Cleaning unit and method for cleaning a sensor of a vehicle

Abstract

A cleaning unit for cleaning a sensor of a vehicle is described, wherein the cleaning unit comprises a wiping element and a guide element for the wiping element. The guide element is designed to guide the wiping element for a wiping movement from a first position, across a surface of the sensor, to a second position. The cleaning unit is designed such that, solely due to the inertia of the wiping element, a wiping movement of the wiping element from the first position, across the surface of the sensor, to the second position is effected in response to a change in the movement of the vehicle.

Description

[0001] The invention relates to a cleaning unit, as well as a method and a corresponding device, which are designed to clean a sensor of a (motor) vehicle in a particularly efficient and reliable manner.

[0002] A vehicle may include one or more sensors, particularly environmental sensors, that may become contaminated during vehicle operation, e.g., due to contaminants on the road surface on which the vehicle is traveling. The sensor data collected by a sensor may be impaired by contamination, which in turn may impair the performance of a vehicle (driving) function that utilizes the sensor data from the contaminated sensor.

[0003] A vehicle sensor can be sprayed with fluid to remove contaminants. Applying fluid to a vehicle sensor is relatively labor-intensive. Furthermore, stubborn, especially dried, contaminants often cannot be removed with fluid.

[0004] The document DE 10 2020 212 049 A1 describes a cleaning device comprising a cleaning nozzle for cleaning a surface to be cleaned. The cleaning device further comprises a rod designed to enable a user of the cleaning device to move the cleaning nozzle over the surface to be cleaned. Furthermore, the cleaning device comprises a body movably mounted on the cleaning device, said body having one or more functional components for a cleaning operation of the cleaning device, wherein the body is movably mounted on the cleaning device such that less force is required to effect a change in the movement of the cleaning nozzle via the rod than if the body were immovably arranged on the cleaning device.

[0005] Document DE 10 2022 106 034 A1 discloses a sensor lens assembly comprising a cylindrical sensor body having a bottom surface, a sensor lens surface, and a side surface extending between the bottom surface and an outer edge of the sensor lens surface; a sensor enclosed within the cylindrical sensor body and adjacent to the sensor lens surface; and a nozzle configured to dispense a fluid near a center of the sensor lens surface. The surface of the sensor lens is concave and rotates relative to the side surface of the cylindrical sensor body, so that centrifugal force causes the fluid to form a film on the surface of the sensor lens, acting as a barrier, cushion, and particle collection medium on the surface of the sensor lens.

[0006] Document WO 2021 / 118819 A1 discloses a sensor cleaning mechanism. At least one sensor is configured to monitor a condition associated with a vehicle. A housing is configured for mounting on the vehicle. The housing has a window surface configured to be substantially within a field of view of the at least one sensor. A fluid supply mechanism is configured to supply fluid to the window surface. An actuation mechanism is configured to rotate the housing at a first speed around the at least one sensor, thereby expelling at least a portion of the fluid from the window surface.The actuating mechanism may also be configured to change the rotational speed of the housing to a second speed greater than zero in response to determining that the window surface is substantially free of liquid.

[0007] This document deals with the technical task of achieving a particularly efficient and reliable cleaning of a sensor, in particular an environmental sensor, of a (motor) vehicle.

[0008] The problem is solved by each of the independent claims. Advantageous embodiments are described, among other things, in the dependent claims. It should be noted that additional features of a patent claim dependent on an independent patent claim can form a separate invention, independent of the combination of all features of the independent patent claim, without the features of the independent patent claim or only in combination with a subset of the features of the independent patent claim, which invention can be made the subject of an independent claim, a divisional application, or a subsequent application. This applies equally to technical teachings described in the description, which can form an invention independent of the features of the independent patent claims.

[0009] According to one aspect, a cleaning unit for cleaning a sensor, in particular an environmental sensor, of a (motor) vehicle is described. The cleaning unit comprises a wiping element and a guide element for the wiping element. The guide element can have one or more guide rails. The wiping element can be configured to slide along the one or more guide rails. The one or more guide rails can each be arranged parallel to a transverse axis (of the cleaning unit and / or the vehicle).

