Shendong Coal Branch, China Shenhua Energy Company Limited

采用三维激光扫描技术提取的煤矿巷道表面点云数据量大且存在较多的冗余数据,而现有点云数据精简方法存在大数量级点云处理过程中细节保留不足的问题。针对上述问题,提出了一种基于二次特征提取的煤矿巷道表面点云数据精简方法。首先对采集到的原始巷道点云数据进行去噪预处理;其次建立K−d树,并利用主成分分析法对去噪后点云数据估算来拟合邻域平面的法向量;然后通过较小的法向量夹角阈值对点云进行初步的特征区域与非特征区域划分,保留特征区域并随机下采样非特征区域,接着依据较大的法向量夹角阈值将特征区域点云划分为特征点和非特征点,并对非特征点进行体素随机采样;最后将2次点云精简结果与特征点合并得到最终的精简数据。仿真结果表明,该方法在百万数据量级点云和高精简率条件下,相较曲率精简方法、随机精简方法和栅格精简方法,在特征保留和重构精度方面都取得了更好的效果,三维重构后计算所得标准偏差平均可低于相同精简率下其他方法30%左右。

The surface point cloud data of coal mine roadways extracted using 3D laser scanning technologyhas a large amount of redundant data. The existing point cloud data simplification methods have the problem ofinsufficient detail preservation in the processing of large-scale point clouds. In order to solve the above problems,a surface point cloud data reduction method for coal mine roadways based on secondary feature extraction isproposed. Firstly, the method performs denoising preprocessing on the collected original roadway point clouddata. Secondly, the method establishes a K-d tree and uses principal component analysis to estimate the denoisedpoint cloud data to fit the normal vector of the neighborhood plane. Thirdly, the point cloud is preliminarilydivided into feature and non-feature regions using a smaller normal vector angle threshold, retaining the featureregions and randomly downsampling the non-feature regions. Fourthly, based on the larger normal vector anglethreshold, the feature region point cloud is divided into feature points and non-feature points. And voxel randomsampling is conducted on the non-feature points. Finally, the method merges the two point cloud simplificationresults with the feature points to obtain the final simplified data. The simulation results show that under milliondata level point clouds and high precision conditions, this method achieves better results in feature preservation and reconstruction precision compared to curvature simplification methods, random simplification methods, andgrid reduction methods. The average standard deviation calculated after 3D reconstruction can be about 30%lower than other methods under the same reduction rate.

中国神华能源股份有限公司神东煤炭分公司科研项目(CEZB220305320)

陈建华,马宝,王蒙. 基于二次特征提取的煤矿巷道表面点云数据精简方法[J]. 工矿自动化,2023,49(12):114-120.

CHEN Jianhua, MA Bao, WANG Meng. A method for simplifying surface point cloud data of coal mine roadways based onsecondary feature extraction[J]. Journal of Mine Automation,2023,49(12):114-120.