Sensor arrangement with heating film and roof module with such sensor arrangement

Abstract

A sensor arrangement for a motor vehicle is proposed, comprising a sensor unit with at least one environmental sensor for detecting the vehicle's surroundings, which emits electromagnetic radiation in a measurement direction to determine a measurement signal, and an aperture element forming a sensor viewing area (30) through which the environmental sensor communicates with the vehicle's surroundings by means of electromagnetic radiation, and which is provided with a heating film (32) comprising a planar heating element. The heating element is designed with at least two separate heating structures (40A, 40B, 40C, 40D) such that at least two heating zones (34A, 34B, 34C, 34D) are formed on the heating film (32).

Description

The invention relates to a sensor arrangement of a motor vehicle, comprising the features of the preamble of claim 1, and to a roof module having such a sensor arrangement.The publication DE 10 2004 049 148 A1 discloses a sensor arrangement of a motor vehicle which is arranged in the region of a front module or bumper and comprises a sensor unit which comprises a radar unit as environment sensor, by means of which a vehicle environment can be detected, with the result that object and pedestrian detection in particular is possible. The radar unit transmits electromagnetic radiation in a specific measurement direction in order to ascertain a measurement signal. In the measurement direction, a diaphragm element is arranged in front of the radar unit, which diaphragm element can be formed by the front module or bumper. A heating foil is arranged on the inside of the aperture element, which heating foil is provided with conductor tracks which represent a heating device, by means of which, for example, defrosting of the aperture element is possible, so that the radar unit has an undisturbed field of view. The conductor tracks form a heating structure which is divided into an inner region and an outer region. In the inner region, the conductor tracks are spaced further apart from one another. The inner region and the outer region are formed by the same heating structure.Furthermore, the development in vehicle construction is increasingly directed to autonomously or semi-autonomously driving vehicles. In order to enable a vehicle controller to control a motor vehicle autonomously or semi-autonomously, a plurality of environment sensors are used, which are integrated, for example, into a vehicle roof designed as a roof module and can ascertain a respective traffic situation by detecting the surrounding area of the vehicle on the basis of the environmental data. The environment sensors transmit and receive corresponding electromagnetic signals for this purpose. By evaluating the obtained signals, a data model of the vehicle environment can be generated and used for vehicle control. The environment sensors are formed, for example, by lidar sensors, radar sensors, cameras and / or the like.In order to enable operation of the environment sensors as uninterrupted as possible even in adverse weather conditions which are associated with snow, ice and / or fog, it is generally necessary to keep the see-through region which is formed by the panel element arranged in front of the environment sensor as free as possible from snow, ice and other moisture. For this purpose, heating foils of the above-described type are used. In particular in the case of large-area heating foils, a high electrical voltage must be applied in order to operate the heating device effectively.The invention is based on the object of creating a sensor arrangement designed according to the type mentioned in the introduction, in which optimized heating of the aperture element is possible.This object is achieved according to the invention by the sensor arrangement having the features of claim 1.A sensor arrangement of a motor vehicle is therefore proposed, which comprises at least one sensor unit having at least one environment sensor for detecting a vehicle environment, which emits electromagnetic radiation in a measurement direction in order to ascertain a measurement signal, and a screen element, which forms a sensor see-through region, via which the environment sensor communicates with the vehicle environment by means of the electromagnetic radiation, and which is provided with a heating film, which comprises an electrical heating device acting in a planar manner. The heating device of the heating film is configured with at least two separate, electrical heating structures in such a way that at least two heating zones are formed on the heating film.The sensor arrangement according to the invention therefore has a heating foil on the aperture element, which is provided with two electrical heating structures which are separate from one another and are formed, for example, by conductor tracks. By means of the one electrical heating structure, which is connected to corresponding electrical connection elements, a heating zone of the heating foil or of the panel element, which zone is limited to a specific surface region and on which the heating foil is arranged, can be heated. By means of the second electrical heating structure, which is likewise connected to corresponding electrical connection elements, a second heating zone, which is limited to a specific surface region, of the heating foil or of the panel element, on which the heating foil is arranged, can be heated. The two heating zones are arranged spatially separated from one another on the heating foil or the shutter element.By forming a plurality of separate heating structures, it is possible to heat a plurality of regions on the panel element with a high heating power, specifically with a lower voltage to be applied compared to known solutions. Since the heating structures are formed on the same heating foil, the assembly effort is just as high as in the case of a heating foil on which only one heating structure is formed. With the sensor arrangement according to the invention, it may be possible to actuate the different heating zones in a time-offset manner and / or with different heating powers or currents, as a result of which, for example, the melting behavior of ice can be influenced.The sensor arrangement according to the invention is in particular part of a system for autonomous or semi-autonomous driving of a vehicle, wherein the panel element represents an outer skin element of the relevant vehicle facing the vehicle environment. For example, the outer skin element is a roof skin element.The environment sensor of the sensor arrangement according to