A simple model‐based nonlinear control strategy for feedback linearizable nonlinear processes

Abstract

In this paper we propose a simple and novel model‐based nonlinear control strategy for feedback linearizable nonlinear processes. The nonlinear controller, called NLC, has a forward static nonlinear element and, if the relative degree of the process is greater than unity, a linear dynamic feedback path. The nonlinear static element is a modified hyperbolic function which involves two tunable parameters used to adjust the linear gain and saturation level of the NLC. The NLC parameters are determined to achieve a desired tracking transfer function of the form (Kcs + 1)/(1 + ϵs) r+1 where Kc and ϵ are parameters relating to NLC controller settings and r the system's relative degree. The effectiveness and applicability of the proposed nonlinear control strategy are demonstrated through the controls of nonlinear chemical processes. Extensive simulation results show that the proposed nonlinear control strategy is a robust model‐based approach for the nonlinear control of dynamic processes.