Study On Robot Trajectories On Complex Mold Surface For Plasma Transferred Arc Surface Modification

With mold manufacturing technology developed, it has proposed higher requirements for mold surface's quality and property. Many mold companies began to introduce surface modification technology in mold manufacturing process. Plasma transferred arc surface modification technology use high-energy plasma transferred arc as source to harden mold surface, it has low cost, small size, high thermal efficiency and other characteristics, which can increase the mold surface hardness and improve surface properties. Our research group combined plasma transferred arc surface modification equipment and robot to develop a three-dimensional surface plasma transferred arc processing system, which can used in complex mold surface plasma transferred arc modification. For robot motion, different trajectories must be accompanied by different plasma arc surface modification effect. So, according to mold complex surface process requirements and plasma transferred arc surface modification processing character, researched the robot trajectory planning method deeply and developed the trajectory generated software based on UG NX.This paper studied three-dimensional plasma transferred arc surface modification system in detail. Through analyze the processing parameters and functional requirements of the system, design each function module and operation interface of system. Elaborated CAM medium height residual method to generate robot trajectories principle and process, and proposed robot initial trajectory planning which based on the CAD / CAM algorithm. Use of linear interpolation algorithm of cubic spline curves successfully, approaching the trajectory by consisting a series of discrete track points to the robot motion trajectory. Write trajectory control code by combining the secondary development of UG NX and Visual Studio, and developed trajectory automatic generation systems based on plasma transferred arc surface modification processing. Finally, process the generated trajectory through coordinate system conversion. The trajectory is transformed into the robot coordinate system, and can add the appropriate processing parameters into trajectory text.Mold test results show that the trajectory planning algorithm used in this paper is feasible. The trajectory of the algorithm generated is the continuing, and with high precision, which can meet the requirements of complex surface mold plasma arc surface modification.