The Automatic Measurement For Estimating Coal Storage Volume In Open Stockyard

In this paper, in order to estimate coal storage volume in open stockyard, we have analyzed the optical triangulation and applied it to the measurement of large surface We have stated the measuring theory of distance with laser and the measuring theory of angle. We have also analyzed main factors influencing measurement precision and studied several key techniques in large-scale measuring such as the problem of non uniformly distributed of distance measuring resolution in large surface measurement, the methods of locating laser spot center and so on.On laser scanning large surface measurement precision is analyzed and the methods of decreasing and correcting error are suggested. Considering that the image spot occupies more pixels and can give the large part of the outline of circular spot, a new method of locating the center of laser spot based on Hough transform is presented. Since time-consuming becomes the bottleneck of he Hough transform algorithm in accordance with the character of image spot in this application. It improves effectively the performance of distance measuring of the system.We have developed an automatic measuring system of volume of large coal heaps based on laser scanning triangulation using the above techniques. It has high measuring speed, high accuracy and it is easy to be carried. The results of the application show that these methods can raise effectively the measuring precision of large scaled 3D surface profile.