Coupled tanks laboratory for teaching multivariable control concepts

This work aims to be a valuable tool for teachers involved in the field of automatic control, especially for those who teach multivariable control systems. In this context, the study of coupling degree of variables is the first step to follow in the way to design a multivariable controller. However, didactical setups which are used in the control labs to conduct multivariable control experiences usually have not a flexible structure to study the effect of different coupling degrees between variables. In this way, this paper presents the design and construction of a two coupled tanks system (MIMO) at laboratory scale which was designed and built by means of open-loop simulation tests and a variables interaction analysis. This platform has the peculiarity of having a manual valve that couples both tanks, which can be driven to modify the variables interaction degree in the process, according its opening level. By using this laboratory, students can identify and face the effects of coupling on a real water tank plant, by analyzing and applying different multivariable control strategies according the interaction degree of variables in the process.