Patent Application
20220317253
Modern vehicles are often equipped with sensors designed to detect objects and landscape features around the vehicle in real-time to enable technologies such as lane change assistance, collision avoidance, and autonomous driving. A commonly used sensor is a light detection and ranging (LiDAR) system.
A LiDAR system may include a light source, also referred to as a transmission module (TX module), and a light detection system, also referred to as a detection module (also referred to as a receiver (RX) module), to estimate distances to environmental features (e.g., pedestrians, vehicles, structures, plants, etc.). The emitted laser beam from the TX module is used to illuminate a target and the RX module receives the reflections from the laser beam in order for the LiDAR system to measure the time it takes for the transmitted laser beam to arrive at the target and then return to the detection module. In some LiDAR systems, the laser beam may be steered across a region of interest according to a scanning pattern to generate a “point cloud” that includes a collection of data points corresponding to target points in the region of interest. The data points in the point cloud may be dynamically and continuously updated, and may be used to estimate, for example, a distance, dimension, and location of an object relative to the LiDAR system, often with very high fidelity (e.g., within about 5 cm) due to the precision of the optical alignment of the components.
In some embodiments, the present technology relates to a method of optically aligning a detection or transmission module with an optical lens assembly in a LiDAR system. The optical lens assembly may be coupled to a chassis, to which the detection or transmission module will also be coupled after alignment. The method may include orienting the detection or transmission module relative to the optical lens assembly to an optically aligned orientation. Optical alignment may be achieved when a path of a laser beam emitted from a laser module of the transmission module is oriented with an optical path in the optical lens assembly to a detection sensor of the detection module. The method may further include applying a first portion of adhesive between a transparent mounting block and the chassis, and applying a second portion of adhesive between the transparent mounting block and the detection or transmission module. The transparent mounting block may be translated to be adjacent to the oriented detection or transmission module. The first and second portions of adhesive may be cured in any order in order to fixedly couple the detection or transmission module relative to the chassis. The transparent mounting block may allow for visual inspection of the cured first and second portions of adhesive through the transparent mounting block.
In some embodiments, the method may be directed toward alignment of a detection module. The detection module may include a detection circuit board assembly comprising a board and the detection sensor, and a bracket. The detection circuit board assembly may be fixedly coupled to the bracket with screws. The method may further include applying the second portion of adhesive between the transparent mounting block and the bracket. In some embodiments, the method may also include the bracket including a planar portion and a tab extending away from the planar portion. The method may further include translating the transparent mounting block adjacent to the oriented detection module so that a first bonding surface of the transparent mounting block is positioned against the tab with the second portion of adhesive there between.
In some embodiments, the method may be directed toward alignment of a transmission module. The transmission module may include a transmission circuit board assembly including a board and the laser module, and a second chassis. The transmission circuit board assembly may be fixedly coupled to the second chassis with screws. Applying the second portion of adhesive includes applying the second portion of adhesive between the transparent mounting block and the second chassis. In some embodiments, the second chassis may include a central portion to which the transmission circuit board assembly is fixedly coupled, and a tab extending away from the central portion. In some embodiments, translating the transparent mounting block adjacent to the oriented transmission module comprises positioning a first bonding surface of the transparent mounting block against the tab with the second portion of adhesive there between.
In some embodiments, curing the first and second portions of adhesive in order to fixedly couple the detection or transmission module relative to the chassis may include emitting ultraviolet radiation through the transparent mounting block in order to cure the first and second portions of adhesive. In some embodiments, the transparent mounting block may be made of glass. In some embodiments, the transparent mounting block may include a rectangular prism shaped body. The rectangular prism shaped body may define a first bonding surface with a first surface roughness, and a second face opposite the first bonding surface with a second surface roughness less than the first surface roughness. The first portion of adhesive may be applied between the first bonding surface and the chassis. the first surface roughness of the first face may be defined by a plurality of grooves.
The present technology may further be direct toward a LiDAR system including a chassis, an optical lens assembly coupled to a chassis, a transparent mounting block adhesively coupled to the chassis with a first portion of adhesive, and a detection or transmission module optically aligned with the optical lens assembly so that a path of a laser beam emitted from a laser module of the transmission module is oriented with an optical path in the optical lens assembly to a detection sensor of the detection module. The detection and/or transmission module may be coupled to the chassis with a second portion of adhesive between the transparent mounting block and detection or transmission module. The transparent mounting block allows visual inspection of the first and second portions of adhesive through the transparent mounting block.
In some embodiments, the system includes a detection module including a detection circuit board assembly including a board and the detection sensor, and a bracket. The detection circuit board assembly may be fixedly coupled to the bracket with screws. the second portion of adhesive may be between the transparent mounting block and the bracket. The bracket may include a planar portion and a tab extending away from the planar portion. A first bonding surface of the transparent mounting block may be positioned against the tab with the second portion of adhesive there between.
In some embodiments, the system includes a transmission module including a transmission circuit board assembly comprising a board and the laser module, and a second chassis. The transmission circuit board assembly may be fixedly coupled to the second chassis with screws. The second portion of adhesive may be between the transparent mounting block and the second chassis. The second chassis may include a central portion to which the transmission circuit board assembly is fixedly coupled and a tab extending away from the central portion. A first bonding surface of the transparent mounting block may be positioned against the tab with the second portion of adhesive there between.
In some embodiments, the transparent mounting block allows the first and second portions of adhesive to be curable via ultraviolet radiation emitted through the transparent mounting block. The transparent mounting block may be made of glass. The transparent mounting block may have a rectangular prism shaped body. The rectangular prism shaped body may define a first bonding surface with a first surface roughness, and a second surface opposite the first bonding surface and with a second surface roughness less than the first surface roughness. The first portion of adhesive may be positioned between the first bonding surface and the chassis. The first surface roughness of the first bonding surface may be defined by a plurality of grooves.
