Method for operating a heating device for tempering a radome of a radar sensor of a vehicle using image data from a camera, computing device, heating control system and vehicle

Abstract

Method for operating a heating device (3) for tempering a radome (4) of a radar sensor (5) of a vehicle (1), comprising the steps: - Receiving environmental data which describe an environment (11) of the vehicle (1) and / or at least one area of the radome (4) of the vehicle (1), wherein image data from at least one camera (8, 9) of the vehicle (1) are received as the environmental data, - detecting a deposit (13) of precipitation on the radome (4) based on the environmental data, wherein the precipitation in the environment (11) and / or in the area of the radome (4) is detected based on the image data, - Outputting a heating signal to the heating device (3) for tempering the radome (4) depending on the detected deposit (13) of the precipitation, characterized in that - to detect the deposit (13), a deposition probability, which describes a probability for the deposition (13) of the precipitation on the radome (4), is determined on the basis of the image data and the heating signal is output as a function of the deposition probability.

Description

The present invention relates to a method for operating a heating device for controlling the temperature of a radome of a radar sensor of a vehicle. The present invention also relates to a computing device and a heating control system. Finally, the present invention relates to a vehicle having such a heating control system.Vehicles with modern driver assistance systems often comprise radar sensors, which serve, for example, to detect objects in the surroundings of the vehicle. In addition, such radar sensors are used together with longitudinal control systems. These radar sensors are covered by a so-called radome and protected from environmental influences. In particular in cold weather conditions in conjunction with precipitation, a deposit forms on the radome, which adversely influences the functionality of the radar and of the driver assistance system.In order to overcome this problem, heating devices for radomes of radar sensors are known from the prior art. The radome can be heated or tempered with these heating devices. In this case, the heating devices according to the prior art are controlled, for example, as a function of the ambient temperature. For example, it can be provided that the heating device is activated in a temperature range from -5° C. to 5° C. A return of information about the current state of the radome is usually not provided in this case.DE 10 2017 221 589 A1 discloses a heating system for a radome of a radar for a motor vehicle, wherein the heating system comprises a heating element for heating the radome, and a control unit connected to the heating element for activating the heating element. The control unit is configured to accept or determine a variable characteristic of an external temperature, to accept or determine a variable associated with a melting point of precipitation deposits on an external radome surface, to determine at least one temperature threshold value as a function of the variable associated with the melting point, and to activate the heating element as a function of a threshold value comparison of the external temperature with the temperature threshold value.Document JP 2021 009 036 A describes a technique for operating a heater in a radome based on an external temperature and the vehicle speed, wherein the heater can be operated even if the vehicle speed signal is erroneous.Document JP 2018 146 342 A describes a technique for detecting adhered foreign matters by an adhesion detector for detecting foreign matters adhered to the surface of a distance sensor.Document JP 2000 321 348 A describes a radar used as a vehicle-mounted radar system capable of detecting a decrease in sensitivity of the radar due to snow or ice adhering to a radome in front of the radar.It is the object of the present invention to show a solution how the temperature control of a radome of a radar sensor of a vehicle can be realized in an energy-efficient manner with little effort.This object is achieved according to the invention by a method, by a computing device, by a heating control system and by a vehicle having the features according to the independent claims. Advantageous further developments of the present invention are specified in the dependent claims.A method according to the invention is used for operating a heating device for tempering a radome of a radar sensor of a vehicle. The method comprises receiving environment data describing an environment of the vehicle and / or at least one area of the radome of the vehicle. The method also relates to the detection of a deposit of a precipitate on the radome on the basis of the environmental data. The method further comprises outputting a heating signal to the heating device for tempering the radome as a function of the detected deposition of the precipitate. Furthermore, it is provided that the environment data image data is received by at least one camera of the vehicle and that the precipitation in the environment and / or on the area of the radome is recognized on the basis of the image data.The radome of the radar sensor is intended to be tempered with the aid of the method. In particular, the radome is to be heated or heated by means of the heating device. The radome serves as a cover for the radar sensor of the vehicle and thus as a protection for the radar sensor against environmental influences. The radome