Research On Deformation Monitoring Technology Of Point Cloud Comparison Based On The Normal Vector

The geological situations are complicated in China mountain area, and unstable rock collapse disasters happen frequently every year. The development process of unstable rock is gradual, and the failure process is sudden. What’s more, the loss caused by such rockfall has been great not only to the natural environment, but also to the society and economy. Therefore, it’s important to monitor the high unstable rock. Terrestrial Laser Scanning can fast acquire high density point cloud data of rock surface in non-contacting way and the point cloud data can characterize rock surface. Compared with traditional deformation monitoring technology, the point cloud data acquired by Terrestrial Laser Scanning are discrete points, and there are no corresponding points in these point cloud data. So it’s impossible to calculate the displacement directly. How to use multi-phase point cloud data is important in rockfall monitoring. The main work of this paper is as follows:(1) Processing the four phases point cloud data of Chongqing Jiguanling unstable rock, including point cloud registration and classification.(2) Summarizing the research in deformation monitoring using Terrestrial Laser Scanning, and according the characteristics of high unstable rocks, we use the point cloud comparison algorithm based on normal vector to monitor the deformation of unstable rock. In this paper, we use synthetic point cloud data to test the algorithm and analyze the result.(3) Using the point cloud comparison algorithm based on normal vector to process the unstable rock point cloud data, calculating the displacement of unstable rock, comparing the difference of displacement’s average value, and analyzing the result.How to monitor the high unstable rocks is difficult at the present stage. We tries to explore the possibility of using point cloud data to monitor rockfall, which provides a view of unstable rock deformation monitoring.