Lidar Noise Source Detection for Crosstalk Mitigation
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Solution Overview
Problem
Lidar cross-talk between autonomous vehicles causes noise and saturation in point clouds, affecting downstream processes like vehicle perception, prediction, and motion planning, especially in environments with multiple AVs using Lidar.
Innovation Solution
A Lidar system with noise source detectors that include a light sensor and timing circuit to detect and track noise sources, providing a timestamp for the direction of noise sources, allowing the vehicle computing system to classify and mitigate noise, thereby reducing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple autonomous vehicles use Lidar systems in close proximity, then the coverage and sensing capability of the environment is improved, but Lidar cross-talk causes noise and saturation in point clouds affecting downstream processes
Solution Approach 1:
The patent detects Lidar cross-talk noise signals and uses them to identify the presence and location of other autonomous vehicles. By converting the harmful cross-talk into useful information about surrounding vehicles, the system transforms an adverse effect into a beneficial sensing capability that enhances overall situational awareness.
Solution Approach 2:
The patent introduces a noise detector as an intermediary component that specifically targets and identifies cross-talk signals from other Lidar systems. This intermediary device filters and characterizes the harmful noise, allowing the main Lidar system to distinguish between valid return signals and cross-talk interference, thereby resolving the contradiction between multi-vehicle coverage and noise interference.
2Measurement precision
If Lidar receivers operate continuously to maintain accurate ranging, then measurement precision is improved, but receiver channels become saturated or get significant noise when another AV using Lidar is within range
Solution Approach 1:
The patent implements a feedback mechanism where the noise detector continuously monitors for cross-talk signals and provides information back to the Lidar system. This feedback allows the receiver to adjust its operation, such as filtering or disregarding contaminated time-of-flight measurements, thereby maintaining ranging accuracy while protecting against receiver saturation from external Lidar sources.
3Reliability
If noise source detectors are added to detect and track noise sources, then the ability to mitigate Lidar cross-talk is improved, but device complexity increases
Solution Approach 1:
The patent designs the noise detector to perform multiple functions: detecting cross-talk noise, identifying the presence of other autonomous vehicles, and providing directional information about noise sources. By making this single component multi-functional, the system achieves reliable cross-talk mitigation without proportionally increasing overall system complexity, as one device serves several purposes.
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
Effectively detects and mitigates Lidar cross-talk by accurately determining the direction and intensity of noise sources, enabling improved vehicle navigation and perception systems by reducing noise-related interference in Lidar data.
Implementation Method 1
A noise source detector includes a light sensor tuned to receive light signals at wavelengths received by detectors in each channel of the Lidar system
Data Source
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AI summary
Aspects of the present disclosure involve systems, methods, and devices for mitigating Lidar cross-talk. Consistent with some embodiments, a Lidar system is configured to include one or more noise source detectors that detect noise signals that may produce noise in return signals received at the Lidar system. A noise source detector comprises a light sensor to receive a noise signal produced by a noise source and a timing circuit to provide a timing signal indicative of a direction of the noise source relative to an autonomous vehicle on which the Lidar system is mounted. A noise source may be an external Lidar system or a surface in the surrounding environment that is reflecting light signals such as those emitted by an external Lidar system.