Roadway Visual Reconstruction And Equipment Collision Warning Technology Research

With the development of coal industry,coal mine intelligence has become the core concept of high quality development of coal industry.In recent years,with the encouragement of national policies,the intelligentization of coal mines has made great progress,but the intelligent level of fully mechanized working face is still insufficient and safety accidents occur frequently.In order to realize the intelligent production of fully mechanized mining face,it is necessary to solve the technical difficulties of roadway three-dimensional reconstruction,equipment positioning and equipment collision warning.Therefore,this paper proposes a method of roadway visual reconstruction and equipment collision warning.By constructing RTAB MAP three-dimensional dense map and determining the pose of fully mechanized mining equipment in coal mine,the virtual model of fully mechanized mining equipment is established in Unity and the map data and pose data are synchronized.According to the distance relationship of OBB bounding box,the collision warning method based on OBB bounding box is realized,which is of great significance to realize intelligent and unmanned coal mine.Aiming at the problem that 3D map of roadway is difficult to reconstruct in complex environment of coal mine,the 3D roadway reconstruction method of RTAB MAP SLAM based on RGBD is studied.By establishing the camera distortion model and analyzing the influence of distortion on the characteristics,the camera internal parameter optimization model based on the adaptive velvet search algorithm is constructed to achieve the camera internal parameter calibration and distortion correction.The camera is tracked directly to form a visual odometer,and the back-end optimization is realized by Bundle Adjustment algorithm.The loop detection in RTAB MAP SLAM is completed according to the similarity detection method,and then the dense 3D point cloud map is constructed by point cloud splicing,which lays a foundation for the display and collision detection of 3D roadway in Unity.In view of the problems of occlusion in visual pose detection of underground mobile equipment in coal mines and large measurement error when dust concentration is different,a pose measurement scheme of underground equipment in coal mines based on point and line features is proposed.The adaptive threshold and the least boundary rectangle method are used to obtain the coordinates of the center of the spot by ellipse fitting method.The center line of the laser line is determined by the LSD gradient outer rectangle and NAF,and the linear characteristics of the laser beam are extracted by the least square method;Using the point and line feature information in the image,the pose measurement model of tunneling equipment is established,and the pose of the equipment fuselage is calculated,providing data support for collision detection.Aiming at the problem that the measurement error of the visual positioning method of the fuselage of the underground tunneling equipment in coal mines along the tunneling direction is large,and it is difficult to meet the requirements of collision detection,the relative positioning method of underground mobile equipment based on tags is studied.The labeling area is identified by Douglas-Peucker algorithm,and the device name is obtained by k-NN feature pattern recognition algorithm.The Hough line fitting is used to obtain the boundary line and calculate the intersection point,which is substituted into the equipment pose detection model based on the characteristics of three laser points.The relative pose between adjacent equipment is calculated,which provides data support for improving the accuracy of collision detection.Aiming at the problems of low efficiency and difficulty in realizing collision detection of underground equipment in coal mine,a collision detection method based on OBB hierarchical bounding box is proposed.By establishing the OBB-based hierarchical bounding box collision detection framework,the boundary of the bounding box is calculated by using the difference between the maximum projection value and the minimum projection value of the three axial directions of the OBB bounding box,and the hierarchical structure model of the OBB bounding box is constructed.By using the distance relationship between the bounding boxes,the equipment collision warning threshold is determined,and the collision warning of the OBB-based hierarchical bounding box is completed to ensure the safe operation of the equipment in the fully mechanized working face.Finally,an experimental platform is built to verify the feasibility of the above method.The results show that the RTAB MAP three-dimensional map construction method has good map reconstruction accuracy.The fuselage positioning method can provide stable and effective posture data of the equipment fuselage,and realize the collision detection and early warning function in Unity.