Aligning optical components in LIDAR systems

• US 10,295,660 B1
• Filed: 04/13/2017
• Issued: 05/21/2019
• Est. Priority Date: 12/30/2016
• Status: Active Grant

• Current Assignee: Zoox Inc. (Amazon.com, Inc.)
• Original Assignee: Panosense Inc.
• Inventors: McMichael, Ryan, Berger, Adam, Pilnick, Brian, Nikitin, Denis, Pesch, Brian Alexander
• Primary Examiner(s): Luu, Thanh
• Application Number:
  US15/487,342
• Time in Patent Office: 768 Days
• CPC Class Codes: G01S 17/10 using transmission of interrupted, pulse-modulated waves determination of distance by phase measurements G01S17/32
• CPC Class Codes: G01S 17/26 wherein the transmitted pulses use a frequency-modulated or phase-modulated carrier wave, e.g. for pulse compression of received signals
• CPC Class Codes: G01S 7/4814 of transmitters alone
• CPC Class Codes: G01S 7/4972 Alignment of sensor
• CPC Class Codes: G02B 7/005 Motorised alignment

Abstract

Techniques are described for aligning optical components within a LIDAR assembly. The techniques may be performed to align the optical components during manufacturing or assembly of the LIDAR assembly. For example, a first optical element (e.g., one of a light source or light sensor) may be installed in the LIDAR assembly. An optimal alignment for a second optical element (e.g., the other of the light source or light sensor) may be determined and the second optical element may be installed at the optimal alignment. The optimal alignment for the second optical element may be determined based on detected signals, for example, which may correspond to an alignment resulting in a strongest return signal, highest quality return signal, and/or minimal interference. Additionally, or alternatively, techniques may be used to align optical components at runtime by using an actuator to move one or more components of the LIDAR assembly during operation.

Claims

1. A system for affixing a laser light source to a LIDAR assembly, the system comprising:

a fixture to support the LIDAR assembly with respect to an object;

a manipulator to maintain the laser light source in an alignment relative to a laser support structure of the LIDAR assembly;

one or more processors; and

one or more computer readable storage media storing instructions that are executable by the one or more processors to;

cause the manipulator to move the laser light source adjacent to the laser support structure;

apply a current to the laser light source to emit light toward the object, the object to reflect the light back towards the LIDAR assembly as reflected light;

determine a characteristic of detected light signals that are produced by a light sensor of the LIDAR assembly in response to the reflected light;

determine, based on the characteristic of the detected light signals, an optimal alignment for the laser light source with respect to the light sensor by;

causing the manipulator to move the laser light source successively through a plurality of alignments with respect to the light sensor;

monitoring the characteristic of the detected light signals that correspond to individual ones of the plurality of alignments; and

designating an individual alignment of the plurality of alignments as the optimal alignment;

cause the manipulator to align the laser light source into the optimal alignment;

couple the laser light source to the laser support structure while the manipulator maintains the laser light source in the optimal alignment; and

cause the manipulator to release the laser light source subsequent to the laser light source being coupled to the laser support structure at the optimal alignment.

2. The system of claim 1, wherein the instructions are further executable by the one or more processors to:

cause an adhesive dispenser to apply an adhesive to at least one of the laser light source or the laser support structure; and

cause the manipulator to maintain the laser light source adjacent to the laser support structure in the optimal alignment for an adhesive cure period.

3. The system of claim 1, wherein the instructions are further executable by the one or more processors to cause a laser driver to transmit an electrical current to the laser light source to generate the light.

4. A method of aligning a laser light source with respect to a light sensor, the method comprising:

causing a manipulator to move the laser light source successively through a plurality of alignments with respect to the light sensor, wherein the light sensor is coupled to a housing;

applying an electric current to at least one first electrical contact of the manipulator to provide the electric current to at least one second electrical contact of the laser light source;

causing the laser light source to emit light at individual alignments of the plurality of alignments, wherein the light exits the housing toward an object that reflects the light to the light sensor that is coupled to the housing;

monitoring detected light signals produced by the light sensor in response to the light emitted by the laser light source while at the individual alignments;

determining, based on the monitoring the detected light signals, an optimal alignment for the laser light source with respect to the light sensor;

causing the manipulator to maintain the laser light source in the optimal alignment; and

coupling the laser light source to the housing while the manipulator maintains the laser light source at the optimal alignment.

5. The method of claim 4, wherein the coupling the laser light source to the housing includes coupling the laser light source to a laser support structure.

6. The method of claim 4, wherein the coupling the laser light source to the housing comprises:

applying an adhesive between the laser light source and a laser support structure; and

subsequent to the applying the adhesive, causing the manipulator to hold the laser light source at the optimal location for an adhesive cure period to enable the adhesive to secure the laser light source to the laser support structure.