[0010] The guide element is designed to guide the wiping element for a wiping movement from a first position, across the surface of the sensor, to a second position. The first position and the second position can be arranged on opposite sides of the surface of the sensor. The first position, the surface of the sensor, and the second position can also be arranged one behind the other along the transverse axis of the cleaning unit. The transverse axis of the cleaning unit preferably corresponds to the transverse axis of the vehicle. The transverse axis can be aligned substantially parallel to the roadway on which the vehicle is parked. Furthermore, the transverse axis can be arranged substantially perpendicular to the longitudinal axis of the vehicle (along which the longitudinal movement of the vehicle occurs).

[0011] The transverse axis can also be arranged perpendicular to the vertical axis of the vehicle, with the vertical axis typically being perpendicular to the roadway traveled by the vehicle. The guide element can thus be configured to effect a wiping movement along the transverse axis, which is arranged perpendicular to the vertical axis of the vehicle.

[0012] The cleaning unit is designed such that, solely due to the inertia of the wiping element, in response to a change in movement of the vehicle, in particular in response to a change in direction of the vehicle and / or in particular in response to a rotation of the vehicle about the vertical axis (which is perpendicular to the roadway), a wiping movement of the wiping element is effected from the first position, over the surface of the sensor, to the second position.

[0013] The cleaning unit can in particular be designed such that • solely due to the mass inertia of the wiping element, in response to a rotation of the vehicle about the vertical axis in a first direction of rotation (e.g. to the left), a wiping movement of the wiping element is effected from the first position, over the surface of the sensor, to the second position (e.g. a wiping movement to the right); and • solely due to the inertia of the wiping element, in response to a rotation of the vehicle about the vertical axis in a second direction of rotation (e.g. to the right), which is opposite to the first direction of rotation, a wiping movement of the wiping element is effected from the second position, over the surface of the sensor, to the first position (e.g. a wiping movement to the left).

[0014] Thus, a cleaning unit is described that comprises a wiping element (e.g., a wiper) designed to mechanically act on the surface of the sensor to ensure reliable and thorough cleaning of the sensor. The movement of the wiping element is effected passively (without a dedicated drive unit for the wiping element) solely by a change in movement, in particular solely by a change in direction, of the vehicle. This allows for particularly efficient cleaning of the sensor.

[0015] The cleaning unit can comprise at least one holding element which is designed to hold the wiping element in the first position or in the second position, so that even in response to a change in movement, in particular a change in direction, of the vehicle, the wiping element is held in the first position or in the second position and thus does not perform a wiping movement. The at least one holding element can further be configured to selectively release the wiping element so that the wiping element can perform a wiping movement in response to a change in movement, in particular a change in direction, of the vehicle. The at least one holding element can in particular be designed to hold the wiping element in the first position and in the second position, respectively, and to selectively release it for a wiping movement starting from the respective position.This means that a dedicated wiping movement can be effected starting from the first position or starting from the second position.

[0016] By providing at least one retaining element, particularly reliable cleaning of the sensor can be achieved without impairing the acquisition of sensor data. For example, cleaning of the sensor can be limited to times when no sensor data is being acquired.

[0017] The cleaning unit (or the vehicle) can comprise a control device configured to determine force information relating to the centrifugal force acting on the wiping element due to a change in movement, in particular a change in direction, of the vehicle. In particular, the component of the centrifugal force acting along the transverse axis can be considered. The force information can be determined using a motion sensor and / or a force sensor of the cleaning unit and / or the vehicle.

[0018] The (control) device can further be configured to cause the holding element, depending on the force information, • to release the wiping element for a wiping movement; or • to hold the wiping element in the first position or in the second position to prevent a wiping movement.

[0019] The force information can, for example, indicate the magnitude of the centrifugal force. The control device can be configured to determine, based on the force information, whether the magnitude of the centrifugal force is greater or less than a predefined force threshold. The force threshold can be such that, with a relatively high probability (e.g., 99% or more), the wiping element will perform a complete wiping movement from the first position to the second position (or from the second position to the first position) if the magnitude of the centrifugal force is greater than the force threshold.

[0020] The (control) device can be designed • to cause the holding element to release the wiping element for a wiping movement when the magnitude of the centrifugal force is greater than the force threshold; and / or • to cause the holding element to hold the wiping element in the first position or in the second position to prevent a wiping movement when the amount of centrifugal force is less than the force threshold value.

