Calibrating a vehicle environment sensor

Abstract

A calibration aid (16) for assisting the calibration of a vehicle environment sensor (4), in particular a camera (22), of a driver assistance system of a motor vehicle (6) comprises: at least one light sensor (20) which is designed to detect light incident on the calibration aid (16); and at least one camera (22) which is designed to optically capture calibration patterns which are formed, for example, on calibration panels (10a, 10b). The calibration aid (16) is designed to be positioned on or against the motor vehicle (6) in the environment of the vehicle environment sensor (4) to be calibrated.

Description

[0001] Description

[0002] title

[0003] Calibrating a

[0004] The invention relates to a calibration aid and a calibration setup for calibrating a vehicle environment sensor, as well as a method for checking whether a calibration setup is suitable for calibrating a vehicle environment sensor.

[0005] State of the art

[0006] Regardless of whether they are equipped with an internal combustion engine or an electric motor, modern motor vehicles are often fitted with driver assistance systems that support the driver in operating the vehicle. These systems typically include vehicle environment sensors to monitor the vehicle's surroundings.

[0007] Vehicle environment sensors may need to be recalibrated after a vehicle repair, e.g., after replacing the vehicle's windshield.

[0008] The recalibration of vehicle environment sensors can be affected by the current conditions, especially the lighting conditions, in the vicinity of the vehicle.

[0009] It is therefore an object of the invention to provide a calibration aid and a method that make it possible to calibrate a

[0010] To improve vehicle environment sensors in a vehicle sensor; in particular to simplify, control the calibration process and increase the quality of the calibration.

[0011] A calibration aid according to the invention for supporting the (re-)calibration of a vehicle environment sensor, in particular a camera, of a driver assistance system of a motor vehicle comprises: a light sensor configured to detect light incident on the calibration aid; and at least one camera configured to optically capture calibration patterns, for example, those formed on calibration targets. The calibration aid is configured to be positioned on or in the vicinity of the vehicle environment sensor to be calibrated on the motor vehicle. The calibration aid can also be configured to be arranged in the interior of the motor vehicle, in particular behind the windshield, facing outwards.

[0012] The invention also includes a calibration setup for calibrating a vehicle environment sensor, in particular a camera, of a driver assistance system of a motor vehicle, wherein the calibration setup comprises: at least one calibration pattern, which is in particular formed on a calibration target; a calibration aid according to the invention and a control device which is configured to communicate with the calibration aid in order to receive measurement data from the calibration aid and to check, on the basis of the measurement data received from the calibration aid, whether the calibration setup is suitable for calibrating the vehicle environment sensor.

[0013] The invention further comprises a method for verifying whether a calibration setup is suitable for calibrating a vehicle environment sensor, in particular a camera, of a driver assistance system. A method according to the invention comprises: positioning a calibration aid according to the invention in, on, or in the vicinity of the vehicle environment sensor to be calibrated in, on, or in the motor vehicle; detecting light incident on the calibration aid with the at least one light sensor of the calibration aid and providing corresponding measurement data; optically capturing at least one calibration pattern with the at least one camera of the calibration aid and providing corresponding measurement data; and evaluating the measurement data supplied by the at least one light sensor and the at least one camera in order to verify whether the calibration setup is suitable for calibrating the vehicle environment sensor.

[0014] With a calibration aid, a calibration setup, and a method according to the invention, it is possible to easily and reliably verify, before starting the calibration of a vehicle environment sensor installed in a motor vehicle, whether the current calibration setup and the (light) conditions at the measuring station are suitable for performing the desired calibration of the vehicle environment sensor with sufficient accuracy. Faulty calibration attempts and / or calibrations that lead to an incorrect or inaccurate calibration of the vehicle environment sensor can thus be avoided. The calibration of vehicle environment sensors can therefore be significantly improved and made more efficient.

[0015] The calibration aid can be positioned on or in the motor vehicle in such a way that the light striking the installation position of the vehicle environment sensor to be calibrated is detected by the light sensor.

[0016] In one embodiment, the calibration aid comprises a fastening device that allows the calibration aid to be detachably fixed in, on, or to the motor vehicle. The fastening device can, for example, have a suction cup or a non-slip mat that allows the calibration aid to be fixed to the roof or windshield of the motor vehicle. The use of a calibration aid according to the invention can thus be simplified.

[0017] The calibration aid may include a mono or stereo camera. At least one camera in the calibration aid can be an inexpensive black and white camera or a color camera.

[0018] In one embodiment, the calibration aid includes a communication device that enables it to communicate with an external device, in particular an external control device. In this way, the measurement data provided by the at least one light sensor and / or the at least one camera of the calibration aid can be transmitted to the external device for evaluation.

