective of this invention is to simplify the calibration of vehicle sensors installed in motor vehicles. Summary of the Invention

[0006] This invention includes a mobile device for determining the position of a calibration tool in front of a motor vehicle, particularly for preparing to calibrate vehicle sensors installed in a motor vehicle. A mobile device according to the invention includes: a bracket; a measuring plate; and at least one camera. The measuring plate and the at least one camera are arranged relative to each other at the bracket in a pre-defined, fixed spatial relationship.

[0007] The present invention also includes a system for determining the position of a calibration tool in front of a vehicle sensor, particularly for preparing to calibrate a vehicle sensor installed in a motor vehicle. The system includes: at least two mobile devices according to the invention; at least one mobile calibration tool capable of being optically detected by the vehicle sensor; and an evaluation device configured to evaluate images provided by cameras of the at least two mobile devices to determine the position of the calibration tool relative to the vehicle sensor.

[0008] The system according to the invention for determining the position of a calibration tool in front of a vehicle sensor can include, in particular, two, three, or four mobile devices.

[0009] The present invention further includes a method for determining the position of a calibration tool in front of a vehicle sensor, particularly for preparing a vehicle sensor. The method according to the invention includes: placing a vehicle with a vehicle sensor on a measurement site; placing at least two mobile devices according to the invention on the measurement site; and placing the calibration tool on the measurement site within the field of view of the vehicle sensor.

[0010] The method further includes: acquiring images of the measurement site using cameras of the at least two mobile devices; identifying a measurement plate mounted on at least one other mobile device in the acquired images, and defining a coordinate system pre-given by the mobile devices; identifying a motor vehicle in the acquired images, and determining the position of the motor vehicle, particularly a vehicle sensor, in the coordinate system defined by the devices; identifying the at least one calibration tool in the acquired images, and determining the position of the at least one calibration tool in the coordinate system defined by the devices; and determining the position of the at least one calibration tool in a local coordinate system of the vehicle sensor.

[0011] The present invention also includes a method for calibrating vehicle sensors, particularly vehicle sensors of driver assistance systems, wherein the method comprises: determining a position of at least one calibration tool in front of a vehicle sensor to be calibrated using a previously described method; detecting the at least one calibration tool using the vehicle sensor to be calibrated; and calibrating the vehicle sensor based on a previously determined position of the at least one calibration tool in front of the vehicle sensor.

[0012] By using a system according to the invention, which includes a mobile device according to the invention, and by using a method according to the invention, the position and orientation of a calibration tool, which serves as a reference for calibrating vehicle sensors, in front of the vehicle sensor to be calibrated can be easily and with high accuracy determined.

[0013] Therefore, it is not necessary to position the calibration tool with high precision in front of the vehicle or in front of the sensor of the vehicle to be calibrated at a fixed, predetermined location.

[0014] Therefore, it simplifies the calibration of vehicle sensors, especially in the workshop area, and reduces costs.

[0015] In one embodiment, the mobile device according to the invention includes a component carrier mounted on a support. The measuring plate and the at least one camera are mounted relative to each other on the component carrier in this embodiment with a pre-defined, fixed spatial relationship. By means of such a component carrier, which is particularly capable of being constructed with exceptional mechanical stability, the spatial relationship between the measuring plate and the at least one camera can be determined particularly reliably and continuously.

[0016] In one embodiment, a two-dimensional pattern, such as a checkerboard pattern, is constructed on the measuring plate of the mobile device.

[0017] In one embodiment, a three-dimensional pattern is constructed on the measuring plate of the mobile device.

[0018] Using a measuring plate with such a pattern constructed on it, the position and orientation of a mobile device with respect to a camera, especially with respect to a camera mounted on another mobile device, can be reliably determined.

[0019] Each mobile device's measuring plate can have a different pattern, allowing for differentiation and clear identification of mobile devices based on the different patterns on the measuring plates.

