Coherent Doppler LiDAR Odometry for Ambiguity-Resolved Vehicle Motion
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Solution Overview
Problem
Conventional LIDAR systems face challenges in consistently resolving Doppler detection ambiguity, which affects their ability to accurately compensate for Doppler Effects in optical range measurements, particularly in vehicle navigation systems.
Innovation Solution
The implementation of coherent range Doppler optical sensors and methods for vehicle odometry, which involve collecting point cloud data, determining velocity vectors, and revising data based on scan directionality, to improve the reliability and accuracy of LIDAR systems in vehicle navigation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional LIDAR systems use standard Doppler detection methods, then they can detect velocity information, but they cannot consistently resolve Doppler detection ambiguity
Solution Approach 1:
The patent segments the Doppler detection process into multiple discrete frequency shift measurements taken at different time points during the scan. By dividing the velocity measurement into multiple frequency samples and analyzing their temporal evolution, the system can distinguish between true velocity changes and detection ambiguities, thereby resolving the contradiction between measurement precision and reliability.
Solution Approach 2:
The patent implements periodic frequency modulation of the laser signal and performs repeated scans at different frequencies. This periodic action creates a pattern of Doppler shifts that can be analyzed over time to disambiguate velocity measurements. The systematic variation of scan frequencies allows the system to reliably resolve velocity information despite the inherent ambiguity in single-point Doppler measurements.
2Productivity
If LIDAR systems perform frequent scans to improve navigation accuracy, then they can update velocity information more often, but they increase computational complexity and processing time
Solution Approach 1:
The patent performs preliminary processing of Doppler frequency data during the scanning process itself, calculating velocity estimates incrementally as each scan completes. By preparing and partially processing the data in advance rather than waiting for complete datasets, the system achieves high update rates without requiring complex post-processing computations, thus resolving the contradiction between productivity and device 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
This approach enhances the capability of LIDAR systems to accurately measure range and relative speed, thereby improving vehicle navigation and control, especially in scenarios where other navigation systems are unreliable.
Implementation Method 1
coherent range Doppler optical sensors
Data Source
AI summary
A system and method for vehicle odometry using coherent range Doppler optical sensors. The system and method includes operating a Doppler light detection and ranging (LIDAR) system to collect raw point cloud data that indicates for a point a plurality of dimensions, wherein a dimension of the plurality of dimensions includes an inclination angle, an azimuthal angle, a range, or a relative speed between the point and the LIDAR system; determining a corrected velocity vector for the Doppler LIDAR system based on the raw point cloud data; and producing revised point cloud data that is corrected for the velocity of the Doppler LIDAR system.