Elasticity and vibration control for manipulators

The motion of a robotic system with elastic joints and links practically consists of the nonlinear path tracking movement and a superimposed vibration due to elasticity. Assuming only small elastic deviations the control problem of an elastic manipulator may efficiently be partitioned into three parts, namely into the control of a somehow optimized reference trajectory as performed by the rigid robot, into the control of the elastic deviations from that reference path and into the control of the elasticity-induced vibrations. Modelling the dynamics is performed by applying elastic multibody theory. The concept of nonlinear decoupling extended by a special correction regarding elasticity and the concept of an optimized output control are used for controlling the'robot. Theoretical and experimental results demonstrate the efficiency of the new procedure.