Model based control of a four-tank system

A multi-disciplinary laboratory for control education has been developed at the University of Delaware to expose students to realistic process system applications and advanced control methods. One of the experiments is level control of a four-tank system. This paper describes two model-based methods students can implement for control of this interacting four-tank system. Sub-space identification is used to develop an empirical state space model of the experimental apparatus. This model is then used for model based control using internal model control (IMC). This represents an application of inner-outer factorization for non-minimum phase multivariable IMC design. Modeling is also performed using step tests and Aspen software for use with dynamic matrix control (DMC). (C) 2000 Elsevier Science Ltd. All rights reserved.