Smith Predictor for Uncertain Systems in the QFT Framework

摘要

Design of controllers for systems with a dominant time delay are notoriously difficult. In the last few decades many research efforts have focused that particular problem, especially in process control. The dynamic behaviour of many industrial processes contains time delays. The presence of time delays greatly increases the difficulty to achieve satisfactory performance of feedback controllers. For openloop stable processes, the tracking problem can be improved substantially by introducing dead-time compensation. perhaps the most popular scheme for those systems is the Smith Predictor Controller SPC, whih was early introduced by O.J.M. Smith [1] in 1957. The SPC contains a model of the process with time delay in an inner loop (Figure 1), and can be easily implemented by using low cost digital micro-ontrollers.