Predictive control of the multivariable time delay processes in an isotope separation column

The secondary processes in a pilot plant carbon isotope cryogenic separation column are multivariable time delay processes. In general, for these types of processes, Smith Predictor control schemes are frequently used, however they exhibit poor robustness due to the explicit use of the process model in the compensation loop and require additional control techniques to enhance robustness against modeling uncertainties. An alternative solution used in this paper is a predictive controller, with intrinsic time delay compensation. The simulations presented show that the predictive controller is also robust to significant time delay estimation errors, without further need to design additional filters for increasing robustness.