US-12618949-B2 - LIDAR system including multifaceted deflector

Abstract

A system and method for scanning of coherent LIDAR. The system includes a motor, a laser source configured to generate an optical beam, and a deflector. A first facet of the plurality of facets has a facet normal direction. The deflector is coupled to the motor and is configured to rotate about a rotation axis to deflect the optical beam from the laser source. The laser source is configured to direct the optical beam such that the optical beam is incident on the deflector at a first incident angle in a first plane, wherein the first plane includes the rotation axis, wherein the first incident angle is spaced apart from the facet normal direction for the first facet. A second facet of the plurality of facets includes an optical element configured to deflect the optical beam at the first incident angle into a deflected angle.

Inventors

• Ryan Galloway
• Edward Angus
• Zeb Barber

Assignees

• AURORA OPERATIONS, INC.

Dates

Publication Date

20260505

Application Date

20231024

Claims (20)

1. 1 . A light detection and ranging (LIDAR) sensor system for a vehicle, comprising: a laser source configured to output a first beam; and an irregular polygon scanner configured to receive the first beam and output the first beam as a second beam, wherein the irregular polygon scanner comprises a multi-faceted deflector having a cross-section with an irregular polygonal shape.
2. 2 . The LIDAR sensor system of claim 1 , wherein the multi-faceted deflector comprises a plurality of facets that are each reflective.
3. 3 . The LIDAR sensor system of claim 1 , wherein the multi-faceted deflector comprises a plurality of facets that each have a diffraction grating.
4. 4 . The LIDAR sensor system of claim 1 , wherein the multi-faceted deflector is a first first multi-faceted deflector configured to rotate about a rotation axis, and wherein the LIDAR sensor system comprises a second deflector configured to rotate about the rotation axis.
5. 5 . The LIDAR sensor system of claim 1 , further comprising a modulator configured to apply at least one of frequency modulation or phase modulation to the first beam.
6. 6 . The LIDAR sensor system of claim 1 , wherein a diameter of the multi-faceted deflector is greater than or equal to about 0.5 centimeters and less than or equal to about 10 centimeters.
7. 7 . The LIDAR sensor system of claim 1 , further comprising a motor configured to rotate the multi-faceted deflector.
8. 8 . An autonomous vehicle control system, comprising: a laser source configured to output a first beam; an irregular polygon scanner configured to receive the first beam and output the first beam as a second beam, wherein the irregular polygon scanner comprises a multi-faceted deflector having a cross-section with an irregular polygonal shape; and one or more processors configured to: determine at least one of a range to an object or a velocity of the object based on a return signal from reflection of the second beam by the object; and control operation of at least one of a steering system or a braking system of an autonomous vehicle based on the at least one of the range or the velocity.
9. 9 . The autonomous vehicle control system of claim 8 , wherein the multi-faceted deflector comprises a plurality of facets that are each reflective.
10. 10 . The autonomous vehicle control system of claim 8 , wherein the multi-faceted deflector comprises a plurality of facets that each have a diffraction grating.
11. 11 . The autonomous vehicle control system of claim 8 , wherein the multi-faceted deflector is a first first multi-faceted deflector configured to rotate about a rotation axis, and wherein the autonomous vehicle control system comprises a second deflector configured to rotate about the rotation axis.
12. 12 . The autonomous vehicle control system of claim 8 , further comprising a modulator configured to apply at least one of frequency modulation or phase modulation to the first beam.
13. 13 . The autonomous vehicle control system of claim 8 , wherein a diameter of the multi-faceted deflector is greater than or equal to about 0.5 centimeters and less than or equal to about 10 centimeters.
14. 14 . The autonomous vehicle control system of claim 8 , further comprising a motor configured to rotate the multi-faceted deflector.
15. 15 . An autonomous vehicle, comprising: a laser source configured to output a first beam; an irregular polygon scanner configured to receive the first beam and output the first beam as a second beam, wherein the irregular polygon scanner comprises a multi-faceted deflector having a cross-section with an irregular polygonal shape; a steering system; a braking system; and a vehicle controller comprising one or more processors configured to: determine at least one of a range to an object or a velocity of the object based on a return signal from reflection of the second beam by the object; and control operation of at least one of the steering system or the braking system based on the at least one of the range or the velocity.
16. 16 . The autonomous vehicle of claim 15 , wherein the multi-faceted deflector comprises a plurality of facets that are each reflective.
17. 17 . The autonomous vehicle of claim 15 , wherein the multi-faceted deflector comprises a plurality of facets that each have a diffraction grating.
