Operational Impact Excitation Method for Milling Robot End Frequency Response Function Identification Under Movement State and Pose-Dependent Dynamic Compliance Analysis

Robot milling has become an important means of machining large structural parts, and the dynamic compliance of the robot end is the key factor affecting machining quality and efficiency. The dynamic characteristics of the milling robot end are different in movement state and static state and have significant pose dependence. In order to effectively evaluate the dynamic compliance of the robot end in the workspace under the movement state, the operational impact excitation method for robot joint relative frequency response function (FRF) identification based on operational modal analysis (OMA) used in machine tool is established, the inertial force generated by the joint acceleration and deceleration movements is used as the excitation force, the robot end relative dynamic compliance index (RERDCI) is proposed to evaluate the dynamic compliance of robot end in different poses, and verified by cutting experiments. Based on RERDCI, the effect of the robot pose on end dynamic compliance is analyzed, and some theoretical guidance for improvement of dynamic performance to resist vibration in milling is given.