Nonlinear Chemical Processes With Variable Dead Time: Comparative Robustness and Performance Analysis for Model Based Predictive Schemes

The objective of this work is to make a comparison of three predictive control schemes: a Robust Smith Predictor and two kinds of model-based predictive control (MPC) which were applied to a continuous stirred tank reactor (CSTR). This process has an elevated and variable dead time due to the location of the temperature transmitter and the flow variation on which the delay depends. The performance of the controllers is tested under tracking and regulation conditions: change in the set point, persistent disturbance applied at a determined time. In the same way, the proposed control strategies are compared and analized each other using the robustness plot.