Method and system for doppler detection and doppler correction of optical chirped range detection

Patent metadata

Field	Value
Publication number	US-12461239-B2
Application number	US-202318469002-A
Country	US
Kind code	B2
Filing date	Sep 18, 2023
Priority date	Nov 30, 2016
Publication date	Nov 4, 2025
Grant date	Nov 4, 2025

Abstract

Techniques for Doppler correction of chirped optical range detection include obtaining a first set of ranges based on corresponding frequency differences between a return optical signal and a first chirped transmitted optical signal with an up chirp that increases frequency with time. A second set of ranges is obtained based on corresponding frequency differences between a return optical signal and a second chirped transmitted optical signal with a down chirp. A matrix of values for a cost function is determined, one value for each pair of ranges that includes one in the first set and one in the second set. A matched pair of one range in the first set and a corresponding one range in the second set is determined based on the matrix. A Doppler effect on range is determined based on combining the matched pair of ranges. A device is operated based on the Doppler effect.

First claim

What is claimed is:

1 . A light detection and ranging (LIDAR) sensor system, comprising:
a laser source configured to generate at least one laser signal; a modulator configured to modulate the at least one laser signal to generate a plurality of first signals that increase in frequency and a plurality of second signals that decrease in frequency; and one or more processors configured to:
determine a plurality of first ranges to an object using a plurality of first return signals from reflection of the plurality of first signals by the object;
determine a plurality of second ranges to the object using a plurality of second return signals from reflection of the plurality of second signals by the object; and
select a first range of the plurality of first ranges that matches a second range of the plurality of second ranges by comparing each first range of the plurality of first ranges with each second range of the plurality of second ranges.

2 . The LIDAR sensor system of claim 1 , wherein the modulator is configured to apply modulation to a current driving the laser source.

3 . The LIDAR sensor system of claim 1 , wherein the modulator is configured to generate the plurality of first signals to increase in frequency based on a bandwidth from about 300 MHz to about 20 GHz, and a duration from about 250 nanoseconds (ns) to about 1 millisecond (ms).

4 . The LIDAR sensor system of claim 1 , further comprising one or more scanning optics configured to output the plurality of first signals and the plurality of second signals.

5 . The LIDAR sensor system of claim 1 , wherein the laser source is configured to output the at least one laser signal as a plurality of pulses.

6 . The LIDAR sensor system of claim 1 , wherein the modulator is configured to generate a given second signal of the plurality of second signals after a given first signal of the plurality of first signals.

7 . The LIDAR sensor system of claim 1 , wherein the one or more processors are configured to move a vehicle to avoid collision with the object based on the selected first range.

8 . The LIDAR sensor system of claim 1 , wherein the modulator comprises a double sideband Mach-Zehnder modulator.

9 . The LIDAR sensor system of claim 1 , wherein the laser source comprises a single optical carrier to generate the at least one laser signal and the modulator is configured to modulate the at least one laser signal by a single RF chirp to produce symmetrical sidebands corresponding to the plurality of first signals and the plurality of second signals.

10 . A vehicle control system, comprising:
a laser source configured to generate at least one laser signal; a modulator configured to modulate the at least one laser signal to generate a plurality of first signals that increase in frequency and a plurality of second signals that decrease in frequency; and one or more processors configured to:
determine a plurality of first ranges to an object using a plurality of first return signals from reflection of the plurality of first signals by the object;
determine a plurality of second ranges to the object using a plurality of second return signals from reflection of the plurality of second signals by the object; and
control a vehicle based on a third range determined by matching a first range of the plurality of first ranges with a second range of the plurality of second ranges by comparing each first range of the plurality of first ranges with each second range of the plurality of second ranges.

11 . The vehicle control system of claim 10 , wherein the modulator is configured to apply modulation to a current driving the laser source.

12 . The vehicle control system of claim 10 , wherein the modulator is configured to generate the plurality of first signals to increase in frequency based on a bandwidth from about 300 MHz to about 20 GHz, and a duration from about 250 nanoseconds (ns) to about 1 millisecond (ms).

13 . The vehicle control system of claim 10 , further comprising one or more scanning optics configured to output the plurality of first signals and the plurality of second signals.

14 . The vehicle control system of claim 10 , wherein the laser source is configured to output the at least one laser signal as a plurality of pulses.

15 . The vehicle control system of claim 10 , wherein the one or more processors are configured to move the vehicle to avoid collision with the object based on the third range.

16 . The vehicle control system of claim 10 , wherein the laser source comprises a single optical carrier to generate the at least one laser signal and the modulator is configured to modulate the at least one laser signal by a single RF chirp to produce symmetrical sidebands corresponding to the plurality of first signals and the plurality of second signals.

17 . A method, comprising:
generating a plurality of first signals that increase in frequency and a plurality of second signals that decrease in frequency; determining a plurality of first ranges to an object using a plurality of first return signals from reflection of the plurality of first signals by the object; determining a plurality of second ranges to the object using a plurality of second return signals from reflection of the plurality of second signals by the object; and controlling a vehicle based on a third range determined by matching a first range of the plurality of first ranges with a second range of the plurality of second ranges by comparing each first range of the plurality of first ranges with each second range of the plurality of second ranges.

18 . The method of claim 17 , further comprising moving the vehicle to avoid collision with the object based on the third range.

Assignees

• Aurora Operations Inc

Inventors

• Crouch Stephen C
• Berg Trenton
• Reibel Randy R
• Curry James

Classifications

• G01S17/34 Primary

  using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal · CPC title

• G01S17/26

  wherein the transmitted pulses use a frequency-modulated or phase-modulated carrier wave, e.g. for pulse compression of received signals · CPC title

• G01S7/4911

  Transmitters · CPC title

• G01S7/493

  Extracting wanted echo signals · CPC title

• G01S17/89

  for mapping or imaging · CPC title