FAST SCANNING LIDAR WITH DYNAMIC VOXEL PROBING

• US 20180120436A1
• Filed: 10/31/2017
• Published: 05/03/2018
• Est. Priority Date: 10/31/2016
• Status: Active Grant

• Current Assignee: Samsung Semiconductor Incorporated (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Smits, Gerard Dirk
• Granted Patent: US 10,067,230 B2
• Time in Patent Office: 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 17/32 using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/4808 Evaluating distance, position or velocity data
• CPC Class Codes: G01S 7/4817 relating to scanning

Abstract

A LIDAR system includes a scanner; a receiver; and one or more processor devices to perform actions, including: scanning a continuous light beam over the field of view in a first scan pass; detecting photons of the continuous light beam that are reflected from one or more objects; determining a coarse range to the one or more objects based on times of departure of the photons of the continuous light beam and times of arrival of the photons at the receiver; scanning light pulses over the field of view in a second scan pass; detecting photons from the light pulses that are reflected from the one or more objects; and determining a refined range to the one or more objects based on times of departure of the photons of the light pulses and times of arrival of the photons at the receiver

Claims

1. A method for measuring a range to a surface of one or more objects, the method comprising:

a) scanning, by a first scanner, a continuous light beam over a field of view in a first scan pass;

b) detecting, by a receiver, photons of the continuous light beam that are reflected from one or more portions of the surface of the one or more objects, wherein the receiver comprises a plurality of pixels;

c) determining, by one or more processor devices, a coarse range to the one or more portions of the surface of the one or more objects based on times of departure of the photons of the continuous light beam from the scanner and times of arrival of the photons at the receiver;

d) scanning, by the first scanner, a plurality of light pulses over the field of view in a second scan pass;

e) detecting, by the receiver, photons from the plurality of light pulses that are reflected from the one or more portions of the surface of the one or more objects; and

f) determining, by the one or more processor devices, a refined range to the one or more portions of the surface of the one or more objects based on times of departure of the photons of the light pulses from the scanner and times of arrival of the photons at the receiver.

2. The method of claim 1, wherein determining the coarse range comprises determining the time of departure of a photon based on a position of the pixel of the receiver that detects the photon.

3. The method of claim 1, wherein the pulse width of the light pulses is either a) no more than 1 nanosecond or b) less than a scan time for the second scan pass divided by the number of pixels in a single row of the receiver.

4. The method of claim 1, further comprising repeating steps d) through f) one or more times to further refine the refined range, wherein, in each repetition, the light pulses for that repetition are offset in time from the light pulses from each preceding scan pass.

5. The method of claim 1, further comprising repeating steps d) through f) one or more times, wherein, in each repetition, the light pulses for that repetition are a different color from the light pulses from each preceding scan pass.

6. The method of claim 5, wherein the scanner comprises a plurality of rows of pixels, wherein, for each of the different colors of the light pulses, one or more rows of pixels is configured to detect light of that color.

7. The method of claim 6, wherein the continuous light beam is a near infrared light beam and the receiver comprises one or more rows of pixels configured to detect near infrared light.

8. The method of claim 1, wherein scanning the continuous light beam comprises scanning, by a sequential combination of the first scanner and a slower second scanner, the continuous light beam over the field of view in the first scan pass, wherein the second scanner scans along an axis different from the first scanner;

and

scanning, by the sequential combination of the first scanner and the second scanner, the plurality of light pulses over the field of view in the second scan pass.

9. The method of claim 8, further comprising repeating steps a) to f) to scan a two-dimensional field of view.

10. The method of claim 8, wherein further comprising one or more of the following:

a) the combination of the first scanner and the second scanner are configured to scan the two-dimensional field of view in a foveation pattern;

or

b) a scan period of the second scanner is no more than 1% of a scan period of the first scanner;

or

c) the receiver comprises a plurality of rows of pixels spaced apart to account for movement of the second scanner relative to the first scanner.

11. A system to measure a range to a surface of one or more objects, comprising:

a first scanner configured to scan received light over a field of view;

a receiver that comprises a plurality of pixels, wherein each of the pixels is configured to detect photons received by the pixel;

one or more memory devices that store instructions; and

one or more processor devices that execute the stored instructions to perform actions, including;

a) scanning, by the first scanner, a continuous light beam over the field of view in a first scan pass;

b) detecting, by the receiver, photons of the continuous light beam that are reflected from one or more portions of the surface of the one or more objects;

c) determining, by the one or more processor devices, a coarse range to the one or more portions of the surface of the one or more objects based on times of departure of the photons of the continuous light beam from the scanner and times of arrival of the photons at the receiver;

d) scanning, by the first scanner, a plurality of light pulses over the field of view in a second scan pass;

e) detecting, by the receiver, photons from the plurality of light pulses that are reflected from the one or more portions of the surface of the one or more objects; and

f) determining, by the one or more processor devices, a refined range to the one or more portions of the surface of the one or more objects based on times of departure of the photons of the light pulses from the scanner and times of arrival of the photons at the receiver.

