Patent Publication Number: US-11391941-B2

Title: Refractive beam steering device useful for automated vehicle LIDAR

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 15/227,622, filed on Aug. 3, 2016, now U.S. Pat. No. 10,598,922, issued on Mar. 24, 2020. 
    
    
     BACKGROUND 
     Advances in electronics and technology have made it possible to incorporate a variety of advanced features on automotive vehicles. Various sensing technologies have been developed for detecting objects in a vicinity or pathway of a vehicle. Such systems are useful for parking assist and cruise control adjustment features, for example. 
     More recently, automated vehicle features have become possible to allow for autonomous or semi-autonomous vehicle control. For example, cruise control systems may incorporate LIDAR (light detection and ranging) for detecting an object or another vehicle in the pathway of the vehicle. Depending on the approach speed, the cruise control setting may be automatically adjusted to reduce the speed of the vehicle based on detecting another vehicle in the pathway of the vehicle. 
     There are different types of LIDAR systems. Flash LIDAR relies upon a single laser source to illuminate an area of interest. Reflected light from an object is detected by an avalanche photodiode array. While such systems provide useful information, the avalanche photodiode array introduces additional cost because it is a relatively expensive component. Additionally, the laser source for such systems has to be relatively high power to achieve sufficiently uniform illumination of the area of interest. Scanning LIDAR systems utilize different components compared to flash LIDAR. One challenge associated with previously proposed scanning LIDAR systems is that additional space is required for the scanning components and there is limited packaging space available on vehicles. Optical phase array LIDAR systems utilize beam multiplexing that tends to introduce relatively significant power loss. 
     There is a need for improvements in components for systems, such as LIDAR systems, that are lower-cost, easier to fit within small packaging constraints, and utilize power efficiently. 
     SUMMARY 
     An illustrative example device for steering radiation includes an optic component including a plurality of concave surfaces on at least one side of the optic component, a plurality of radiation sources respectively aligned with the plurality of concave surfaces, and at least one actuator that selectively moves the optic component relative to the plurality of light sources to selectively change a direction of respective beams of radiation passing through the plurality of concave surfaces. 
     In an example embodiment having one or more features of the device of the previous paragraph, the radiation sources emit respective beams of radiation in a first direction and the at least one actuator selectively moves the optic component in a second direction that is transverse to the first direction. 
     In an example embodiment having one or more features of the device of either of the previous paragraphs, the at least one actuator comprises a first actuator on one side of the optic component and a second actuator on a second side of the optic component. 
     In an example embodiment having one or more features of the device of any of the previous paragraphs, the at least one actuator selectively moves the optic component in a third direction that is opposite and parallel to the second direction. 
     In an example embodiment having one or more features of the device of any of the previous paragraphs, the at least one actuator comprises a micro-electro-mechanical (MEMs) actuator. 
     An example embodiment having one or more features of the device of any of the previous paragraphs includes a plurality of collimating lenses respectively between the laser diodes and the concave surfaces. 
     An example embodiment having one or more features of the device of any of the previous paragraphs includes a housing including a base, a cover spaced from the base at least one side wall between the base and the cover, and wherein the radiation sources are supported within the housing near the base, the optic component is supported within the housing between the radiation sources and the cover, and the at least one actuator selectively moves the optic component in opposite directions generally parallel to the cover 
     In an example embodiment having one or more features of the device of any of the previous paragraphs, the at least one sidewall comprises two oppositely facing side walls, the at least one actuator comprises a first actuator supported on one of the two oppositely facing side walls and a second actuator supported on the other of the two oppositely facing side walls, and the first and second actuators move the optic component respectively closer to or further away from the two oppositely facing side walls. 
     In an example embodiment having one or more features of the device of any of the previous paragraphs, the radiation sources, the optic component and the at least one actuator are all within the housing, the at least one actuator has a portion supported on the housing, and the optic component is supported by another portion of the at least one actuator. 
