Abstract: Non-linear process control is a difficult problem in process industries. Conical tank level control is one among them. Conical tanks are widely used in many industries due to its shape which provides easy discharge of water when compared to other tanks. Moreover, liquid level control of a conical tank is still challenging for typical process control because of its nonlinearities by a reason of constantly changing cross section area. By using fuzzy logic, designers can realize lower development costs, superior features, and better end product performance. Fuzzy is often the very best way as they are faster and cheaper. One of successful application that used fuzzy control is liquid tank level control. The purpose of this project is to design a simulation system of fuzzy logic controller for liquid tank level control by using simulation package which is Fuzzy Logic Toolbox and Simulink in MATLAB software. In this paper the mathematical modeling of two non-interacting conical tanks by PID controller and fuzzy. In this paper, we take the liquid level water tank, and use MATLAB to design a Fuzzy Control. Then we analyze the control effect and compare it with the effect of PID controller. As a result of comparing, Fuzzy Control is superior to PID control. Especially it can give more attention to various parameters, such as the time of response, the error of steadying and overshoot. Comparison of the control results from these two systems indicated that the fuzzy logic controller significantly reduced overshoot and steady state error.

Keywords: Conical Tank, Level Control, Fuzzy Logic Toolbox, Simulink, MATLAB.