[0021] Alternatively or additionally, the force information can indicate the direction of the centrifugal force. The control device can be configured to determine that the wiping element is held in the first position. Furthermore, based on the force information, it can be determined whether the centrifugal force acts in a direction that moves the wiping element from the first position to the second position.

[0022] The (control) device can further be configured • to cause the holding element to release the wiping element for a wiping movement when the centrifugal force acts in a direction by which the wiping element is moved from the first position to the second position; and / or • to cause the holding element to hold the wiping element in the first position (to prevent the wiping movement) when the centrifugal force does not act in a direction by which the wiping element is moved from the first position to the second position.

[0023] By taking into account force information relating to the centrifugal force acting on the wiping element, particularly reliable cleaning of the sensor can be achieved without impairing the acquisition of sensor data.

[0024] According to a further aspect, a (motor) vehicle (in particular a passenger car or a truck or a bus or a motorcycle) is described which comprises the cleaning unit described in this document for cleaning a sensor of the vehicle.

[0025] According to one aspect, a method for cleaning a sensor of a vehicle is described using the cleaning unit described in this document. The method comprises determining force information relating to the centrifugal force acting on the wiping element of the cleaning unit due to a change in movement, in particular due to a change in direction (e.g., due to rotation), of the vehicle. The method further comprises causing, depending on the force information, the wiping element to be released (or not released) for a wiping movement across the surface of the sensor.

[0026] It should be noted that the aspects described in connection with the device, in particular the claims described in connection with the device, are also to be applied to the method as corresponding method features.

[0027] According to another aspect, a software (SW) program is described. The SW program can be configured to be executed on a processor (e.g., on a vehicle control unit) and thereby to carry out the method described in this document.

[0028] According to a further aspect, a storage medium is described. The storage medium can comprise a software program configured to be executed on a processor and thereby to carry out the method described in this document.

[0029] It should be noted that the methods, devices, and systems described in this document can be used both alone and in combination with other methods, devices, and systems described in this document. Furthermore, any aspects of the methods, devices, and systems described in this document can be combined in a variety of ways. In particular, the features of the claims can be combined in a variety of ways. Furthermore, features listed in parentheses are to be understood as optional features.

[0030] The invention will be described in more detail below using exemplary embodiments. Fig. 1 exemplary components of a vehicle; Fig. 2 an exemplary cleaning unit for a sensor of a vehicle; and Fig. 3 is a flowchart of an exemplary method for cleaning a sensor of a vehicle.

[0031] As stated at the beginning, this document deals with the efficient and thorough cleaning of a sensor, in particular an environmental sensor, of a vehicle. In this context, Fig. 1 shows an exemplary vehicle 100 with one or more environmental sensors 102, each configured to collect sensor data (also referred to as environmental data) relating to the surroundings of the vehicle 100. Exemplary environmental sensors 102 include a camera, a radar sensor, a lidar sensor, an ultrasonic sensor, etc.

[0032] A (control) device 101 of the vehicle 100 can be configured to evaluate the environmental data, e.g., to detect one or more objects (e.g., other vehicles) in the environment of the vehicle 100. Furthermore, the device 101 of the vehicle 100 can be configured to detect, based on the sensor data of a sensor 102, that the sensor 102 is contaminated. A cleaning unit 105 of the vehicle 100 can then be prompted to clean the sensor 102, in particular the contaminated surface of the sensor 102.

[0033] As explained above, the cleaning unit 105 can be configured to spray a cleaning fluid onto the surface of the sensor 102 in order to clean the surface of the sensor 102. However, installing a fluid container and a spray device is relatively complex. Furthermore, stubborn dirt (such as insects) often cannot be removed by spraying a cleaning fluid.

[0034] Fig. Figure 2 shows an exemplary cleaning unit 105 for cleaning the surface of a sensor 102. The cleaning unit 105 comprises a wiping element 201, which is designed to sweep over the surface of the sensor 102 to mechanically clean the surface of the sensor 102. This allows even stubborn dirt to be reliably removed.

[0035] The cleaning unit 105 is designed to hold the wiping element 201 in a first position. The wiping element 201 can be arranged in the first position on a first support 202 (e.g., on the right-hand side of the surface of the sensor 102). The cleaning unit 105 can further comprise one or more guide elements 203, e.g., one or more guide rails, along which the wiping element 201 can be transferred over the surface of the sensor 102 into a second position (on a second support 202, which is arranged, e.g., on the left-hand side of the surface of the sensor 102). The cleaning unit 105 preferably comprises one or more holding elements 204 to hold the wiping element 201 in the first or second position.

