Method and apparatus for calibrating sensors of a vehicle

Abstract

The invention provides a method for calibrating a sensor (20) of a vehicle (18). In this case, a sensor measurement value is received with the aid of a data processing device (10) together with a measurement position and a measurement time. If the measurement time of the sensor measurement value and the reference measurement time deviate from each other by a maximum of 30 minutes, the sensor measurement value is assigned to at least one reference measurement value based on the measurement position and the measurement time, which reference measurement value has been determined with the aid of a reference sensor (26) of a reference vehicle (24) at a reference position and at a reference measurement time. In addition, at least one reference calibration value of the reference sensor (26) is transmitted to the vehicle and / or provided to the vehicle, so that the current calibration value of the sensor (20) can be matched based on the reference calibration value. Overall, an improved method for calibrating the sensor (20) can be provided.

Description

Technical Field

[0001] The invention relates to a method for calibrating a sensor of a vehicle. In addition, the invention also relates to a data processing device for calibrating a sensor of a vehicle. Background Art

[0002] Modern vehicles are equipped with a plurality of sensors, which can be used in particular for detecting the environment of the vehicle. In vehicles of a vehicle type, such as vehicles of a vehicle series and / or in vehicles of different vehicle types, the same sensor can sometimes provide different sensor measurements and / or measurement values. This can be caused by the following: the parameters of the sensors themselves, such as, for example, the installation position and / or orientation, of the corresponding sensors are different from each other. Vehicle-specific parameters can also influence the sensor measurements detected by means of the corresponding sensors. Examples of such vehicle-specific parameters are, for example, towing load, trailer operation, tire size and / or transport load. Accessories on the individual vehicles, such as, for example, rear spoilers, bicycle racks, roof main beams and / or luggage racks can also influence the sensor measurements detected by means of the corresponding sensors. Such influences on the sensor measurements can be compensated by means of suitable calibration values.

[0003] However, vehicle-specific and / or vehicle-individual calibration of sensors and / or use of sensors in individual vehicles may sometimes be expensive and lead to increased development costs. Summary of the invention

[0004] By means of specific embodiments of the present invention, an improved method for calibrating a sensor of a vehicle may advantageously be provided.

[0005] One aspect of the invention relates to a method for calibrating a sensor of a vehicle. The method comprises the following steps: receiving, by means of a data processing device, at least one sensor measurement value determined by means of the sensor, a measurement position on the roadway at which the sensor measurement value was determined, and a measurement time at which the sensor measurement value was determined. The measurement time may be a measurement time and / or a time period. The method is characterized in particular by the following steps:

[0006] assigning the sensor measured value to at least one reference measured value based on the measurement position and the measurement time, the at least one reference measured value having been determined by means of a reference sensor of a reference vehicle at a reference position of the roadway and at a reference measurement time, wherein the sensor measured value is assigned to the reference measured value if the measurement time of the sensor measured value and the reference measurement time deviate from one another by a maximum of 30 minutes;

[0007] At least one reference calibration value of the reference sensor is provided and / or transmitted to the vehicle for matching a current calibration value of the sensor based on the reference calibration value.

[0008] The sensor measurement value obtained by means of the sensor can generally be a sensor raw value and / or a measurement value obtained based on at least one current calibration value of the sensor. The sensor can be configured and / or set in particular for detecting the environment of the vehicle. The sensor measurement value obtained by means of the sensor can be provided to the data processing device together with the measurement position and the measurement time, for example, based on transmission and / or transmission from the vehicle to the data processing device. Such transmission and / or transmission can be implemented in particular wirelessly, for example, via an Internet connection, a Bluetooth connection and / or a telephone network. It can also be provided that the current calibration value of the sensor is provided to the data processing device and / or the current calibration value of the sensor is transmitted to the data processing device. The data processing device can be arranged at least partially in the vehicle here. Alternatively or additionally, the data processing device can be a data processing device outside the vehicle. For example, the data processing device can have at least one server and / or a cloud server. The data processing device can also have a plurality of data processing elements, so that the method according to the present invention can be implemented partially on the data processing element of the vehicle itself and partially on the data processing element outside the vehicle. The sensor type of the sensor can also be transmitted and / or provided to the data processing device. Furthermore, the measurement position can include geographical coordinates which have been determined, for example, using a positioning device (eg GPS) of the vehicle.

