SENSOR ASSEMBLY WITH MOVABLE COVER

Abstract

A sensor assembly includes a sensor and a sensor cover disposed adjacent to the sensor and within a field of view of the sensor. The sensor cover has an inner surface facing the sensor and an outer surface facing away from the sensor. The sensor cover has spring elements attached to a first end and a bracket attached to a second end. At least one of the spring elements has a first spring stiffness and another of the spring elements has a second spring stiffness. A drive motor is in mechanical communication with the bracket and is configured to rotate the sensor cover relative to the sensor.

Description

INTRODUCTION

[0001] The present disclosure relates generally to sensors and, more particularly, to a sensor assembly with a movable cover for cameras, sensors, lidar, and the like.

[0002] Some vehicles include sensors to detect and / or measure various parameters. The sensors may have covers that should be cleaned to ensure optimal sensor performance. In particular, various contaminants (e.g., dust, water, snow) should be removed from the sensor cover. The sensor covers may also have hydrophilic or hydrophobic coatings to keep the covers clean.

[0003] DE 10 2018 118 729 A1 describes a sensor arrangement comprising a base, a sensor attached to the base, and a cover which is permeable to the sensor and forms a spherical connection with the base.

[0004] DE 10 2020 210 422 A1 describes a sensing device. The sensing device can comprise a housing, a sensor assembly mounted in the housing, and a wiper assembly that removes an outer material adhering to the sensor assembly. The sensor assembly comprises a sensor module and a sensor housing surrounding the sensor module, and the sensor housing is made of a transparent material. The sensor housing is rotatably mounted in the housing. The sensor housing is rotatably mounted with respect to a hollow shaft in the housing, and the hollow shaft is mounted in the housing.

[0005] US 2007 / 0 103 579 A1 describes an imaging device for easily removing foreign matter adhering to the surface of an optical filter. A rubber member holding an optical low-pass filter seals an imaging sensor and the optical low-pass filter, and a piezoelectric element vibrates an edge portion of the optical low-pass filter in the direction of an optical axis, imparting a rotational force to the optical low-pass filter about an axis orthogonal to an optical imaging axis. DESCRIPTION

[0006] A sensor assembly is presented here. The sensor assembly includes a sensor and a sensor cover disposed adjacent to the sensor and within a field of view of the sensor. The sensor cover has an inner surface facing the sensor and an outer surface facing away from the sensor. Spring elements are attached to the sensor cover at a first end and a bracket at a second end. At least one of the spring elements has a first spring stiffness and another of the spring elements has a second spring stiffness. A drive motor is in mechanical communication with the bracket and is configured to rotate the sensor cover relative to the sensor.

[0007] Another aspect of the disclosure may be that the plurality of spring elements are arranged around a circumference of the sensor cover.

[0008] Another aspect of the disclosure may be that the drive motor is a piezoelectric drive motor.

[0009] A further aspect of the disclosure may be that the plurality of spring elements comprise at least one coil spring.

[0010] Another aspect of the disclosure may be that the sensor comprises an optical sensor with a lens.

[0011] Another aspect of the disclosure may be that the sensor cover is made of a transparent material.

[0012] Another aspect of the disclosure may be that the holder forms a ring.

[0013] Another aspect of the disclosure may be that the plurality of spring elements comprises a first pair of spring elements arranged along a first pair of opposite sides of the sensor cover and a second pair of spring elements having a second pair arranged along a second pair of opposite sides of the sensor cover.

[0014] A further aspect of the disclosure may be that the first pair of spring elements each has a first stiffness and the second pair of spring elements each has a second stiffness that is less than the first stiffness.

[0015] Another aspect of the disclosure may be that the first pair of spring elements comprises a first pair of different spring stiffnesses and the second pair of spring elements comprises a second pair of different spring stiffnesses, each of which is smaller than the first pair of different spring stiffnesses.

[0016] Another aspect of the disclosure may be that the first pair of spring elements has a spring stiffness of greater than or equal to 3000 N / m and less than or equal to 6000 N / m.

[0017] Another aspect of the disclosure may be that the second pair of spring elements has a spring stiffness of more than or equal to 30 N / m and less than or equal to 300 N / m.

