Method and system for ladar transmission employing dynamic scan patterns with macro patterns and base patterns

• US 10,042,043 B2
• Filed: 08/14/2015
• Issued: 08/07/2018
• Est. Priority Date: 08/15/2014
• Status: Active Grant

• Current Assignee: AEye, Inc.
• Original Assignee: AEye, Inc.
• Inventors: Dussan, Luis Carlos
• Primary Examiner(s): Hellner, Mark
• Application Number:
  US14/827,195
• Publication Number:
  US 20160047899A1
• Time in Patent Office: 1,089 Days
• Field of Search: 356 401
• 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 17/42 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 17/87 Combinations of systems using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 7/4814 of transmitters alone
• CPC Class Codes: G01S 7/4817 relating to scanning
• CPC Class Codes: G01S 7/484 Transmitters
• CPC Class Codes: G01S 7/4861 Circuits for detection, sampling, integration or read-out
• CPC Class Codes: G01S 7/499 using polarisation effects

Abstract

Various embodiments are disclosed for improved scanning ladar transmission, including but not limited to an example embodiment where a dynamic scan pattern for a scanning ladar transmission system includes a macro pattern having a base pattern embedded therein.

Claims

1. A method comprising:

processing a shot list, the shot list comprising a plurality of range points for targeting by a scanning ladar transmission system;

controlling a dynamic scan pattern for the scanning ladar transmission system by scanning a mirror to a plurality of mirror scan positions based on the processed shot list to target the range points of the processed shot list, wherein the mirror scan positions define where the scanning ladar transmission system is targeted, wherein the dynamic scan pattern comprises a macro scan pattern and a base dynamic scan pattern embedded within the macro scan pattern, wherein the macro scan pattern segments a scan area into a plurality of blocks, and wherein the controlling step comprises scanning the mirror to target the range points on the processed shot list in a manner that proceeds from block portion to block portion such that a plurality of the consecutively scanned block portions are for block portions of different blocks; and

transmitting, by the controlled scanning ladar transmission system, a plurality of ladar pulses toward the range points of the processed shot list in accordance with the dynamic scan pattern.

2. The method of claim 1 wherein the controlling step further comprises scanning the mirror to target the range points such that the base dynamic scan pattern is embedded within each block portion.

3. The method of claim 2 wherein the macro scan pattern operates to proceed from block portion to block portion consecutively for each of the blocks before returning to a block for which a block portion has already been scanned.

4. The method of claim 2 wherein the macro scan pattern operates to switch between the scanning of the block portions of two blocks successively until all of the block portions of the two blocks have been scanned before proceeding to additional blocks.

5. The method of claim 2 wherein the base dynamic scan pattern includes a member selected from the group consisting of (1) an interline skip, (2) an interline detour, (3) a line repeat, and (4) a line skip within at least one of the block portions.

6. The method of claim 1 wherein the mirror comprises a first mirror and a second mirror, the first mirror being scanable with respect to a first axis for targeting the scanning ladar transmission system along the first axis, the second mirror being scanable with respect to a second axis that is orthogonal to the first axis for targeting the scanning ladar transmission system along the second axis, wherein the combination of the mirror scan positions for the first and second mirrors defines the range points to which the scanning ladar transmission system is targeted;

and

wherein the controlling step comprises;

scanning the first mirror in a plurality of directions in a resonant mode; and

scanning the second mirror in a plurality of directions in a non-resonant mode based on the processed shot list.

7. The method of claim 1 wherein the mirror comprises a first mirror and a second mirror,

the first mirror being scanable with respect to a first axis for targeting the scanning ladar transmission system along the first axis, the second mirror being scanable with respect to a second axis that is orthogonal to the first axis for targeting the scanning ladar transmission system along the second axis, wherein the combination of the mirror scan positions for the first and second mirrors defines the range points to which the scanning ladar transmission system is targeted;

and

wherein the controlling step comprises;

scanning the first mirror in one direction in a non-resonant mode based on the processed shot list; and

scanning the second mirror in a plurality of directions in a non-resonant mode based on the processed shot list.

8. The method of claim 7 wherein the first mirror comprises a spinning polygon mirror.

9. The method of claim 1 further comprising;

generating the shot list to define the dynamic scan pattern.

10. An apparatus comprising:

a scanning ladar transmission system configured to direct a plurality of ladar pulses toward a plurality of range points via a plurality of scanable mirrors, wherein the scanning ladar transmission system comprises;

a beam scanner, the beam scanner including a first mirror and a second mirror, wherein the beam scanner is configured to (1) scan the first mirror to a plurality of mirror scan positions in response to a first control signal to target the scanning ladar transmission system along a first axis, and (2) scan the second mirror to a plurality of mirror scan positions in response to a second control signal to target the scanning ladar transmission system along a second axis, and wherein the combination of the mirror scan positions for the first and second mirrors defines the range points to which the scanning ladar transmission system is targeted;

a beam scanner controller, wherein the beam scanner controller is configured to generate the first and second control signals for use by the beam scanner such that the first and second control signals define a dynamic scan pattern for the scanning ladar transmission system with respect to the range points, wherein the dynamic scan pattern comprises a macro scan pattern with and a base dynamic scan pattern embedded within the macro scan pattern, wherein the macro scan pattern segments a scan area into a plurality of blocks; and

a light source positioned and configured to direct a plurality of ladar pulses onto the first mirror, whereupon the first mirror is configured to reflect the ladar pulses onto the second mirror, whereupon the second mirror is configured to reflect the ladar pulses for transmission toward the targeted range points, the targeted range points being defined by the combination of mirror scan positions for the first mirror and the second mirror when the ladar pulses are incident thereon; and

wherein the beam scanner is further configured to scan the first and second mirrors in response to the first and second control signals to target range points in a manner that proceeds from block portion to block portion such that a plurality of the consecutively scanned block portions are for block portions of different blocks.

11. The apparatus of claim 10 wherein the beam scanner is further configured to scan the first and second mirrors in response to the first and second control signals such that the base dynamic scan pattern is embedded within each block portion.

12. The apparatus of claim 11 wherein the beam scanner is further configured to scan the first and second mirrors in response to the first and second control signals such that the macro scan pattern operates to proceed from block portion to block portion consecutively for each of the blocks before returning to a block for which a block portion has already been scanned.

13. The apparatus of claim 11 wherein the beam scanner is further configured to scan the first and second mirrors in response to the first and second control signals such that the macro scan pattern operates to switch between the scanning of the block portions of two blocks successively until all of the block portions of the two blocks have been scanned before proceeding to additional blocks.

14. The apparatus of claim 11 wherein the beam scanner is further configured to:

scan the first mirror in a plurality of directions in a resonant mode in response to the first control signal; and

scan the second mirror in a plurality of directions in a non-resonant mode based on the processed shot list in response to the second control signal.

15. The apparatus of claim 11 wherein the beam scanner is further configured to:

scan the first mirror in one direction in a non-resonant mode based on the processed shot list in response to the first control signal; and

scan the second mirror in a plurality of directions in a non-resonant mode based on the processed shot list in response to the second control signal.

16. The apparatus of claim 15 wherein the first mirror comprises a spinning polygon mirror.

17. The apparatus of claim 11 wherein the base dynamic scan pattern includes a member selected from the group consisting of (1) an interline skip, (2) an interline detour, (3) a line repeat, and (4) a line skip within at least one of the block portions.