[0009] The reference vehicle can generally represent any other vehicle. However, unlike the sensors of the subject vehicle, the reference sensors of the reference vehicle can be correctly calibrated based on reference calibration values. One or more reference measurement values ​​of the reference sensor together with the associated reference measurement position and reference measurement time can be stored in the data processing device and / or in a data memory of the data processing device. One or more reference calibration values ​​can also be stored in the data processing device. In addition, the type and / or type name of each reference sensor can be stored in the data processing device. The vehicle type of the reference vehicle can also be stored in the data memory.

[0010] According to the invention, it is provided that the sensor measurement values ​​together with the measurement position and the measurement time are provided to the data processing device, in particular during operation of the vehicle. The data processing device can determine at least one reference measurement value based on the measurement position, which has been determined at a position on the roadway that is similar and / or identical to the measurement position. Furthermore, the data processing device can determine at least one reference measurement value based on the measurement time, the reference measurement time of the at least one reference measurement value not deviating from the measurement time by more than 30 minutes. In this way, one or more reference measurement values ​​can be assigned to the sensor measurement values.

[0011] Optionally, the data processing device and / or a data processing element of the data processing device can then determine the deviation between a reference measured value (or multiple reference measured values) based on a comparison of these values ​​with the sensor measured values. The data processing device and / or the associated data processing element can be arranged in the vehicle or outside the vehicle. If the determined deviation reaches or exceeds a threshold value, which can be stored, for example, in a data memory of the vehicle and / or of the data processing device, the data processing device can provide the vehicle with a reference calibration value. The reference calibration value can be transmitted to the vehicle and / or provided to the vehicle by the data processing device.

[0012] Based on the reference calibration value, the current calibration value of the vehicle can be adapted and / or changed. The reference calibration value can here denote a correction value for the current calibration value, based on which the current calibration value can be adapted. Alternatively or additionally, the reference calibration value can denote a parameterization value for the sensor, based on which the sensor can be parameterized. The reference calibration value can thus, for example, overwrite the current calibration value.

[0013] The present invention can be considered in particular as being based on the knowledge described below. Sometimes, the environmental conditions of the vehicle, the roadway state and / or the roadway parameters can change in a relatively short period of time. For example, the friction value between the vehicle and the roadway, the light influence, the snow layer on the roadway and / or the water level can change relatively quickly at a certain roadway position, wherein the water level on the roadway also includes the humidity of the roadway. The comparison of the reference measurement value, which has been obtained at the same roadway position as the sensor measurement value but at a reference measurement time long before or long after the measurement time of the sensor measurement value, can therefore lead to a significant deviation of the reference measurement value from the sensor measurement value. However, such a deviation cannot be caused by an erroneous calibration value of the sensor, but rather essentially by a deviation of the reference measurement time from the measurement time of the sensor measurement value and the resulting change of the associated measurement variable.

[0014] According to the invention, it is therefore provided that a sensor measurement value is assigned to a reference measurement value only if the reference measurement time and the measurement time of the sensor measurement value deviate from each other by a maximum of 30 minutes. This ensures that the reference measurement value and the sensor measurement value are ascertained under similar, identical and / or substantially identical conditions. Overall, errors in the ascertainment of the reference calibration value can thus be avoided. In other words, it can thus be ensured that the vehicle is always provided with a correct reference calibration value. Overall, an improved and more robust method for calibrating sensors of a vehicle can thus be provided.

[0015] According to one specific embodiment of the invention, the sensor measured value is assigned to the reference measured value if the measurement time of the sensor measured value deviates from the reference measured time by a maximum of ten minutes, in particular by a maximum of five minutes. In other words, it can be provided that the sensor measured value is assigned to the reference measured value only if the measurement time and the reference measured time deviate from each other only in the range of less than ten minutes. This ensures that the conditions under which the reference measured value has been determined and the conditions under which the sensor measured value has been determined are substantially the same, similar and / or unchanged, so that a correct reference calibration value can be provided to the vehicle based on the assigned reference measured value.

[0016] According to one specific embodiment, the method further comprises the following steps: ascertaining a deviation between a reference measured value and a sensor measured value and comparing the ascertained deviation with a threshold value, wherein the at least one reference calibration value of the reference sensor is transmitted to the vehicle if the ascertained deviation exceeds the threshold value.