[0019] If the external device concludes during evaluation that the current lighting conditions at the measuring station are not suitable for calibrating the vehicle environment sensor with sufficient accuracy, the external device may be designed to issue a corresponding warning message informing the user that the current (lighting) conditions at the measuring station are not suitable for calibrating the vehicle environment sensor.

[0020] Accordingly, the external device can be designed to inform the user that the current (light) conditions are suitable for calibrating the vehicle environment sensor.

[0021] The external device can also be designed to verify that the correct calibration pattern(s) are displayed.

[0022] Optionally, the calibration aid can be equipped with additional sensors, e.g. a temperature sensor and / or a humidity sensor, which make it possible to measure and check the environmental conditions in the vicinity of the vehicle.

[0023] The communication device can be designed for wired communication, e.g. via a USB connection, and / or for wireless communication, e.g. via a WLAN or Bluetooth® connection.

[0024] In one embodiment, the evaluation of the measurement data supplied by the at least one light sensor and the at least one camera of the calibration aid is not performed in an external device, but rather within the calibration aid itself. The evaluation can, in particular, be carried out in an evaluation unit integrated into the calibration aid. In this case, only one result of the evaluation is transmitted from the calibration aid to the external device via the communication device. The evaluation unit can include a microprocessor on which a suitable program is executed to evaluate the measurement data supplied by the at least one light sensor and the at least one camera of the calibration aid.

[0025] In one embodiment, the calibration aid is equipped with an electrical energy source, in particular a solar cell, an electric battery and / or an electric accumulator, to enable autonomous operation of the calibration aid.

[0026] Alternatively or additionally, the calibration aid can be supplied with electrical energy via a cable connection.

[0027] In one embodiment, the control device of a calibration setup according to the invention is designed to guide a user through a method for calibrating the vehicle environment sensor.

[0028] The invention particularly includes a method for calibrating a vehicle environment sensor, wherein the method comprises a method according to the invention for checking whether a calibration setup is suitable for calibrating a vehicle environment sensor of a driver assistance system; and, if the check shows that the calibration setup is suitable for calibrating the vehicle environment sensor, issuing instructions to a user that guide the user through a method for calibrating the vehicle environment sensor.

[0029] This simplifies the calibration process and reduces the risk of faulty calibration.

[0030] In one embodiment, the calibration setup includes an electronic display device or calibration target that allows different calibration patterns to be displayed. In such an embodiment, the calibration pattern displayed on the display device / calibration target can be adapted to different vehicle environment sensors, driver assistance systems, and / or lighting conditions to enable optimal calibration in each case.

[0031] In one embodiment, the electronic display device / calibration chart can be controlled by the control device. In this case, the control device can be designed, in particular, to take into account the data provided by a display device / calibration aid according to the invention when controlling the electronic display device / calibration chart. This allows the calibration pattern displayed on the electronic display device / calibration chart to be adapted particularly efficiently to the current lighting conditions at the measuring station.

[0032] An embodiment of the invention is described below with reference to the accompanying figures.

[0033] Short the

[0034] Figure 1 shows a measuring station with a calibration setup for calibrating a vehicle environment sensor in a motor vehicle.

[0035] Figure 2 shows a front view of the motor vehicle with a vehicle environment sensor to be calibrated.

[0036] Figure 3 shows a schematic view of a calibration aid designed according to an embodiment of the invention.

[0037] Figure 1 shows a measuring station 2 with a motor vehicle 6 and with a calibration setup 1 for calibrating a vehicle environment sensor 4, which is installed in the motor vehicle 6.

[0038] The vehicle environment sensor 4 can, in particular, be a camera positioned behind the windshield 7 of the motor vehicle 6. The vehicle environment sensor 4 can also be located at another point on the motor vehicle 6.

[0039] A calibration device 8 is positioned on the measuring station 2 in front of the motor vehicle 6. The calibration device 8 comprises two calibration targets 10a, 10b, each of which has a calibration pattern formed on it, which is not visible in Figure 1.

[0040] The calibration patterns formed on the calibration targets 10a, 10b can be optically detected by the vehicle environment sensor 4, so that the vehicle environment sensor 4 can be calibrated using the calibration patterns formed on the calibration targets 10a, 10b.

[0041] The calibration device 8 also includes two cameras 12a, 12b, which are designed to optically detect measuring plates 14 attached to the wheels 5 (not visible in Figure 1, see Figure 2) of the motor vehicle 6. The position and orientation of the calibration device 8 in front of the motor vehicle 6 can be determined from the images captured by the two cameras 12a, 12b. In this way, the calibration device 8 can be positioned with high accuracy at a location suitable for calibrating the vehicle's surroundings sensor 4.

