The Research of Geometric Error Modeling of Robotic Machining: II Parameter Identification and Pose Optimization

Abstract

According to the built spatial motion chain, the geometric error of robotic machining is not only related to the pose parameter identification errors of hand-eye/workpiece/tool, but the joint kinematic error and weak stiffness deformation of robot. This paper investigates the new methods of hand-eye pose parameter identification considering the joint kinematic error, the workpiece pose parameter identification considering the onsite measuring defects and the tool pose parameter identification based on the error evaluation of practical machined surface, and deals with the problem that the pose parameter identification accuracy is limited by various factors such as robot motion accuracy, unclosed/uneven/noisy measured points and machined jitter/stress deformation/rotation error. Then consider the joint kinematics error, weak rigidity deformation and error compensation, a general model of machining error compensation and robotic pose optimization is built, and can be applied to kinds of machining error control such as normal depth(grinding/milling), tangential slip(drilling) and angle incline (trimming). Finally, the experiments of hand-eye/workpiece/tool pose parameter identification, overall error compensation and robotic machining are carried out to verify the effectiveness of the proposed methods.