[0017] According to one embodiment of the present invention, the method further comprises the following steps: determining the following lane: the vehicle is located on the lane during the determination of the sensor measurement value. The lane can be determined by the vehicle and transmitted to the data processing device. The data processing device can also determine the lane, for example, based on the measurement position. Alternatively or additionally, the method comprises the following steps: providing, transmitting and / or receiving lane-related parameters to the data processing device, wherein if the reference measurement value has been determined by the reference vehicle on the same lane, the sensor measurement value is assigned to the reference measurement value. For example, the water level on different lanes can be significantly different at a certain measurement position. By assigning the reference measurement value to the sensor value if two values ​​have been determined on the same lane, it can be ensured that the reference measurement value and the sensor measurement value are determined under substantially the same and / or similar conditions. As a result, the method for calibrating the sensor can be further improved and more robustly and less prone to error.

[0018] According to one specific embodiment of the invention, the method further comprises the following steps: determining the driving direction in which the vehicle is located during the determination of the sensor measurement values. The driving direction can be determined by the vehicle and / or the data processing device, for example based on two measurement positions of two consecutive sensor measurement values. Alternatively or additionally, the method comprises the following steps: providing, transmitting and / or transferring a variable related to the driving direction to the data processing device, wherein the sensor measurement value is assigned to the reference measurement value if the reference measurement value has already been determined by a reference vehicle in the same driving direction. In a similar manner to the lane-based assignment, the method for calibrating the sensor can thereby be further improved and configured more robustly and less prone to errors.

[0019] The sensor type of the sensor can also be ascertained, provided and / or transmitted to the data processing device. For example, the data processing device can assign the sensor measured value to a reference measured value of a reference sensor of the same sensor type.

[0020] According to one specific embodiment of the invention, the sensor measured value is assigned to the reference measured value if the reference vehicle was in the same lane and in the same driving direction as the vehicle during the determination of the reference measured value. In other words, the reference measured value can be assigned to the sensor measured value if the vehicle and the reference vehicle were successively in the same lane in the same driving direction for a period of maximum 30 minutes. This can also increase the robustness of the method for calibrating the sensor and reduce the susceptibility to errors.

[0021] According to one embodiment of the invention, the data processing device is a vehicle-external data processing device. Alternatively or additionally, the data processing device has at least one cloud server and / or is configured as a cloud server. The data processing device can have, for example, a data memory having a plurality of reference measured values ​​and / or reference calibration values ​​of a plurality of reference vehicles stored in the data memory. Thus, a comprehensive database can be provided for calibrating a plurality of sensors.

[0022] According to one embodiment of the present invention, at least one sensor is provided for determining at least one parameter, the at least one parameter being selected from the group consisting of: water level on the road, brightness, friction value, precipitation, snow layer, road icing, road roughness, wind speed, ambient temperature, air pressure and air humidity. The sensor may be, for example, a sensor for detecting the state of the road, the condition of the road, the environment of the vehicle and / or the surrounding environment. Such a measurement variable may, for example, change in a relatively short period of time compared to an object on the road, which object may be identified by means of a camera within the scope of object identification, so that the method according to the present invention may be applied in a particularly advantageous manner to such a sensor. However, it should be emphasized that the present invention is not limited to the aforementioned sensors, but can in principle be used to calibrate any sensor.

[0023] According to one specific embodiment of the invention, the method further comprises a step of ascertaining the vehicle type of the vehicle. Alternatively or additionally, the method comprises a step of providing, transmitting and / or transferring current calibration values ​​and vehicle type-dependent variables.

[0024] According to one embodiment of the present invention, the method further comprises a step of obtaining an average value and / or a standard deviation of a plurality of current calibration values ​​of a plurality of vehicles of the same vehicle type by means of a data processing device. Alternatively or additionally, the method comprises the following steps: providing the average value as an average calibration value and / or the standard deviation to at least one other vehicle of the same vehicle type for calibrating another sensor of the at least one other vehicle. In this way, sensors of vehicles of, for example, a vehicle type and / or a vehicle series can be calibrated by means of the average calibration value. Therefore, precalibration at the vehicle manufacturer can be omitted. A plurality of current calibration values ​​can also be matched in advance by one or more reference calibration values ​​of one or more reference vehicles. By applying the current calibration values ​​thus matched to calibrate another sensor, the correctness of the calibration values ​​thus matched of another vehicle can be ensured. The accuracy and / or precision of the average calibration value can also be improved by forming the average value. In addition, the standard deviation can be used to estimate the inaccuracy of the average value and / or the average calibration value.