[0036] The sensor-relevant surface of the sensor 102 is preferably not covered by the wiping element 201 when the wiping element 201 is arranged in the first or second position. The sensor data of the sensor 102 are thus not impaired by the wiping element 201 when the wiping element 201 is held in the first or second position.

[0037] The cleaning unit 105 is designed such that the wiping element 201 can be moved between the first position and the second position solely due to its mass inertia. When the direction of movement of the vehicle 100 changes, e.g., when cornering, a centrifugal force 206 can be exerted on the wiping element 201, by which the wiping element 201 is moved (depending on the sign of the change in direction) from the first position to the second position or from the second position to the first position. The wiping element 201 can thus be moved over the surface of the sensor 102 solely by the movement of the vehicle 100 in order to clean the surface of the sensor 102. In this way, particularly efficient cleaning of the sensor 102 can be achieved.

[0038] The vehicle 100 may include a motion sensor, in particular an inertial measurement unit, 103, which is configured to acquire sensor data relating to the movement of the vehicle 100. The (control) device 101 may be configured to determine, based on the sensor data of the motion sensor 103, force information relating to the (centrifugal) force 206 acting on the wiping element 201. In particular, the direction (e.g., the sign) and / or the magnitude of the force 206 acting on the wiping element 201 can be determined as force information.

[0039] The vehicle 100 can include a position sensor 104, e.g., a GNSS (Global Navigation Satellite System) receiver, such as a GPS receiver, configured to acquire position data relating to the current position of the vehicle 100. The position data can be evaluated together with a digital map of the road network traveled by the vehicle 100, in particular to detect an upcoming change in direction of the roadway traveled by the vehicle 100. The force information relating to the force 206 acting on the wiping element 201 can be determined, in particular predicted, based on the position data in conjunction with the digital map.

[0040] The (control) device 101 can be configured to check, based on the force information, whether the force 206 acting on the wiping element 201 is or will be sufficiently high to move the wiping element 201 from the first position to the second position. If it is detected that the force 206 is or will be sufficiently high, the holding element 204 can be opened to allow the wiping element 201 to be moved from the first position to the second position by the force 206 (caused solely by the movement of the vehicle 100), thereby cleaning the surface of the sensor 102. The wiping element 201 is then held in the second position by the holding element 204.

[0041] It can subsequently be checked whether at a subsequent point in time a sufficiently high force 206 acts or will act on the wiping element 201 in order to move the wiping element 201 from the second position to the first position and to thereby clean the surface of the sensor 102 again.

[0042] The movement of the vehicle 100 can thus be used (as the exclusive drive) to move the wiping element 201 of the cleaning unit 105 over the surface of the sensor 102, and in doing so to clean the sensor 102. By controlling one or more holding elements 204 depending on the respectively determined force information, it can be ensured that the wiping element 201 is always held in a defined position between two wiping processes (i.e., between two wiping movements) and does not move uncontrollably over the surface of the sensor 102, which could impair the detection quality of the sensor 102.

[0043] Thus, centrifugal force 206 is used to drive a sensor cleaning mechanism to clean a sensor 102 in an autonomous driving and driver assistance system of a vehicle 100. In particular, a wiping mechanism is described that utilizes the centrifugal force 206 generated during normal vehicle operation of the vehicle 100. A wiping element 201 with an effective weight is designed such that the wiping element 201 glides over the surface of the sensor 102, effectively removing dirt without the need for an additional actuation system. The centrifugal force 206 acts as the (sole) driving force for the movement of the wiping element 201 (i.e., the wiper) and ensures thorough cleaning.

[0044] To initiate the cleaning process, the centrifugal force 206 can be detected and measured. The measured force information relating to the centrifugal force 206 can serve as a trigger to release the wiping element 201 when the centrifugal force (i.e., the centrifugal force) 206 exceeds a certain force threshold. This ensures that the cleaning mechanism is activated while driving, eliminating the need for manual intervention or separate control systems. Furthermore, the current state (i.e., the position) of the wiping element 201 can be stored and taken into account when evaluating the force information to determine the direction in which the wiping element 201 will move during the next wiping movement.

