Design and Simulation of Auto Tuning of PID Controller using MRAC Technique for Coupled Tanks System

In chemical and petroleum industries, liquid level controllers are used very frequently. In control laboratory coupled tanks system is used to design liquid level controllers. The coupled tanks system is a nonlinear and dynamic plant. However, conventional fixed gain and normal feedback controller are unable to give desired performance. To overcome this difficulty, controller must be adaptive in nature. In this paper an auto tuning of proportional integral derivative (PID) controller based on model reference adaptive control (MRAC) by using MIT rule is designed. The proposed controller typically consists of a linear time-invariant Proportional, Integral and Derivative (PID) controller with an adjustment mechanism which tunes the PID parameters in such a way that error between reference model-s output and actual plant-s output will be minimised. The proposed algorithm is applied on coupled tanks system. Simulation results show the effectiveness of proposed controller.