Research on extraction technology of coal wall and roof boundary basedon laser point cloud

The acquisition and processing of laser scanning data is one of the key technologies for the intelligent working face of coal mines. As an important mean to monitor the cutting trajectory of coal shearers,3D laser scanning technology has been increasingly valued because of its characteristics of non-contact,high precision and less effect by smoke and dust. However,due to the massive,discrete and redundant characteristics of laser point cloud data,in actual production,at present,only the 3D point cloud information of the working face can be obtained remotely and the spatial characteristics of the laser point cloud data cannot be used to directly extract the coal cutting roof line of the shearer,namely feedback information of the current shearer cutting trajectory cannot be provided. For real-time acquisition and prediction of current shearer cutting coal roof line position data，on the basis of constructing the initial transparent working face based on data such as geophysical prospecting,drilling,roadway sketching and laser scanning,the laser scanner is used to perceive and obtain the laser point cloud data of the fully mechanized coal mining face in real time so as to fully understand the laser scanning device. Under the premise of the operation principle and the characteristics of laser point cloud data,aiming at the problems of data dispersion,large amount of information and difficult feature extraction of the three-dimensional laser point cloud,a complete set of feature extraction process of 3D laser point cloud of working face is established by removing outliers,filtering point cloud,slicing point cloud and feature point extraction based on spatial morphology,which realizes the automatic extraction of coal cutting roof line of laser point cloud in fully-mechanized mining face,and is combined with the visual interpretation method. The extracted coal cutting roof line data are compared and verified,and the points with error less than 0.04 m account for 84%,and the points with error less than 0.08 m account for 96%,which verifies the feasibility of extracting the current algorithm of the cutting coal roof line of the shearer. The cutting stroke of the shearer with the next or next cuts provides data reference.