[0020] In one embodiment, the at least one camera is a wide-angle camera, particularly a so-called "fisheye," to enable optical inspection of the entire measurement site using motor vehicles, calibration tools, and other mobile equipment as much as possible.

[0021] In one implementation, the camera is a 2D camera. 2D cameras are particularly inexpensive.

[0022] In one implementation, the camera is a 3D camera. The 3D camera provides images that include three-dimensional information.

[0023] In one implementation, the camera is high frame rate. A camera with a high frame rate is advantageous when the calibration tool or a portion of the calibration tool moves during image acquisition.

[0024] In one embodiment, the mobile device is additionally equipped with a lidar sensor, which is arranged in a fixed spatial relationship relative to the measuring plate and the at least one camera. The lidar sensor can be mounted, in particular, in a fixed spatial relationship on the component carrier.

[0025] With the help of lidar sensors, the accuracy of measurement results can be further improved, especially at greater distances between motor vehicles and mobile equipment.

[0026] In one embodiment, the system according to the invention includes at least one vehicle measuring plate configured for mounting on a vehicle. By mounting the vehicle measuring plate on the vehicle, particularly at the wheels of the vehicle, the accuracy of the position of the motor vehicle determined by the acquired images can be further improved, and thus the accuracy of the determined position of the calibration tool in front of the motor vehicle can also be further improved.

[0027] In one embodiment, the method for calibrating a vehicle sensor according to the invention includes moving at least one calibration tool about the vehicle sensor to be calibrated during calibration.

[0028] Here, the at least one calibration tool can be moved to different pre-given positions in an automated process, and / or positioned in different orientations in front of the vehicle sensor to be calibrated.

[0029] The method may include, in particular, the at least one calibration tool moving in a oscillating motion around the vehicle sensor to be calibrated during calibration.

[0030] As an alternative or additional solution, it is possible to enable at least one calibration tool to move linearly with respect to the vehicle sensor motion.

[0031] In one embodiment, the method for calibrating vehicle sensors according to the invention includes continuously or temporarily arranging the at least one calibration tool above the engine hood of a motor vehicle during calibration.

[0032] Embodiments of the present invention will now be described with reference to the accompanying drawings. Attached Figure Description

[0033] Figure 1 A schematic diagram of a measurement site is shown, including a motor vehicle, a calibration tool, and a system according to the invention for determining the position of the calibration tool in front of the motor vehicle. Figure 2 A mobile device according to the invention for determining the position of a calibration tool in front of a motor vehicle is shown; and Figure 3 This is a flowchart of a method for determining the position of a calibration tool in front of a motor vehicle according to an embodiment of the present invention. Detailed Implementation

[0034] Figure 1 A schematic top view of a measurement site is shown, featuring a motor vehicle 2 equipped with at least one vehicle sensor 8. The vehicle sensor 8 can be, in particular, a sensor for a driver assistance system 9. The vehicle sensor 8 can be, for example, an optical sensor, particularly a camera, radar sensor, or laser sensor (LiDAR).

[0035] The motor vehicle 2 has four wheels 4, and vehicle measuring plates 6 are installed at each of the wheels.

[0036] Although Figure 1 The invention is shown as a motor vehicle 2 with four wheels 4, but it can also be used in conjunction with motor vehicles 2 having two, three or more wheels 4.

[0037] A calibration tool 10 is arranged in front of the motor vehicle 2, particularly in front of the vehicle sensor 8, which is capable of calibrating the vehicle sensor 8. In order to calibrate the vehicle sensor 8 by means of the calibration tool 10, the position and orientation of the calibration tool 10 with respect to the motor vehicle 2, and particularly with respect to the vehicle sensor 8, must be known with sufficient accuracy.

[0038] In order to determine the position and orientation of the calibration tool 10 with respect to the motor vehicle 2, and especially with respect to the vehicle sensor 8, the calibration tool 10 is equipped with a calibration tool measuring plate 11. The calibration tool measuring plate 11 has a calibration tool measuring plate pattern, such as a checkerboard pattern.

