Lidar Pulse Control for Retroreflector Saturation Mitigation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lidar systems are adversely affected by highly-reflective objects known as retroreflectors, which cause saturation and crosstalk, temporarily disabling the system.
Innovation Solution
A lidar system that dynamically adjusts light-emission parameters based on the presence of retroreflectors, using a controller to trigger test pulses, determine their presence, and adjust subsequent detection pulses accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional lidar systems use fixed light-emission parameters for detection, then the system structure is simple and operation is straightforward, but retroreflectors cause detector saturation and crosstalk that temporarily disable the system
Solution Approach 1:
The patent applies dynamics by transitioning from fixed light-emission parameters to dynamically adjustable parameters. The system continuously monitors return signal intensities and adapts emission parameters (pulse energy, repetition rate, duration) in real-time based on detected retroreflector conditions, enabling continuous operation without permanent disablement from saturation events
Solution Approach 2:
The patent implements feedback by using return signal intensity information from detectors to control subsequent light-emission parameters. The controller receives detector output signals and uses this feedback to adjust emission parameters dynamically, preventing detector saturation while maintaining reliable operation in the presence of retroreflectors
2Measurement precision
If lidar systems emit high-energy light pulses to improve detection range and accuracy, then measurement precision is improved, but retroreflectors reflect these high-energy pulses back with sufficient intensity to saturate detectors and create crosstalk
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting light-emission parameters (pulse energy, repetition rate, duration) based on detected retroreflector conditions. The system modifies these parameters in real-time to prevent detector saturation from high-energy retroreflector returns while maintaining sufficient detection accuracy for normal objects, resolving the contradiction between high-energy emission benefits and saturation risks
3Productivity
If lidar systems use higher pulse repetition rates to improve scanning speed and coverage, then productivity is improved, but the likelihood of detecting retroreflectors increases, leading to more frequent saturation events and system disablement
Solution Approach 1:
The patent applies dynamics by making pulse repetition rate adjustable rather than fixed. The system dynamically modifies the repetition rate based on retroreflector detection - using higher rates when no retroreflectors are present to maintain productivity, and adjusting rates when retroreflectors are detected to prevent saturation and maintain detection continuity
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
Mitigates the effects of retroreflectors by reducing saturation and crosstalk, ensuring continuous operation and accurate detection.
Implementation Method 1
a plurality of light-emitter devices configured to emit light pulses into an environment
Implementation Method 2
a plurality of detectors... receiving, from at least one detector, information indicative of at least one return test pulse
Implementation Method 3
Retroreflectors are both very reflective and also direct incoming light back in the direction of the source with minimal scatter in other directions
Data Source
AI summary
The present disclosure relates to light detection and ranging (lidar) systems, lidar-equipped vehicles, and associated methods. An example method includes causing a firing circuit to trigger emission of an initial group of detection pulses from at least one light-emitter device of a lidar system in accordance with an initial set of one or more light-emission parameters. The method also includes causing the firing circuit to trigger emission of one or more test pulses and receiving, from at least one detector, information indicative of one or more return test pulses. The method yet further includes determining, based on the received information, a presence of a retroreflector based on an intensity of the return test pulse. The method additionally includes determining a subsequent set of light-emission parameters and causing the firing circuit to trigger emission of a subsequent group of detection pulses in accordance with the subsequent set of light-emission parameters.