Modelling and control of nonlinear resonating processes: part II—model based control using orthogonal basis function based Wiener models

Abstract

This paper is an extension of the work presented by Reddy and Saha (Int J Dyn Control 2016) i.e. Part I of this series of papers. Reddy and Saha (2016) developed Wiener type nonlinear models using orthogonal basis filters which were proved to be ideal candidates for modeling nonlinear resonating systems such as continuous stirred tank reactor(s). Those nonlinear models have further been employed in the present work for developing nonlinear model based control strategies and their closed-loop control performance have been evaluated through simulation case studies involving same continuous stirred tank reactor(s). Two types of model based control strategies are adopted viz. nonlinear model predictive control and nonlinear internal model control. In case of nonlinear internal model controller, the problem of model inversion has been addressed, first of its kind in approach, through tactful modification of Wiener model coupled with optimization technique. Deletion of positive zeros from orthogonal basis filters while modifying Wiener model is the uniqueness of this paper and it ensures stability of the controller.