[0039] In addition, four mobile devices 12 are arranged on the measurement site, which are capable of determining the position and orientation of the calibration tool 10 with respect to the motor vehicle 2, and especially with respect to the vehicle sensor 8.

[0040] The system according to the invention for determining the position of calibration tool 10 in front of motor vehicle 2 includes, in addition to mobile device 12, evaluation device 24, which is configured to evaluate the image provided by mobile device 12 in order to determine the position and orientation of calibration tool 10 relative to motor vehicle 2.

[0041] The evaluation device 24 can be constructed as part of the mobile device 12 or spatially separate from the mobile device 12.

[0042] Although Figure 1 The illustrated embodiment contains four mobile devices 12, but a system according to the invention for determining the position and orientation of a calibration tool 10 may also include fewer than four mobile devices 12, such as two or three mobile devices 12.

[0043] Figure 2 A three-dimensional illustration of an embodiment of the mobile device 12 according to the present invention is shown.

[0044] The mobile device 12 includes a support 14, particularly a tripod, which supports the mobile device 12 on the ground of the measurement site.

[0045] A component carrier 16 is mounted at the bracket 14. The component carrier 16 can be mounted at the bracket 14 with particular height adjustment.

[0046] A measuring plate 18 and a camera 20 are mounted on the component carrier 16. Optionally, a laser sensor (LiDAR sensor) 22 can be additionally mounted on the component carrier 16.

[0047] The measuring plate 18, camera 20 and laser sensor 22 (wherever they are) are mounted on the component carrier 16 in a predetermined fixed spatial relationship relative to each other, in particular at a predetermined angle and interval relative to each other, such that their positions and orientations are determined relative to each other.

[0048] A characteristic pattern, such as a checkerboard pattern, is constructed on the measuring plate 18 mounted on the component carrier 16. The pattern can be a two-dimensional pattern or a three-dimensional pattern.

[0049] Each mobile device 12's measuring plate 18 can have a different pattern, making it possible to distinguish and clearly identify the mobile device 12 based on the measuring plate 18 with different patterns.

[0050] exist Figure 2 A three-dimensional pattern is shown. The 3D effect of the three-dimensional pattern is strongly exaggerated, therefore the 3D effect is... Figure 2 It can be clearly seen from the middle.

[0051] refer to Figure 3 The following describes a method 100 for determining the position and orientation of a calibration tool 10 with respect to a motor vehicle 2 according to an embodiment of the present invention.

[0052] In the first step 110, the motor vehicle 2 equipped with the vehicle sensor 8, the calibration tool 10, and the mobile device 12 are placed on the measurement site. Here, the motor vehicle 2, the calibration tool 10, and the mobile device 12 can be placed on the measurement site in any time sequence.

[0053] In the optional second step 120, the vehicle measuring plate 6 can be mounted on the wheel 4 of the motor vehicle 2, as if it were... Figure 1 As shown in the diagram.

[0054] In the next step 130, the camera 20 of each of the mobile devices 12 arranged on the measurement site optically detects the measuring plate 18 of at least one other mobile device 12 arranged on the measurement site. Each camera 20 acquires at least one image of the measuring plate 18 that is optically detected.

[0055] The images captured by camera 20 also include at least one range of motor vehicle 2. At least one image captured by camera 20 of at least one of the mobile devices 12 also includes calibration tool 10, and in particular calibration tool measuring plate 11 of calibration tool 10.

[0056] The images captured by camera 20 are transmitted to evaluation device 24.

[0057] Images captured by camera 20 can be transmitted to evaluation device 24 via wired or wireless means, such as WLAN or Bluetooth® connection. For this purpose, camera 20 and evaluation device 24 can be configured with suitable transmitters and receivers, which are configured to... Figure 1 and Figure 2 It is not explicitly shown in the text.

[0058] In step 140, the evaluation device 24 evaluates the image captured by the camera 20 and determines a global coordinate system G, which is defined by the mobile device 12.

