Robust Stability of Smith Predictor Controllers for Time-Delay Systems

摘要

Smith predictor control structures for multivariable process plant with separable delays on the output are considered. The robustness of the control scheme with respect to mismatch between the real plant and its model, and to simultaneous changes in plant dynamic is analyzed. The cases of additive and feedback mismatch are examined, using a contraction mapping fixed point theorem. Frequency domain results for feedback mismatch in a typical Smith scheme reduce to the inverse Nyquist array criterion as plant and model delays tend to zero. Results are presented graphically as stability criteria.