Lidar Window Absorption and Geometry for False Signal Reduction
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Solution Overview
Problem
Lidar systems generate false positive alarms due to light being guided and scattered within the thickness of the lidar window, leading to inaccurate distance measurements and noise interference, particularly from near-field objects.
Innovation Solution
Increase the propagation loss for guided light within the lidar window by adjusting the optical absorption coefficient of the window material and tailoring its shape to direct guided light away from the detection system, ensuring the intensity of scattered light remains below the detection threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If light propagates through the lidar window, then the window provides protection and optical transmission, but guided light is scattered and causes false positive alarms
Solution Approach 1:
The patent converts the harmful effect of light scattering within the window into a beneficial outcome by designing the window with specific optical absorption properties. The scattered light that would normally cause false alarms is absorbed by the window material, transforming the harmful scattering phenomenon into a mechanism that eliminates false positives while maintaining legitimate signal transmission
Solution Approach 2:
The patent changes the optical absorption parameter of the window material to selectively attenuate guided light that causes false alarms. By adjusting the absorption coefficient and window geometry, the system differentiates between useful transmitted light and harmful scattered light, suppressing the latter while preserving the former
2Object-generated harmful factors
If the lidar window material has high optical absorption, then guided light is attenuated and false signals are reduced, but legitimate light transmission may be affected
Solution Approach 1:
The patent applies local quality by creating non-uniform optical absorption within the window structure. Different regions of the window have different absorption characteristics, allowing the window to selectively attenuate guided light in specific paths while maintaining high transmission for legitimate optical signals. This localized differentiation enables simultaneous achievement of false signal reduction and efficient light transmission
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
Reduces the probability of false return signals by attenuating guided light within the lidar window, maintaining accurate distance measurements and improving the reliability of lidar systems without altering the original design or architecture.
Implementation Method 1
Increase the propagation loss for guided light within the lidar window by adjusting the optical absorption coefficient of the window material
Data Source
AI summary
Various methods and systems are disclosed to reduce the false alarm in a lidars having a lidar window surrounding the lidar system, by increasing the propagation loss for a portion of incident light that propagates within the thickness of the lidar window and may be guided toward the detection system of the lidar via an indirect path. Alternatively, or in addition, the shape of the lidar window may be tailored to direct the portion of incident light that propagates within the thickness of the lidar window away from the lidar detection system.