Cleaning device for an external sensor of a motor vehicle

Abstract

Cleaning device (1) for an external sensor (2) of a motor vehicle, wherein a cleaning unit (5) is arranged in a housing (3), wherein the cleaning unit (5) is designed to clean a flexible protective element (4), wherein the protective element (4) is arranged above a field of view of the sensor (2) in an operating state of the sensor (2) and is contacted with the cleaning unit (5) during a cleaning process, wherein the housing (3) is arranged around the sensor (2) such that the sensor (2) is mounted in the housing (3), wherein the cleaning unit (5) comprises two deflection rollers (6) and a cleaning device arranged therebetween, wherein the cleaning device has a cleaning module (7) and two stripping modules (8), wherein a cleaning unit (5) is arranged mirrored on two opposite sides next to the sensor (2) in the housing (3), characterized in that a stripping module (8) is provided in each of two opposite regions relative to the cleaning module (7), wherein the protective element (4) is moved back and forth via the two deflection rollers (6) in order to contact the protective element (4) with a cleaning module (7) and at least one stripping module (8).

Description

[0001] The invention relates to a cleaning device for an external sensor of a motor vehicle. The invention also relates to a method for cleaning a viewing area of ​​an external sensor of a motor vehicle.

[0002] Lidar systems are used to detect the surroundings of autonomous vehicles, especially those with Level 2 and 3 sensors. These systems are typically located at the front of the vehicle, for example, near the radiator grille. They can also be installed on a roof, for example, near the front roof frame. All of these areas are exposed to dirt and environmental influences, and are particularly susceptible to splashing water.

[0003] Lidar systems, in particular, comprise a sensor whose field of view must be protected from dirt and splash water or cleaned for the sensor to function. Therefore, various cleaning methods are known from the state of the art, including windshield wipers, spray nozzles, and drying nozzles.

[0004] Such a cleaning device is known from DE 10 2016 006 039 A1, in which spray nozzles are used.

[0005] DE 10 2017 221 496 A1 describes a cleaning device for cleaning a protective film, which can be arranged over a lidar.

[0006] DE 10 2020 206 829 A1 discloses a sensor device for environmental detection, in particular for analyzing agricultural land, and with means for at least indirectly keeping a field of view free from contamination. For this purpose, various protective elements are used, which are alternately applied to the field of view, whereby the protective elements not in use in this state can be cleaned during this process.

[0007] For further prior art, reference can also be made to DE 23 09 849 A and DE 198 56 195 A1, each of which discloses a device for collecting and removing dirt from the visible surfaces of a headlight. Furthermore, reference is made to DE 10 2018 207 813 A1, DE 10 2020 215 939 A1, DE 43 45 147 A1, DE 20 16 854 A, DE 10 2017 211 349 A1, DE 10 2021 210 699 A1, and US 2005 / 0 141 996 A1.

[0008] The disadvantage of such systems is that they require several individual components that must be arranged next to the lidar. These components impair the visual impression and are also exposed to contamination.

[0009] The object of the present invention is to provide a device and a method which overcome the aforementioned disadvantages.

[0010] According to the invention, this object is achieved by a cleaning device having the features of claim 1, and in particular in the characterizing part of claim 1. Advantageous embodiments and further developments emerge from the dependent claims. Furthermore, a method for cleaning a field of view of an external sensor of a motor vehicle is described.

[0011] At the core of the cleaning device according to the invention, a cleaning unit is arranged in a housing, wherein the cleaning unit is designed to clean a flexible protective element, wherein the protective element is arranged above a field of view of the sensor in an operating state of the sensor and is contacted with the cleaning unit during a cleaning process, wherein the housing is arranged around the sensor in such a way that the sensor is mounted in the housing. The cleaning unit comprises two deflection rollers and a cleaning device arranged therebetween, wherein the cleaning device has a cleaning module and two stripping modules, wherein a cleaning unit is arranged in each case in a mirror image on two opposite sides next to the sensor in the housing.A stripping module is provided at each of two opposite areas relative to the cleaning module, wherein the protective element is moved back and forth over the two deflection rollers in order to contact the protective element with a cleaning module and at least one stripping module.

[0012] The housing can be individually adapted to the required installation space or other aerodynamic conditions. The individual components of the cleaning unit can be arranged as desired to maximize the available space. Advantageously, all components of the cleaning device, as well as the lidar system itself, are located in the housing. This allows for a closed housing that blends visually with the vehicle structure. In particular, the cleaning system can be installed in a way that is not visible from the outside.

