LIDAR Optical Filtering and Shuttering Against External Light
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Solution Overview
Problem
LIDAR devices are vulnerable to damage and false data generation due to external light sources, which can interfere with their operation and accuracy.
Innovation Solution
Implementing a mitigation system with filters such as interference, absorptive, adaptive, and spatial filters, and a control system that varies emission characteristics or activates a shutter to block or filter out external light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the LIDAR device operates without mitigation systems, then the device structure remains simple and cost-effective, but the device becomes vulnerable to damage and false data generation from external light sources
Solution Approach 1:
The patent introduces filters as intermediary components positioned in the optical path between external light sources and the LIDAR detector. These filters selectively block harmful external light wavelengths while allowing the LIDAR's own emitted light to pass through, thereby protecting the detector without requiring fundamental redesign of the LIDAR system architecture.
Solution Approach 2:
The mitigation system is segmented into multiple independent components including wavelength-selective filters, spatial filters, and temporal gating mechanisms. Each component addresses a specific aspect of external light interference, allowing the system to maintain simplicity while providing comprehensive protection through modular additions.
2Reliability
If filters are added to the LIDAR device to block external light, then protection against external light improves, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The filters designed in the patent serve multiple functions simultaneously: they block harmful external light wavelengths, maintain transmission of the LIDAR's operational wavelengths, and can be integrated into existing LIDAR housings without requiring complete manufacturing redesign. This multi-functionality reduces overall manufacturing complexity despite adding protection capabilities.
3Measurement precision
If the control system proactively varies emission characteristics to avoid external light interference, then measurement precision improves, but the system complexity and energy consumption increase
Solution Approach 1:
The control system implements periodic variation of emission characteristics, cycling through different wavelengths or temporal patterns in a predetermined sequence. This periodic action allows the system to proactively avoid external light interference by switching to less interfered-with wavelengths or time windows, while maintaining relatively low energy consumption through efficient cycling rather than continuous high-power operation.
4Reliability
If a shutter is activated to block external light, then protection against external light improves, but the response time and productivity of the LIDAR device decrease
Solution Approach 1:
The system uses preliminary detection mechanisms that identify the approach of external light interference before it reaches the detector. This allows the shutter to be activated in advance, blocking the harmful light before it can cause damage or false readings, while minimizing the duration of shutter closure to maintain scanning productivity.
Solution Approach 2:
When external light interference is detected, the system rapidly skips through the brief period when the shutter is closed by accelerating the scanning process or adjusting the timing of subsequent measurements. This rushing through the interruption minimizes the overall impact on scanning speed and productivity while maintaining protection during the critical blocking period.
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
Protects the LIDAR device from external light interference, preventing damage and false data points, ensuring accurate environmental scanning.
Implementation Method 1
the LIDAR device may include an interference filter
Implementation Method 2
the LIDAR device may include an absorptive filter
Data Source
AI summary
Described herein are methods and systems for protecting a light detection and ranging (LIDAR) device against external light that is originated at a light source other than a light source of the LIDAR device and that is being emitted towards the LIDAR device. In particular, the LIDAR device may be equipped with a mitigation system that includes an interference filter, an absorptive filter, an adaptive filter, and/or a spatial filter. Additionally or alternatively, the LIDAR device may be operated to carry out reactive and/or proactive mitigation operations. For example, the LIDAR device may be operated to vary over time characteristics with which light is being emitted and to only detect light having characteristics that match the characteristics with which light is being emitted. In another example, the LIDAR device may be operated to activate a shutter to block the external light from being detected by the LIDAR device.