[0025] According to one specific embodiment of the invention, the method further comprises the following steps: determining an upper limit and a lower limit of the average calibration value based on the determined mean value and the determined standard deviation. In addition, the method comprises the following steps: providing, transmitting and / or transferring the upper limit and the lower limit to at least one further vehicle of the same vehicle type for calibrating the further sensor of the at least one further vehicle. The upper limit and the lower limit can be used as a measure of the uncertainty and / or accuracy of the average calibration value. This uncertainty can be taken into account, for example, by the control device of the vehicle within the scope of the processing and / or evaluation of the sensor measurement values ​​of the sensor.

[0026] According to one specific embodiment of the invention, the method further comprises the step of determining the median of a plurality of reference calibration values ​​of a plurality of reference vehicles by means of the data processing device and the step of transmitting the median as a reference calibration value to the vehicle. As a result, the method can advantageously be configured more robustly with respect to outliers of the reference calibration values ​​and the calibration can be improved further overall. Such outliers can occur, for example, when the reference sensor is defective and / or when accessories, such as roof rails or the like, are located on the associated reference vehicle.

[0027] Another aspect of the invention relates to a data processing device for calibrating a sensor of a vehicle, wherein the data processing device is configured to implement a method as described previously and below. The data processing device may have a data memory and a processor. Program elements and / or software instructions may be stored on the data memory, which, when executed on the processor, instruct the data processing device to implement a method as described previously and below. One or more reference measurement values ​​may also be stored on the data memory together with the associated reference measurement positions and reference measurement times. One or more reference calibration values ​​may also be stored in the data memory. In addition, one or more sensor measurement values ​​may be stored on the data memory together with the associated measurement positions, measurement times and / or current calibration values. The data storage device may in particular have one or more cloud servers.

[0028] Features, elements and / or steps of the method as described before and in the following may be features and / or elements of the data processing apparatus and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Hereinafter, embodiments of the present invention are described in detail with reference to the accompanying drawings.

[0030] Figure 1 A data processing device according to an embodiment of the present invention is shown;

[0031] Figure 2 shows a data processing device and a vehicle according to an embodiment of the present invention; and

[0032] Figure 3 A flow chart is shown for explaining the steps of a method for calibrating a sensor according to one exemplary embodiment of the present invention.

[0033] The drawings are only schematic and not to scale. In the drawings, identical, identically acting or similar elements are provided with the same reference numerals. DETAILED DESCRIPTION

[0034] Figure 1 A data processing apparatus 10 according to an embodiment of the present invention is shown.

[0035] The data processing device 10 has a data memory 12 and a processor 18 .

[0036] One or more reference measured values ​​together with the associated reference measuring position and reference measuring time can be stored in the data memory 12. One or more reference calibration values ​​can also be stored in the data memory 12. In addition, one or more sensors 20 (see Figure 2) together with the associated measuring position, measuring time and / or current calibration values ​​of the corresponding sensor.

[0037] In particular, the data storage device 10 can include one or more cloud servers and / or be designed in the form of one or more cloud servers.

[0038] Furthermore, the data processing device 10 has a device for communicating with the vehicle 18 (see Figure 2 ) communication, in particular for bidirectional and / or wireless communication interface 16. Based on this interface, for example, an Internet connection, a telephone network connection, a data network connection, a Bluetooth connection and / or any other wireless connection can be established with one or more vehicles 18.

[0039] Figure 2 The data processing device 10 and the vehicle 18 according to one embodiment of the present invention are shown. Unless otherwise described, Figure 2 The data processing device 10 has Figure 1 The data processing device 10 has the same elements and features as the data processing device 10.

[0040] The vehicle 18 has a sensor 20. The sensor 20 can be provided to determine the water level on the road, brightness, friction value, precipitation, snow layer, road icing, road roughness, wind speed, ambient temperature, air pressure and air humidity. The vehicle can also have a plurality of such sensors 20.

[0041] Furthermore, the vehicle 18 has an interface 22 for communicating with the data processing device 10 . The interface 22 of the vehicle 18 can be designed in a manner corresponding to the interface 16 of the data processing device 10 .

