Approaches of Discrete Feedforward Control for Vibration Cancellation in Multimode Single-Link Flexible Manipulators

This paper presents a new approach to the feedforward control of flexible arms. The objective is the end-point position control and vibration suppression in a single-link flexible manipulator with several vibration modes. The feedfoward controller is designed based on the so-called dynamic model inversion technique derived from a discretization of its dynamic model. By modifying the system dynamics with a feedback of the torque at the base of the arm, this technique can be applied in a very simple way. The proposed method is general in the sense that it removes remaining oscillations in the steady state under any number of significant vibration modes. A numerical example of the application of the method on an experimental robot arm is carried out and finally, some preliminary experimental results are presented