Scanning LiDAR system and method with spatial filtering for reduction of ambient light

• US 10,838,043 B2
• Filed: 11/15/2017
• Issued: 11/17/2020
• Est. Priority Date: 11/15/2017
• Status: Active Grant

• Current Assignee: Veoneer, Inc. (SSW Partners LP)
• Original Assignee: Veoneer US Inc. (SSW Partners LP)
• Inventors: Hansson, Peter
• Primary Examiner(s): Xiao, Yuqing
• Assistant Examiner(s): Askarian, Amir J
• Application Number:
  US15/813,404
• Publication Number:
  US 20190146070A1
• Time in Patent Office: 1,098 Days
• Field of Search: None
• CPC Class Codes: G01S 17/32 using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 7/4811 common to transmitter and receiver
• CPC Class Codes: G01S 7/4812 transmitted and received beams following a coaxial path
• CPC Class Codes: G01S 7/4815 using multiple transmitters
• CPC Class Codes: G01S 7/4816 of receivers alone
• CPC Class Codes: G01S 7/4817 relating to scanning
• CPC Class Codes: G01S 7/4863 Detector arrays, e.g. charge-transfer gates
• CPC Class Codes: G01S 7/4914 of detector arrays, e.g. charge-transfer gates

Abstract

A LiDAR detection system includes optical sources disposed along a first direction and a scanning device for scanning optical signals over a second direction different than the first direction into the region. A receiver receives reflected optical signals generated by reflection of the transmitted optical signals and generates receive signals indicative of the reflected optical signals. A mask is disposed near the receiver between the region and the receiver, the mask comprising a plurality of optically transparent slits through which at least a substantial portion of the reflected optical signals pass and an optically opaque portion adjacent to the slits being adapted to substantially block ambient light from reaching the receiver. A processor coupled to the receiver receives and processes the receive signals to generate detections of one or more objects in the region.

Claims

1. A LiDAR detection system, comprising:

a plurality of optical sources disposed along a first direction for transmitting a respective plurality of transmitted optical signals into a region;

a scanning device for scanning the plurality of transmitted optical signals over a second direction different than the first direction;

a receiver for receiving reflected optical signals generated by reflection of the transmitted optical signals and generating receive signals indicative of the reflected optical signals, wherein the receiver comprises a two-dimensional array of optical detectors;

a mask disposed in proximity to the receiver between the region and the receiver, the mask comprising a plurality of optically transparent slits through which at least a substantial portion of the reflected optical signals pass and an optically opaque portion adjacent to the slits, the optically opaque portion of the mask being adapted to substantially block ambient light from reaching the receiver, wherein the plurality of slits in the mask are disposed along a direction aligned with a first dimension of the array of optical detectors, wherein the receive signals are generated for a set of detectors in the array disposed along the first dimension of the array and aligned with the slits in the mask and exposed to the received optical signals, wherein the receive signals are generated for one set of detectors at a time, the sets of detectors being offset with respect to each other along a second dimension of the array of optical detectors substantially orthogonal to the first dimension of the array of optical detectors; and

a processor coupled to the receiver for receiving the receive signals and processing the receive signals to generate detections of one or more objects in the region;

wherein

each set of detectors is activated only when generating its receive signals and is deactivated when another set of detectors is generating its receive signals, activating and deactivating sets of detectors being synchronized with the scanning device.

2. The LiDAR detection system of claim 1, wherein the first direction is substantially orthogonal to the second direction.

3. The LiDAR detection system of claim 1, wherein the scanning device comprises a scanning mirror.

4. The LiDAR detection system of claim 3, wherein the scanning mirror is a micro-electromechanical system (MEMS) scanning mirror.

5. The LiDAR detection system of claim 1, wherein the optical detectors comprise an avalanche photodiode (APD).

6. The LiDAR detection system of claim 1, wherein the optical detectors comprise a silicon photomultiplier (SiPM).

7. The LiDAR detection system of claim 1, wherein the optical detectors comprise a multi-pixel photon counter (MPPC).

8. The LiDAR detection system of claim 1, wherein each detector in a set of detectors comprises multiple regions, a first region of each detector receiving a received optical signal at a first time and a second region of each detector receiving another received optical signal at a second time later than the first time.

9. The LiDAR detection system of claim 8, wherein the first and second times occur during different sweeps of the array of optical detectors.

10. The LiDAR detection system of claim 1, wherein the plurality of optical sources comprises at least two groups of optical sources, a first group of optical sources being disposed in a line along the first direction and the second group of optical sources being disposed in a second line along the first direction parallel to the first line and displaced from the first line along the second direction.

11. The LiDAR detection system of claim 10, wherein each group of optical sources comprises eleven optical sources.

12. The LiDAR detection system of claim 10, wherein each group of optical sources is offset with respect to each other along the first direction.

13. The LiDAR detection system of claim 1, wherein the optical sources comprise lasers.

14. The LiDAR detection system of claim 1, wherein the LiDAR detection system is an automotive LiDAR detection system.

15. The LiDAR detection system of claim 1, wherein the LiDAR detection system is a biaxial system.

16. The LiDAR detection system of claim 1, wherein the LiDAR detection system is a coaxial system.