Robustness and Sensitivity of Smith Predictor Controllers for Time-Delay Systems

摘要

The robustness theorem for the extended Smith scheme is derived. Parameter optimality problems are discussed. Results indicate that the performance is improved by temporal mismatch or properly chosen feedback component. Minimization of the performance index can be one of the criterions for choosing the temporal model. When the feedback in either inner or outer loop is not unity, the steady state error should be carefully checked even though an integral action is included in the controller. The sensitivity functions for Smith scheme in the multivariable case are established. In spite of their complex structure they can be checked numerically.