     An illustrative example embodiment of a method of steering radiation includes directing radiation through a plurality of concave surfaces on at least one side of an optic component and selectively moving the optic component to control a direction of respective beams of radiation passing through the plurality of concave surfaces. 
     An example embodiment having one or more features of the method of any of the previous paragraphs includes emitting respective beams of radiation in a first direction and selectively moving the optic component in a second direction that is transverse to the first direction. 
     An example embodiment having one or more features of the method of any of the previous paragraphs includes selectively moving the optic component in a third direction that is opposite and parallel to the second direction. 
     An example embodiment having one or more features of the method of any of the previous paragraphs includes using at least one actuator for selectively moving the optic component. 
     In an example embodiment having one or more features of the method of any of the previous paragraphs, the at least one actuator comprises a micro-electro-mechanical (MEMs) actuator. 
     An example embodiment having one or more features of the method of any of the previous paragraphs includes using laser diodes as sources of the radiation. 
     In an example embodiment having one or more features of the method of any of the previous paragraphs, the optic component is within a housing including a base, a cover spaced from the base at least one side wall between the base and the cover and the method includes selectively moving the optic component in opposite directions generally parallel to the cover. 
     An illustrative example embodiment of a LIDAR device for use on a vehicle includes an optic component including a plurality of concave surfaces on at least one side of the optic component, a plurality of radiation sources respectively aligned with the plurality of concave surfaces, and at least one actuator that selectively moves the optic component relative to the plurality of light sources, wherein a direction of respective beams of radiation passing through the plurality of concave surfaces depends on a position of the concave surfaces relative to the radiation sources. 
     In an example embodiment having one or more features of the LIDAR device of the previous paragraph, the at least one actuator comprises a micro-electro-mechanical (MEMs) actuator. 
     An example embodiment having one or more features of the LIDAR device of either of the previous paragraphs includes a housing including a base, a cover spaced from the base at least one side wall between the base and the cover, and wherein the radiation sources are supported within the housing near the base, the optic component is supported within the housing between the radiation sources and the cover, and the at least one actuator selectively moves the optic component in opposite directions generally parallel to the cover. 
     the at least one sidewall comprises two oppositely facing side walls, the at least one actuator comprises a first actuator supported on one of the two oppositely facing side walls and a second actuator supported on the other of the two oppositely facing side walls, and the first and second actuators move the optic component respectively closer to or further away from the two oppositely facing side walls. 
     In an example embodiment having one or more features of the LIDAR device of any of the previous paragraphs, the radiation sources, the optic component and the at least one actuator are all within the housing, the at least one actuator has a portion supported on the housing, and the optic component is supported by another portion of the at least one actuator 
     Various features and advantages of at least one disclosed example embodiment will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  schematically illustrates a vehicle including a detection device having beam steering components designed according to an embodiment of this invention. 
         FIG. 2  schematically illustrates an example device for steering radiation designed according to an embodiment of this invention. 
         FIG. 3  schematically illustrates the example device of  FIG. 2  directing beams of radiation differently than that shown in  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  schematically illustrates a vehicle  20  including a detection device  22 . One example use for the detection device  22  is to provide sensing or guidance information for a vehicle, engine or brake controller, such as an automated vehicle controller. For discussion purposes, the detection device  22  is a LIDAR device that emits at least one beam of radiation  24  that is useful for detecting objects in a vicinity or pathway of the vehicle  20 . In this example, the beam of radiation  24  comprises light that is directed at a selected angle relative to the vehicle  20 . 
     Embodiments of this invention provide additional beam steering and scanning capability while requiring lower power and occupying less space compared to other proposed arrangements. Embodiments of this invention allow for achieving a desired level of beam control using less power and occupying less space, which makes embodiments of this invention well-suited for automated vehicle LIDAR systems. In this example, the radiation comprises light. A source of radiation  30  includes a plurality of laser diodes  32 . Each of the laser diodes  32  in this example emits a separate beam of light  24 . 
