Optimization-based PI/PID control for a binary distillation column

This paper presents the PI/PID control of a binary distillation column via a genetic searching algorithm (GSA). The time-domain design criterion, expressed as an integral of the squared error, is reformulated in the frequency-domain using the Parseval´s relation and Pade approximation. A genetic algorithm is then used to search over the stability region in the controller parameter space for the best settings to minimize the design criterion. Our results indicate that the genetic algorithm can provide better solutions for the PI/PID control schemes as compared to those using the single-loop and multi-loop Ziegler-Nichols tuning methods. We found that the GSA is easier to use than traditional optimization techniques. In addition, no knowledge of complex mathematics is required to use the GSA effectively.