Sliding Mode Control of Non-Minimum Phase Nonlinear Uncertain Input-Delay Chemical Processes

In this paper, a sliding mode control scheme, which integrates a time-advanced nonlinear predictor and a statically equivalent output map, is developed for nonlinear, non-minimum phase, uncertain processes in the presence of input-delay. The convergence properties of the proposed sliding mode control system are guaranteed theoretically by a Lyapunov-based approach. For demonstration, we applied it to the regulation control of a Van de Vusse reactor in the presence of input-delay, non-minimum phase behavior, and diversified uncertainties such as unmodeled side reaction, measuring error, parameter uncertainties, and/or extra unmeasured disturbances. The potential use of a sliding observer along with the proposed scheme is also investigated in this work. Extensive simulation results reveal that the proposed sliding mode control system design methodology is applicable and promising.