An LMI Approach for Robust Design of Disturbance Feedback Control

Disturbance Feedback Control (DFC) is a control technique that augments robustness of existing control systems with an extra feedback loop for the purpose of attenuation of disturbances and model errors. In this work, we propose a DFC design method based on output feedback control via Linear Matrix Inequalities (LMIs). A parametric uncertainty model is used to represent mismatches between a nominal model and the actual plant. LMIs are formulated for the control design using a linearizing change of variables, the bounded real lemma, and regional pole placement. Simulation results demonstrate that the proposed method improved the performance of the existing feedback loop.