A time delay compensation strategy for uncertain single-input single- output nonlinear processes

Abstract

The dynamic behavior of many processes is characterized by time delays due to transportation lags and measurement delays, which put severe limitations on the performance of control systems. In this paper, a new time delay compensation strategy for single-input single-output nonlinear processes subject to modeling uncertainty is proposed. At first, controller design based on input-output feedback linearization for a class of nonlinear systems with an input time delay is presented. Then, the input-output linearization controller is used in an internal model control (IMC) structure with time delay compensation. Finally, IMC with feedback compensation is proposed to reduce the effect of modeling errors on the performance and robustness. An adjustable parameter in the feedback compensation can be tuned to satisfy a particular specification. The effectiveness of the proposed method is illustrated via simulation on the temperature and concentration control of a nonisothermal chemical reactor with an input delay.