Adaptive control of nonlinear processes: Continuous-time versus delta model parameter estimation

Abstract

The paper deals with continous-time adaptive control of nonlinear processes. A nonlinear model of the process is approximated by a continuous-time external linear model. the parameters of the CT external linear model of the process are estimated in two ways. In the first case, direct estimation of the CT model is used. In the second case, the parameters of a corresponding delta model are recursively estimated. the 2DOF control system configuration is considered. the controller design is based on the polynomial approach. the resulting proper controller ensures stability of the control system as well as asymptotic tracking of the step reference and step load disturbance attenuation. the adaptive control is tested on the nonlinear system represented by a model of two spheric liquid tanks in series. Copyright © 2004 IFAC