the invention can be designed in a variety of ways, use electromagnetic radiation and comprise, for example, a lidar sensor, a radar sensor, an optical sensor such as a camera, and / or the like.If the environment sensor is a lidar sensor, it preferably operates in a wavelength range of approximately 905 nm or also of approximately 1550 nm. A camera used as a surroundings sensor may operate in the wavelength range of visible light and / or in the infrared range.The sensor unit of the sensor arrangement according to the invention preferably comprises a sensor housing in which the at least one environment sensor is accommodated. The sensor housing, which at least partially encloses the environment sensor, can be arranged as a whole behind the aperture element or can also form the aperture element itself, which is provided with the heating foil.The aperture element of the sensor arrangement according to the invention is expediently made transparent to the electromagnetic radiation used by the at least one environment sensor and preferably from a material, for example a polycarbonate material, which is in particular dimensionally stable and / or break-resistant. Alternatively, it is also conceivable that the sensor see-through area is formed from a glass element.In particular, it is advantageous if the transmittance is given for a wavelength range between 300 nm and 2000 nm. When the environment sensor is designed as a radar sensor, the aperture element is expediently also transmissive for radar beams.The sensor unit of the sensor arrangement according to the invention can in particular also comprise a plurality of environment sensors which are situated next to one another and each use the aperture element as a sensor see-through region. In this case, one heating zone of the aperture element can be assigned to one environment sensor and another heating zone of the aperture element can be assigned to the other environment sensor.In a preferred embodiment of the sensor arrangement according to the invention, the heating zones formed on the heating foil are arranged in series next to each other. Each of the heating zones can be assigned to a specific environment sensor. The heating foil thus extends at the aperture element over the sensor see-through regions of a plurality of environment sensors. The different sensor see-through regions can be heated in particular independently of one another by the different heating zones and can thereby be kept free of ice, snow and / or mist.In an alternative embodiment of the sensor arrangement according to the invention, a first heating zone is at least partially surrounded by a second heating zone. The one heating zone then extends in the manner of an angular or round ring around the other heating zone, which can likewise be angular or round. Thus, it is also possible, among other things, to control the melting behavior of ice by heating the different heating zones at different times. For example, the first heating structure is first actuated, which is located on the outside, in order to thaw the ice in a ring-shaped manner. As a result, an ice layer adhering to the panel element can be influenced in such a way that it simply slides downward in the direction of gravity, in particular by subsequently actuating the second, inner heating structure, so that the relevant sensor see-through region becomes free of ice.In a further specific embodiment of the sensor arrangement according to the invention, the electrical heating structures of the individual heating zones are connected to common busbars for the purpose of supplying power. The busbars can each be designed in the manner of a busbar and be connected to a suitable electrical control device, so that the individual heating structures which are formed on the heating foil can be operated separately and independently of one another by means of the control device.In an alternative embodiment of the sensor arrangement according to the invention, the heating structures of the individual heating zones are each provided with their own connecting lines for supplying power. It is thus possible in a simple manner from a circuit standpoint to operate the individual heating zones or the individual heating structures independently of one another by means of an electrical control device.The heating device having the plurality of heating structures which is formed on the heating foil can be formed by a printing structure and / or a vapor deposition structure which is applied to a carrier foil.The invention also relates to a roof module of a motor vehicle, comprising a sensor arrangement of the type described above. This section can also be formed by a window of a sensor housing, which fills a recess in the roof skin.The roof module according to the invention preferably forms in an integrated manner a component in which components are accommodated which are required for autonomous or semi-autonomous driving of the vehicle in question. The roof module thus forms a compact structural unit in which a plurality of functional elements can be integrated and which can be connected to a vehicle body or a vehicle body shell on the side of a vehicle manufacturer, which can comprise roof carrier elements, such as roof side rails and / or roof cross rails. The roof module represents, in particular, a so-called sensor roof module or Roof Sensor Module (RSM), which enables autonomous or semi-autonomous driving of the relevant vehicle.The vehicle which is equipped with the sensor arrangement according to the invention or the roof module according to the invention and is designed as an autonomously driving vehicle drives independently in the autonomous driving mode at least without significant interventions by a driver. In a partially autonomous driving mode, the sensor arrangement or the roof module forms, for example, part of a driver assistance system.In particular, the sensor arrangement according to the invention or the roof module according to the invention is part of a passenger vehicle, but can also be part of a vehicle which is formed, for example, as a delivery truck, as a bus, as an autonomously driving small bus, such as a so-called pople mover, or else as a truck tractor.Further advantages and advantageous embodiments of the subject matter of the invention can be derived from the description, the drawing and the patent claims. All combinations of at least two features disclosed in the description, the claims and / or the figures fall within the scope of the invention, i.e. each feature mentioned in the description can be part of the claimed subject matter separately from the further features and / or concreteizations