[0042] Vehicle 18 can transmit sensor measurement values ​​of sensor 20, measurement location, measurement time, sensor type of sensor 20, lane - on which vehicle 18 is located, driving direction - along which vehicle 18 is moving, driving speed, vehicle type of vehicle 18 and / or other parameters or variables to data processing device 10 via an interface.

[0043] In addition, Figure 2 , a reference vehicle 24 is shown, which can transmit one or more reference measurement values ​​of one or more reference sensors 28 of the reference vehicle 24 to the data processing device 10. The associated reference measurement positions, reference measurement times can also be transmitted. For this purpose, the reference vehicle 24 has an interface 28 for communication with the data processing device 10. Via the interface 28, at least one reference calibration value can also be transmitted to the data processing device 10. The sensor type of the reference sensor 26, the vehicle type of the reference vehicle 24, the lane, the driving direction, the driving speed of the reference vehicle 24 and / or other variables can also be transmitted to the data processing device 10.

[0044] Figure 3 A flow chart is shown for explaining the steps of a method for calibrating sensor 20 of vehicle 18 according to one exemplary embodiment of the present invention.

[0045] In step S1, at least one sensor measurement value determined by means of sensor 20, a measurement position on the roadway at which the sensor measurement value was determined, and a measurement time at which the sensor measurement value was determined are provided to data processing device 10. For example, the sensor measurement value, the measurement position, and the measurement time can be transmitted to data processing device 10 via interfaces 22 and 16.

[0046] Optionally, in step S1 , the sensor type of sensor 20 , the lane on which vehicle 18 is moving, the driving direction in which vehicle 18 is moving, the driving speed of vehicle 18 , the vehicle type of vehicle 18 and / or further variables may be determined and / or provided to data processing device 10 .

[0047] In a further step S2, the sensor measured value is assigned to at least one reference measured value, wherein the reference measured value has been determined at a reference position of the roadway and at a reference measuring time by means of a reference sensor 26 of a reference vehicle 24. The sensor measured value is assigned to the reference measured value if the measuring time of the sensor measured value and the reference measuring time deviate from each other by a maximum of 30 minutes, for example a maximum of 10 minutes and in particular a maximum of 5 minutes.

[0048] Optionally, in step S2, the sensor measurement value can be assigned to the reference measurement value only when the reference vehicle 24 and the vehicle 18 are moving in the same lane and / or in the same direction of travel. The sensor type of the sensor 20 and the reference sensor 26, the vehicle speed and / or the vehicle type of the reference vehicle 24 and the vehicle 18 can also be taken into account in the assignment.

[0049] In a further step S3 , a deviation between the reference measured value and the sensor measured value is ascertained and the ascertained deviation is compared with a threshold value. This step can be performed in vehicle 18 and / or in data processing device 10 .

[0050] In a further step S4 , at least one reference calibration value of reference sensor 26 is transmitted by data processing device 10 to vehicle 18 if the deviation ascertained in step S3 reaches and / or exceeds a threshold value.

[0051] Optionally, in step S4, a median of a plurality of reference calibration values ​​of a plurality of reference vehicles 24 may also be determined. The determined median may then be transmitted to the vehicle 18 as a reference calibration value.

[0052] In an optional step S5, the current calibration value of the sensor 20 of the vehicle 18 can be matched based on the transmitted reference calibration value. For example, the current calibration value can be changed, corrected and / or overwritten based on the reference calibration value.

[0053] Further optional steps of the method are described below, which can be performed alternatively or additionally to one or more of the previous steps. For example, a mean value and / or a standard deviation of a plurality of current calibration values ​​of a plurality of vehicles 18 of the same vehicle type can be determined by means of the data processing device 10. The standard deviation and / or the mean value can be transmitted as a mean calibration value to at least one other vehicle of the same vehicle type for calibrating further sensors of the at least one other vehicle. An upper limit and a lower limit of the mean calibration value can also be determined based on the determined mean value and / or standard deviation. The upper limit and the lower limit can also be transmitted to at least one other vehicle for calibrating further sensors of the at least one other vehicle.

[0054] Aspects, features and / or steps of the invention are summarized below. If a vehicle 18 with a sensor 20 to be calibrated and a reference vehicle 24 are driven one after the other, the sensor 20 to be calibrated can be matched to the reference measured values ​​of a reference sensor 26 of the reference vehicle 24 according to the invention.

