SENSOR CLEANING SYSTEM AND METHOD

A sensor cleaning system includes a shutter having a first position outside of a field of view of the sensor and a second position blocking the field of view of the sensor. A solvent nozzle is disposed on a side of the shutter facing the sensor and configured to spray solvent onto the sensor. An air nozzle is disposed on the side of the shutter facing the sensor and configured to spray air onto the sensor.

FIELD OF THE INVENTION

The present disclosure relates generally to a system and method for cleaning debris from a sensor mounted on a vehicle surface, and more particularly to a system and method for determining if the sensor requires cleaning, and if so, cleaning debris from the sensor with cleaning solvent, allowing the cleaning solvent to drain away, and drying the sensor.

BACKGROUND

Sensors are commonly disposed on surfaces of modern vehicles, and are becoming more sensitive for collecting data on the vehicle surroundings for use in critical tasks, for example, including autonomous driving modes. It is crucial that such sensors function accurately without being fouled by debris coating the sensor and interfering with optimum sensing. A need therefore exists for a robust and reliable cleaning system that can clean vehicle mounted sensors in any driving environment. It would be useful if such a cleaning system could check the cleanliness status of the sensors to determine if cleaning is necessary.

SUMMARY OF THE INVENTION

In one aspect of the invention, a sensor cleaning system comprises a shutter having a first position outside of a field of view of the sensor and a second position blocking the field of view of the sensor. A solvent nozzle is disposed on a side of the shutter facing the sensor and configured to spray solvent onto the sensor. An air nozzle is disposed on the side of the shutter facing the sensor and configured to spray air onto the sensor.

In another aspect of the invention, a sensor cleaning system comprises a shutter having a first position outside of a field of view of the sensor and a second position blocking the field of view of the sensor. A solvent nozzle is disposed on a side of the shutter facing the sensor and configured to spray solvent onto the sensor. An air nozzle is disposed on the side of the shutter facing the sensor and configured to spray air onto the sensor. The shutter is configured to move back and forth between the first and second positions, wherein an edge of the shutter moves across the field of view of the sensor when the shutter moves from the first position to the second position, and wherein the solvent and air nozzles are proximate to the edge of the shutter.

In a further aspect of the invention, a sensor cleaning system comprises a shutter having a first position outside of a field of view of the sensor and a second position blocking the field of view of the sensor. A solvent nozzle is disposed on a side of the shutter facing the sensor and configured to spray solvent onto the sensor. An air nozzle is disposed on the side of the shutter facing the sensor and configured to spray air onto the sensor. The shutter is configured to move back and forth between the first and second positions, wherein an edge of the shutter moves across the field of view of the sensor when the shutter moves from the first position to the second position, and wherein the solvent and air nozzles are proximate to the edge of the shutter. The shutter in the second position is spaced from the sensor to provide a debris drainage gap therebetween.

In the following detailed description, various embodiments are described with reference to the appended drawings. The skilled person will understand that the accompanying drawings are schematic and simplified for clarity. Like reference numerals refer to like elements or components throughout. Like elements or components will therefore not necessarily be described in detail with respect to each figure.

DETAILED DESCRIPTION

Referring toFIG.1, an embodiment of an exemplary sensor cleaning system (SCS)10includes a sensor20having a field of view as represented by the ellipse bounded by the arrows labeled F. In an embodiment the SCS10includes a shutter30illustrated in four positions inFIG.1. In an embodiment the shutter30has a first position, A, outside of the field of view, F, of the sensor20and a second position, D, blocking the field of view, F, of the sensor20. In an embodiment the shutter30when disposed in the second position D is spaced from the sensor20to provide a debris drainage gap, G, therebetween. In an embodiment the sensor20is disposed on a vehicle body surface25and the shutter30is attached to the vehicle body28proximate the sensor20.

In an embodiment the sensor20is an optical sensor, for example, a video camera. In other embodiments the sensor20is a light direction and ranging (LIDAR) sensor. In further embodiments the sensor20is a radio detection and ranging (RADAR) sensor, an infrared sensor, a sonic sensor, or any sort of sensor for which debris coated thereon causes a performance decrease.

In an embodiment the shutter30has a side33that faces the sensor20. In an embodiment the shutter30is configured to move back and forth between the first position A and the second position D via two intermediate positions (shown inFIG.1at B and C) that are not stopping positions, but that are included to illustrate the path of rotation of the shutter30from first position A to second position D and back. In an embodiment, an edge37of the shutter30moves across the field of view F of the sensor20when the shutter30moves from the first position A to the second position D.

In an embodiment the shutter30is attached by one or more arms35that rotate relative to the body28to push the shutter30out of the body and over the sensor20. In an embodiment the shutter30is rotatably attached to the vehicle body28proximate the sensor20by the one or more arms35. In an embodiment the shutter30is recessed into the vehicle body28in the first position A.

In an embodiment the one or more arms35are driven to rotate to push the shutter30from position A to position D and back, for example, by a motor36that drives the one or more arms35, for example, around a pin or axle38. In an embodiment the one or more arms35are attached to the shutter30via a flexible link or along a pin or other connector that allows the shutter to rotate around the flexible link so that the angle between the one or more arms35and the shutter can change as the shutter30moves from position A to position D.