[0018] Disclosed herein is a cleaning assembly for a sensor. The assembly includes a sensor housing, a sensor disposed within the sensor housing, and a sensor cover disposed adjacent to the sensor and within a field of view of the sensor. The sensor cover includes an inner surface facing the sensor and an outer surface facing away from the sensor. The sensor cover has spring elements attached to a first end and a bracket attached to a second end. At least one of the spring elements has a first spring stiffness, and another of the spring elements has a second spring stiffness. A drive motor is in mechanical communication with the bracket and is configured to rotate the sensor cover relative to the sensor. A controller is in electrical communication with the drive motor to operate the drive motor in a first operating state.

[0019] A vehicle is disclosed herein. The vehicle includes a passenger compartment, wheels supporting the passenger compartment, and a sensor assembly mounted relative to the passenger compartment. The sensor assembly includes a sensor and a sensor cover disposed adjacent to the sensor and within a field of view of the sensor. The sensor cover has an inner surface facing the sensor and an outer surface facing away from the sensor. Spring elements are attached to the sensor cover at a first end and a bracket at a second end. At least one of the spring elements includes a first spring stiffness and another of the spring elements includes a second spring stiffness. A drive motor is in mechanical communication with the bracket and is configured to rotate the sensor cover relative to the sensor. DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram of a vehicle having a plurality of sensor assemblies. Fig. 2 is a schematic side view of a sensor with a sensor cover assembly in one of the plurality of sensor assemblies of Fig. 1 with a sensor cover in a first position. Fig. 3 is a schematic side view of the sensor with the sensor cover in a second position. Fig. 4 is a perspective view of the sensor cover assembly.

[0020] Some embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings. The same reference number represents the same element or type of element in the drawings. DETAILED DESCRIPTION

[0021] The present disclosure may be embodied in many different forms. Representative examples of the disclosure are illustrated in the drawings and are disclosed in detail herein as non-limiting examples of the disclosed principles. To this end, elements and limitations described in the "Summary," "Introduction," "Summary," and "Detailed Description" sections, but not expressly set forth in the claims, should not be incorporated into the claims, individually or collectively, by implication, inference, or otherwise.

[0022] For the purposes of this specification, the use of the singular includes the plural and vice versa, unless expressly excluded; the terms "and" and "or" apply both subjunctive and disjunctive; and the words "including," "containing," "comprising," "with," and the like mean "including without limitation." Furthermore, words of approximation such as "about," "almost," "substantially," "generally," "approximately," etc. may be used herein to mean "at, near, or almost at," or "within 0-5% of," or "within acceptable manufacturing tolerances," or logical combinations thereof. A component "designed" to perform a particular function is capable of performing the stated function without modification, rather than merely having the potential to perform the stated function after further modifications.In other words, if the hardware described is expressly designed to perform the specified function, it is specifically selected, created, implemented, used, programmed, and / or designed to perform the specified function.

[0023] According to an exemplary embodiment, Fig. 1 a vehicle 20 that can be operated in an autonomous mode or automated mode. The vehicle 20 can be a fully autonomous vehicle or a semi-autonomous vehicle. The vehicle 20 includes a body that defines a passenger compartment supported by wheels 25, and a drive system 22 that controls the autonomous operation of the vehicle 20. The drive system 22 includes a sensor system 24 for sensing information about the environment or surroundings of the vehicle 20 and a controller 26 for calculating possible actions for the autonomous vehicle based on the sensed information and for performing one or more of the possible actions, as well as a human-machine interface 28 for communicating with an occupant of the vehicle, for example a driver or passenger. The sensor system 24 can include at least one optical sensor 30, such as at least one camera, at least one distance sensor 32, such asa depth camera (RGB-D) or lidar, and a gaze monitoring system 34. In the example shown, the optical sensor 30 and the distance sensor 32 have at least partially overlapping fields of view to correlate the information acquired by each of the sensors.

[0024] The controller 26 may include processing circuitry, which may include an application-specific integrated circuit (ASIC), an electronic circuit, a processor (collectively, dedicated, or as a group), and memory executing one or more software or firmware programs, combinational logic circuitry, and / or other suitable components that provide the described functionality. The controller 26 may include a non-transitory computer-readable medium storing instructions that, when processed by one or more processors of the controller 26, implement a method of operating a sensor assembly with a movable cover according to one or more embodiments described herein.

