Should we forget the Smith Predictor?
Journal article, Peer reviewed
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Original versionElsevier IFAC Publications / IFAC Proceedings series. 2019, 51 (4), 769-774. https://doi.org/10.1016/j.ifacol.2018.06.203
The PI/PID controller is the most used controller in industry. However, for processes with large time delays, the common belief is that PI and PID controllers have sluggish performance, and that a Smith predictor or similar dead-time compensator can give much improved performance. We claim in this paper that this is a myth. For a given robustness level in terms of the peak sensitivity (Ms), we find that the performance improvement with the Smith predictor is small even for a pure time delay process. For other first-order processes a PID controller is generally better for a given robustness level. In addition, the Smith Predictor is much more sensitive to time delay errors than pi and pid controllers.3rd IFAC Conference on Advances in Proportional-Integral-Derivative Control, Ghent, Belgium, May 9-11, 2018