       FIG. 2  schematically illustrates a portion of the LIDAR device  22  that is useful for steering radiation (e.g., the beams of light  24 ) in a desired direction, manner or pattern. An optic component  34  includes a plurality of concave surfaces  36  on at least one side of the optic component  34 . The concave surfaces  36  are respectively aligned with the laser diodes  32  such that each beam of light  24  originates from one of the laser diodes  32  and passes through one of the concave surfaces  36 . 
     The optic component  34  comprises a suitable optic material, such as that useful for making lenses. The concave surfaces  36  provide refractive surfaces for steering the beams of radiation  24  in a desired direction. At least one actuator  38  is associated with the optic component  34  to cause selective movement of the optic component  34  relative to the source of radiation  30  for selectively changing the direction of the beams  24 . In this example, there are two actuators  38 , one associated with each end of the optic component  34 . 
     As schematically represented by the arrow  40  in  FIG. 2 , the actuators  38  move the optic component  34  into the illustrated position, which corresponds to movement to the left according to the drawing. The position of the optic component  34  in  FIG. 2  directs the beams  24  away from the device  22  in the illustrated direction. As shown in  FIG. 3 , the optic component  34  is moved or translated toward the right according to the drawing as schematically shown by the arrow  42 . In the position shown in  FIG. 3 , the concave surfaces  36  refract the beams of light  24  in the illustrated direction, which is different than that accomplished with the condition of the device  22  shown in  FIG. 2 . 
     A controller (not illustrated) of the device  22  causes desired operation of the actuators  38  to cause selective movement of the optic component  34  to realize a desired direction of radiation emanating from the device  22  or to realize a desired beam scanning pattern. Given this description, those skilled in the art will realize how to achieve a desired control strategy to realize a beam scanning pattern that will suit their particular needs. 
     In some example embodiments, the actuators  38  comprise micro-electro-mechanical (MEMs) actuators. Such actuators are useful for embodiments where the device  22  is intended to fit within a relatively small space. Other example embodiments include different actuators, such as piezoelectric actuators. 
     The example embodiment of  FIGS. 2 and 3  includes a stationary optic component  50  that controls the beams emitted by the laser diodes  32 . In this example, the optic component  50  comprises a plurality of collimating lenses  52  that prevent the beams emitted by the laser diodes  32  from spreading undesirably. 
     The source of radiation  30 , the optic component  34 , the actuators  38 , and the collimating lenses  52  are all situated within a housing  60 . In this example, the housing  60  includes a base  62 , which may comprise a substrate that supports the laser diodes  32 . A cover  64  comprises an optically transparent material. At least one sidewall  66  extends between the base  62  and the cover  64 . In the illustrated example, the actuators  38  are at least partially supported by the housing  60 . According to the arrangement shown in  FIGS. 2 and 3 , the actuators  38  are supported on oppositely facing sidewalls  66  of the housing  60 . Other arrangements for supporting the actuators within a housing are possible. The stationary optic component  50  is also supported by the sidewalls  66  in this example. One example embodiment includes copper traces etched into the cover  64  for facilitating providing power and signals to the actuators  38 . 
     As can be appreciated from the drawings, the laser diodes  32  emit the beams of light  24  in a first direction (e.g., vertical according to the drawings). The actuators  38  selectively move the optic component  34  in a second direction that is transverse to the first direction (e.g., to the right or left according to the drawing). The actuators  38  also selectively move the optic component  34  in a third direction that is opposite and parallel to the second direction (e.g., to the left or right according to the drawing). 
     One feature of the illustrated embodiment is that it allows for realizing a LIDAR (light detection and ranging) device  22  that is useful for automated vehicle applications. The illustrated embodiment is capable of fitting within very tight packaging constraints, operating using relatively low power, and providing a wide range of beam direction capability. Another feature of the illustrated example embodiment is that it reduces the number of components compared to devices that rely upon an external mirror arrangement, such as a MEMs mirror for directing light. With the illustrated arrangement, no external directing mirrors are needed, no additional beam folding space is required and there is less emitter energy loss compared to other proposed LIDAR devices. 
     The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this invention. The scope of legal protection given to this invention can only be determined by studying the following claims.