A PREDICTION APPROACH TO INTRODUCE DEAD-TIME PROCESS CONTROL IN A BASIC CONTROL COURSE

This paper presents a methodology to introduce the control of dead-time processes using a simple and intuitive predictive approach. A trivial solution for the control of a process with a dead-time is first proposed. From this strategy the idea of the predictor based controller is derived. Open-loop predictors and closed-loop ones are then used to analyze the obtained solution. A simple tuning of the proposed structure for a first order plus dead-time process together with a polynomial approximation of the dead-time allows to derive a pro controller. Thus, the approach based on the idea of prediction can be used to interpret the use of a PID to control a dead-time process. It is illustrated how the performance of the pro controller is limited by the modelling error introduced in the approximation. The presented approach gives a measurement of the achievable performance. Several simulation examples illustrate the results.