[0025] Fig. 2 schematically shows a side view of one of the sensor assemblies 200, e.g., a sensor cleaning assembly. The sensor assembly 200 includes a sensor housing 202 in which one or more sensors 204 are housed. The sensor housing 202 can be mounted at several different locations relative to the vehicle 20, for example, adjacent to a front or rear portion of the vehicle 20. A sensor cover 206 allows the sensor 204 to have a field of view outside the sensor housing 202. The sensor cover 206 could, for example, be cylindrical and made of a transparent material that allows the sensor 204 to have a field of view outside the sensor housing 202. The sensor cover 206 is supported relative to a rotatable mount 208, e.g., a ring, by a plurality of spring elements 210, e.g., spring elements 210A, 210B, 210C, and 210D.In the example shown, the sensor cover 206 is supported by four separate spring elements 210A, 210B, 210C and 210D (. Fig. 4), such as coil springs. However, instead of coil springs, other types of spring elements, e.g., elastomer-based spring elements, could be used. Furthermore, fewer than four spring elements 210 or more than four spring elements, e.g., six spring elements 210, could be used to support the sensor cover 206 relative to the bracket 208.

[0026] In the illustrated example, the spring elements 210A, 210B, 210C, 210D have spring stiffnesses K1, K2, K3, and K4, respectively. In one example, the spring stiffnesses K1 and K2 are each greater than the spring stiffnesses K3 and K4. Furthermore, the spring stiffnesses K1 and K2 for the spring elements 210A and 210B, respectively, can be the same. Likewise, the spring stiffnesses K3 and K4 for the spring elements 210C and 210D can be the same. Alternatively, the spring stiffnesses K1 and K2 can vary relative to one another, and the spring stiffnesses K3 and K4 can vary relative to one another, with the spring stiffnesses K3 and K4 each being smaller than the spring stiffnesses K1 and K2, respectively. In one example, the spring stiffnesses K1 and K2 are greater than or equal to 3000 N / m and less than or equal to 6000 N / m and the spring stiffnesses K3 and K4 are greater than or equal to 30 N / m and less than or equal to 300 N / m.

[0027] Each of the spring elements 210A, 210B, 210C, and 210D is attached to the sensor cover 206 at a first end with a first spring attachment point and to a bracket 208 at a second end with a second spring attachment point. In one example, the first spring attachment point is located adjacent a perimeter of the sensor cover 206, and the first and second spring attachments include a pivotal connection. The bracket 208 is rotatable about an axis A that extends longitudinally through a sensor 204 and a sensor lens 216. A drive motor 218, e.g., a piezoelectric motor, drives the bracket 208 via a mechanical connection, e.g., a gear train or a belt drive, to rotate the sensor cover 206.

[0028] During operation of the sensor assembly 200, aerodynamic conditions, such as airflow represented by arrow F, may cause the sensor cover 206 to move or wobble relative to the housing 202. The movement may occur when the aerodynamic forces acting on the sensor cover 206 cause at least one of the spring elements 210 to compress. As shown in Fig. 3-4, spring elements 210A and 210B have stiffnesses K1 and K2 that are greater than stiffnesses K3 and K4. This may result in one of spring elements 210C and 210D compressing and the other of spring elements 210C and 210D expanding or elongating as sensor cover 206 rotates about spring elements 210A, 210B. Spring elements 210A and 210B may form a pivot axis for sensor cover 206 about the first attachment points for each of spring elements 210A, 210B. Alternatively, spring elements 210A and 210B may be slightly compressed and still form the axis about which sensor cover 206 can pivot. This causes the sensor cover 206 to wobble or move away from the axis of the sensor 204.

[0029] The tilting and rocking motion of the sensor cover 206 helps clean an outer surface 206E of the sensor cover 206 of dust particles or water droplets. The outer surface 206E is located on a side of the sensor cover 206 opposite the inner surface 206I. The outer surface 206E may also be continuous with an outer surface of the housing 202 when it is not tilted or rocking, or transverse to a portion of the outer surface of the housing 202 when it is tilted or rocking.