may be formed by a region of a bumper, an emblem and / or a trim element of the vehicle. During operation of the radar sensor, electromagnetic beams are emitted by the radar sensor through the radome and received again.The method may be performed with a computing device of the vehicle. This computing device can be formed by at least one electronic control unit. With this computing device, the environment data can be received. This environment data can describe the environment of the vehicle or an area of the environment of the vehicle. Alternatively or additionally, the environmental data can describe the radome itself or a part thereof. Based on the environmental data, the computing device can determine whether the deposition of the precipitation is present on the radome. The precipitate can be, in particular, ice, snow and / or water including impurities. This precipitate can deposit on the radome, in particular at ambient temperatures below the freezing point. This may result in the emission and / or the reception of the electromagnetic radiation being negatively influenced through the radome. In order to be able to remove this deposit of the precipitate from the radome, the heating device is activated. For this purpose, the heating signal is transmitted from the computing device to the heating device. The heating signal can be output as an electrical voltage and / or as an electrical current. In order to activate the heating device, an electrical voltage can thus be applied to the heating device and / or an electrical current can flow through the heating device. The heating signal can be used to preset or adapt a heating power of the heating device.According to the present invention, it is provided that the image data is received as the environmental data. This image data may comprise a digital image or a sequence. In particular, the image data can describe the visible wavelength range. This image data can be provided by a camera of the vehicle. The image data can describe the precipitation present in the environment. For example, it may be determined whether ice or snow is present in the environment based on the image data. Alternatively or additionally, the image data can describe the radome itself or a region thereof. In order to be able to provide such image data, a camera of the vehicle can be used, in the detection region of which the radome is located at least in regions.According to the present invention, it is therefore provided that the image data are used by the camera, which is usually present in any case on modern vehicles. It is therefore not necessary for an additional sensor, for example a temperature sensor, to be installed. The image data can be used for regulating the heating device. Overall, the heating device of the radome can thus be operated in a simple manner in an energy-efficient manner.For recognizing the deposit, a deposit probability describing a probability for depositing the deposit on the radome is determined from the image data, and the heating signal is output depending on the deposit probability. The probability of deposition can thus be determined on the basis of the image data. The precipitation and, if appropriate, also the type of precipitation can be recognized on the basis of the image data. On the basis of this information, it can now be estimated whether the precipitate has deposited on the radome and / or will deposit. With a high probability of deposition, the heating signal can be output or a relatively high heating power can be provided by the heating device. With a low probability of deposition, the output of the heating signal can be omitted or a relatively low heating power can be provided by the heating device. In this way, the heating of the radome can be carried out as required and in an energy-efficient manner.In a further embodiment, the image data describe the region of the radome and / or the deposition of the precipitate on the region of the radome. The camera of the vehicle can be arranged on the vehicle, for example, in such a way that the region or the entire radome is located in the capture region of the camera. The camera can be arranged, for example, on the radome itself. The camera can also be arranged on a component of the vehicle which adjoins the radome. In particular, the camera can have a detection range of approximately 180°. Here, the camera may have a fisheye lens or the like. An outer side of the radome can be captured at least partially by means of the camera. The outer side describes that side of the radome which faces a viewer who is standing in front of the vehicle.In this case, the deposition of the precipitate on the radome is recognized on the basis of an evaluation of the image data. The area of the image data associated with the radome may be known. In this case, it can be checked whether the deposit can be detected in this region of the image data or in the corresponding pixels. In addition, the precipitate can be recognized on the basis of its color and can thus be distinguished from other soiling. In addition, the precipitate can be recognized on the basis of the color of the pixels. For example, the precipitate may have a gray and / or white color.In another embodiment, an amount of the precipitate may also be detected. The amount of precipitation can be detected, for example, on the basis of the layer thickness on the basis of the image data. Depending on the detected quantity, the heating power of the heating device can be adapted. Based on the image data, the precipitate can also be characterized. For example, a distinction can