Development Of Slop Displacement Detection And Safety Evaluation System Based On UAV Photography

Slope engineering is a common but quite risky engineering which is closely relative to people's lives and properties.Its displacement on the top surface is the most apparent parameter to indicate deformations and developments of the slope.At present,in the field of slope detection there are some usual and traditional methods which are specialization,high-cost and heavy workload both external and internal including geodetic detection,GPS,3D laser scanning method and so on.Recently,along with the development of UAV and computer vision technique,digital images obtained by UAV and processed by computer can satisfy the requirements of calculating surface displacement and deformation of the slope.Compared with the traditional one,this method is low-cost,safer,none-contact and quicker.Based on above,in virtue of Visual C++ programing language and open resources including OpenCV and VKT,this article developed Slop Displacement Detection and Safety Evaluation System Development Based on UAV Photography.The research contents mainly includes the following aspects:(1)Characteristic points recognizing and matching: using computer vision technique to process the photographs and analyzing the advantages and differences among different algorithms,then choosing an appropriate one to recognize and match the photographs and taking out matching errors to obtain homonymy points in different images which are to be used in calculating 3-demention coordinates.(2)Surface model reconstruction: get the internal and external orientation elements of UAV photography,according to the processing results of the digital photographs of the slope area and combined with the basic principle of photogrammetry and SFM,the three-dimensional coordinates of the characteristic points are calculated,so as to obtain the slope point cloud data.Then based on the reconstruction algorithm of the surface model,the discrete point cloud is divided into triangular meshes,and the surface model of the slope is generated.(3)Displacement calculation research: according to the characteristics of computer vision,there are two kinds of methods aimed at displacement calculation designed in this article.The first one is based on detected points.Recognize the preset detected points and compare the 3D coordinates of different images to calculate its displacement.Non-detection points' displacement can be calculated by interpolation algorithm.Another method is on the basic of surface model by comparing the surface model generated by the two UAV photographs,the displacement of each triangular mesh node along the three axises is obtained based on the model of the first aerial photograph.(4)System development: according to the research above,combining the related knowledge of system development,this article designed the system framework and system interface,wrote related codes,and accomplished the calculation and evaluation system—Slop Displacement Detection and Safety Evaluation System Development Based on UAV Photography.