A sliding observer for nonlinear process control

Sliding observers are considered as nonlinear state estimators with good robustness to bounded modeling errors. In this paper we have developed sliding observers for process control. The observer is hence designed so as to possess invariant dynamic modes which can be assigned independently to achieve the desired performance. Convergence of the estimating algorithm is formulated by using Lyapunov stability theorems. Conditions for robustness to modeling errors are derived by analyzing the norms of estimation errors. For process control, servo-tracking and disturbance rejection for chemical reactors have been discussed by making use of this sliding observer. Simulation examples to demonstrate the construction and performance of this proposed sliding observer for chemical process control are also presented. (C) 1997 Elsevier Science Ltd.