Comparison for Level Control of a Coupled-Tank using PI, PI-plus-Feedforward, and IMC Controllers

Abstract

This paper investigates the performance of various control schemes for level control of a coupled tank process. The nonlinear dynamic model of the system was derived using the analytical and empirical approaches. To investigate the performance of the controllers, proportional plus integral control, proportional plus integral plus feedforward control and internal model control (IMC) have been proposed. The PI gains were determined using pole placement, Ciancone correlation, and Cohen-Coon tuning techniques. Time response specification and mean absolute error (MAE) are used to assess the level control performance of the designed controllers. Comparative MATLAB simulation assessments have shown that IMC with the least MAE value and fastest settling time has the best tracking performance as compared to other controllers.