be made between an ice layer, a snow layer and / or a deposit from a snowmat. Depending on the characterization, the heating power of the heating device can be adjusted accordingly.In a further embodiment, the image data describe the precipitation on and / or next to a roadway on which the vehicle is located. Alternatively or additionally, the image data describes the falling precipitate. On the basis of the image data, ice or snow, which is located on the roadway, can be recognized, for example, as the precipitation. In principle, ice or snow which has deposited in the environment of the vehicle can be detected. This information can be taken into account in the determination of the deposition probability. On the basis of the image data, it can also be detected whether the precipitation is currently depositing or falling in the environment. If, for example, snowfall is detected, the probability of precipitation can also be increased, since it can be assumed that the snow is also depositing on the radome. In this case, a temperature in the environment can also be taken into account.It is furthermore advantageous if the image data describes the precipitation spin-on during a following travel, in which a further road user drives in front of the vehicle. A following trip describes the traffic situation in which the further road user is located in front of the vehicle and drives in the same direction of travel. In particular, during this subsequent travel through the road user's wheels, the precipitation that has deposited on the roadway can be agitated and can precipitate on the radome of the radar sensor. In such a follow-up travel with fluidized precipitation, the probability of precipitation may increase. The temperature in the environment can also be taken into account here.A further refinement provides that further data are received as the environmental data, said data describing a temperature in the environment, an atmospheric humidity in the environment and / or a position of the vehicle, wherein the precipitation is characterized on the basis of the image data and / or the further data. In addition to the image data, further environmental data can also be received and taken into account in the regulation of the heating device. For example, data may be received from a temperature sensor that describes the temperature in the environment of the vehicle. In addition, data describing an ambient humidity may be received. In addition, position data describing the position or a latitude in which the vehicle is currently located can be received. On the basis of this position data, it is possible, for example, to infer the melting temperature of the precipitate and thus to adapt the heating power. Also, it can be determined from the position data whether salt for lowering the melting point is scattered in this region. In addition, speed data may be received from a speed sensor. On the basis of these speed data, the deposit and / or the amount of precipitation on the radome can be deduced. This is suitable in particular during a following travel as described above. Overall, the further data or environmental data can also be taken into account in the determination of the deposition probability.In addition, it can be provided that the precipitate is characterized. This means in particular that a distinction can be made between ice, snow, snowmats, hagel, grey scale, mist, water or the like. This distinction can be made on the basis of the image data. For this purpose, known algorithms can be used for image processing, for example. In addition, the further data or environment data can be used to characterize the precipitation. Furthermore, data of weather services can also be taken into account.In this context, it is also possible to distinguish between different types of snow. At very low temperatures, for example at temperatures below -1° C., and / or low atmospheric humidity, powder snow usually occurs. This powder snow does not stick together even under pressure and thus does not deposit on the radome, or only to a small extent. In this powder snow, heating of the radome is counterproductive. This could lead, for example, to this powder snow being partly thawed and thus more easily adhering to the radome. In contrast, at higher temperatures, for example at temperatures above 0° C., and / or high atmospheric humidity, wet snow, wet snow and / or putrefaction usually occurs. These types of snow tend to become more deposited and require a higher heating power. By taking into account the various types of precipitation or snow and the heating strategy associated therewith, the functional availability of the radar sensor and of the driver assistance system associated therewith can be improved.In addition, a deposit of the precipitate on the camera or a lens of the camera can be detected. This deposit can be recognized on the basis of the image data. If this deposit is detected, the heating signal can be output or the operation of the heating device can be regulated.A computing device according to the invention for a heating control system for a radome of a vehicle is configured to carry out a method according to the invention and advantageous refinements thereof. The computing device can comprise at least one electronic control unit.A heating control system according to the invention for a radome of a vehicle comprises a computing device according to the invention. In addition, the heating control system comprises a heating device for tempering the radome. For example, the heating device can comprise corresponding wires through