Performance Analysis of a Nonlinear Coupled-Tank System Using PI Controller

In the process industry many of the control applications deal with liquid level, flow, temperature and pressure processes. This paper presents the approach of modeling and controller design of liquid level control system for a nonlinear Coupled-Tank System. First of all, the mathematical equations for the nonlinear system are explored. And then, proportional plus integral (PI) controller is designed to control the level of the second tank for the nonlinear model, through variable manipulation of water pump in the first tank. The simulation study is done using MATLAB and the performance analysis in time domain of the controller is identified. In addition, ITAE criterion is used to evaluate the controller performance. Finally, the simulation results indicate that the controller work very well and the proposed controller has the ability to reject the effect of the disturbance.