Robust PI controller design for Coupled-Tank process: LMI approach

This paper proposes an approach to a robust PI controller design for real uncertain Coupled-Tank process in time domain. Only the first independent tank is considered (single-input single-output system). Polytopic model of uncertain system is considered as a plant model to be controlled. Stability and performance of the closed loop system is determined through the LMI region, where the closed loop poles of whole uncertainty domain are placed. A robust stability condition based on the parameter-dependent Lyapunov function (PDLF) is used.