[0059] The image acquired by camera 20 of mobile device 12 and transmitted to evaluation device 24 also includes a local area of ​​motor vehicle 2. When two vehicle measuring plates 6 are mounted at the wheels 4 of the motor vehicle, such as when they are... Figure 1 As shown in the figure, the acquired images also include images of the vehicle measuring plate 6 mounted on the wheel 4 of the motor vehicle 2.

[0060] In the next step 150, the evaluation device 24 evaluates the images captured by the camera 20 in order to determine the position and spatial orientation of the motor vehicle 2 on the measurement site in the global coordinate system G defined by the mobile device 12.

[0061] This can include, in particular, evaluating images of a vehicle measuring plate 6 mounted on the wheel 4 of the motor vehicle 2.

[0062] As an alternative or additional approach, representative features of the vehicle body 2 can be identified from images captured by camera 20, for example, using artificial intelligence. The position and orientation of vehicle 2 in the global coordinate system G can then be determined based on these representative features of the vehicle body 2.

[0063] The position and orientation of the vehicle sensor 8 used for calibration in the local coordinate system L of the motor vehicle 2 are known. This information is provided, for example, by the manufacturer of the motor vehicle 2 and / or the vehicle sensor 8.

[0064] In step 160, the position and orientation of the vehicle sensor 8 in the local coordinate system L of the motor vehicle 2 for calibration are retrieved from the database or manually input into the evaluation device 24.

[0065] After the position and orientation of the vehicle 2 in the global coordinate system G have been determined, the position and orientation of the vehicle sensor 8 used for calibration can also be transformed from the local coordinate system L of the vehicle 2 to the global coordinate system G in step 170.

[0066] The images captured by the camera 20 of at least one of the mobile devices 12 also include images of the calibration tool 10, and in particular images of the calibration tool measuring plate 11 of the calibration tool 10.

[0067] In step 180, the position and orientation of the calibration tool 10 in the global coordinate system G are determined by evaluating these images.

[0068] Having known not only the position and orientation of the vehicle sensor 8 used for calibration in the global coordinate system G, but also the position and orientation of the calibration tool 10, the position and orientation of the calibration tool 10 in the local coordinate system S of the vehicle sensor 8 can be determined in the next step 190.

[0069] Using this information, the vehicle sensor 8 can be reliably and with high accuracy calibrated.

[0070] Optionally, the method for calibrating a vehicle sensor 8 according to the invention can include moving at least one calibration tool 10 about the vehicle sensor 8 during the calibration process. The method can particularly include moving at least one calibration tool 10 in an oscillating motion about the vehicle sensor 8. Alternatively or additionally, at least one calibration tool 10 can be moved about the vehicle sensor 8 in a linear motion.

[0071] At least one calibration tool 10 is capable of moving to different pre-given positions in an automated process and / or being positioned in different orientations in front of the vehicle sensor 8 to be calibrated.

[0072] The method for calibrating vehicle sensor 8 according to the present invention may also include continuously or temporarily arranging at least one calibration tool 10 above the engine hood of the motor vehicle 2.

[0073] By means of the lidar sensor 22 which can be optionally located at the mobile device 12, the accuracy of the measurement results can be further improved, especially at a greater distance between the motor vehicle 2 and the mobile device 12, and the position and orientation of the calibration tool 10 in the local coordinate system S of the vehicle sensor 8 can be determined more accurately.

Claims

1. A mobile device (12) for determining the position of a calibration tool (10) in front of a motor vehicle (2), particularly for preparing for calibration of a vehicle sensor (8) installed in the motor vehicle (2), in, The mobile device (12) has: Support (14); Measuring plate (18) and At least one camera (20), and The measuring plate (18) and the at least one camera (20) are mounted relative to each other at the bracket (14) in a pre-given fixed spatial relationship.

2. The mobile device (12) according to claim 1, comprising a component carrier (16) mounted on the bracket (14), wherein, The measuring plate (18) and the at least one camera (20) are mounted relative to each other on the component carrier (16) in a pre-given fixed spatial relationship.

