Design of a sliding mode control system 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. To demonstrate 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 un-modeled side reaction, measuring error, and/or extra unmeasured disturbances. The potential use of a sliding observer along with the proposed scheme is also investigated. Extensive simulation results reveal that the proposed design methodology is applicable, promising, and provides robust and high control performance for the regulation of nonlinear uncertain chemical processes in the presence of input-delay.