Robust linearising controllers for nonlinear time-delay systems

A salient feature of robust control schemes for nonlinear systems with delay on the state and the input is addressed. Using a state delay-dependent feedback linearisation algorithm, a nonlinear state-delay system having a linear input-output map can be determined. Composed of the Smith-type prediction and feedback linearisation, the nominal time-delay system can be completely compensated. An extended Lyapunov-based control technique is integrated into the linearising controller as prediction such that the uncertain time-delay system can be stabilised and the tracking trajectory will have uniform ultimate boundedness. Finally, a chemical reactor with delays in the recycle stream and manipulated input is demonstrated.