Fuzzy Logic Controller Design for Liquid Level System

A fuzzy logic control system is an alternative method to control linear system and non-linear systems, also it has been approved in many applications and one of the most reliable for it is liquid control. This type of control is replacing conventional control with modern control that gives more accurate results. To find a reliable design that stabilizes the level of liquid, a water tank with a valve system has been designed in a MATLAB environment using the Simulink tool and controlled by three controllers which are PID, FL control with five rules, and FL control with twenty-five rules. Firstly, we used PID control and in this method, we found that overshoot is present but not much as in FL with 5 rules, also Ts is less in PID. Secondly, for the third one which used FL with 25 rules and two inputs which are error and change of error, simulation results were better because overshoot is not present, and Ts was less than PID. Finally, the steady-state errors for all were not present.