Feedforward control of multimode single-link flexible manipulators based on an optimal mechanical design

This paper proposes a method to modify the dynamics of single-link flexible arms in order to allow the design of a control system which is more robust to changes in the payload value. This is achieved by attaching some small lumped masses at some points of the link. Therefore, connections between the dynamics and the feedforward control of single-link flexible manipulators are considered to simplify the control and make the system faster and more robust. The feedforward controller design is based on the so-called dynamic model inversion technique derived from a discretization of the system dynamic model. A comparative assessment between the discrete model inversion based on feedforward control and the command preshaping technique is presented. Numerical examples and experimental results thus changing the payload values are carried out.