Research on visual positioning method of digging and anchoring equipment based on single laser beam information

Intelligent digging and anchoring equipment in underground coal mines is the key to improve the mining imbalance problem in the industry, and the precise positioning of digging and anchoring equipment is the prerequisite to realize its intelligence. Compared with other traditional positioning methods, the vision-based pose measurement method has been initially applied in underground coal mines for its advantages of no contact and no cumulative error. Aiming at the problems of complex structure of cooperative target and cumbersome calibration of the current visual positioning method of the digging anchor equipment in the face of the underground coal mine, combining with the characteristics of the original laser pointers in the face of the digging, a visual positioning method of the digging and anchoring equipment based on the information of a single laser beam is proposed. By analyzing the laser pointer spot and beam image features, the method proposes a laser spot center extraction method based on two-dimensional inverse tangent function fitting and a laser beam centerline extraction method based on Hough straight line detection, and constructs a binocular visual position solving model based on the point and line features, which results in the real-time position of the anchor digging equipment in the roadway. Finally, in order to verify the feasibility and accuracy of the proposed feature extraction method and visual positioning method, experiments were conducted in the laboratory by building a platform to simulate the working condition environment of the digging face. The results show that the visual localization method of digging and anchoring equipment based on the information of mining laser pointers has high accuracy of position measurement. Within the test range of 50 m, the average measurement errors of the body position along the X-axis, Y-axis and Z-axis under the roadway coordinate system are 25.44, 58.64 and 31.08 mm, respectively, and the maximum errors are 55.16, 127.39 and 63.57 mm, respectively; and the average measurement errors of the pitch angle, yaw angle and roll angle of the body attitude under the roadway coordinate system are 0.22°, 0.22°, 0.41°, and their maximum errors are 0.29°, 0.37°, 0.58°, respectively. The maximum errors are 0.29°, 0.37° and 0.58°, respectively. It meets the requirement of positioning accuracy for the construction of underground roadway in coal mine.