Research On Surface Reconstruction Method And Disassembly Trajectory Planning Of Nuclear Robot Disassembly Target

Accurate disassembly can effectively reduce the secondary damage to nuclear-related devices in nuclear emergency rescue operations,but there is no robot disassembly equipment to meet the needs at present.It is of great significance to carry out the research of nuclear-related disassembly robots.In this paper,with the support of the national key R & D projects,the precise positioning technology of dismantling targets is studied based on surface reconstruction and trajectory planning for the common box,pipeline and sphere devices in nuclear accident emergency rescue.The main research results are as follows :According to the requirements of precise disassembly operation,based on the selection of five-degree-of-freedom hybrid manipulator,the rotating joint of manipulator is designed,and the stiffness analysis and verification of rotating bracket are carried out,thus forming a series-parallel-series six-degree-of-freedom high stiffness disassembly manipulator.The anti-radiation protection design for the selection of adhesive for the unfolding and dismantling detection sensor is proposed.Based on the reverse optical path of the molybdenum mirror,the wrapped protection scheme of the laser rangefinder is proposed to solve the radiation protection problem of the sensor in the nuclear emergency environment.Based on the reconstruction technology,a feature extraction method for dismantling targets is proposed.The neighborhood decision strategy is used to extract the point cloud data of dismantling targets,and the NURBS surface reconstruction algorithm is used to reconstruct the surface of the point cloud information after noise reduction.The disassembly trajectory curve is extracted by projection method,and the point cloud position information on the disassembly trajectory is extracted based on the equal arc length method.The method of extracting feature vector information from point cloud of disassembly trajectory based on neighborhood plane vector realizes the extraction of point cloud position and attitude information.Based on the structural analysis of the dismantling manipulator,the inverse kinematics,forward kinematics and velocity analysis of the manipulator are carried out.According to the requirements of disassembly,a fast disassembly method based on tool axis vector arc interpolation and an accurate disassembly method based on tool axis vector NURBS curve interpolation are proposed.The relationship between the position and vector of the tool axis of the manipulator and the time is established.The disassembly trajectory planning is completed and the execution file of the workpiece disassembly operation is generated.The experiments of sensor calibration,feature extraction of disassembly target and disassembly operation were carried out.The results show that the trajectory planning method proposed in this paper can effectively extract the position feature information of disassembly target,and realize the operation of typical workpiece,which verifies the rationality and feasibility of the disassembly operation system scheme.The results of the above disassembly operation system have been partially applied to the design and development of the disassembly operation robot system,which provides technical support for the design and integration of the disassembly robot system,and has obvious theoretical significance and practical application value.