[0030] The sensor cover 206 can rotate about the axis A by the drive motor 218 in driving engagement with the bracket 208, as shown in the Fig.2-4. A feature of the drive motor 218 driving the mount 208 is that the sensor cover 206 does not remain stuck in a single tilted position relative to axis A because it can rotate about axis A. This allows the sensor cover 206 to clean itself of contaminants such as dust particles or water droplets. In addition, the controller 26 can actuate the drive motor 218, which rotates the mount 208, which causes the sensor cover 206 to rotate up to a predetermined speed of the vehicle 20, such as an operating speed of the vehicle 20. The controller 26 is in electrical communication and configured to operate the drive motor 218 in response to a first operating condition. In one example, the first operating condition may include a speed of the vehicle 20 that is within a predetermined operating range.

[0031] The terms "a" and "an" do not imply a quantitative limitation, but rather denote the presence of at least one of the mentioned elements. The term "or" means "and / or" unless the context clearly indicates otherwise. Whenever "an aspect" is mentioned throughout the description, this means that a particular element (e.g., a feature, structure, step, or property) described in connection with the aspect is included in at least one of the aspects described therein and may or may not be present in other aspects. Furthermore, the described elements in the various aspects may be combined as appropriate.

[0032] When an element, such as a layer, film, region, or substrate, is described as being "on" another element, it may be directly on top of the other element, or there may be intervening elements. Conversely, when an element is described as being "directly on" another element, there are no intervening elements.

[0033] Unless otherwise indicated herein, examination standards are the most recent standard in force as of the filing date of that application or, if priority is claimed, the filing date of the earliest priority application in which the examination standard appears.

[0034] Unless otherwise defined, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0035] Although the above disclosure has been described with reference to exemplary embodiments, those skilled in the art will understand that various changes may be made and equivalent elements may be substituted without departing from the scope of the disclosure. Furthermore, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without violating the scope of the disclosure. Therefore, the present disclosure is not intended to be limited to the particular embodiments, but is intended to include embodiments falling within the scope of the disclosure.

Claims

[1] A sensor assembly (200) comprising: a sensor (204); a sensor cover (206) disposed adjacent to the sensor (204) and within a field of view of the sensor (204), the sensor cover (206) having an inner surface (206I) facing the sensor (204) and an outer surface (206E) facing away from the sensor (204); a plurality of spring elements (210) attached to the sensor cover (206) at a first end and to a bracket (208) at a second end, wherein at least one of the plurality of spring elements (210) has a first spring stiffness (K1) and another of the plurality of spring elements (210) has a second spring stiffness (K2); and a drive motor (218) which is in mechanical connection with the holder (208) and is configured to rotate the sensor cover (206) relative to the sensor (204). [2] The sensor assembly (200) of claim 1, wherein the plurality of spring elements (210) are arranged around a periphery of the sensor cover (206). [3] The sensor assembly (200) of claim 1, wherein the drive motor (218) is a piezoelectric drive motor (218). [4] The sensor assembly (200) of claim 1, wherein the plurality of spring elements (210) comprise at least one coil spring. [5] The sensor assembly (200) of claim 1, wherein the sensor (204) comprises an optical sensor (204) having a lens (216). [6] The sensor assembly (200) of claim 1, wherein the sensor cover (206) is made of a transparent material. [7] The sensor assembly (200) of claim 1, wherein the holder (208) forms a ring. [8] The sensor assembly (200) of claim 1, wherein the plurality of spring elements (210) comprises a first pair of spring elements (210) disposed along a first pair of opposite sides of the sensor cover (206) and a second pair of spring elements (210) having a second pair disposed along a second pair of opposite sides of the sensor cover (206). [9] Sensor assembly (200) according to claim 8, wherein the first pair of spring elements (210) each has a first stiffness (K1) and the second pair of spring elements (210) each has a second stiffness (K2) which is less than the first stiffness (K1). [10] The sensor assembly (200) of claim 8, wherein the first pair of spring elements (210) comprises a first pair of different spring stiffnesses and the second pair of spring elements (210) comprises a second pair of different spring stiffnesses, each of which is smaller than the first pair of different spring stiffnesses.

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