Systems and methods for instantaneous scanning by a LiDAR sensor at multiple wavelengths

Patent metadata

Field	Value
Publication number	US-11448759-B2
Application number	US-201916266383-A
Country	US
Kind code	B2
Filing date	Feb 4, 2019
Priority date	Feb 4, 2019
Publication date	Sep 20, 2022
Grant date	Sep 20, 2022

Abstract

In one embodiment, a wide-band laser beam is split into a plurality of sub-laser beams, with each sub-laser beam at a discrete wavelength. Each of the sub-laser beams is transmitted simultaneously through an antenna, with each sub-laser beam transmitted at a different angle due to properties of the antenna. Sub-laser beams that reflect off an object are received back at the same, or a different, antenna and passed to a demultiplexor. The demultiplexor passes each sub-laser to a different waveguide based on the discrete wavelength associated with each sub-laser beam. A detector receives the sub-lasers beam through the waveguides, and calculates the positions of various points on the object based in-part on which waveguide each sub-laser beam is received from and the frequency of each sub-laser beam.

First claim

What is claimed is:

1. A method for instantaneous scanning by a LiDAR sensor at multiple wavelengths, the method comprising:
receiving a laser beam, wherein the laser beam is associated with a wavelength band;
dividing the laser beam into a plurality of discrete wavelengths, wherein each discrete wavelength is a sub-band of the wavelength band associated with the laser beam;
for each wavelength of the plurality of discrete wavelengths, transmitting a sub-laser beam of the laser beam, wherein each sub-laser beam is associated with a different discrete wavelength of the plurality of discrete wavelengths;
receiving some or all of the sub-laser beams, wherein the some or all of the sub-laser beams were reflected off an object;
providing each sub-laser beam, of the some or all of the sub-laser beams, to a different waveguide of a plurality of waveguides, wherein each waveguide corresponds to a different discrete wavelength of a plurality of discrete wavelengths reflected off the object;
receiving, via the plurality of waveguides, the some or all of the sub-laser beams, wherein each discrete wavelength is associated with a corresponding detector of an array of detectors;
for the each discrete wavelength, calculating, using the array of detectors, an estimate of an actual power of a corresponding sub-laser beam, the estimate incorporating an adjustment of a detected power of the corresponding sub-laser beam, the adjustment associated with at least one characteristic of at least one pair of a waveguide and a corresponding detector, the at least one characteristic associated with a difference between the detected power and the actual power, wherein the estimate of the actual power of the corresponding sub-laser beam is an element of a first vector, the first vector representing estimates of the actual power for the some or all of the sub-laser beams, the detected power of the corresponding sub-laser beam is an element of a second vector, the second vector representing the detected power for the some or all of the sub-laser beams, and the array of detectors calculates the estimate by multiplying the second vector by a matrix, the matrix having, for each pair of the waveguide and the corresponding detector, at least one value associated with the at least one characteristic associated with the difference between the detected power and the actual power; and
determining, based on estimates of the actual power of the some or all of the sub-laser beams, positions of a plurality of points on the object.

2. A system for instantaneous scanning by a LiDAR sensor at multiple wavelengths, the system comprising:
a comb generator configured to:
receive a laser beam, wherein the laser beam is associated with a wavelength band; and
divide the laser beam into a plurality of discrete wavelengths, wherein each discrete wavelength is a sub-band of the wavelength band associated with the laser beam;

a first antennae configured to:
receive the laser beam divided into the plurality of discrete wavelengths; and
for each wavelength of the plurality of discrete wavelengths, transmit a sub-laser beam of the laser beam, wherein each sub-laser beam is associated with a different discrete wavelength of the plurality of discrete wavelengths;

a second antennae configured to receive some or all of the sub-laser beams, wherein the some or all of the sub-laser beams were reflected off an object;
a demultiplexer configured to provide each sub-laser beam, of the some or all of the sub-laser beams, to a corresponding waveguide of a plurality of waveguides, wherein each waveguide is for a corresponding discrete wavelength of a plurality of discrete wavelengths reflected off the object; and
an array of detectors configured to:
receive, via the plurality of waveguides, the some or all of the sub-laser beams, wherein each discrete wavelength is associated with a corresponding detector of the array of detectors;
for the each discrete wavelength, calculate an estimate of an actual power of a corresponding sub-laser beam, the estimate incorporating an adjustment of a detected power of the corresponding sub-laser beam, the adjustment associated with at least one characteristic of at least one pair of a waveguide and a corresponding detector, the at least one characteristic associated with a difference between the detected power and the actual power; and
determine, based on estimates of the actual power of the some or all of the sub-laser beams, positions of a plurality of points on the object,

wherein:
the estimate of the actual power of the corresponding sub-laser beam is an element of a first vector, the first vector representing estimates of the actual power for the some or all of the sub-laser beams,
the detected power of the corresponding sub-laser beam is an element of a second vector, the second vector representing the detected power for the some or all of the sub-laser beams,
the array of detectors is configured to calculate the estimate by multiplying the second vector by a matrix, the matrix having, for each pair of the waveguide and the corresponding detector, at least one value associated with the at least one characteristic associated with the difference between the detected power and the actual power.

3. A system, comprising:
waveguides configured to receive sub-laser beams reflected off an object, each of the sub-laser beams having a wavelength different from another wavelength associated with another of the sub-laser beams; and
detectors configured to:
calculate estimates of actual power of the sub-laser beams, the estimates incorporating adjustments of detected power of the sub-laser beams, the adjustments associated with characteristics of pairs of a waveguide and a corresponding detector of the detectors, the characteristics associated with differences between the detected power and the actual power; and
determine, based on the estimates, positions of points on the object,

wherein a count of wavelengths for which the estimates of actual power are calculated is greater than a count of the detectors.

4. The system of claim 2 , wherein the first antenna is the same as the second antennae.

5. The system of claim 2 , wherein the demultiplexer is a grating etalon.

6. The system of claim 2 , wherein the comb generator is a ring resonator.

7. The system of claim 2 , wherein the comb generator is tunable.

8. The system of claim 2 , wherein the system comprises a CMOS chip.

9. The system of claim 2 , wherein the wavelength band is approximately 1480 nm to 1620 nm.

10. The method of claim 1 , wherein:
the transmitting the sub-laser beam comprises transmitting, from a first antenna, the sub-laser beam; and
the receiving the some or all of the sub-laser beams comprises receiving, from a second antenna, the some or all of the sub-laser beams.

11. The method of claim 1 , further comprising:
receiving the some or all of the sub-laser beams, wherein each sub-laser beam is received from a different waveguide of the plurality of waveguides; and
based at least in part on the waveguides that each of the some or all of the sub-lasers are received from, determining positions of a plurality of points on the object.

12. The method of claim 1 , wherein the providing the sub-laser beam to the corresponding waveguide of the plurality of waveguides is performed using a grating etalon.

13. The method of claim 1 , wherein the dividing the laser beam is performed using a comb generator.

14. The method of claim 13 , wherein the comb generator is a ring resonator.

15. The method of claim 13 , wherein the comb generator is tunable.

Assignees

• Toyota Eng & Mfg North America

Inventors

• Schmalenberg Paul Donald

Classifications

• G01S7/4911

  Transmitters · CPC title

• G02B6/2938

  for multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM · CPC title

• G02B6/34

  utilising prism or grating {(G02B6/293 takes precedence)} · CPC title

• G01S7/4814

  of transmitters alone · CPC title

• G02B6/29323

  Coupling to or out of the diffractive element through the lateral surface of the light guide (evanescent grating couplers G02B6/29332) · CPC title