State variable analysis of four tank system

Many industrial processes of manufacturing, refining, etc., typically requires control over at least two variables. This could use at least two control loops and makes it as multi-input multi-output (MIMO) or multivariable systems. Quadruple tank process (QTP) is one of the multivariable laboratory processes with four interconnected water tanks. This novel deals with mathematical modeling of the QTP by linearization principles and Jacobian matrix formation to represent the system in state space. The linearized dynamics of the system have a multivariable zero that can be placed in both the left and right half of s-plane. The interaction between the control loops are studied using RGA and analysed using LabVIEW. This process is ideal for illustrating multivariable control concept and also the performance limitations due to multivariable right half-plane zeros.