Fuzzy Logic Based Control for Parallel Cascade Control

In chemical industries parallel cascade controllers are used to improve the dynamic performance of a control system. Cascade controllers has two controllers, primary and secondary controllers in cascade. In this paper, a fuzzy based control is designed for the primary controller to improve the performance of the parallel cascade control. The secondary controller is implemented with internal model control (IMC) method. The dead time in the process is compensated by incorporating Smith predictor in the primary loop. The use of fuzzy logic controller is more effective than the conventional controller. It contributes to achieve quick response and high accuracy to variations in input parameter fluctuations during operations in systems, and also provides robust control performance. The performance of the proposed method has been evaluated by conducting experiments on two different systems. The simulation results revealed that the proposed method outperforms other recently reported methods in performance measures for both transient and steady state conditions.