Controller Order Reduction by Direct Closed Loop Identification (Output Matching)

Abstract A new approach for controller order reduction based on the closed loop identification is presented. The output error between the closed loop nominal system and the closed loop system with the reduced order controller is minimized. The frequency bias distribution of the parameter estimates shows that the reduced order controller preserves the performances of the nominal closed loop system. It is shown that while identification is performed using the real data, the robustness of the reduced order controller is improved with respect to the additive modeling error. The stability of the closed loop system with the reduced order controller is studied. Simulation results illustrate the performances of the proposed approach.