12. The system of claim 11, wherein determining the coarse range comprises determining the time of departure of a photon based on a position of the pixel of the receiver that detects the photon.

13. The system of claim 11, wherein the instructions are configured so that the pulse width of the light pulses is either a) no more than 1 nanosecond orb) less than a scan time for the second scan pass divided by the number of pixels in a single row of the receiver.

14. The system of claim 11, wherein the actions further comprise repeating actions d) through f) one or more times to further refine the refined range, wherein, in each repetition, the light pulses for that repetition are offset in time from the light pulses from each preceding scan pass.

15. The system of claim 11, wherein the actions further comprise repeating actions d) through f) one or more times, wherein, in each repetition, the light pulses for that repetition are a different color from the light pulses from each preceding scan pass.

16. The system of claim 15, wherein the scanner comprises a plurality of rows of pixels, wherein, for each of the different colors of the light pulses, one or more rows of pixels is configured to detect light of that color.

17. The system of claim 15, wherein the light source is configured to emit the continuous light beam as a near infrared light beam and the receiver comprises one or more rows of pixels configured to detect near infrared light.

18. The system of claim 11, wherein scanning the continuous light beam comprises scanning, by a sequential combination of the first scanner and a slower second scanner, the continuous light beam over the field of view in the first scan pass, wherein the second scanner scans along an axis different from the first scanner;

and

scanning, by the sequential combination of the first scanner and the second scanner, the plurality of light pulses over the field of view in the second scan pass.

19. The system of claim 18, further comprising one or more of the following:

a) the combination of the first scanner and the second scanner are configured to scan the two-dimensional field of view in a foveation pattern;

or

b) a scan period of the second scanner is no more than 1% of a scan period of the first scanner.

20. The system of claim 18, wherein the receiver comprises a plurality of rows of pixels spaced apart to account for movement of the second scanner relative to the first scanner.

21. A non-transitory processor readable storage media that includes instructions for measuring a range to a surface of one or more objects, wherein execution of the instructions by one or more processor devices cause the one or more processor devices to perform actions, comprising:

a) scanning, by a first scanner, a continuous light beam over a field of view in a first scan pass;

b) detecting, by a receiver, photons of the continuous light beam that are reflected from one or more portions of the surface of the one or more objects, wherein the receiver comprises a plurality of pixels arranged in one or more rows;

c) determining, by one or more processor devices, a coarse range to the one or more portions of the surface of the one or more objects based on times of departure of the photons of the continuous light beam from the scanner and times of arrival of the photons at the receiver r;

d) scanning, by the first scanner, a plurality of light pulses over the field of view in a second scan pass;

e) detecting, by the receiver, photons from the plurality of light pulses that are reflected from the one or more portions of the surface of the one or more objects; and

f) determining, by the one or more processor devices, a refined range to the one or more portions of the surface of the one or more objects based on times of departure of the photons of the light pulses from the scanner and times of arrival of the photons at the receiver.

22. The non-transitory processor readable storage media of claim 21, wherein determining the coarse range comprises determining the time of departure of a photon based on a position of the pixel of the receiver that detects the photon.

23. The non-transitory processor readable storage media of claim 21, wherein the pulse width of the light pulses is either a) no more than 1 nanosecond or b) less than a scan time for the second scan pass divided by the number of pixels in a single row of the receiver.

24. The non-transitory processor readable storage media of claim 21, wherein the actions further comprise repeating actions d) through f) one or more times to further refine the refined range, wherein, in each repetition, the light pulses for that repetition are offset in time from the light pulses from each preceding scan pass.

25. The non-transitory processor readable storage media of claim 21, wherein the actions further comprise repeating actions d) through f) one or more times, wherein, in each repetition, the light pulses for that repetition are a different color from the light pulses from each preceding scan pass.

26. The non-transitory processor readable storage media of claim 25, wherein the scanner comprises a plurality of rows of pixels, wherein, for each of the different colors of the light pulses, one or more rows of pixels is configured to detect light of that color.

27. The non-transitory processor readable storage media of claim 25, wherein the continuous light beam is a near infrared light beam and the receiver comprises one or more rows of pixels configured to detect near infrared light.

28. The non-transitory processor readable storage media of claim 21, wherein scanning the continuous light beam comprises scanning, by a sequential combination of the first scanner and a slower second scanner, the continuous light beam over the field of view in the first scan pass, wherein the second scanner scans along an axis different from the first scanner;

and

scanning, by the sequential combination of the first scanner and the second scanner, the plurality of light pulses over the field of view in the second scan pass.

29. The non-transitory processor readable storage media of claim 28, further comprising one or more of the following:

a) the combination of the first scanner and the second scanner are configured to scan the two-dimensional field of view in a foveation pattern;

or

b) a scan period of the second scanner is no more than 1% of a scan period of the first scanner.

30. The non-transitory processor readable storage media of claim 28, wherein the receiver comprises a plurality of rows of pixels spaced apart to account for movement of the second scanner relative to the first scanner.