In an embodiment, a controller or user interface55is in electrical communication with the sensor20and the motor36. In an embodiment the controller or user interface55is in electrical communication with the sensor20and the motor36via a wired connection, for example, via wires56, but in other embodiments the electrical communication can be wireless.

Referring toFIG.2, in an embodiment the shutter30includes at least one solvent nozzle40disposed on the side33of the shutter30facing the sensor20and configured to spray solvent onto the sensor20. In an embodiment the shutter30includes at least one an air nozzle50disposed on the side33of the shutter30facing the sensor20and configured to spray air onto the sensor20. In an embodiment the solvent40and air50nozzles are proximate to the edge37of the shutter30. In an embodiment the shutter30comprises a calibration mark60disposed on the side33of the shutter30facing the sensor20. The calibration mark60is illustrated as a simple elliptical feature, but in other embodiments the calibration mark60can be any shape as needed or desired for image comparison purposes required for calibration.

Referring now toFIGS.3A-3D, in an embodiment the shutter30is configured to move between the first position A and the second position D, as indicated by arrow70. In an embodiment the shutter30occupies a home position at position A and a closed position at position D. The air nozzle50is configured to spray air, as indicated by the arrow77, on the sensor20while the shutter30moves from the first position A to the second position D. In an embodiment as shown in FIG.3D, the air nozzle50is configured to spray air, as indicated by the arrow77, on the sensor20while the shutter30is in the second position D.

Referring now toFIGS.4A-4D, in an embodiment the shutter30is configured to move between the second position D and the first position A, as indicated by arrow72. In an embodiment the solvent nozzle40is configured to spray solvent, as indicated by the arrow75, on the sensor20while the shutter30moves from the second position D to the first position A. In an embodiment as shown inFIG.4A, the solvent nozzle40is configured to spray solvent, as indicated by the arrow75, on the sensor20while the shutter30is in the second position D.

Referring now toFIGS.1-5, in an embodiment a method100for applying the SCS10begins at step110wherein a cleaning request is received from the controller55or manually triggered by a user via the user interface55. In an embodiment, the controller55periodically sends cleaning requests to the SCS10, where the frequency of the requests can be based on a predetermined schedule or based upon other inputs or factors. In an embodiment the SCS10includes the option of allowing a user to make a cleaning request via the user interface55. In an embodiment, at step120the shutter30is moved from the first or home position A to the second or closed position D.

In an embodiment, at step130a first image of the calibration mark60is acquired with the sensor20, and the first image is compared with a stored image of the calibration mark60. This first image acquisition and comparison of the first image with the stored image of the calibration mark60are made before any cleaning steps, and are useful for determining the cleaning efficiency of the SCS10. For example, the first image is compared to a 100% clean image (which would be a complete unobstructed calibration mark60). Then, later in the method100after a cleaning step and after a second image is acquired, the second image is compared to a 100% clean image. The results of the comparisons of the first and second acquired images with the 100% clean image (before and after cleaning) can help to determine the percentage of obstruction cleaned off the sensor20with each cleaning cycle, which provides a level of confidence for the system performance. The results of the before and after cleaning comparisons also provide data on how efficient a cleaning cycle is, and if there is improvement in repeating a cleaning cycle. If no improvement is made after repeating the cleaning cycle, then other appropriate corrective action, for example, an alarm or a request for a manual intervention, can be made.

At step140solvent is sprayed from the solvent nozzle onto the sensor while moving the shutter from the second position to the first position. In an embodiment, at step150, air is sprayed from the air nozzle onto the sensor20while moving the shutter from the first position to the second position. In an embodiment, at step160a second image of the calibration mark60is acquired with the sensor20, and the second image is compared with a stored image of the calibration mark. In an embodiment at step170, a determination is made as to whether the comparison of the second image with the calibration mark indicates that the sensor20is clean or dirty. If the sensor20is clean, then at step175the shutter30is moved from the second position D to the first position A and the method100ends. If the sensor20is dirty, then step180repeats steps140to170. Steps140to170can be repeated as many times as necessary to completely clean all debris off of the sensor20. The next check for debris on the sensor20could be determined via the controller55by passage of time or other diagnostic for determining the veracity of the data collected by the sensor20, or by a manually triggered cleaning request via the user interface55, whereupon the method100starts again at step110.

With respect to the use of plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity. Unless otherwise noted, the use of the words “approximate,” “about,” “around,” “substantially,” etc., mean plus or minus ten percent.

INDUSTRIAL APPLICABILITY

A system determines whether a sensor mounted on a vehicle surface is fouled by debris, and if so, the system cleans the sensor with a solvent spray and dries the sensor with an air spray. The system can be manufactured in industry for use on vehicles purchased by consumers.

Numerous modifications to the present invention will be apparent to those skilled in the art in view of the foregoing description. It is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. Accordingly, this description is to be construed as illustrative only of the principles of the invention and is presented for the purpose of enabling those skilled in the art to make and use the invention and to teach the best mode of carrying out same. The exclusive rights to all modifications which come within the scope of the appended claims are reserved. All patents, patent publications and applications, and other references cited herein are incorporated by reference herein in their entirety.