Reflectance Map Construction via Global Pose Optimization
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Solution Overview
Problem
Current methods for constructing reflectance maps, particularly in large regions, face significant precision issues due to errors in GPS and inertial navigation device outputs, leading to reduced merging precision and accuracy of laser point clouds.
Innovation Solution
A method and apparatus that select key frame laser point clouds, perform global pose optimization, and construct reflectance maps based on adjusted positions and Euler angles to improve the accuracy of laser radar center coordinates, thereby enhancing the precision of reflectance map construction in large regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If GPS device and inertial navigation device outputs are directly used as laser radar center position and Euler angle, then the construction process is simple, but the position and Euler angle have large errors leading to reduced merging precision
Solution Approach 1:
The patent introduces key frame laser point clouds as an intermediary to establish a more accurate coordinate system. Instead of directly using GPS and inertial navigation outputs, the system selects key frames, performs ICP registration between them, and uses the registered key frames as mediators to transform and merge all laser point clouds. This intermediary step corrects the cumulative errors from GPS and inertial navigation devices.
2Area of stationary object
If massive laser point clouds are merged to construct reflectance map of large region, then the coverage area is large, but the merging precision is significantly reduced due to accumulated coordinate errors
Solution Approach 1:
The patent segments the large region into multiple collection regions, each containing a subset of key frame laser point clouds. By dividing the massive dataset into manageable segments, the system performs ICP registration and merging within each segment, reducing the accumulation of coordinate errors. This segmentation approach maintains high merging precision while achieving large overall coverage through concatenation of multiple reflectance maps.
3Measurement precision
If key frame laser point clouds are selected and global pose optimization is performed, then the position and Euler angle precision is improved, but the construction process becomes more complex
Solution Approach 1:
The patent performs preliminary actions by selecting key frame laser point clouds in advance and performing ICP registration between them before merging all laser point clouds. This preliminary establishment of accurate key frame positions and Euler angles simplifies the subsequent merging process, as the key frames serve as pre-computed reference points. The complexity is front-loaded but enables more precise and efficient overall construction.
Data Source
AI summary
In a specific implementation of the method a reflectance map is constructed based on a position and an Euler angle, obtained through a global optimization and used for constructing a reflectance map, of a center of a laser radar corresponding to each frame laser point cloud used for constructing the reflectance map collected in each collection region. This implementation implements the level-by-level pose optimization of laser point clouds used for constructing a reflectance map that are collected in each collection region in an excessively large region, to obtain an accurate position and Euler angle, used for constructing the reflectance map, of a laser radar center corresponding to each frame laser point cloud used for constructing the reflectance map.