mentioned in the respective context.Exemplary embodiments of a sensor arrangement according to the invention are shown schematically in simplified form in the drawing and are explained in more detail in the following description. It shows: FIG. 1 is a perspective view of a vehicle roof with a roof module according to the invention, which comprises a sensor arrangement; FIG. 2 is a perspective view of the roof module; FIG. 3 shows a view of a heating foil of the sensor arrangement; FIG. 4 shows a second embodiment of a heating film; and FIG. 5 shows a third embodiment of a heating film.A motor vehicle 10 is shown with reference to FIGS. 1 to 3, which has a vehicle roof 12 which spans a vehicle interior and is provided on the front side with a roof module 14, which is shown in isolation in FIG. 2. The roof module 14 represents a compact structural unit which, in particular, accommodates electrical and mechanical devices which allow autonomous driving operation of the motor vehicle 10. The roof module 14, which is designed as a sensor roof module or Roof Sensor Module (RSM), has a one-part or multi-part roof skin arrangement 16, which is fastened on a roof frame 18, which is a component of a roof substructure of the roof module 14 and forms an interface of the roof module 14 with roof longitudinal members 20 and a cowl 22 of a vehicle body.The roof module 14 has a sensor arrangement which comprises four sensor units 24A, 24B, 24C and 24D next to one another in the transverse direction of the vehicle, which sensor units are each provided with a surroundings sensor 26A, 26B, 26C and 26D, respectively, by means of which the vehicle surroundings can be detected in order to realize the autonomous driving of the motor vehicle 10. By evaluating the measurement signals of the environment sensors 26A, 26B, 26C and 26D, a respective traffic situation can be determined by means of a control device of the motor vehicle 10, so that the motor vehicle 10 can adapt autonomously or independently to the respective traffic situation and behave accordingly. In a manner not shown, the environment sensors 26A to 26D are each accommodated in a housing of the relevant sensor unit 24A, 24B, 24C and 24D, respectively, which is arranged on the roof frame 18.As can be seen in particular from FIG. 2, the roof skin arrangement 16, which forms a panel element of the sensor arrangement, has a step 28, which forms a sensor see-through region 30 for the four environment sensors 26A, 26B, 26C and 26D on its end side. In particular, the sensor see-through region 30 of the roof skin arrangement 16 is made of a material which is transparent to the wavelengths used by the environment sensors 26A, 26B, 26C and 26D.The environment sensors 26A to 26D can each be configured in a variety of ways and comprise, for example, a lidar sensor, a radar sensor, a camera, an antenna device and / or another suitable sensor.In order to be able to prevent icing, snow deposits or moisture-related fogging on the sensor see-through region 30 in the region of the environment sensors 26A, 26B, 26C and 26D, a heating film 32 is arranged on the sensor see-through region 30, which heating film extends over the entire width of the step 28 and forms a heating zone 34A, 34B, 34C and 34D for the individual environment sensors 26A, 26B, 26C and 26D, respectively.The heating foil 32, which is shown in isolation in FIG. 3, comprises a carrier foil 36 on which an electrical conductor arrangement is printed as heating device, which comprises two collecting conductors 38A and 38B formed as so-called busbars, between which four separate heating structures 40A, 40B, 40C and 40D are formed. The conductor arrangement comprising the busbars 38A and 38B and the heating structures 40A to 40D is applied to the carrier film 36 by a screen printing method. The heating structures 40A to 40D arranged in series next to one another can be controlled independently of one another by means of a suitable control device 42 via the busbars 38A and 38B, so that the heating zones 34A to 34D, which are each assigned to one of the environment sensors 26A to 26D, can be operated independently of one another depending on the requirement. The heating structures 40A to 40D are formed from thin electrical lines, for example, in the manner of a resistance heater.FIG. 4 shows a heating film 32', which forms an alternative embodiment and which, in the present case, comprises two heating structures 40A and 40B for forming two heating zones 34A and 34B, which heating structures are each connected to separate connecting lines 38A and 38B, which are formed as busbars and are electrically connected to a common controller device 42. As in the embodiment shown in FIG. 3, the heating device formed from the heating structures 40A and 40B and the connecting lines 38A and 38B is arranged on a carrier film 36 as a printed structure or as a vapor-deposited structure. The heating film 32' is likewise part of a sensor arrangement of the type described with reference to FIGS. 1 to 3, which comprises a sensor unit with a surroundings sensor and a diaphragm element with a sensor see-through region for each of the two heating zones 34A and 34B, which is provided with the heating film 32'.FIG. 5 shows a heating film 32'', which is correspondingly part of a sensor arrangement, which comprises a sensor unit with a surroundings sensor and a diaphragm element, which is located in the beam path of the electromagnetic radiation used by the surroundings sensor and which is provided with the heating film 32''. The heating film 32'' likewise has a carrier film 36 on which an electrical heating device is vapor-deposited, which comprises two separate heating structures 40A and 40B, by means of which two heating zones 34A and 34B are formed. The heating zone 34A or the heating structure 40A surrounds the heating zone 34B arranged centrally. The two heating structures 40A and 40B are provided with separate connecting lines which are connected to a common control device. It is thus possible to control and supply current to the heating structures 40A and 40B independently of one another, for example offset in time and / or with different powers or currents.List of reference characters10 Motor vehicle 12 Vehicle roof 14 Roof module 16 Roof skin arrangement 18 Roof frame 20 Longitudinal roof rail 22 Cowl 24A, B, C, D Sensor unit 26A, B, C, D Environment sensor 28 Step 30 Sensor transparency region 32, 32', 32" Heating foil 34A, B, C, D Heating zone 36 Carrier foil 38A, B Bus bar, connecting line 40A, B, C, D Heating structure 42 Control deviceReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 10 2004 049 148 A1

