Continuous Wave Lidar Scanner Range Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional Lidar systems face inefficiencies in power usage, dynamic range limitations, and complex processing due to modulation of laser pulses, which can lead to saturation and difficulty in detecting far-range targets, especially in cluttered environments and large search areas.

Innovation Solution

A Lidar system utilizing continuous wave (CW) laser light and a scanner that determines target range based on the displacement of received CW laser light, proportional to the angular velocity of the scanner, allowing for efficient detection without the need for high pulse repetition frequencies or complex encodings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If laser pulses are modulated to enable time of flight measurement, then range detection capability is improved, but power consumption increases and system complexity increases

Engineering Contradiction:

Improverange detection capabilityVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent employs continuous wave laser illumination instead of pulsed laser with modulation. The continuous wave approach eliminates the need for complex pulse modulation schemes while maintaining continuous measurement capability, thereby reducing power consumption and simplifying the system architecture while preserving range detection functionality through frequency modulation and heterodyne detection.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The patent replaces mechanical pulse generation and modulation systems with a continuous wave laser system that uses frequency modulation and optical heterodyne detection. This substitution eliminates the need for Q-switched lasers and complex pulse encoding mechanisms, reducing both power consumption and system complexity while achieving the same range measurement objective.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If pulse repetition frequency is increased to detect targets in large search areas, then detection coverage is improved, but range ambiguity occurs and system complexity increases

Engineering Contradiction:

Improvedetection coverageVSAvoidsystem complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The continuous wave laser system provides uninterrupted illumination and measurement capability, allowing the scanner to continuously sweep across large search areas without the need for high pulse repetition frequencies. This eliminates range ambiguity issues that occur when pulse intervals are shorter than round-trip flight times, while maintaining comprehensive detection coverage.

Inventive Principle:

Principle #20Continuity of useful action

3Measurement precision

If system is tuned to detect far range targets, then far range detection is improved, but near range signals cause saturation

Engineering Contradiction:

Improvefar range detectionVSAvoidsignal saturation

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent employs dynamic frequency modulation of the continuous wave laser and corresponds frequency tuning of the local oscillator in the heterodyne detection system. This dynamic approach allows the system to process signals of varying intensities from different ranges simultaneously, preventing saturation from near-range targets while maintaining sensitivity for far-range detection through frequency-based signal separation.

Inventive Principle:

Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach reduces power consumption, enhances detection of distant targets by minimizing saturation from near-range signals, and simplifies processing, enabling effective range determination in various environments.

Implementation Method 1

A Lidar system utilizes continuous wave (CW) laser light and a scanner that determines target range based on the displacement of received CW laser light, proportional to the angular velocity of the scanner

Methodology Applied

Scientific EffectScanner rotation and light deflection:

Implementation Method 2

The signal is scattered off hard targets and/or volumetrically distributed scatterers, such as molecules or other particles

Methodology Applied

Scientific EffectLight scattering: Scattering

Data Source

PatentUS11237267B2Continuous wave laser detection and ranging

Publication Date: 2022.02.01 ARETE ASSOCIATES INC

AI summary

Systems and methods herein provide for Laser Detection and Ranging (Lidar). In one embodiment, a Lidar system includes a laser operable to propagate continuous wave (CW) laser light and a scanner operable as a transmitter and a receiver for the CW laser light. The Lidar system also includes a detector for determining a range to a target based on displacement of the CW laser light received by the receiver. The displacement of the CW laser light is proportional to an angular velocity of the scanner.