The posture optimization method based on deformation index in robotic milling process

Compared with traditional CNC machine tools, industrial robots have higher flexibility and lower cost in the machining field. However, the relatively low stiffness of the robot makes it difficult to meet the accuracy requirements. In this paper, a robot machining posture optimization method is proposed to improve the performance. First, a deformation index considering the robot stiffness compensation matrix K_C is proposed to evaluate the stiffness performance of the robot machining trajectory. Then, by minimizing the deformation index under consideration of kinematic constraints, a robot posture optimization model is established. The discrete Dijkstra optimization method is proposed to solve the global optimal solution to the model. Finally, the effectiveness of the robot deformation index and posture optimization method has been verified by a series of simulations and experiments in the Motoman ES165D robot.