Aligning optical components in LIDAR systems

Patent metadata

Field	Value
Publication number	US-11255951-B1
Application number	US-201715487380-A
Country	US
Kind code	B1
Filing date	Apr 13, 2017
Priority date	Dec 30, 2016
Publication date	Feb 22, 2022
Grant date	Feb 22, 2022

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.

First claim

What is claimed is:

1. A system comprising:
a laser light source to emit light from a housing toward a surface outside the housing that reflects the light towards the housing as reflected light;
a light sensor within the housing to produce detected light signals in response to receiving at least a portion of the reflected light;
one or more optical elements disposed in an optical path between the laser light source and the light sensor;
an actuator coupled to the one or more optical elements to control a direction that the reflected light travels toward the light sensor;
one or more processors; and
one or more computer readable storage media storing instructions that are executable by the one or more processors to:
monitor the detected light signals produced by the light sensor in response to the at least the portion of the reflected light; and
determine, based on the detected light signals, an adjustment to the one more optical elements to optimize at least one characteristic of the detected light signals, the adjustment being determined to calibrate the system to correct a misalignment of the system; and
cause the actuator to move the one or more optical elements to implement the adjustment.

2. The system of claim 1 , wherein the one or more optical elements comprise at least one lens, and moving the one or more optical elements comprises tilting or translating the at least one lens.

3. The system of claim 1 , wherein determining the adjustment to the direction of the light to optimize the at least one characteristic of the detected light signals comprises:
causing the actuator to successively move the one or more optical elements of the system through a plurality of adjustments; and
monitoring the detected signals while the one or more optical elements of the system are moved through the plurality of adjustments; and
selecting an optimal adjustment from among the plurality of adjustments based at least in part on the detected signals.

4. The system of claim 3 , wherein the optimal adjustment corresponds to an adjustment that at least one of:
maximizes an intensity of the detected signals;
minimizes parallax; or
maximizes a signal to noise ratio of the detected signals.

5. A system comprising:
a laser light source to emit light from a housing toward a surface outside the housing that reflects the light towards the housing as reflected light;
a light sensor within the housing to produce detected light signals in response to receiving at least a portion of the reflected light;
one or more processors; and
one or more computer readable storage media storing instructions that are executable by the one or more processors to:
monitor the detected light signals produced by the light sensor in response to the at least the portion of the reflected light; and
determine, based on the detected light signals, an adjustment to one or more components of the system to optimize at least one characteristic of the detected light signals, the adjustment being determined to calibrate the system to correct a misalignment of the system; and
cause at least one actuator to move the one or more components of the system to implement the adjustment.

6. The system of claim 5 , further comprising the at least one actuator, wherein the at least one actuator is configured to actuate one or more optical components to control a direction that the light travels toward the surface, wherein the detected light signals vary based on the direction of the light.

7. The system of claim 5 , wherein the at least one actuator is configured to move at least one lens to control a direction that the reflected light travels toward the light sensor.

8. The system of claim 5 , wherein the at least one actuator is configured to move the laser light source to control a direction that the light travels toward the surface.

9. The system of claim 5 , wherein the at least one actuator is configured to move the light sensor.

10. The system of claim 5 , wherein the instructions are further executable by the one or more processors to determine a distance from the system to the surface based on the detected light signals while the at least one actuator maintains the one or more components of the system in an optimal position achieved by implementing the adjustment.

11. The system of claim 5 , wherein the laser light source includes a plurality of laser light sources, and wherein the light sensor includes a plurality of light sensing elements, individual laser light sources of the plurality of laser light sources corresponding to individual light sensors of the plurality of light sensing elements.

12. The system of claim 5 , wherein the at least one characteristic includes an intensity of the detected light signals that is based at least partially on a direction of the light, wherein the instructions are further executable by the one or more processors to:
determine a plurality of adjustments based on a plurality of changes to the intensity of the detected signals; and
cause the at least one actuator to successively move the one or more components of the system through the plurality of adjustments to determine an optimal adjustment.

13. The system of claim 12 , wherein the optimal adjustment corresponds to maximizing the intensity of the detected signals.

14. The system of claim 5 , wherein the at least one characteristic includes parallax, and optimization of the at least one characteristic includes minimizing the parallax.

15. The system of claim 5 , wherein the at least one characteristic includes signal-to-noise ratio (SNR), and optimization of the at least one characteristic includes maximizing the SNR.

16. The system of claim 5 , wherein the at least one actuator comprises at least one of a piezo electric actuator, a Tunable Acoustic Gradient (TAG) index of refraction lens, or a liquid lens.

17. The system of claim 5 , wherein the at least one characteristic is an intensity of the detected light signals that is based at least partially on a direction of the light, wherein the instructions are further executable by the one or more processors to:
monitor the detected light signals to identify a reduction to the intensity that is based on a proximity of the surface to the system; and
cause the at least one actuator to move the one or more components of the system in response to the reduction to the intensity of the detected signals.

18. A method of calibrating a LIDAR assembly, the method comprising:
causing a laser to emit light from a housing of the LIDAR assembly and along an optical path toward a surface outside the housing that reflects the light back to the LIDAR assembly as reflected light;
monitoring detected light signals produced in response to at least a portion of the reflected light received by a light sensor within the housing;
determining, based at least in part on the detected light signals, an adjustment to one or more components of the LIDAR assembly to optimize at least one characteristic of the detected light signals, the adjustment being determined to calibrate the LIDAR assembly to correct a misalignment of the LIDAR assembly; and
implementing the adjustment to the one or more components of the LIDAR assembly by causing at least one actuator to move the one or more components to adjust the at least one characteristic of the detected light signals.

19. The method of claim 18 , wherein the causing the at least one actuator to move the one or more components comprises causing the at least one actuator to tilt or displace at least one of

Assignees

• Zoox Inc

Inventors

• Mcmichael Ryan
• Berger Adam
• Pilnick Brian
• Nikitin Denis
• Pesch Brian Alexander

Classifications

• G01S17/10

  using transmission of interrupted, pulse-modulated waves (determination of distance by phase measurements G01S17/32) · CPC title

• G02B7/005

  Motorised alignment · CPC title

• G01S7/4972 Primary

  Alignment of sensor · CPC title

• G01S17/26

  wherein the transmitted pulses use a frequency-modulated or phase-modulated carrier wave, e.g. for pulse compression of received signals · CPC title

• G01S7/4814 Primary

  of transmitters alone · CPC title