PIECE-WISE CAUSAL INVERSION BY OUTPUT REDEFINITION FOR A FLEXIBLE LINK MANIPULATOR

A new causal dynamic end-effector inversion method for a single flexible link manipulator is introduced. Contrary to the available non-causal inversion technique, this method does not lead to pre-actuation and works even in the presence of the purely imaginary zeros for the transfer function. Based on this approach, the desired end-effector trajectory is divided into a finite number of segments. In each segment, the desired trajectory is redefined so that a bounded continuous torque through causal dynamic inversion is obtained. The redefinition of the desired trajectory at each segment employs summation of stable exponential functions. This leads to a family of answers for the redefined trajectory, which is an advantage for control engineers. The results of the simulation and experimental studies show the feasibility and effectiveness of this new technique.