LiDAR detection methods and systems

Patent metadata

Field	Value
Publication number	US-12529797-B2
Application number	US-202117329255-A
Country	US
Kind code	B2
Filing date	May 25, 2021
Priority date	Jun 1, 2020
Publication date	Jan 20, 2026
Grant date	Jan 20, 2026

Abstract

A LiDAR system and a method for operation thereof are provided. The LiDAR system comprises: a frequency-modulated continuous wave (FMCW) light source configured to produce an FMCW signal; and an amplitude modulator configured to modulate an amplitude of at least a portion of the FMCW signal, thereby producing an Amplitude-Frequency-Modulated-Continuous-Wave (AFMCW) signal; a splitter configured to split one of the FMCW signal and the AFMCW signal into a first portion and a second portion, the first portion being an output signal for reflecting off the object, thereby producing a reflected signal, and the second portion being a reference signal for amplifying the reflected signal; and a detector configured to amplify the reflected signal based on the reference signal as a function of a distance from the LiDAR system to an object, thereby generating an amplified reflected signal for determining the distance to the object.

First claim

The invention claimed is:

1 . A LiDAR system having a threshold ranging distance, the threshold ranging distance being indicative of a longest distance at which the LiDAR system is configured to detect an object, the LiDAR system comprising:
a light source configured to produce a continuous wave; a frequency modulator configured to modulate a frequency of the continuous wave,
thereby producing a Frequency-Modulated-Continuous-Wave (FMCW) signal; and
an amplitude modulator configured to modulate an amplitude of the FMCW signal in accordance with a periodic function associated with an amplitude modulation period, the periodic function comprising an asymptotic periodic function,
thereby producing an Amplitude-Frequency-Modulated-Continuous-Wave (AFMCW) signal having an asymptotically increasing amplitude,
the amplitude modulation period being pre-determined based on the threshold ranging distance;
a splitter configured to split the AFMCW signal into a first portion and a second portion,
the first portion being to be outputted by the LiDAR system for reflecting off the object, thereby producing a reflected signal, and
the second portion being to be used for amplifying the reflected signal; and
a detector configured to amplify the reflected signal based on the second portion by increasing amplification of the reflected signal as a function of a distance of the object from the LiDAR system,
thereby generating an amplified reflected signal, and
the amplified reflected signal being indicative of the distance of the object from the LiDAR system.

2 . The LiDAR system of claim 1 , wherein the detector has a threshold amplitude, and wherein the amplified reflected signal has an amplitude that is below the threshold amplitude.

3 . The LiDAR system of claim 2 , wherein the periodic function has been pre-determined such that the amplitude of the amplified reflected signal is below the threshold amplitude of the detector.

4 . The LiDAR system of claim 3 , wherein the detector is further configured to receive the reflected signal.

5 . The LiDAR system of claim 3 , wherein:
the splitter is configured to split the AFMCW signal; and the detector is further configured to receive the second portion of the AFMCW signal for amplifying the reflected signal.

6 . The LiDAR system of claim 3 , wherein:
the splitter is configured to split the FMCW signal; the amplitude modulator is further configured to receive the second portion of the FMCW signal; the amplitude modulator being configured to modulate the amplitude of the FMCW signal comprises the amplitude modulator being configured to modulate the amplitude of the second portion of the FMCW signal; and the detector is further configured to receive the AFMCW signal from the amplitude modulator for amplifying the reflected signal.

7 . The LiDAR system of claim 3 , wherein the amplitude modulator being configured to modulate the amplitude of the FMCW signal comprises the amplitude modulator being configured to:
produce the AFMCW signal having a continuously increasing amplitude within the amplitude modulation period.

8 . The LiDAR system of claim 3 , wherein the amplitude modulator being configured to modulate the amplitude of the FMCW signal comprises the amplitude modulator being configured to:
produce the AFMCW signal having a linearly increasing amplitude within the amplitude modulation period.