[0045] The wiper mechanism is preferably designed such that the wiping element 201 slides to the opposite end of the sensor surface (i.e., to the respective opposite position) whenever a sufficiently high centrifugal force 206 is detected in a specific direction. This enables comprehensive cleaning, since the wiping element 201 covers the entire surface of the sensor 102. If a centrifugal force 206 in the opposite direction is subsequently detected, the wiping element 201 repeats the wiping process in the opposite direction. This allows for efficient, cost-effective, and low-maintenance sensor cleaning in autonomous driving and driver assistance systems. Using the centrifugal force 206 as the driving force for the cleaning mechanism eliminates the need for complex actuation systems.

[0046] The described sensor cleaning mechanism can thus comprise a wiping element 201 and a centrifugal force sensing component. The wiping element 201, with a locking and unlocking mechanism 204, is preferably designed such that the wiping element 201 glides over the surface of the sensor 102, removing dirt in the process. The centrifugal force sensing component is responsible for detecting the centrifugal force 206 occurring during vehicle operation and triggering the release of the wiping element 201. The wiping element 201 is made, for example, of a flexible material that ensures effective cleaning without damaging the sensor surface. The wiping element 201 can be attached to a rail system 203 located above the sensor 102. The rail system 203 enables a controlled movement of the wiping element 201 over the sensor surface.The centrifugal force detection component 206 can be integrated into the control system 101 of the vehicle 100 and includes one or more sensors 103 capable of measuring acceleration and / or rotation. These one or more sensors 103 detect changes in the centrifugal force 206 that occur during driving. If the measured centrifugal force 206 exceeds a predetermined force threshold, the detection component sends a signal to release the wiping element 201. Upon receipt of the release signal, the wiping element 201 is released from its initial position and slides over the sensor surface due to the centrifugal force 206 generated during vehicle operation. The wiping element 201 moves unidirectionally until the wiping element 201 reaches the other end of the sensor 102.At this point, a reversing mechanism or other detection component may be arranged that detects a changing centrifugal force and initiates the return movement of the wiping element 201 to clean the sensor 102 in the opposite direction.

[0047] Various variations in the design of the wiping element 201 are conceivable, e.g., with regard to the shape and / or material, in order to optimize the cleaning performance for different types of sensors 102. The centrifugal force detection component can be implemented using various sensor technologies, e.g., an accelerometer or a gyroscope sensor, to measure the centrifugal force 206 and, based on this, trigger the release of the wiping element 201. A signal can also be taken into account that takes into account the state of the autonomous driving system and / or the driver assistance system in order to prevent the activation of the wiping element 201 during system operation, if necessary.

[0048] Fig.3 shows a flowchart of a (possibly computer-implemented) method 300 for cleaning a sensor 102 of a vehicle 100 using the cleaning unit 105 described in this document. The method 300 can be executed by a control device 101 of the cleaning unit 105 and / or the vehicle 100.

[0049] The method 300 comprises determining 301 force information relating to a centrifugal force 206 acting on the wiping element 201 of the cleaning unit 105 due to a change in movement, in particular due to a change in direction, of the vehicle 100. The force information can, in particular, indicate the magnitude and / or the direction or the sign of the centrifugal force 206. The force information can be determined based on a motion sensor 103 and / or a force sensor of the cleaning unit 105 and / or the vehicle 100. Alternatively or additionally, the force information can be determined, in particular predicted, based on the position data of a position sensor 104 in conjunction with a digital map.

[0050] The method 300 further includes causing 302, depending on the force information, the wiping element 201 to be released for a wiping movement across the surface of the sensor 102. In particular, a holding element 204 can be caused to release or not release the wiping element 201 depending on the force information.

[0051] The measures described in this document can achieve efficient and reliable cleaning of a sensor 102 of a vehicle 100.

[0052] The present invention is not limited to the embodiments shown. In particular, it should be noted that the description and figures are intended only to illustrate the principle of the proposed methods, devices, and systems by way of example.

