机载LiDAR点云中电力线的提取和重建研究

为了实现输电线走廊的有效监管,采用了一种基于机载激光雷达(LiDAR)点云的电力线提取和重建的方法.首先利用点云的回波信息滤除大部分地物点,保留电力线的全部信息,然后基于格网高差和高程阈值剔除大部分非电力线点云,实现电力线的初提取.针对初步提取出的电力线点云,通过Hough变换分离出单根输电线点.为提高电力线点的提取精度,对Hough变换提取的结果进行了改进,利用局部极值点检测的方法确定杆塔的位置,最后通过带有限制条件的多项式模型对每档电力线进行分段拟合,实现电力线模型的3维重建.结果表明,利用该算法提取出了424个电力线点,总的提取精度达到87.603%,拟合出的电力线模型效果较好.该算法可以自动、精确地实现LiDAR点云数据中电力线的提取和重建,对输电线走廊巡检具有很好的实用价值.

Power line extraction and reconstruction from airborne LiDAR point cloud

In order to achieve effective supervision of transmission line corridors, a method of power line extraction and reconstruction was proposed based on airborne laser radar(LiDAR) point cloud. Firstly, echo information of point clouds was used to filter out the most of ground objects and keep all information about power line. And then, most non-power line point clouds were removed based on grid height elevation and elevation threshold. The initial extraction of power line was realized. For the preliminary extracted point cloud of power line, a single transmission line point was separated by Hough transform. In order to improve the accuracy of power line point extraction, the extraction result of Hough transform was improved. Then the location of the tower was determined by means of local extreme point detection. Finally, a polynomial model with constraints was used to segment each power line and realize 3-D reconstruction of power line model. The results show that, 424 power line points are extracted by this algorithm and the total extraction accuracy is 87.603%. The fitted power line model has a good effect. The algorithm can automatically and accurately extract and reconstruct power lines from LiDAR point cloud data. It has a good practical value for the inspection of transmission line corridors.