[0002]

Claims

Sensor arrangement of a motor vehicle, comprising at least one sensor unit (24A, 24B, 24C, 24D) with at least one environment sensor (26A, 26B, 26C, 26D) for detecting a vehicle environment, which emits electromagnetic radiation in a measurement direction for determining a measurement signal, and a diaphragm element, which forms a sensor transmission area (30), via which the environment sensor (26A, 26B, 26C, 26D) communicates with the vehicle environment by means of the electromagnetic radiation, and which is provided with a heating film (32, 32', 32") which comprises a heating device acting in a planar manner, characterized in that the heating device is formed with at least two separate heating structures (40A, 40B, 40C, 40D) in such a way that the heating film (32, 32', is provided with a heating film, 32") at least two heating zones (34A, 34B, 34C, 34D) are formed.Sensor arrangement according to Claim 1, characterized in that the heating zones (34A, 34B, 34C, 34D) are arranged in series next to one another.Sensor arrangement according to Claim 1 or 2, characterized in that a first heating zone (34B) is at least partially surrounded by a second heating zone (34A).Sensor arrangement according to one of Claims 1 to 3, characterized in that the heating structures (40A, 40B, 40C, 40D) of the individual heating zones (34A, 34B, 34C, 34D) are connected to common busbars (38A, 38B) for the purpose of supplying power.Sensor arrangement according to one of Claims 1 to 3, characterized in that the heating structures (40A, 40B) of the individual heating zones (34A, 34B) are each provided with dedicated connecting lines (38A, 38B).Sensor arrangement according to one of Claims 1 to 5, characterized in that the heating device is formed by a pressure structure and / or a vapour-deposition structure.Sensor arrangement according to one of Claims 1 to 6, characterized bya control device (42), by means of which the heating structures (40A, 40B, 40C, 40D) of the heating device can be controlled independently of one another.Sensor arrangement according to one of Claims 1 to 7, characterized in that the heating structures (40A, 40B, 40C, 40D) are provided with a control device (42) which is preferably designed to operate the individual heating structures (40A, 40B, 40C, 40D) in a manner offset in time and / or with different powers and / or with different currents.Roof module of a motor vehicle, comprising a sensor arrangement according to one of Claims 1 to 8, wherein the sensor see-through region (30) is formed by a section of a roof skin (16).

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