Fuzzy logic Control of Chemical Processes

Abstract

The objective of this study was to investigate the closed-loop control strategies for a batch reactor and batch distillation column by using two different control methods. In this paper, Fuzzy logic control is developed and compared with conventional proportional-/integral-derivative controller. In the design of fuzzy controller, the knowledge obtained from the process reaction curve procedure is employed to determine proper membership functions. Fine tuning is obtained alteration the output scaling factor. The forty nine rules are employed to regulate the manipulating variables to a variety of operating conditions and acquire a more flexible learning ability. The robustness of this control structure is studied in the case of set point changes and the fitness function for fuzzy controller is chosen as the integral of the absolute value of the error (IAE). The experimental results suggest that such fuzzy controllers can provide excellent set point-tracking and disturbance rejection. The results show that the fuzzy logic controller has a higher performance, in terms of robustness, response speed and the offset has a smaller average value than that of the conventional controller. According to experimental results, the fuzzy controller was considered more suitable and reliable for the batch reactor and distillation processes control with respect to the conventional controller.