Scanning Flash LiDAR With Geiger Mode Photodiodes for High Spatial Resolution
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Solution Overview
Problem
Current LiDAR systems face limitations in achieving high spatial resolution for obstacle detection and avoidance in autonomous driving systems, particularly in terms of spatial angle resolution within the field of view.
Innovation Solution
A scanning flash LiDAR system incorporating a light transmitter, an opto-mechanical beam steering device, and Geiger mode avalanche photodiodes, where the beam steering unit can be a MEMS resonant mirror or mechanical rotating mirror/prism, to generate high spatial angle resolutions by steering and capturing non-visible pulse light and reflected light efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional LiDAR system uses a single light source and detector, then the device complexity is low, but the spatial angle resolution is insufficient for high-precision obstacle detection
Solution Approach 1:
The patent divides the light detection function into multiple Geiger mode avalanche photodiodes arranged in an array, where each detector corresponds to a specific spatial angle. This segmentation of the detection field enables high spatial angle resolution by independently measuring return light from different directions, directly resolving the contradiction between measurement precision and device complexity.
Solution Approach 2:
The patent transitions from a single-point detection approach to a two-dimensional array of photodiodes, adding spatial dimensionality to the detection system. This dimensional expansion allows simultaneous measurement of multiple spatial angles across both horizontal and vertical fields of view, achieving high resolution without proportionally increasing system complexity through clever optical path sharing.
2Measurement precision
If the LiDAR system uses a scanning mechanism to achieve high spatial resolution, then the measurement precision improves, but the data capture time increases reducing productivity
Solution Approach 1:
The patent employs periodic pulsed light emission from multiple light sources, where each light source emits pulses at different time intervals. This periodic action allows the system to sequentially illuminate different regions of the field of view while the Geiger mode photodiodes capture return signals simultaneously, achieving high spatial resolution without sacrificing data capture rate.
Solution Approach 2:
The system pre-positions multiple light sources and Geiger mode photodiodes in corresponding spatial relationships before operation begins. Each light source is paired with specific photodiodes that will receive its reflected light, establishing predetermined optical paths that enable parallel processing of multiple spatial channels simultaneously, thus maintaining high productivity while achieving fine spatial resolution.
3Measurement precision
If the LiDAR system uses Geiger mode avalanche photodiodes and multiple light sources, then the spatial angle resolution and ranging accuracy improve, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent designs the optical system with shared optical paths where a single beam steering unit controls light paths for multiple light sources and serves multiple photodiode arrays. This multi-functionality allows the same optical components to handle multiple wavelengths and detection channels, reducing the total number of manufacturing steps and assembly operations despite the increased functional requirements.
Solution Approach 2:
The system uses multiple light sources emitting at different wavelengths that are optically copied through the same beam steering and detection path. By designing the optical system to handle wavelength-multiplexed signals through identical structural paths, the patent reduces manufacturing complexity while achieving high ranging accuracy through multi-wavelength time-of-flight measurements.
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 system achieves high spatial resolution point cloud data within a single frame, enhancing ranging accuracy and facilitating size reduction while maintaining fast data capture rates, thereby improving obstacle detection capabilities in autonomous driving applications.
Implementation Method 1
a plurality of light sources, each of the plurality of light sources is configured to emit pulse light, and the pulse light is non-visible
Implementation Method 2
the light receiver is a Geiger mode avalanche photodiode receiver comprising a plurality of light detectors
Data Source
AI summary
A scanning flash light detection and ranging apparatus includes a light transmitter, a beam steering unit configured to steer pulse light and the reflected pulse light, and a light receiver configured to capture the reflected pulse light. The light transmitter includes a plurality of light sources. Each of the plurality of light sources is configured to emit the pulse light. The pulse light is non-visible. The reflected pulse light represents the pulse light reflected by at least one object. The pulse light incident on the beam steering unit and the reflected pulse light deflected by the beam steering unit are parallel or coaxial. Alternatively, the pulse light deflected by the beam steering unit and the reflected pulse light incident on the beam steering unit are parallel or coaxial. The light receiver is a Geiger mode avalanche photodiode receiver including a plurality of light detectors.