[0055] The reference vehicle 24 with the calibrated reference sensor 26 and the vehicle 18 to be calibrated can periodically send their position and / or driving direction to the data processing device 10. If the reference vehicle 24 and the vehicle 18 to be calibrated are traveling one after the other, the data processing device 10 can request the two vehicles 18, 24 to transmit, for example, their sensor raw values ​​and the measured values ​​calculated therefrom, i.e., the reference measured values ​​and the sensor measured values ​​together with their reference measured position and reference measured time or together with the measured position and measured time to the data processing device 10. The corresponding lane, the driving direction and other parameters, such as, for example, the driving speed, can also be transmitted. Since many environmental conditions do not differ significantly for the two vehicles 18, 24 at the same position at the same time, the long-term systematic deviation in the sensors 20, 26, whose sensor measured values ​​deviate from the reference measured values, can be attributed to the influence of their installation position and / or deviating vehicle characteristics on the sensor system.

[0056] If a sensor 20 of the vehicle 18 to be calibrated, for example a water level sensor 20, measures a higher water level on the road over a longer period of time than a reference sensor 26 of the reference vehicle 24, then the current calibration values ​​(or corresponding correction values) of the vehicle 18 can be adapted in such a way that, with the aid of the adapted calibration values, the vehicle 18 to be calibrated provides the same measured values ​​or sensor measured values ​​as the reference vehicle 24 under the same environmental conditions. The same applies to any other sensors.

[0057] The learned correction values ​​and / or updated or adapted calibration values ​​can be exchanged between structurally identical vehicles 18 via data processing device 10. It is thus possible to combine adapted calibration values ​​from a plurality of vehicles 18 and transmit them to vehicles 18 which themselves have not yet been calibrated with reference to reference vehicle 24 using the above-described method.

[0058] In order to avoid errors during calibration, the minimum and maximum limits of the calibration values ​​of a plurality of vehicles 18 can first be determined on the factory side. These limits can be limited and / or adapted again by the data processing device 10. The data processing device 10 can determine the limited limits from the average value and / or standard deviation of the calibration values ​​and / or the corresponding correction values ​​of a plurality of vehicles 18 of identical structure and transmit them together with the average value to all other vehicles 18 of identical structure of the same series, for example. The vehicle can use the average value as a substitute value for the calibration value until the vehicle has had the opportunity to calibrate its sensors according to the reference vehicle 24. Since the replacement value may be inaccurate, it may be advantageous to replace the replacement value as quickly as possible by the reference calibration value of the reference vehicle 24. If there is no reference vehicle 24 nearby, which can achieve learning, it may still be advantageous to accept the replacement value of the vehicle 18, which itself has been calibrated by the reference vehicle 24. However, as soon as the vehicle 18 has the possibility of receiving the reference calibration value directly from the reference vehicle 24, the current calibration value and / or the replacement value can be overwritten.

[0059] The vehicle 18 can attempt to calibrate the sensor measured values ​​based on as many different reference vehicles 18 as possible. It is therefore conceivable that a reference calibration value (and / or a correction value) is determined at the same measuring position using a plurality of reference vehicles 24 and the data processing device 10 determines the median or median value from these reference calibration values ​​(and / or correction values) and transmits it as a reference calibration value to the other vehicles 18. Since the reference vehicles can also be modified in principle (wide tires, low suspension, roof rack, trailer, etc.), the data processing device 10 can check whether these reference vehicles 24 provide consistent reference measured values, for example, if the reference vehicles 24 travel the same distance within a short period of time. The more consistent the reference measured value is with other values ​​of the other reference vehicles 24, the more strongly the corresponding reference measured value is taken into account when calibrating the other vehicles 18.

[0060] Overall, the development costs for vehicle 18 can be advantageously reduced by the present invention, since a new vehicle model can automatically calibrate certain parts of its sensor system during the first operating hours. This also makes it possible to integrate new sensors into the vehicle model more quickly. In addition, the present invention enables a more robust determination of the correct calibration values ​​for vehicle 18, since, for example, changes in vehicle 18, including the influence of the sensor system, for example, due to contamination or the connection of a trailer, can be automatically taken into account by calibration with the aid of reference vehicle 24.

