LiDAR system

Patent metadata

Field	Value
Publication number	US-11442149-B2
Application number	US-201616313247-A
Country	US
Kind code	B2
Filing date	Oct 6, 2016
Priority date	Oct 6, 2016
Publication date	Sep 13, 2022
Grant date	Sep 13, 2022

Abstract

A light detection and ranging (“LIDAR”) system includes a coherent light source that generates a frequency modulated optical signal comprising a series of optical chirps. A scanning assembly transmits the series of optical chirps in a scan pattern across a scanning region, and receives a plurality of reflected optical chirps corresponding to the transmitted optical chirps that have reflected off one or more objects located within the scanning region. A photodetector mixes the reflected optical chirps with a local oscillation (LO) reference signal comprising a series of LO reference chirps. An electronic data analysis assembly processes digital data derived from the reflected optical chirps and the LO reference chirps mixed at the photodetector to generate distance data and optionally velocity data associated with each of the reflected optical chirps.

First claim

What is claimed is:

1. A light detection and ranging (LiDAR) system, comprising:
a laser for generating light;
a scanning assembly comprising a mirror and a mirror driver, the scanning assembly (a) transmits the light in a scan pattern for a frame across a scanning region and (b) receives reflected light that has reflected off one or more objects located within the scanning region; and
an electronic data analysis and control assembly comprising a processing device, the electronic data analysis and control assembly (a) generates a plurality of data points each of which comprises distance data associated with a portion of the reflected light and (b) generates the scan pattern for the frame to be used by the scanning assembly for transmitting the light generated by the laser based on scan parameters for the frame, wherein the scan parameters for the frame identify (i) a frame size for the frame comprising either a full frame size or a reduced frame size, (ii) a spatial resolution for the frame having the identified frame size, and (iii) when the frame has the reduced frame size, a non-zero offset for the reduced frame size relative to the full frame size, wherein the electronic data analysis and control assembly generates a differing scan pattern for a differing frame to be used by the scanning assembly for transmitting the light generated by the laser based on differing scan parameters for the differing frame.

2. The LiDAR system of claim 1 , wherein the full frame size is larger than the reduced frame size.

3. The LiDAR system of claim 1 , wherein the spatial resolution defines the number of scan lines and the number of pixels per scan line for the frame having a particular frame size.

4. The LiDAR system of claim 1 , wherein the offset comprises a displacement of a reduced size frame having the reduced frame size relative to a full size frame having the full frame size in at least one dimension such that the reduced size frame is not centered with respect to the full size frame.

5. The LiDAR system of claim 1 , wherein a first set of the scan parameters for the frame enables coarse scanning to locate one or more objects of interest in the frame having the full frame size and a second set of the scan parameters for the differing frame enables fine scanning on the one or more objects of interest in the differing frame having the reduced frame size.

6. The LiDAR system of claim 1 , wherein the distance data indicates a distance of the object that provided the portion of the reflected light relative to the system.

7. The LiDAR system of claim 1 , wherein the generated light comprises a frequency modulated optical signal comprising a series of optical chirps.

8. The LiDAR system of claim 7 , wherein each of the data points also comprises velocity data associated with the portion of the reflected light.

9. The LiDAR system of claim 8 , wherein the velocity data associated with the portion of the reflected light indicates a velocity of the object that provided the portion of the reflected light relative to the system.

10. The LiDAR system of claim 7 , wherein the frequency modulated optical signal comprises a frequency modulated continuous wave sawtooth waveform.

11. The LiDAR system of claim 7 , wherein the frequency modulated optical signal comprises a frequency modulated continuous wave triangular waveform.

12. The LiDAR system of claim 7 , wherein the frequency modulated optical signal comprises a frequency modulated pulsed triangular waveform.

13. The LiDAR system of claim 7 , wherein the frequency modulated optical signal comprises a frequency modulated continuous wave sigmoid-shaped waveform.

14. A method for providing adaptive scanning, comprising:
generating a frequency modulated optical signal comprising a series of optical chirps;
generating a scan pattern for a frame for a scanning region, the scan pattern for the frame being generated based on scan parameters for the frame, wherein the scan parameters for the frame identify (i) a frame size for the frame comprising either a full frame size or a reduced frame size, (ii) a spatial resolution for the frame having the identified frame size, and (iii) when the frame has the reduced frame size, a non-zero offset for the reduced frame size relative to the full frame size;
transmitting the series of optical chirps in the scan pattern for the frame across the scanning region;
receiving a plurality of reflected optical chirps corresponding to the transmitted optical chirps that have reflected off one or more objects located within the scanning region;
mixing the reflected optical chirps with a local oscillation (LO) reference signal comprising a series of LO reference chirps; and
processing digital data derived from the reflected optical chirps and the LO reference chirps mixed at the photodetector to generate distance data associated with each of the reflected optical chirps;
wherein a differing scan pattern for a differing frame is generated based on differing scan parameters for the differing frame.

15. The method of claim 14 , wherein:
the full frame size is larger than the reduced frame size;
the spatial resolution defines the number of scan lines and the number of pixels per scan line for the frame having a particular frame size; and
the offset comprises a displacement of a reduced size frame having the reduced frame size relative to a full size frame having the full frame size in at least one dimension such that the reduced size frame is not centered with respect to the full size frame.

16. The method of claim 14 , wherein a first set of the scan parameters for the frame enables coarse scanning to locate one or more objects of interest in the frame having the full frame size and a second set of the scan parameters for the differing frame enables fine scanning on the one or more objects of interest in the differing frame having the reduced frame size.

17. The method of claim 14 , wherein the processing step further comprises generating velocity data associated with each of the reflected optical chirps.

18. A method for providing adaptive scanning, comprising:
generating light;
generating a scan pattern for a frame for transmitting the light across a scanning region, the scan pattern for the frame being generated based on scan parameters for the frame, wherein the scan parameters for the frame identify (i) a frame size for the frame comprising either a full frame size or a reduced frame size, (ii) a spatial resolution for the frame having the identified frame size, and (iii) when the frame has the reduced frame size, a non-zero offset for the reduced frame size relative to the full frame size;
transmitting the light in the scan pattern for the frame across the scanning region;
receiving reflected light that has reflected off one or more objects located within the scanning region; and
generating a plurality of data points each of which comprises distance data associated with a portion of the reflected light;
wherein a differing scan pattern for a differing frame for transmitting the light is generated based on differing scan parameters for the differing frame.

19. The method of claim 18 , wherein:
the full frame size is larger than the reduced frame size;
the spatial resolution defines the number of scan lines and the number of pixels per scan line for the frame having a particular frame size; and
the offset comprises a displacement of a reduced size frame having the reduced frame size relative to a full size frame having the full frame size in at least one dimension su

Assignees

• Strobe Inc
• Gm Global Tech Operations Llc

Inventors

• Maleki Lutfollah
• Singer Scott

Classifications

• G01S7/4817 Primary

  relating to scanning · CPC title

• G01S17/58

  Velocity or trajectory determination systems; Sense-of-movement determination systems · CPC title

• G01S17/42 Primary

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

• G01S17/34

  using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal · CPC title

• G01S7/4911

  Transmitters · CPC title