Deadtime compensation for nonlinear processes with disturbances

Abstract The control problem of time delay non-linear systems that are perturbed by disturbances is discussed. By coordinate transformations and feedback and prediction of the transformed states, we first linearize the perturbed non-linear systems into controllable quasi-linear systems with disturbances. Then, we can apply the well-developed linear control theory to stabilize the transformed systems. Thus, stable quasi-linear systems with time delay can be obtained. Furthermore, we may implement powerful deadtime compensation methods to study the performance of the proposed dynamic compensators, a Smith predictor and a new modified Smith predictor, for disturbance rejection. Finally, a typical non-linear chemical process, a continuous stirred tank reactor, is used as an example system to demonstrate the effectiveness of these deadtime compensators