Claims

[1] Cleaning unit (105) for cleaning a sensor (102) of a vehicle (100); wherein - the cleaning unit (105) comprises a wiping element (201) and a guide element (203) for the wiping element (201); - the guide element (203) is designed to guide the wiping element (201) for a wiping movement from a first position, over a surface of the sensor (102), to a second position; and - the cleaning unit (105) is designed such that, solely due to the inertia of the wiping element (201), in response to a change in movement of the vehicle (100), a wiping movement of the wiping element (201) is effected from the first position, over the surface of the sensor (102), to the second position. [2] Cleaning unit (105) according to claim 1, wherein - the vehicle (100) is designed to carry out changes in movement, in particular changes in direction, around a vertical axis; - the guide element (203) is designed to effect a wiping movement along a transverse axis which is arranged perpendicular to the vertical axis; and - in particular the first position, the surface of the sensor (102) and the second position are arranged one behind the other along the transverse axis. [3] Cleaning unit (105) according to one of the preceding claims, wherein the cleaning unit (105) is designed such that - solely due to the mass inertia of the wiping element (201), in response to a rotation of the vehicle (100) about a vertical axis in a first direction of rotation, a wiping movement of the wiping element (201) is effected from the first position, over the surface of the sensor (102), to the second position; and - solely due to the mass inertia of the wiping element (201), in response to a rotation of the vehicle (100) about the vertical axis in a second direction of rotation which is opposite to the first direction of rotation, a wiping movement of the wiping element (201) is effected from the second position, over the surface of the sensor (102), to the first position. [4] Cleaning unit (105) according to one of the preceding claims, wherein the cleaning unit (105) comprises at least one holding element (204) which is designed - to hold the wiping element (201) in the first position or in the second position, so that even in response to a change in the movement of the vehicle (100), the wiping element (201) is held in the first position or in the second position and does not perform a wiping movement; and - selectively release the wiping element (201) so that the wiping element (201) can perform a wiping movement in response to a change in movement of the vehicle (100). [5] Cleaning unit (105) according to claim 4, wherein the at least one holding element (204) is designed to hold the wiping element (201) in the first position and in the second position, and to release it selectively for a wiping movement starting from the respective position. [6] Cleaning unit (105) according to one of claims 4 to 5, wherein the cleaning unit (105) comprises a control device (101) which is arranged - to determine force information relating to a centrifugal force (206) acting on the wiper element (201) due to a change in the movement of the vehicle (100); and - to cause the holding element (204) to actuate in dependence on the force information, - to release the wiping element (201) for a wiping movement; or - to hold the wiping element (201) in the first position or in the second position in order to prevent a wiping movement. [7] Cleaning unit (105) according to claim 6, wherein the force information indicates an amount of the centrifugal force (206); and wherein the control device (101) is arranged - to determine, on the basis of the force information, whether the magnitude of the centrifugal force (206) is greater or less than a predefined force threshold value; - to cause the holding element (204) to release the wiping element (201) for a wiping movement when the magnitude of the centrifugal force (206) is greater than the force threshold value; and - to cause the holding element (204) to hold the wiping element (201) in the first position or in the second position in order to prevent a wiping movement if the amount of the centrifugal force (206) is less than the force threshold value. [8] Cleaning unit (105) according to one of claims 6 to 7, wherein the force information indicates a direction of the centrifugal force (206), and wherein the control device (101) is arranged - to determine that the wiping element (201) is held in the first position; - to determine on the basis of the force information whether the centrifugal force (206) acts in a direction by which the wiping element (201) is moved from the first position to the second position; - to cause the holding element (204) to release the wiping element (201) for a wiping movement when the centrifugal force (206) acts in a direction by which the wiping element (201) is moved from the first position to the second position; and - to cause the holding element (204) to hold the wiping element (201) in the first position when the centrifugal force (206) does not act in a direction by which the wiping element (201) is moved from the first position to the second position. [9] Vehicle (100) comprising - a sensor (102); and - a cleaning unit (105) for cleaning the sensor (102), which is designed according to one of the preceding claims. [10] Method (300) for cleaning a sensor (102) of a vehicle (100) using a cleaning unit (105) designed according to one of claims 1 to 8; wherein the method (300) comprises - determining (301) force information relating to a centrifugal force (206) acting on the wiping element (201) of the cleaning unit (105) due to a change in movement, in particular a change in direction, of the vehicle (100); and - causing (302), depending on the force information, the wiping element (201) to be released for a wiping movement over a surface of the sensor (102).

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