[0042] The position and orientation of the calibration device 8 in front of the vehicle 6 may, for example, be specified by the manufacturer of the vehicle environment sensor 4 and / or by the manufacturer of the driver assistance system. The specific position of the calibration device 8 in front of the vehicle 6 can be taken into account during the calibration of the vehicle environment sensor 4.

[0043] Figure 2 shows a front view of the motor vehicle 6 as seen by the two cameras 12a, 12b of the calibration device 8. It is also possible that each of the two cameras 12a, 12b does not see the entire motor vehicle 6, but only a partial area of ​​the motor vehicle 6, for example, on one side of the motor vehicle 6. A calibration aid 16 according to the invention is arranged on the motor vehicle 6 above the vehicle environment sensor 4. The calibration aid 16 can, in particular, be arranged on / at the windshield 7 or on the roof 9 of the motor vehicle 6.

[0044] The calibration aid 16 can be arranged on or attached to the motor vehicle 6 in such a way that the distance between the calibration aid 16 and the vehicle environment sensor 4 to be calibrated is less than 50 cm, in particular less than 30 cm.

[0045] The calibration aid 16 can, for example, include a suction cup and / or a non-slip mat 18, which makes it possible to attach the calibration aid 16 securely but releasably to the motor vehicle 6.

[0046] Alternatively or additionally, the calibration aid 16 can also be attached to the motor vehicle 6 using a magnet.

[0047] Figure 3 shows a schematic view of a calibration aid 16, which is designed according to an embodiment of the invention.

[0048] The calibration aid 16 comprises at least one light sensor 20 configured to detect light incident on the calibration aid 16, for example, sunlight, and at least one camera 22 configured to optically capture the calibration patterns formed on the calibration plates 10a, 10b. The calibration aid 16 also comprises an electrical energy source 25, for example, a solar cell, an electric battery, or an electric accumulator, to supply the calibration aid 16 with electrical energy. Alternatively, the calibration aid 16 can be supplied with electrical energy via an electrical conductor not shown in the figures.

[0049] The calibration aid 16 also includes a communication device 24, which enables the calibration aid 16 to communicate with an external device 28, in particular with an external control device 28 of the calibration device 8 (see Figure 1), and in particular to transmit the measurement data provided by the at least light sensor 20 and by the at least one camera 22 to the external device 28.

[0050] The communication device 24 can be configured for wired data transmission, for example via a USB cable, and / or for wireless data transmission, for example via a WLAN or Bluetooth data connection.

[0051] The external device 28 can be configured to receive and evaluate the data provided by the calibration aid 16 in order to check whether the current calibration setup 1 is suitable for calibrating the vehicle environment sensor 4.

[0052] The external device 28 can, for example, be configured to determine whether the light incident on the calibration aid 16 and the adjacent vehicle environment sensor 4, which has been detected by the light sensor 20, is too great, e.g. due to reflections and / or direct sunlight, to be able to carry out a proper calibration of the vehicle environment sensor 4.

[0053] The external device 28 can also be configured to determine whether the calibration patterns formed on the calibration targets 10a, 10b are sufficiently recognizable to enable proper calibration of the vehicle environment sensor 4.

[0054] Should the external device 28 determine during evaluation that the current lighting conditions at the measuring station 2 are unsuitable for calibrating the vehicle environment sensor 4 with sufficient accuracy, the external device 28 can issue a corresponding warning message, e.g., via a display device 30 (see Figure 1), informing the user that the current lighting conditions are unsuitable for calibrating the vehicle environment sensor 4. Conversely, the user can be informed that the current lighting conditions are suitable for calibrating the vehicle environment sensor 4.

[0055] Optionally, the warning message can also contain detailed information to inform the user why the calibration cannot be performed; e.g., "excessive light exposure" or "measurement charts not visible".

[0056] If the external device 28 determines that the current lighting conditions are suitable for calibrating the vehicle environment sensor 4, it can issue instructions to the user, for example via the display device 30, guiding the user through a procedure for calibrating the vehicle environment sensor 4. The risk of faulty or inaccurate calibration can thus be reduced.

[0057] In an alternative embodiment, the evaluation of the measurement data supplied by the at least one light sensor 20 and the at least one camera 22 of the calibration aid 16 is not carried out in the external device 28, but in the calibration aid 16 itself. The evaluation can, in particular, be carried out in an evaluation unit 26 that is integrated into the calibration aid 16. In this case, only the result of the evaluation is transmitted from the calibration aid 16 to the external device 28 by means of the communication device 24.

