Light source characterization system

Patent metadata

Field	Value
Publication number	US-2023213629-A1
Application number	US-202117566461-A
Country	US
Kind code	A1
Filing date	Dec 30, 2021
Priority date	Dec 30, 2021
Publication date	Jul 6, 2023
Grant date	—

Abstract

Various measurement systems and methods are disclosed to enable characterizing the optical characteristics of light beams emitted by a light detection and range finding (LIDAR) system or sensor and evaluating the range finding function of user selected lidar channels while the lidar operates under a real operational condition and is exposed to a range of user defined environmental conditions.

First claim

What is claimed is:

1 . A method, comprising:
causing a laser range finder to emit a plurality of light beams during rotation of the laser range finder about a rotational axis, wherein the plurality of light beams are emitted by a plurality of channels of the laser range finder, wherein during a first portion of a rotational period, a first at least one light beam of the plurality of light beams is directed toward a target through a straight optical path; evaluating a range finding function of the laser range finder based at least in part on at least one reflected light beam, wherein the at least one reflected light beam corresponds to the first at least one light beam reflected by the target; determining at least one optical characteristic of a second at least one light beam, wherein the second at least one light beam is emitted during a second portion of the rotational period of the laser range finder and is received by a measurement device; and identifying at least one operating parameter of the laser range finder for modification based at least in part on at least one of the range finding function or the at least one optical characteristic of the second at least one light beam.

2 . The method of claim 1 , wherein the plurality of light beams are emitted by the plurality of channels of the laser range finder in a plurality of directions about an emission axis.

3 . The method of claim 1 , further comprising controlling at least one of a temperature or humidity of an environment surrounding the laser range finder.

4 . The method of claim 1 , wherein evaluating a range finding function of the laser range finder comprises determining a distance between the laser range finder and the target.

5 . The method of claim 1 , wherein the at least one optical characteristic comprises at least one of optical intensity, optical power, polarization, wavelength, or optical spectrum.

6 . The method of claim 1 , wherein the measurement device comprises an optical spectrum analyzer configured to measure an optical spectrum of the second at least one light beam.

7 . The method of claim 1 , wherein the measurement device comprises an optical power meter configured to measure an average optical power of the second at least one light beam.

8 . The method of claim 1 , wherein the first portion of the rotational period is shorter than the second portion of the rotational period.

9 . The method of claim 1 , further comprising directing a third at least one light beam of the plurality of light beams away from the target during the first portion of the rotational period.

10 . The method of claim 9 , wherein directing the third at least one beam of the plurality of light beams away from the target during the first portion of the rotational period comprises reflecting the third at least one light beam away from the target using at least one optical guard.

11 . The method of claim 10 , wherein the laser range finder is housed in a cavity formed by a housing.

12 . The method of claim 11 , wherein the first at least one light beam is directed to the target via a first aperture of the housing and wherein the second at least one light beam is received by the measurement device through a second aperture of the housing.

13 . The method of claim 12 , wherein the second at least one light beam is received by the measurement device after at least one reflection off of an internal surface of the housing.

14 . The method of claim 12 , wherein the first aperture extends along a polar direction from a top edge to a bottom edge on an internal surface of the housing.

15 . The method of claim 14 , wherein at least one optical guard is positioned proximate at least one of the top edge or the bottom edge, wherein the optical guard directs the third at least one light beam away from the target during the first portion of the rotational period.

16 . The method of claim 12 , wherein the cavity is a spherical cavity.

17 . The method of claim 16 , wherein the plurality of light beams are emitted by the plurality of channels of the laser range finder in a plurality of directions about an emission axis and wherein the housing further comprises a rotational stage positioned inside the cavity, wherein the laser range finder is mounted on the rotational stage and the rotational stage is configured to rotate the laser range finder around a channel selection axis perpendicular to the rotational axis and the emission axis.

18 . The method of claim 17 , wherein the rotational stage is further configured to align the first at least one light beam with the first aperture to enable the first at least one light beam to exit the cavity via the first aperture during the first portion of the rotational period without interacting with the housing.

19 . A system, comprising:
at least one processor configured to:
cause a laser range finder to emit a plurality of light beams during rotation of the laser range finder about a rotational axis, wherein the plurality of light beams are emitted by a plurality of channels of the laser range finder,
wherein during a first portion of a rotational period, a first at least one light beam of the plurality of light beams is directed toward a target through a straight optical path;
evaluate a range finding function of the laser range finder based at least in part on at least one reflected light beam, wherein the at least one reflected light beam corresponds to the first at least one light beam reflected by the target;
determine at least one optical characteristic of a second at least one light beam, wherein the second at least one light beam is emitted during a second portion of the rotational period of the laser range finder; and
identify at least one operating parameter of the laser range finder for modification based at least in part on at least one of the range finding function or the at least one optical characteristic of the second at least one light beam.

20 . Non-transitory, computer-readable media storing computer-executable instructions that, when executed by a computing device, causes the computing device to:
cause a laser range finder to emit a plurality of light beams during rotation of the laser range finder about a rotational axis, wherein the plurality of light beams are emitted by a plurality of channels of the laser range finder, wherein during a first portion of a rotational period, a first at least one light beam of the plurality of light beams is directed toward a target through a straight optical path; evaluate a range finding function of the laser range finder based at least in part on at least one reflected light beam, wherein the at least one reflected light beam corresponds to the first at least one light beam reflected by the target; determine at least one optical characteristic of a second at least one light beam, wherein the second at least one light beam is emitted during a second portion of the rotational period of the laser range finder; and identify at least one operating parameter of the laser range finder for modification based at least in part on at least one of the range finding function or the at least one optical characteristic of the second at least one light beam.

Assignees

• Motional Ad Llc

Inventors

• Zhou Yong
• Fu Geng

Classifications

• G01S7/4814 Primary

  of transmitters alone · CPC title

• G01S7/4813

  Housing arrangements · CPC title

• G01S17/42

  Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S17/46) · CPC title

• G01S7/497 Primary

  Means for monitoring or calibrating · CPC title

• G01S7/4818

  using optical fibres · CPC title