A robust predictor for nonlinear systems with dead time

The presence of single input delay, also known as dead time, complicates the control of processes. To attenuate this problem, predictors structures are used. They allow the control of this type of process with a delay-free nominal model, which simplifies the control design. In this paper, a Nonlinear Filtered Smith Predictor (NLFSP) structure is proposed for nonlinear systems. It is shown that the NLFSP maintains the characteristics of the linear Smith Predictor and that, with appropriate tuning, it can increase the robustness of the closed-loop system. A simulated example is used to illustrate the theoretical results.