[0058] The evaluation unit 26 can, for example, comprise a microprocessor 27 on which a suitable program is executed to evaluate the measurement data supplied by the at least one light sensor 20 and by the at least one camera 22 of the calibration aid 16.

[0059] In one embodiment, the calibration targets 10a, 10b can be designed as electronic calibration targets 10a, 10b, which are capable of selectively displaying different measurement patterns. The electronic calibration targets 10a, 10b can, in particular, be controlled by the control device 28. When controlling the electronic calibration targets 10a, 10b, the control device 28 can, in particular, use the measurement results provided by the calibration aid 16 to control the electronic calibration targets 10a, 10b, for example, depending on the current lighting conditions at the measuring station 2.

[0060] For example, the contrast of the calibration patterns displayed on the electronic calibration charts 10a, 10b can be increased, or a different calibration pattern can be selected if the current calibration patterns are poorly or not at all visible from the calibration aid 16.

Claims

1. Calibration aid (16) for supporting the calibration of a vehicle environment sensor (4), in particular a camera (22), of a driver assistance system of a motor vehicle (6), wherein the calibration aid (16) comprises: at least one light sensor (20) configured to detect light incident on the calibration aid (16); and at least one camera (22) configured to optically detect calibration patterns, for example, formed on calibration targets (10a, 10b); wherein the calibration aid (16) is configured to be positioned in the vicinity of the vehicle environment sensor (4) to be calibrated on or in the motor vehicle (6).

2. Calibration aid (16) according to claim 1, wherein the calibration aid (16) comprises a fastening device (18) which makes it possible to detachably attach the calibration aid (16) to or on the motor vehicle (6); wherein the fastening device (18) in particular comprises a suction cup or a non-slip mat.

3. Calibration aid (16) according to claim 1 or 2, wherein the calibration aid (16) comprises a mono camera (22) or a stereo camera (22).

4. Calibration aid (16) according to one of the preceding claims, wherein the calibration aid (16) has a communication device (24) which enables the calibration aid (16) to communicate with an external device (28), in particular with an external control device (28).

5. Calibration aid (16) according to claim 4, wherein the communication device (24) is configured for wired communication and / or wireless communication.

6. Calibration aid (16) according to one of the preceding claims, wherein the calibration aid (16) comprises an electrical energy source (25), in particular a solar cell, an electric battery and / or an electric accumulator.

7. Calibration setup (1) for calibrating a vehicle environment sensor (4), in particular a camera (22), of a driver assistance system of a motor vehicle (6), wherein the calibration setup (1) comprises: at least one calibration pattern, which is in particular formed on a calibration target (1 Oa, 10b); a calibration aid (16) according to one of the preceding claims, a control device (28) which is configured to communicate with the calibration aid (16) in order to receive measurement data from the calibration aid (16) and to check, on the basis of the measurement data received from the calibration aid (16), whether the calibration setup (1) is suitable for calibrating the vehicle environment sensor (4).

8. Calibration setup (1) for calibrating a vehicle environment sensor (4) according to claim 7, wherein the control device (28) is configured to guide a user through the calibration of the vehicle environment sensor (4).

9. Calibration setup (1) for calibrating a vehicle environment sensor (4) according to claim 7 or 8, wherein the calibration setup (1) comprises an electronic display device or calibration target (10a, 10b) which makes it possible to display different calibration patterns and which can be controlled by the control device (28).

10. Method for checking whether a calibration setup (1) is suitable for calibrating a vehicle environment sensor (4), in particular a camera (22), of a driver assistance system of a motor vehicle (6), wherein the method comprises: positioning a calibration aid (16) according to one of claims 1 to 6 in the vicinity of the vehicle environment sensor (4) to be calibrated on or in the motor vehicle (6); detecting light incident on the calibration aid (16) with the at least one light sensor (20) of the calibration aid (16) and providing corresponding measurement data; optically capturing at least one calibration pattern with the at least one camera (22) of the calibration aid (16) and providing corresponding measurement data; and evaluating the measurement data supplied by the at least one light sensor (20) and by the at least one camera (22) in order to check whether the calibration setup (1) is suitable for calibrating the vehicle environment sensor (4).

11. Method for calibrating a vehicle environment sensor (4), wherein the method comprises: a method for checking whether a calibration setup (1) is suitable for calibrating a vehicle environment sensor (4), in particular a camera (22), of a driver assistance system of a motor vehicle (6), to perform according to claim 10; and, if the calibration setup (1) is suitable for calibrating the vehicle environment sensor (4), issuing instructions to a user that guide a user through the method for calibrating a vehicle environment sensor (4).

Images