Control of a flexible arm by means of robustified MPC

This paper proposes the application of advanced control techniques to the main axis movement of a 4-axis strongly non-linear cardiovascular robot, more precisely a flexible arm. Measurements are taken on the motor shaft, consequently involving difficulties on the control of the load because of the flexibility of the mechanical chain. Two advanced control strategies are further compared: an off-line robustified Model Predictive Control (MPC) technique and a state-feedback linear quadratic (LQ) control. The LQ controller is designed in order to damp the resonant modes due to flexible mechanical structure. Its robust stability is a posteriori verified. The robust stability under both unstructured and polytopic uncertainties is explicitly considered in the robustified MPC synthesis.