Model-error feedback design for systems with time-varying delay based on mixed H2/H∞ control

This paper proposes a controller design method using modeling-error feedback to improve steady-state performance for a system with time delay. The controller is designed based on the mixed H2/H∞ control assuring the stability condition with Lyapunov-Krasovskii functional. The proposed method resolves the problem of steady-state error due to model error which the conventional method using a communication disturbance observer (CDOB) faces. Experimental results are also shown to evaluate performance of the designed controller.