Selective Light Emitter Pulse Circuit for Retroreflective LIDAR
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
LIDAR devices face interference from retroreflective surfaces, which can flood light detectors and introduce ambiguity in 3D point cloud data, making it difficult to accurately represent and interpret environmental data.
Innovation Solution
A pulser circuit with capacitors and switches is used to selectively control light emission from laser diodes, allowing for precise control of light pulses and avoiding highly reflective surfaces by disabling light emission towards them, thereby reducing interference and improving data accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If light emitters continuously emit light to scan the environment, then the LIDAR device can capture comprehensive environmental data, but retroreflective surfaces cause interference that floods light detectors and introduces ambiguity in 3D point cloud data
Solution Approach 1:
The patent divides the light emission control into individual controllable units (light emitters) with separate capacitors and discharge-control switches. This segmentation allows selective disabling of specific light emitters that would illuminate retroreflective surfaces, while other light emitters continue to operate normally to maintain comprehensive environmental scanning capability.
Solution Approach 2:
The patent pre-charges capacitors for each light emitter in advance during a first period when the pulse-control switch restricts current flow. This preliminary charging enables rapid selective discharge in subsequent periods, allowing the system to quickly respond to detected retroreflective surfaces by disabling specific light emitters before interference occurs.
2Reliability
If the LIDAR device disables light emission towards retroreflective surfaces to reduce interference, then data accuracy improves, but the ability to scan those portions of the environment is reduced
Solution Approach 1:
The patent applies different operational states to different light emitters based on their specific directional characteristics. Light emitters pointed toward retroreflective surfaces are selectively disabled, while light emitters oriented toward other areas continue to operate. This local differentiation maintains overall scanning productivity while eliminating interference from problematic directions.
3Adaptability or versatility
If all light emitters are controlled individually with separate capacitors and switches, then selective light emission control is achieved, but the circuit complexity increases
Solution Approach 1:
The patent employs a standardized capacitor-switch module that can be replicated for each light emitter. This universal module design, where each capacitor and discharge-control switch follows the same configuration pattern, simplifies the overall circuit architecture compared to custom designs for each emitter. The modular approach enables selective control while maintaining circuit regularity and reducing design complexity.
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 effectively reduces interference from retroreflective surfaces, enhancing the accuracy of 3D point cloud data generation and reducing ambiguity in edge detection and object recognition operations.
Implementation Method 1
A plurality of capacitors are provided, wherein each capacitor in the plurality of capacitors corresponds to a respective light emitter in the plurality of light emitters
Implementation Method 2
discharge one or more undischarged capacitors of the plurality of capacitors through one or more corresponding light emitters of the plurality of light emitters, thereby causing the one or more corresponding light emitters to emit respective pulses of light
Data Source
AI summary
An example circuit includes a plurality of light emitters connected in parallel between a first node and a second node. The circuit also includes a plurality of capacitors, with each capacitor corresponding to one of the light emitters, and a plurality of discharge-control switches, with each discharge-control switches corresponding to one of the capacitors. The circuit further includes a pulse-control switch connected to the plurality of light emitters. During a first period, the pulse-control switch restricts current flow, and each of the plurality of capacitors is charged via the first node. During a second period, one or more of the plurality of discharge-control switches allows current flow that discharges one or more corresponding capacitors. During a third period, the pulse-control switch allows current flow that discharges one or more undischarged capacitors of the plurality of capacitors through one or more corresponding light emitters.