[0013] The cleaning device is designed for an external sensor of a motor vehicle. The cleaning device is therefore particularly suitable for solid-state systems that do not have freely moving parts. These are used, for example, in a front lidar. Such a front lidar can be arranged or integrated, for example, in the area of ​​the bumper or on the roof near the front roof frame. The cleaning device can be adapted to the dimensions of the lidar to be cleaned.

[0014] The cleaning unit comprises two deflection rollers and a cleaning device arranged between them, wherein the cleaning device has a cleaning module and at least one stripping module. The protective element can be moved away from the sensor's field of vision via the deflection rollers and guided to the cleaning unit with the cleaning module. A stripping module can be arranged to the right and left of the cleaning module, which can strip excess dirt or excess cleaning fluid from the protective element.

[0015] According to the invention, a respective cleaning unit is arranged on two opposite sides of the lidar or the sensor. As a result, the cleaning device can have symmetrically arranged cleaning units which are constructed so as to be mirrored about an axis which runs through the sensor. The sensor is located in a dry area and is in particular arranged behind the surface to be cleaned. The surface to be cleaned is a protective element which can be designed, for example, as a protective film or another type of flexible and transparent element. The protective element can be moved back and forth via the deflection rollers, in other words moved in an oscillating manner. The protective element can be cleaned in the process. In the area of ​​the sensor, the protective element slides over a cover, in particular a cover of a lidar.

[0016] According to a very advantageous development of the concept, a counterpressure element can be arranged opposite the cleaning module, so that the protective element can be cleaned from one side and supported from the other. This allows the protective element to be pressed against the cleaning module, ensuring adequate cleaning.

[0017] A further advantageous embodiment can provide for a container and a pump to be included in the housing, wherein cleaning fluid is stored in the container and the pump is designed to transport the cleaning fluid towards the protective element. A line can lead from the container directly to the cleaning module so that the cleaning fluid can be introduced directly into the cleaning module. The cleaning agent can in particular be a type of sponge or a brush. In particular, a pump can also be provided to control the flow of cleaning fluid. For example, water with a non-streaking cleaning agent can be used as the cleaning fluid.

[0018] The invention further relates to a method for cleaning a field of view of an external sensor of a motor vehicle using a cleaning device according to the invention.

[0019] At the core of the method, a flexible protective element is moved from a field of view of the sensor towards a cleaning unit, whereby the protective element is cleaned with the cleaning unit during a cleaning process and moved back into the field of view of the sensor after the cleaning process. The cleaning process takes place in a housing in which the sensor is also arranged. The protective element is moved back and forth between two cleaning units so that the protective element can be cleaned from both sides of a sensor. Accordingly, a cleaning unit is provided symmetrically to the right and left of the sensor in order to provide a cleaning device that is optimized for the installation space and can be integrated to the right and left of the sensor in a common housing.

[0020] It is provided that the protective element can be moved back and forth via two deflection rollers in order to contact the protective element with a cleaning module and at least one stripping module.

[0021] The same features and advantages continue to apply to the process as already described with regard to the cleaning device.

[0022] With the described embodiments, a clean field of view for a sensor can advantageously always be provided, enabling reliable and long-term operation of the sensor. At the same time, scratching of the protective element is avoided, as the cleaning unit enables gentle cleaning. The device has a particularly modular design, which requires little installation space and, in particular, allows adaptation to the available installation space. In particular, this makes it possible to provide an automated and low-maintenance system.

[0023] Further advantageous embodiments of the cleaning device according to the invention and of the method also emerge from the exemplary embodiment which is illustrated in more detail below with reference to the figure.

[0024] Showing: Fig. 1 a possible embodiment of the cleaning device.