9 . The LiDAR system of claim 3 , wherein:
the frequency of the continuous wave is modulated in accordance with a frequency modulation period; and the frequency modulation period is equal to the amplitude modulation period.

10 . The LiDAR system of claim 3 , wherein the amplitude modulation period is pre-determined as a time value corresponding to an amount of time between:
(i) a first moment in time when the second portion is outputted from the LiDAR system; and (ii) a second moment in time when the reflected signal would be received by the detector if the object is at the threshold ranging distance from the LiDAR system.

11 . The LiDAR system of claim 3 , wherein the frequency modulator is integral with the light source.

12 . The LiDAR system of claim 3 , wherein the amplitude modulator is integral with the light source.

13 . The LiDAR system of claim 3 , wherein the amplitude modulator is at least one of:
a MEMS variable optical modulator; an electro-optical modulator; a magneto-optical modulator; a fiber-optical amplifier; a semiconductor optical amplifier; and an other light source.

14 . The LiDAR system of claim 3 , wherein the LiDAR system is equipped to a Self Driving Car (SDC).

15 . The LiDAR system of claim 3 , wherein the amplified reflected signal is further indicative of a velocity of the object relative to the LiDAR system.

16 . The LiDAR system of claim 15 , wherein the distance of the object is used for controlling operation of the SDC.

17 . A LiDAR system having a threshold ranging distance, the threshold ranging distance being indicative of a longest distance at which the LiDAR system is configured to detect an object, the LiDAR system comprising:
a light source configured to produce a continuous wave; a frequency modulator configured to modulate a frequency of the continuous wave,
thereby producing a Frequency-Modulated-Continuous-Wave (FMCW) signal; and
a splitter configured to split the FMCW signal into a first portion and a second portion,
the first portion being to be outputted by the LiDAR system for reflecting off the object, thereby producing a reflected signal, and the second portion being to be used for amplifying the reflected signal;
an amplitude modulator configured to modulate an amplitude of the second portion of the FMCW signal in accordance with a periodic function associated with an amplitude modulation period, the periodic function comprising an asymptotic periodic function,
thereby producing an Amplitude-Frequency-Modulated-Continuous-Wave (AFMCW) signal having an asymptotically increasing amplitude,
the amplitude modulation period being pre-determined based on the threshold ranging distance; and

a detector configured to amplify the reflected signal based on the AFMCW signal by increasing amplification of the reflected signal as a function of a distance of the object from the LiDAR system,
thereby generating an amplified reflected signal, and
the amplified reflected signal being indicative of the distance of the object from the LiDAR system.

18 . A LiDAR system having a threshold ranging distance, the threshold ranging distance being indicative of a longest distance at which the LiDAR system is configured to detect an object, the LiDAR system comprising:
a light source configured to produce a continuous wave; a frequency modulator configured to modulate a frequency of the continuous wave,
thereby producing a Frequency-Modulated-Continuous-Wave (FMCW) signal; and
a splitter configured to split the FMCW signal into a first portion and a second portion,
the second portion being to be used for amplifying the reflected signal;
an amplitude modulator configured to modulate an amplitude of the first portion of the FMCW signal in accordance with a periodic function associated with an amplitude modulation period, the periodic function comprising an asymptotic periodic function,
thereby producing an Amplitude-Frequency-Modulated-Continuous-Wave (AFMCW) signal having an asymptotically increasing amplitude,
the amplitude modulation period being pre-determined based on the threshold ranging distan

Assignees

• Yandex Self Driving Group Llc
• Y E Hub Armenia Llc

Inventors

• Solomentsev Dmitry Valentinovich
• Golikov Andrey Viktorovich
• Orlov Nikolay Evgenevich
• Kuznetsov Vladimir Albertovich

Classifications

• G01S7/484

  Transmitters · CPC title

• G01S7/4806

  Road traffic laser detectors · 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

• G01S17/931 Primary

  of land vehicles · CPC title

• G01S17/42

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