3. The mobile device (12) according to claim 1 or 2, wherein, Two-dimensional or three-dimensional patterns are constructed on the measuring plate (18).

4. The mobile device (12) according to any one of the preceding claims. in, The camera (20) is a wide-angle camera, and / or The camera (20) is either a 2D camera (20) or a 3D camera (20).

5. The mobile device (12) according to any one of the preceding claims, wherein, The mobile device (12) additionally has a lidar sensor (22) arranged in a fixed spatial relationship with respect to the measuring plate (18) and the at least one camera (20) on the bracket (14); wherein the lidar sensor (22) is particularly mounted on the component carrier (16).

6. A system (10, 12, 24) for determining the position of a calibration tool (10) in front of a vehicle sensor (8), particularly for preparing for calibration of a vehicle sensor (8) installed in a motor vehicle (2), wherein, The system (10, 12, 24) has: At least two mobile devices (12) according to any one of the preceding claims; At least one calibration tool (10) that can be optically detected by vehicle sensors (8); and Evaluation device (24), configured to evaluate images provided by cameras (20) of the at least two mobile devices (12) in order to determine the position of the calibration tool (10) relative to the vehicle sensor (8).

7. The system (10, 12, 24) for determining the position of the calibration tool (10) in front of the vehicle sensor (8) according to claim 6, wherein, The system (10, 12, 24) includes two, three, or four mobile devices (12).

8. The system (10, 12, 24) for determining the position of the calibration tool (10) in front of the motor vehicle (2) according to claim 6 or 7, wherein, The patterns constructed on the measuring plates (18) of different mobile devices (12) are different from each other.

9. The system (10, 12, 24) for determining the position of the calibration tool (10) in front of the motor vehicle (2) according to any one of claims 6 to 8, wherein, The system (10, 12, 24) has at least one vehicle measuring plate (6) configured for mounting on the vehicle (2).

10. A method for determining the position of a calibration tool (10) in front of a vehicle sensor (8), particularly for preparing to calibrate the vehicle sensor (8), wherein, The method includes: Place the vehicle (2) equipped with vehicle sensor (8) on the measurement site; Place at least two mobile devices (12) according to any one of claims 1 to 5 on the measurement site; Place the calibration tool (10) in the field of view of the vehicle sensor (8) at the measurement site; Images are acquired using the cameras (20) of the at least two mobile devices (12); Identify the measuring plate (18) installed at at least one other mobile device (12) in the acquired images, and define a coordinate system (G) pre-given by the mobile device (12). Identify the motor vehicle (2) in the acquired images and determine the position of the motor vehicle (2), and in particular the vehicle sensor (8), in the coordinate system (G) defined by the mobile device (12); Identify the at least one calibration tool (10) in the acquired images and determine the position of the at least one calibration tool (10) in the coordinate system (G) defined by the mobile device (12); and Determine the position of the at least one calibration tool (10) in the local coordinate system (S) of the vehicle sensor (8).

11. A method for calibrating vehicle sensors (8), particularly vehicle sensors (8) of driver assistance systems (9), wherein, The method includes: The position of at least one calibration tool (10) in front of the vehicle sensor (8) to be calibrated is determined using the method according to claim 10; The vehicle sensor (8) to be calibrated is detected by the at least one calibration tool (10), and the vehicle sensor (8) is calibrated based on a previously determined position of the at least one calibration tool (10) in front of the vehicle sensor (8).

12. The method for calibrating a vehicle sensor (8) according to claim 11, wherein, The method includes moving the at least one calibration tool (10) about the vehicle sensor (8) during calibration; wherein, in particular, the method includes moving the at least one calibration tool (10) in an oscillating motion about the vehicle sensor (8) during calibration.

13. The method for calibrating a vehicle sensor (8) according to claim 11 or 12, wherein, The method includes arranging the at least one calibration tool (10) above the engine hood of the motor vehicle (2).

Images