A New Method for Measuring the Attitude and Straightness of Hydraulic Support Groups Based on Point Clouds

This study proposes a measuring method to measure the altitude and straightness of hydraulic support groups based on point clouds to tackle the shortcomings in the current measuring methods for measuring the attitude and straightness of hydraulic support groups. First, we build an experimental platform and use three RGB-D cameras to obtain the point cloud of the hydraulic supports from different angles. Then, we calibrated the depth camera and determined the conversion relationship between the camera coordinate system and the world coordinate system. After point clouds preprocessing, we use the method of SAC-IA combined with ICP to conduct point clouds registration, to obtain the complete point cloud of the hydraulic support groups. We analyzed the geometric attitude of a single hydraulic support point cloud and selected characteristic points on each hydraulic support to solve the straightness. Finally, experimental verification is conducted. We did a comparative experiment between SAC-IA combined with the ICP method and ICP method, which proved that the former can effectively reduce the matching error; moreover, we conducted the hydraulic support groups attitude and straightness measurement experiment and compared it with the measured value of the sensors. We found that the errors are all within the acceptable range. It proves the feasibility of adopting point clouds to measure the attitude and straightness of the hydraulic support groups, which is important to realize the transparency and unmanned measuring of the fully mechanized mining face.