The features of the various embodiments described above, as well as other features and advantages of certain embodiments of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:
Throughout the drawings, it should be noted that like reference numbers are typically used to depict the same or similar elements, features, and structures.
Aspects of the present disclosure relate generally to optical alignment and improved adhesive bonding for coupling a detection module and/or transmission module to a chassis. The detection module and transmission module are optically aligned relative to an optical lens assembly and secured to a chassis with transparent mounting blocks adhesively bonded to the chassis and bonding surfaces of the detection module and transmission module. The chassis, detection module, transmission module, and optical lens assembly may be part of a LiDAR assembly, according to certain embodiments.
In the following description, various examples of improved adhesive bonding for coupling a detection module and a transmission module to a chassis are described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the embodiments. However, it will be apparent to one skilled in the art that certain embodiments may be practiced or implemented without every detail disclosed. Furthermore, well-known features may be omitted or simplified in order to prevent any obfuscation of the novel features described herein.
The following high-level summary is intended to provide a basic understanding of some of the novel innovations depicted in the Figures and presented in the corresponding descriptions provided below.
Generally, aspects of the technology are directed to implementations of fixedly coupling a detection module and/or a transmission module to a chassis so that the respective module is optically aligned with an optical lens assembly, also coupled to the chassis. For example, a Light Detection and Ranging (LiDAR) assembly of an autonomous vehicle may include a detection module, also referred to as a receiving module (RX), and a transmission module (TX), or a combination transmission and receiving module (TX/RX). The detection module comprises a detection circuit board assembly coupled to a bracket, for example a shown in
Specifically, the present technology relates to the use of a transparent mounting block, as shown in
The transparent mounting blocks 200 are adhesively coupled to the chassis 101, and also adhesively coupled to the detection module 300 and transmission module 400. In embodiments, no fasteners are used to secure the detection module 300 and transmission module 400 to the chassis 101, and the detection module 300 and transmission module 400 are solely coupled to the chassis 101 with adhesive via the transparent mounting blocks 200.
The transparent mounting blocks 200 define bonding surfaces and inspection surfaces. The bonding surfaces may include characteristics for increasing adhesive bond strength relative to a polished surface. The inspection surfaces, may be polished surfaces providing an optically clear imaging path to visually inspect the bonding surfaces through the body of the transparent mounting block 200. For example, the bonding surface and underlying adhesive may be inspector by a person or via a camera. In embodiments, the surface roughness of a bonding surface of the transparent mounting block is greater than the surface roughness of an inspection surface.
In embodiments, the transparent mounting block 200 may be formed of glass, for example borosilicate glass such as BK7. In embodiments, the increased surface roughness of the bonding surfaces is formed via machining, chemical etching and/or mechanical etching. In embodiments, the increased surface roughness may be defined by a plurality of grooves on the bonding surface.
In
The bottom surface 202, which is a bonding surface, and which may be referred to as a first bonding surface, may be adhesively coupled to the chassis 101, and the one or more side surfaces 203 defining bonding surfaces may be adhesively coupled to the detection module 300 or transmission module 400.
As shown in
The bracket 302 may be solid and formed monolithically, for example molded and/or machined from a single piece of material. In embodiments, the bracket 302 is comprised of a metal with a high thermal conductivity, for example aluminum, copper and/or steel. Solid monolithically formed metal brackets 302 are advantageous in conducting thermal energy compared to hollow, webbed, multi-component and/or non-metal constructions.
As shown in
As shown in
To optically align the detection module 300 relative to the optical lens assembly 102, the detection module 300 may be manipulated about one or more of the six degrees of freedom, i.e. xyz translation and xyz rotation, and an output beam emitted from the transmission module 400 through the optical lens assembly 102 may be received by the detection sensor 304 to determine that the detection module 300, and therefore detection sensor 304, is in an optically aligned orientation.
With the detection module 300 held in place with an alignment jig and optically aligned as shown in
With the detection module 300 held in place with an alignment jig and the transparent mounting blocks 200 positioned with adhesive between the transparent mounting blocks 200 and the chassis 101, and between the transparent mounting blocks 200 and the detection module 300, as shown in
In embodiments, due to the glass composition of the transparent mounting blocks 200, heat generated by the detection module 300 may not be adequately transferred to the chassis and a thermal management block may be mounted to the chassis 101, as shown in
As shown in
With the transmission module 400 held in place with an alignment jig and optically aligned as shown in
With the transmission module 400 held in place with an alignment jig and the transparent mounting blocks 200 positioned with adhesive between the transparent mounting blocks 200 and the chassis 101, and between the transparent mounting blocks 200 and the transmission module 400, as shown in
Other variations are within the spirit of the present disclosure. Thus, while the disclosed techniques are susceptible to various modifications and alternative constructions, certain illustrated examples thereof are shown in the drawings and have been described above in detail. It should be understood, however, that there is no intention to limit the disclosure to the specific form or forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions and equivalents falling within the spirit and scope of the disclosure, as defined in the appended claims. For instance, any of the examples, alternative examples, etc., and the concepts thereof may be applied to any other examples described and/or within the spirit and scope of the disclosure.
The use of the terms “a” and “an” and “the” and similar referents in the context of describing the disclosed examples (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. The term “connected” is to be construed as partly or wholly contained within, attached to, or joined together, even if there is something intervening. The phrase “based on” should be understood to be open-ended, and not limiting in any way, and is intended to be interpreted or otherwise read as “based at least in part on,” where appropriate. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate examples of the disclosure and does not pose a limitation on the scope of the disclosure unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the disclosure.
