A predictor-based sliding mode control strategy for nonlinear uncertain input-delay processes

A sliding mode control strategy with the incorporation of a prediction scheme is developed for nonlinear uncertain input-delay chemical processes. A Lyapunov-based approach is employed to guarantee both the robust stability and performance of the closed-loop system. For demonstrating the effectiveness and applicability of the proposed nonlinear strategy, we applied it to the regulation control of a continuously stirred tank reactor (CSTR) in the presence of a large input delay and various process uncertainties, such as unmodeled side reaction, measuring error and/or extra unmeasured disturbances. The potential use of a sliding observer along with the proposed scheme is also investigated as a whole. Extensive simulation results reveal that the proposed design methodology is applicable and promising, which provides robust and high control performance for the regulation of nonlinear uncertain chemical processes in the presence of input-delay.