[0061] The invention can advantageously be used in all networked vehicles 18 , 24 . The method can be particularly advantageous for use in a “hydroplane warning system”, for example in order to keep the application effort to a minimum over vehicle variants and to enable the feature to be mass-produced as quickly as possible.

[0062] In addition, it should be pointed out that "comprising" does not exclude other elements, and "one" or "single" does not exclude a plurality. In addition, it should be pointed out that features that have been described with reference to one of the above embodiments can also be applied in combination with other features of other embodiments of the above embodiments. The reference numerals in the claims should not be regarded as limitations.

Claims

1. A method for calibrating a sensor (20) of a vehicle (18), the method comprising the following steps: At least one sensor measurement value ascertained by means of the sensor (20), a measurement position on the roadway at which the sensor measurement value was ascertained, and a measurement time are received by means of a data processing device (10), characterized in that: The method further comprises the following steps: assigning the sensor measurement value to at least one reference measurement value based on the measurement position and the measurement time, the at least one reference measurement value having been determined at a reference position of the roadway and at a reference measurement time by means of a reference sensor (26) of a reference vehicle (24), wherein the reference sensor (26) of the reference vehicle (24) is calibrated, wherein, if the measurement time of the sensor measurement value and the reference measurement time deviate from each other by a maximum of 30 minutes, the sensor measurement value is assigned to the reference measurement value; determining a deviation between the reference measured value and the sensor measured value and comparing the determined deviation with a threshold value, wherein if the determined deviation exceeds the threshold value, at least one reference calibration value of the reference sensor (26) is transmitted to the vehicle and / or provided to the vehicle, wherein the reference calibration value represents a correction value for a current calibration value of the sensor (20), based on which the current calibration value of the sensor (20) is adapted, The method further comprises the following steps: Determining a median of a plurality of reference calibration values ​​of a plurality of reference vehicles (24) by means of the data processing device (10); and The median is transmitted to the vehicle (18) as a reference calibration value.

2. The method according to claim 1, wherein: If the measurement time of the sensor measured value and the reference measurement time deviate from one another by a maximum of ten minutes, the sensor measured value is assigned to the reference measured value.

3. The method according to claim 1, wherein: If the measurement time of the sensor measured value and the reference measurement time deviate from one another by a maximum of five minutes, the sensor measured value is assigned to the reference measured value.

4. The method according to any one of claims 1 to 3, further comprising: determining a lane in which the vehicle (18) is located during the determination of the sensor measured values; and / or Providing parameters related to the lane; in, If the reference measured value has already been ascertained by the reference vehicle (24) in the same lane, the sensor measured value is assigned to the reference measured value.

5. The method according to any one of claims 1 to 3, further comprising: Ascertaining the driving direction in which the vehicle (18) is located during the ascertainment of the sensor measured values; and / or Providing parameters related to the driving direction; in, If the reference measured value has already been ascertained in the same direction of travel by the reference vehicle (24), the sensor measured value is assigned to the reference measured value.

6. The method according to any one of claims 1 to 3, wherein: The data processing device (10) is a data processing device (10) external to the vehicle; and / or, The data processing device (10) has at least one cloud server.

7. The method according to any one of claims 1 to 3, in, The sensor (20) is configured to determine at least one parameter selected from the group consisting of: water level on the roadway, brightness, friction value, precipitation, snow cover, roadway icing, road roughness, wind speed, ambient temperature, air pressure and air humidity.

8. The method according to any one of claims 1 to 3, further comprising: Determining the vehicle type of the vehicle (18); and / or, The current calibration value and parameters related to the vehicle type are provided.

9. The method according to claim 8, further comprising: Determining, by means of the data processing device (10), a mean value and / or a standard deviation of a plurality of current calibration values ​​of a plurality of vehicles (18) of the same vehicle type; and The standard deviation and / or the mean value is provided as a mean calibration value to at least one further vehicle of the same vehicle type for calibrating a further sensor of the at least one further vehicle.

10. The method according to claim 9, further comprising: Determining an upper boundary and a lower boundary of the average calibration value based on the determined average value and the determined standard deviation; and The upper limit and the lower limit are provided to at least one further vehicle of the same vehicle type for calibrating the further sensor of the at least one further vehicle.

11. A data processing device (10) for calibrating a sensor (20) of a vehicle (18), wherein: The data processing device (10) is configured to carry out a method according to any one of the preceding claims.

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