MATLAB Graphical User Interface based Fuzzy Logic Controllers for Liquid Level Control System

Abstract

This paper presents the design and development of MATLAB graphical user interface (GUI) based fuzzy logic controller (FLC) and integrated fuzzy logic controller (IFLC) for liquid level control system. The main objective of this work is to design and develop a MATLAB based GUI for liquid level control system. In this application, the inflow of water to the tank is controlled. The necessary algorithm is developed in MATLAB. The liquid level in a cylindrical tank is measured by using differential-pressure sensor (SX05DN). The sensor converts change in water level into change in resistance which is further converted into voltage and applied to an instrumentation amplifier. The computer acquires voltage through Analog to Digital–Digital to Analog Converter (AD-DA) board designed indigenously for this application. The Digital Input/ Output and Timer (DIOT) card is used to interface AD-DA board with PC. To control liquid level, MATLAB/GUI based PIDC, FLC, and IFLC is developed. The performance of these controllers is tested for a step input of 15 cm. The results show that IFLC exhibits the best response in terms of less rise time and settling time, negligible overshoot and undershoot. The proposed MATLAB/GUI provides various graphical user interfaces for easy access, tuning, and visual display of performance of controllers implemented.

Keywords

• Fuzzy logic controller
• GUI
• Level
• MATLAB
• Water tank