Convolved augmented range lidar nominal area

Patent metadata

Field	Value
Publication number	US-12455356-B2
Application number	US-202418428827-A
Country	US
Kind code	B2
Filing date	Jan 31, 2024
Priority date	May 18, 2018
Publication date	Oct 28, 2025
Grant date	Oct 28, 2025

Abstract

A method of lidar imaging pulses a scene with laser pulse sequences from a laser light source. Reflected light from the scene is measured for each laser pulse to form a sequence of time resolved light signals. Adjoining time bins in the time resolved light signals are combined to form super time bins. A three dimensional image of the scene is created from distances determined based on maximum intensity super time bins. One or more objects are located within the image. For each object, the time resolved light signals are combined to form a single object time resolved light signal from which to determine distance to the object.

First claim

What is claimed is:

1. A system comprising:
at least one hardware implemented computer processor for lidar imaging configured to:
pulse each of a plurality of scan locations in a scene with a light pulse sequence from a light source;
measure reflected light from the scene for each light pulse to form at least one time resolved light signal for each scan location in the scene, wherein each time resolved light signal indicates a measure of received light in each of a series of time bins, wherein to measure the reflected light includes to simultaneously adaptively adjust a stop frequency of a filter for each of the time resolved light signals responsive to determining scattering effects of the measured reflected light;
responsive to a minimum number of photons in the time bins failing to be received, combine adjoining time bins to those time bins to form super time bins, wherein each super time bin indicates a measure representing a sum of the received light in the adjoining time bins;
create a three dimensional image of the scene from the measures in the super time bin;
locate one or more objects depicted in a plurality of the scan locations in the image; and
for each object, combine the time resolved light signals for a plurality of the scan locations of the one or more objects to form a single object time resolved light signal for each object from which to determine distance to the object.

2. The system according to claim 1 , wherein creating a three dimensional image comprises to identify a super time bin at each scan location having a maximum intensity peak.

3. The system according to claim 1 , wherein to measure the reflected light includes to high-pass filter the time resolved light signals to offset scattering effects in the measured reflected light.

4. The system according to claim 1 , wherein to adaptively filter includes to use a Kalman filter.

5. The system according to claim 1 , wherein to adaptively filter includes to adaptively adjust filter bandwidth.

6. The system according to claim 1 , wherein the program instructions further comprise to: operate an autonomous vehicle based on the determined distance to the one or more objects.

7. A non-transitory computer-program product comprising instructions for lidar imaging, that when executed by at least one hardware implemented computer processor cause the at least one hardware implemented computer processor to perform operations including to:
pulse each of a plurality of scan locations in a scene with a light pulse sequence from a light source;
measure reflected light from the scene for each light pulse to form at least one time resolved light signal for each scan location in the scene, wherein each time resolved light signal indicates a measure of received light in each of a series of time bins, wherein to measure the reflected light includes to simultaneously adaptively adjust a stop frequency of a filter for each of the time resolved light signals responsive to determining scattering effects of the measured reflected light;
responsive to a minimum number of photons in the time bins failing to be received, combine adjoining time bins to those time bins to form super time bins, wherein each super time bin indicates a measure representing a sum of the received light in the adjoining time bins;
create a three dimensional image of the scene from the measures in the super time bin;
locate one or more objects depicted in a plurality of the scan locations in the image; and
for each object, combine the time resolved light signals for a plurality of the scan locations of the one or more objects to form a single object time resolved light signal for each object from which to determine distance to the object.

8. The non-transitory computer-program product according to claim 7 , wherein creating a three dimensional image comprises to identify a super time bin at each scan location having a maximum intensity peak.

9. The non-transitory computer-program product according to claim 7 , wherein to measure the reflected light includes to high-pass filter the time resolved light signals to offset scattering effects in the measured reflected light.

10. The non-transitory computer-program product according to claim 7 , wherein to adaptively filter includes to use a Kalman filter.

11. The non-transitory computer-program product according to claim 7 , wherein to adaptively filter includes to adaptively adjust filter bandwidth.

12. The non-transitory computer-program product according to claim 7 , wherein the program instructions further comprise to: operate an autonomous vehicle based on the determined distance to the one or more objects.

Assignees

• Charles Stark Draper Laboratory Inc

Inventors

• Hollmann Joseph
• Hoffman Zachary R

Classifications

• G01S17/42

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

• G01S7/4876

  by removing unwanted signals (G01S7/495 takes precedence) · CPC title

• G05D1/249

  from positioning sensors located off-board the vehicle, e.g. from cameras · CPC title

• G01S17/10

  using transmission of interrupted, pulse-modulated waves (determination of distance by phase measurements G01S17/32) · CPC title

• G05D1/0231

  using optical position detecting means (position-fixing by using electromagnetic waves other than radio waves, e.g. optical position detecting means G01S5/16) · CPC title