A Performance Study of Control Systems with Dead Time

This paper discusses the performance of the Smith Dead Time (SDT) controller for systems with appreciable dead time. Tuning, modeling accuracy, and the effects of parameter variations and measurement noise are all studied using a simulated second-order process with dead time. The corresponding performance of the conventional proportional plus integral (PI) controller is used as a reference for comparison. It is shown that the SDT controller yields improved results over the PI controller if the plant is fairly stationary and the noise level is moderate. Otherwise adaptive filtering and control will be needed to maintain the superiority of the SDT controller over the PI controller.