which electrical current flows as a result of the output of the heating signal. The heating device can be electrically connected to the computing device. Furthermore, the heating control system can have at least one camera for providing image data. The at least one camera can be connected to the computing device for the data transmission or for the transmission of the image data. The camera can also have a camera heater in order to avoid deposition of the precipitation on the camera or a lens of the camera.A vehicle according to the invention comprises a heating control system according to the invention. The vehicle can be designed in particular as a passenger car. The camera is preferably arranged on the vehicle in such a way that at least one region of the radome is located in a detection region of the camera. The camera can be part of a surround view system, for example, and can be arranged at the front of the vehicle.Alternatively or additionally, the camera may be disposed behind a windshield of the vehicle. The vehicle or the heating control system may have a first camera at the front of the vehicle and a second camera behind the windshield. Thus, even in vehicles which have only the second camera behind the windshield, an estimate can already be made on the basis of the precipitation in the environment and / or the swirling precipitation during a subsequent travel about the deposition of the precipitation on the radome.In particular, if the vehicle is designed as an at least partially electrically driven vehicle, the energy-efficient operation of the heating device is advantageous. In comparison with known heating control systems, which often require a heating power of up to 80 W, according to the invention, the heating power can be increased or decreased in a targeted manner. As a result, the range can be increased, in particular in the case of at least partially electrically driven vehicles.A further aspect of the invention relates to a computer program comprising instructions which, when the program is executed by a computing device, cause the latter to execute a method according to the invention and the advantageous embodiments thereof. Furthermore, the invention relates to a computer-readable (storage) medium comprising instructions which, when executed by a computing device, cause the computing device to execute a method according to the invention and the advantageous embodiments thereof.The preferred embodiments presented with reference to the method according to the invention and the advantages thereof correspondingly apply to the computing device according to the invention, to the heating control system according to the invention, to the vehicle according to the invention, to the computer program according to the invention and to the computer-readable (storage) medium according to the invention.Further features of the invention are evident from the claims, the figures and the description of the figures. The features and combinations of features mentioned above in the description, and the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respectively specified combination but also in other combinations or alone without departing from the scope of the invention.The invention will now be explained in more detail on the basis of preferred exemplary embodiments and with reference to the appended drawings. The following are shown: FIG. 1 shows a schematic illustration of a vehicle which has a heating control system for controlling the temperature of a radome of a vehicle; FIG. 2 is an enlarged view of the vehicle of FIG. 1 showing deposition of precipitation on the radome; and FIG. 3 shows the vehicle according to FIG. 1 during a following trip, in which a further road user is located in front of the vehicle.In the figures, identical or functionally identical elements are provided with the same reference numerals.FIG. 1 shows a schematic illustration of a vehicle 1, which is designed as a passenger car, in a side view. The vehicle 1 comprises a heating control system 2. this heating control system 2 comprises a heating device 3 which serves to temperature control or heat a radome 4 of the vehicle 1. Radome 4 serves as a cover for a radar sensor 5 of vehicle 1.In addition, the heating control system 2 comprises a computing device 7, which can comprise at least one electronic control unit. Furthermore, the heating control system 2 comprises a first camera 8, which is arranged at a front of the vehicle 1 in the example. In addition, the heating control system 2 has a second camera 9, which is arranged behind a windshield 10 of the vehicle 1 in the example. With the first camera 8 and with the second camera 9, image data can be provided in each case, which describe an environment 11 of the vehicle 1. This image data represents environment data. As further environmental data, data can be provided which describe a temperature and / or an air humidity in the environment 11. In addition, the environment data can describe a current position of the vehicle 1. This further environment data is provided by means of a unit 12 in the example.FIG. 2 shows an enlarged illustration of the vehicle 1 according to FIG. 1, it being evident here that a deposit 13 of a deposit is located on the radome 4. Precipitation may be ice, snow, snowmats or the like. This deposit 13 negatively influences the radar sensor 5 when transmitting and / or receiving a radar signal or electromagnetic radiation. In order to remove the deposit 13 from the radome 4 or to melt the deposit 13, the heating device 3 is provided. This heating device 3 can be