7. The method of claim 6, further comprising:

coupling a laser driver to the housing; and

subsequent to adhering the laser light source to the laser support structure, connecting the laser driver to the laser light source to enable the laser driver to cause the laser light source to emit the light.

8. The method of claim 4, further comprising causing a clamp of the manipulator to grip the laser light source to selectively mate the at least one first electrical contact and the at least one second electrical contact, wherein the causing the laser light source to emit light includes providing the electric current from the at least one first electrical contact to the at least one second electrical contact.

9. The method of claim 4, wherein the monitoring the detected light signals includes selecting the light sensor from an array of light sensors based on a determination that the light sensor corresponds to the laser light source, and wherein other light sensors of the array of light sensors correspond to other laser light sources of an array of laser light sources.

10. The method of claim 4, wherein the individual alignments are directed toward at least one mirror that is positioned to:

redirect the light through a first lens toward the object; and

redirect reflected light that is reflected by the object through a second lens toward the light sensor.

11. The method of claim 4, wherein the optimal alignment is determined based at least in part on at least one of a quality or an intensity of the detected light signal.

12. The method of claim 4, wherein causing the manipulator to move the laser light source successively through the plurality of alignments is performed until a quality of the detected light signal ceases to improve or the quality of the signal reaches a predetermined signal quality.

13. The method of claim 4, further comprising installing additional optical components into the LIDAR assembly prior to causing the laser light source to emit the light.

14. A system for aligning light sensors within a LIDAR assembly, the system comprising:

a fixture to support the LIDAR assembly with respect to a surface to enable at least one laser light source of the LIDAR assembly to emit light toward the surface;

a first light sensor to produce detected light signals in response to receiving reflected light that is reflected by the surface back toward the LIDAR assembly;

a manipulator to install a second light sensor at an optimal location of a sensor board, wherein the sensor board is configured to secure the second light sensor within the LIDAR assembly upon the sensor board being installed into the LIDAR assembly;

one or more processors; and

one or more computer readable storage media storing instructions that are executable by the one or more processors to;

determine, based on the detected light signals, a region of the first light sensor having received the reflected light;

map a location of the region of the first light sensor to a location of the sensor board;

determine the optimal location of the sensor board at which to install the second light sensor based at least in part on the region of the first light sensor;

cause the manipulator to align the second light sensor at the optimal location of the sensor board; and

cause the manipulator to release the second light sensor subsequent to the second light sensor being coupled to the sensor board at the optimal location.

15. The system of claim 14, wherein the sensor board is configured support a sensor array comprising a plurality of individual light sensors, the plurality of individual light sensors including the second light sensor, and wherein an aggregated photo-sensitive area corresponding to the plurality of individual light sensors is smaller than a photo-sensitive area corresponding to the first light sensor.

16. The system of claim 14, wherein the detected light signals correspond to a plurality of laser light sources that are caused to successively emit the light according to an emission pattern, and wherein the instructions are further executable by the one or more processors to:

determine, based on the detected light signals, a plurality of regions of the first light sensor having received the reflected light, wherein individual regions of the plurality of regions correspond to individual laser light sources of the plurality of laser light sources; and

map the individual regions to the individual laser light sources based on the detected light signals and the emission pattern.

17. The system of claim 14, wherein causing the manipulator to align the second light sensor at the optimal location of the sensor board is based on a known relationship between a location of the light sensor and a location of the sensor board.

18. A method for aligning one or more light sensors within a LIDAR assembly, the method comprising:

coupling at least one laser light source to a housing of the LIDAR assembly at an alignment to direct light emitted by the at least one laser light source toward a surface that is remote from the LIDAR assembly;

positioning a first light sensor within the LIDAR assembly by mating the first light sensor to a mounting structure of the LIDAR assembly;

causing the at least one laser light source to emit the light toward the surface while the first light sensor is positioned within the LIDAR assembly to generate reflected light that is reflected by the surface;

monitoring detected light signals produced by the first light sensor to determine at least one region of the first light sensor that receives the reflected light;

determining, based on the at least one region of the first light sensor, at least one optimal alignment within the LIDAR assembly to position at least one second light sensor with respect to the at least one laser light source;

customizing a sensor board by positioning the at least one second light sensor on the sensor board based on the at least one region to generate a customized sensor board; and

subsequent to removing the first light sensor from the LIDAR assembly, coupling the at least one second light sensor to the housing at the at least one optimal alignment, wherein coupling the at least one second light sensor to the housing includes coupling the customized sensor board to the mounting structure.

19. The method of claim 18, wherein the at least one region of the first light sensor includes a plurality of regions and the at least one laser light source includes a plurality of laser light sources, and wherein individual regions of the plurality of regions corresponds to individual laser light sources of the plurality of laser light sources.

20. The method of claim 18, wherein the at least one region of the first light sensor that receives the reflected light is determined by an intensity of the reflected light and a location of the first light sensor that receives the reflected light.