18. 18 . The autonomous vehicle of claim 15 , further comprising a modulator configured to apply at least one of frequency modulation or phase modulation to the first beam.
19. 19 . The autonomous vehicle of claim 15 , wherein a diameter of the multi-faceted deflector is greater than or equal to about 0.5 centimeters and less than or equal to about 10 centimeters.
20. 20 . The autonomous vehicle of claim 15 , further comprising a motor configured to rotate the multi-faceted deflector.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 17/558,021, filed Dec. 21, 2021, which is a continuation of U.S. patent application Ser. No. 16/888,003, filed May 29, 2020, which is a continuation of U.S. patent application Ser. No. 16/730,120, filed Dec. 30, 2019, which claims the benefit of and priority to U.S. Provisional Patent Application No. 62/788,415, filed Jan. 4, 2019. The entire disclosures of U.S. patent application Ser. No. 17/558,021, U.S. patent application Ser. No. 16/888,003, U.S. patent application Ser. No. 16/730,120, and U.S. Provisional Patent Application No. 62/788,415 are incorporated herein by reference. BACKGROUND Optical detection of range using lasers, often referenced by a mnemonic, LIDAR, for light detection and ranging, also sometimes called laser RADAR, is used for a variety of applications, from altimetry, to imaging, to collision avoidance. LIDAR provides finer scale range resolution with smaller beam sizes than conventional microwave ranging systems, such as radio-wave detection and ranging (RADAR). Optical detection of range can be accomplished with several different techniques, including direct ranging based on round trip travel time of an optical pulse to an object, and chirped detection based on a frequency difference between a transmitted chirped optical signal and a returned signal scattered from an object, and phase-encoded detection based on a sequence of single frequency phase changes that are distinguishable from natural signals. SUMMARY The present application relates to optical scanning systems, and more specifically to optical scanning systems that use multi-faceted deflectors. Aspects of the present disclosure relate generally to light detection and ranging (LIDAR) in the field of optics, and more particularly to systems and methods for multifaceted deflector for scanning of coherent LIDAR to support the operation of a vehicle. One implementation disclosed herein is directed to a system for multifaceted deflector for scanning of coherent LIDAR to support the operation of a vehicle. In some implementations, a LIDAR system includes a motor. In some implementations, the LIDAR system includes an optical source configured to generate an optical beam. In some implementations, the LIDAR system includes a deflector that includes a plurality of facets. In some implementations, a first facet of the plurality of facets has a facet normal direction. In some implementations, the deflector is coupled to the motor and is configured to rotate about a rotation axis to deflect the optical beam from the laser source. In some implementations, the laser source is configured to direct the optical beam such that the optical beam is incident on the deflector at a first incident angle in a first plane. The first plane includes the rotation axis. The first incident angle is spaced apart from the facet normal direction. In some implementations, the system includes a second facet of the plurality of facets that includes an optical element configured to deflect the optical beam at the first incident angle into a deflected angle. In some implementations, the optical element is a reflective blazed grating with a facet ruling normal direction equal to half the first incident angle for each ruling on the facet. In some implementations, the optical beam is incident on the deflector in the first plane at a different second incident angle in the first plane within 40 degrees of the first incident angle. In some implementations, a second facet of the deflector is covered with a second optical element having a second spacing that is different from the spacing of the optical element of the at least one facet of the deflector. In some implementations, wherein a second facet of the deflector is covered with a second optical element, the second optical element deflects the optical beam at the first incident angle into a second deflected angle that is different than the deflected angle. In another aspect, the present disclosure is directed to a deflector for scanning of coherent LIDAR to support the operation of a vehicle. In some implementations, the deflector includes a body with a plurality of outward facing facets relative to an axis of the body. In some implementations, a facet of the plurality of outward facing facets has a facet normal direction. In some implementations, the facet of the plurality of outward facing facets is covered with an optical element having a spacing that is less than ten times the operating wavelength that is in a range of 0.8 microns to 10 microns. Still other aspects, features, and advantages are readily apparent from the following detailed description, simply by illustrating a number of particular implementations and implementations, including the best mode contemplated for carrying out the implementations described in this disclosure. Other implementations are also capable of other and different features a