activated or activated by means of the computing device 7.Based on the image data of the first camera 8, the deposit 13 on the radome 4 can be recognized. In this case, the first camera 8 is arranged on the vehicle 1 in such a way that the radome 4 is located at least in regions in a detection region of the first camera 8. The first camera 8 can preferably capture objects in an angle range of approximately 180°. In order to recognize the deposit 13, the image data of the first camera 8 can be transmitted to the computing device 7 and evaluated by means of the computing device 7. In this case, the deposit 13 can be recognized in a region of the image data assigned to the radome 4. In particular, the deposit 13 can be recognized on the basis of the color information. For example, a deposit 13 comprising snow can be recognized on the basis of the white or gray color.The information about a presence and / or a configuration of the deposit, which is determined on the basis of the image data, is used to enable a control circuit for heating the radome 4. In particular, depending on the detected deposit 13, a type of deposit 13 and / or an amount of deposit 13, a heating power provided by the heating device 3 can be regulated.FIG. 3 shows a schematic illustration of the vehicle from FIG. 1 during a following journey. During this following travel, a further road user 14 drives in front of the vehicle 1, wherein the vehicle 1 and the further road user 14 move in the same direction of travel. The further road user 14 is likewise a passenger car in the example. It is assumed that the precipitation is located on a roadway 15 on which the vehicle 1 and the further road user 14 are located. For example, snow may be present on roadway 15 as precipitation. This precipitation on the roadway 15 and next to the roadway 15 can be recognized on the basis of the image data of the first camera 8 and / or the second camera 9.In addition, the precipitation on the roadway 15 can be thrown up or thrown up by the wheels of the further road user 14 rolling on the roadway 15. This fluidized precipitate is illustrated in the present case by the lines 16. This fluidized precipitation can also be detected on the basis of the image data of the first camera 8 and / or of the second camera 9. A deposition probability, which describes a probability for the deposition 13 of the precipitation on the radome 4, is determined on the basis of the image data. In addition, the further environmental data can also be taken into account for determining the deposition probability. For example, the deposition probability can additionally be determined on the basis of the temperature, the air humidity, the position of the vehicle 1 and / or the current speed of the vehicle 1.

Claims

Method for operating a heating device (3) for tempering a radome (4) of a radar sensor (5) of a vehicle (1), having the steps: - receiving environment data which describe an environment (11) of the vehicle (1) and / or at least one region of the radome (4) of the vehicle (1), wherein image data are received as the environment data from at least one camera (8, 9) of the vehicle (1), - detecting a deposit (13) of a precipitate on the radome (4) on the basis of the environment data, wherein the precipitate in the environment (11) and / or on the region of the radome (4) is detected on the basis of the image data, - outputting a heating signal to the heating device (3) for tempering the radome (4) on the basis of the detected deposit (13) of the precipitate, characterized in that, determining a deposition probability, which describes a probability for the deposition (13) of the precipitation on the radome (4), from the image data in order to recognize the deposition (13), and outputting the heating signal as a function of the deposition probability.Method according to Claim 1, characterized in that the image data describe the region of the radome (4) and / or the deposition of the precipitate on the region of the radome (4).Method according to Claim 1 or 2, characterized in that the image data describe the precipitation on and / or next to a roadway (15) on which the vehicle (1) is located, and / or in that the image data describe the falling precipitation.Method according to one of the preceding claims, characterized in that the image data describe the precipitation spin-on during a following travel in which a further road user (14) drives in front of the vehicle (1).Method according to one of the preceding claims, characterized in that further data are received as the environmental data, which data describe a temperature in the environment (11), an air humidity in the environment (11) and / or a position of the vehicle (1), wherein the precipitation is characterized on the basis of the image data and / or the further data.Computing device (7) for a heating control system (2) for a radome (4) of a vehicle (1), wherein the computing device (7) is configured to carry out a method according to one of the preceding claims.Heating control system (2) for a radome (4) of a vehicle (1) comprising a computing device (7) according to claim 6, a heating device (3) for tempering the radome (4) and at least one camera (8, 9) for providing image data.Vehicle (1), in particular passenger motor vehicles, comprising a heating control system (2) according to Claim 7.Vehicle (1) according to Claim 8, characterized in that the at least one camera (8, 9) is arranged on the vehicle (1) in such a way that at least one region of the radome (4) is located in a detection region of the at least one camera (8, 9).

Images