Design of optimal controllers for a three tank proces

A typical three tank process has the difficulty in controller design because of assumed non linear flow and interaction between tanks. This paper deals with design methodology of full state feedback (FSFB) controller and linear quadratic controller (LQC) with pre compensator. The performance of proposed controllers is compared with Zeigler-Nichols (ZN) tuned proportional plus integral plus derivative (PID) controller for servo and regulatory response. The FSFB controller with pre compensator yields better performance compared to other controllers. The transient response specifications and performance indices are compared and which indicates the efficacy of FSFB controller over LQC. The stability analysis is carried out using the vector gain margin (VGM) index and it is evident that VGM lies well within the range for LQC than FSFB controller