Application of eigenvalue assignment problem to coupled tank system

The Coupled-Tank system consists of two tanks of uniform cross sections and has been widely used for control education. It is a SISO system and by this way wide range of control theory can easily be applied to system. Two Coupled-Tank plants can also be used simultaneously and coupled to obtain more complex Multi-Input-Multi-Output (MIMO) experiment named Quadruple Tank System-QTS. This system is especially used to analyze performance limitations due to multivariable right half-plane zeros or input-output pairing problems. This paper presents the non-linear and linear mathematical modeling of coupled-tank and quadruple tank system. First of all eigenvalue assignment problem with state feedback has been studied on coupled-tank experiment set by calculating system states with an observer. Then control signal is generated with the help of multiplication of feedback matrix and estimated states. This combination of observer and state feedback is known as separation principle. After that pole assignment problem has been studied on five algorithms different from well-known Ackerman and Bass-Gura formula for MIMO Quadruple Tank System. We used three of them for our system. Results we had from the algorithms for our system are compared. After comparison the most efficient algorithm is proposed. Multivariable systems exhibit complex dynamics because of the interactions between inputs and outputs. For this reason best input-output pair must be determined for the system performance.In this thesis we also studied on the relative gain array, Nyquist array and diagonal dominance problems for quadruple tank system two determine best input-pairs and analyze system performance. Keywords: Coupled tank system, quadruple tank system, pole assignment, state observer, relative gain array, Nyquist array