Finite element approach to the dynamics of a machining robot

A complete dynamic analysis for robot manipulators with elastic links is presented in this paper. For this purpose the dynamic performance of a serial manipulator performing a machining task is studied specifying the machining forces as end effector loads. The time varying load specified for the analysis is a function of end effector displacement. Input functions of joint actuators are obtained by performing inverse dynamic analysis. Input functions obtained from the inverse dynamic analysis are approximated by cubic spline curves and specified as loads for the forward dynamic analysis. The correction to be applied at the end effector is the difference between the end effector's desired and generated motion. A three-dimensional beam element of FEM was used for discretizing the manipulator structure. The method is illustrated by a 6R manipulator performing a machining task.