PERFORMANCE COMPARISON OF PID CONTROLLER AND FUZZY LOGIC CONTROLLER FOR WATER LEVEL CONTROL WITH APPLYING TIME DELAY

Abstract

Liquid level control is a system often found in most industrial facilities. Usually, embedded control systems are used, as these systems play an increasingly important role in control engineering. Time delay is one of the most important parameters which affects the control systems performance. This study aims to design a water level control system in MATLAB/ Simulink environment using the proportional integral derivative (PID) controller and Fuzzy Logic (FL) controller and then to investigate the effect of the time delay on their performance. The two control systems were tested and compared in terms of performance, with and without applying a time delay. The study highlights the application of two types of delays (distributed time delay and discrete-time delay) to the output of the built-in control system and discusses the results. The results showed that the FL controller is better than the PID controller in terms of stability and performance. Although the rise time of both controllers was almost the same, the FL controller showed higher performance in terms of overshoot and settling time. While the overshoot for the PID controller was 9.33 %, it did not appear when using the FL controller. Moreover, the settling time of the PID controller was 10 seconds, while the FL controller took only 8.6 seconds to achieve stabilization. As a result, the FL controller has demonstrated the ability to eliminate the overshoot problem that appears when using PID controllers and stabilize faster.