[0025] In the presentation of the Fig.1 shows a possible embodiment of the cleaning device 1. A cleaning unit 5 and a sensor 2 are arranged in a common housing 3. The sensor, which can be designed, for example, as a sensor of a lidar system, is located in a dry area that is separated from the cleaning unit 5. The element to be cleaned, which is arranged as a flexible protective element 4 in a field of vision of the sensor 2, can slide back and forth over a cover of the sensor 2. For this purpose, the cleaning unit 5 comprises at least two deflection rollers 6, with at least one of the deflection rollers 6 being driven by a drive 12. As a result, the protective element 4 can be moved in an oscillating manner in the horizontal direction to the left and right in the illustration. The cleaning device 1 shown is designed in the same way, mirrored on the right side of the sensor 2, in order to reliably accomplish a back and forth movement of the protective element 4.During design, care must be taken to ensure that the entire surface of the protective element 4 can be cleaned by moving it. This can be controlled and adjusted in particular by adjusting the length of the protective element 4 to be rolled up, the number of revolutions around the deflection rollers 6, and the drives 12. If the protective element 4 is moved from the left deflection roller 6 to the right deflection roller in the illustration, the protective element 4 can be cleaned via the cleaning module 7. The protective element 4 can be pressed against a counter-pressure element 9 by the cleaning module 7. The right-hand scraper module 8 can scrape liquid off the protective element 4 before the protective element 4 is rolled up onto the right-hand deflection roller 6. Once the protective element 4 is at least half rolled up, the protective element 4 can be returned to the left.The protective element 4 can then be cleaned again by the cleaning module 7. Excess fluid can then be removed from the protective element 4 by the stripping module 8 (on the left in the illustration). During this return movement, it is preferably provided that the stripping module 8 is previously rotated or positioned by the associated drive 12 such that the left stripping module 8 now rests on the protective element 4 and, at the same time, the right stripping module 8 is rotated away from the protective element 4.

[0026] In an exemplary embodiment, at least one sealing element 13 can also be included, which is arranged in the region of the housing 3. The sealing element 13 can, on the one hand, seal the entire system from the outside. Furthermore, the sealing element 13 can be arranged in the region in which the protective element 4 is inserted into the housing 3. The sealing element 13 is preferably made of rubber, for example, as a rubber roller, so that micro-scratches on the protective element 4 can be avoided. Alternatively, for example, two sealing rollers can be provided, through which the protective element 4 is guided.

[0027] In a further embodiment, the liquid draining from the bottom can be collected in a collecting tray, which can, for example, be concave. The liquid can be pumped from the collecting tray back into the container 10 via another pump, or via pump 11. Advantageously, the liquid is cleaned beforehand for subsequent reuse. Alternatively, the liquid can also be drained to the outside through openings, which can be provided in the housing 3.

[0028] If a cleaning unit 5 is provided on each of two opposite sides of the sensor 2, the drives 12 are preferably controlled synchronously to keep the protective element 4 under a corresponding voltage at all times. For example, the protective element 4 can always be moved halfway to the left or right to clean the right and left sides of the sensor 2. Controlled stepper motors, for example, can be used as drives 12. These can be controlled via a programmed control unit.

[0029] In a further embodiment, the cleaning device 1 can be coupled to an existing rain sensor to be activated when a certain amount of rain and / or a certain degree of soiling is detected. It is also conceivable for the cleaning device 1 to initiate a cleaning process at the beginning of each journey to ensure reliable functioning of the sensor 2.

Claims

[1] Cleaning device (1) for an external sensor (2) of a motor vehicle, wherein a cleaning unit (5) is arranged in a housing (3), wherein the cleaning unit (5) is designed to clean a flexible protective element (4), wherein the protective element (4) is arranged above a field of view of the sensor (2) in an operating state of the sensor (2) and is contacted with the cleaning unit (5) during a cleaning process, wherein the housing (3) is arranged around the sensor (2) such that the sensor (2) is mounted in the housing (3), wherein the cleaning unit (5) comprises two deflection rollers (6) and a cleaning device arranged therebetween, wherein the cleaning device has a cleaning module (7) and two stripping modules (8), wherein a cleaning unit (5) is arranged mirrored on two opposite sides next to the sensor (2) in the housing (3), characterized by , that a stripping module (8) is provided in each of two opposite regions relative to the cleaning module (7), wherein the protective element (4) is moved back and forth via the two deflection rollers (6) in order to contact the protective element (4) with a cleaning module (7) and at least one stripping module (8). [2] Cleaning device (1) according to claim 1, characterized by that a counter-pressure element (9) is arranged opposite the cleaning module (7) so that the protective element (4) can be cleaned from one side and supported from the other side. [3] Cleaning device (1) according to claim 1 or 2, characterized by that a container (10) and a pump (11) are included in the housing (3), wherein cleaning fluid is stored in the container (10) and the pump (11) is designed to transport the cleaning fluid in the direction of the protective element (4). [4] Method for cleaning a field of view of an external sensor (2) of a motor vehicle with a cleaning device (1) according to one of claims 1 to 3, characterized by in that a flexible protective element (4) is displaced from a field of view of the sensor (2) in the direction of a cleaning unit (5), wherein the protective element (4) is cleaned with the cleaning unit (5) during a cleaning process and is moved back into the field of view of the sensor (2) after the cleaning process, wherein the cleaning process takes place in a housing (3) in which the sensor (2) is also arranged.

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