Adaptive Flash LiDAR Illumination for Wide FOV at Lower Power

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Solution Overview

Problem

Conventional lidar systems for autonomous vehicles face challenges with high power consumption, eye safety concerns, and limited packaging flexibility due to the need for high laser power to achieve a wide field of view, which results in inefficient energy use and potential image distortion.

Innovation Solution

An adaptive flash lidar system with a periodically modulated light source and a spatial light modulator (SLM) that generates varying illumination zones within a small visible output aperture, allowing for a wide field of view while reducing power requirements by increasing light intensity with distance and decreasing angular range, using a computer-generated hologram to control light distribution based on range and environmental conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If high laser power is used to achieve a wide field of view, then the field of view is improved, but power consumption increases and eye safety is compromised

Engineering Contradiction:
Improvefield of viewVSAvoidpower consumption
Core Design Contradiction:
Area of stationary objectVSUse of energy by moving object

Solution Approach 1:

The patent applies local quality by using a spatial light modulator to create non-uniform illumination zones with different light intensities across the field of view. The system concentrates higher light intensity in specific regions where obstacles are more likely to be detected, rather than uniformly distributing high power across the entire field of view. This allows achieving effective wide-field coverage with lower overall power consumption.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system dynamically adjusts the illumination pattern and light intensity distribution in real-time based on detected obstacles and environmental conditions. The spatial light modulator modifies the illumination zones adaptively, concentrating power where needed and reducing it elsewhere, thereby maintaining effective detection coverage while minimizing overall power consumption and ensuring eye safety.

Inventive Principle:
Principle #15Dynamics

2Area of stationary object

If high laser power is used to achieve a wide field of view, then the field of view is improved, but eye safety is worsened

Engineering Contradiction:
Improvefield of viewVSAvoideye safety
Core Design Contradiction:
Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The system uses local quality by implementing spatially varying illumination zones where light intensity is optimized locally rather than uniformly applied. The spatial light modulator creates regions of different brightness levels, providing sufficient illumination for detection in critical areas while maintaining lower intensity in other regions, thereby reducing the risk of eye damage while preserving wide field of view coverage.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The illumination pattern is dynamically adjusted based on real-time obstacle detection and environmental conditions. The system concentrates light intensity adaptively where obstacles are detected or likely to be present, and reduces intensity in regions without obstacles, thereby maintaining effective detection coverage while minimizing exposure to harmful laser radiation and ensuring eye safety.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If uniform light intensity is used across the field of view, then simplicity is improved, but energy efficiency is worsened

Engineering Contradiction:
Improveillumination controlVSAvoidenergy efficiency
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent implements local quality by dividing the field of view into multiple illumination zones with different light intensities. The spatial light modulator independently controls the intensity in each zone, allowing the system to apply higher power only where obstacles are detected or likely to be present, and reduce or eliminate illumination in regions without obstacles. This significantly improves energy efficiency compared to uniform illumination while maintaining relatively simple system architecture.

Inventive Principle:
Principle #3Local quality

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 system achieves energy efficiency, reduced power consumption (from 280 watts to 8 watts), and enhanced eye safety by dynamically adjusting light intensity and zone size, enabling effective obstacle detection over a 200-meter range with improved packaging flexibility and accuracy.

Implementation Method 1

The transmitter includes a periodically modulated light source, i.e., a light source that is pulsed or has a time-dependent modulation

Methodology Applied
Scientific EffectLight modulation: Phase Modulation

Implementation Method 2

The lidar processing system is configured to generate a computer generated hologram (CGH). The phase only CGH, comprising a spatial arrangement of phase levels between 0 and at least 2 PI

Methodology Applied
Scientific EffectHolography:

Implementation Method 3

The lidar processing system is also tasked with performing time of flight (ToF) measurements on data acquired by the sensor array

Methodology Applied
Scientific EffectTime of flight: Time of Flight

Implementation Method 4

The SLM preferably includes a dielectric mirror configured to achieve high reflectivity at the operating wavelength of the lidar system's light source

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 5

The SLM may be comprised of an active matrix backplane located on a first side of a liquid crystal layer and a transparent electrode located on the second side of the liquid crystal layer

Methodology Applied
Scientific EffectLiquid crystal modulation: Liquid Crystals

Data Source

PatentEP3489718B1Flash lidar with adaptive illumination
Publication Date: 2023.05.24 ATIEVA INC(US)
  • EP3489718B1 patent drawingFigure 1
  • EP3489718B1 patent drawingFigure 2~3
  • EP3489718B1 patent drawingFigure 4~5

AI summary

A light detection and ranging (lidar) system is provided that is incorporated into a vehicle and which is configured to efficiently adapt to varying road conditions as well as potential obstacles that may lie in the vehicle's pathway. The system employs a spatial light modulator (SLM) to create a plurality of illumination zones within the system's field of view. The SLM allows the lidar system to alter the size of each illumination zone as well as the light intensity within each of the zones as required by road conditions and potential obstacles.