An intelligent self-tuning fuzzy-PID controller to coupled tank liquid level system

The primary objective of this paper is to design an intelligent controller for controlling the level of fluid in the coupled-tanks. Mathematical model of the real-time coupled-tank system (CTS) is first derived, and it is taken up further for the design of controller. The research study develops a self-tuning fuzzy PID (STF-PID) controller applied to a dynamic linear model of CTS to regulate the liquid level. The heuristic rules are formulated with the help of self-institution learned from experience. This forms the novel idea for designing a STF-PID controller. The performance effectiveness of the fuzzy logic based PID controller is compared with PID controller using simulation in MATLAB Simulink. From the simulation results of output, it can be observed that the STF-PID controller performs very well with no overshoot, drastic reduction in rise time, faster settling time and thereby producing minimum ISE, IAE, and ITAE.