Lidar Beam Steering via Acousto-Optic Modulation and Curved Mirror

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Solution Overview

Problem

Conventional light detection and ranging (lidar) systems for vehicles rely on moving parts, which can be complex and prone to mechanical failures, limiting their reliability and field of view.

Innovation Solution

A lidar system utilizing a beam steering device, such as a liquid crystal grating, and a curved mirror with a fixed position, allowing for the steering and reflection of laser beams over a wide angle range without moving parts, enabling a large field of view and simplified design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a movable mirror is used to deflect laser pulses, then the lidar system can detect objects, but the system becomes complex and prone to mechanical failures

Engineering Contradiction:

Improvesystem reliabilityVSAvoidmechanical complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the movable mirror mechanism with a fixed curved mirror combined with an acousto-optic modulator. The beam steering function is achieved through acoustic field modulation rather than mechanical movement, eliminating moving parts and improving reliability while reducing mechanical complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses acoustic waves (sound waves) to control the phase and direction of laser beams through the acousto-optic modulator. This acoustic field manipulation replaces mechanical mirror movement, achieving beam steering without mechanical components.

Inventive Principle:

Principle #29Pneumatics and hydraulics

2Adaptability or versatility

If a movable mirror is used to steer beams, then the system can adjust beam direction, but the field of view is limited and mechanical parts increase complexity

Engineering Contradiction:

Improvefield of viewVSAvoidmechanical complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical beam steering with an acousto-optic modulator that uses acoustic waves to control laser beam direction. This allows for electronic control of beam steering without mechanical parts, expanding the field of view while reducing complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs a curved mirror surface to reflect and steer laser beams. The curvature of the mirror enables a wider field of view by reflecting beams at multiple angles from a single fixed position, eliminating the need for mechanical movement.

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Measurement precision

If conventional lidar systems with moving parts are used, then object detection is possible, but accuracy is reduced due to mechanical limitations

Engineering Contradiction:

Improvedetection accuracyVSAvoidmechanical complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces mechanical beam steering with an acousto-optic modulator that provides precise control over laser beam direction through acoustic phase modulation. This eliminates mechanical errors and improves detection accuracy while reducing system complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the control parameter from mechanical position to acoustic frequency and phase. By modulating the acoustic field parameters, the system achieves precise beam steering and improved measurement accuracy without mechanical components.

Inventive Principle:

Principle #35Parameter changes

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

The solution provides a reliable and efficient lidar system with a large field of view, eliminating mechanical complexities and enhancing accuracy in detecting ambient objects, suitable for autonomous vehicle operations and driver assist systems.

Implementation Method 1

A curved mirror reflects the steered beams at any desired angle or direction

Methodology Applied

Scientific EffectReflection: Reflection

Implementation Method 2

A beam steering device steers beams emitted by the laser at a desired angle

Methodology Applied

Scientific EffectLight refraction and diffraction: Refraction

Implementation Method 3

A known light detection and ranging (lidar) system for a vehicle may have a laser that emits laser pulses

Methodology Applied

Scientific EffectLight propagation: Light

Implementation Method 4

A time of flight measurement of the laser pulses is used to measure the distance to the detected objects

Methodology Applied

Scientific EffectTime of flight: Time of Flight

Data Source

PatentUS11536808B2Light detection and ranging system and method

Publication Date: 2022.12.27 ZF ACTIVE SAFETY & ELECTRONICS US LLC

AI summary

A light detection and ranging system includes at least one laser that emits a laser beam. A beam steering device steers beams emitted by the laser at a desired angle. A curved mirror reflects the steered beams at any desired angle or direction. A method of providing a light detection and ranging system is also provided.