Internal Model Control based controller design for a Stirred Water Tank

In this paper, we adapt a recently proposed Internal Model Control (IMC) based controller design approach for simultaneous decoupling and disturbance rejection for a practical Multiple Input Multiple Output (MIMO) system, namely, for designing a controller for a Stirred Water Tank System (Two Input Two Output). While retaining the central aspect of the reported method, namely using the off-diagonal elements of controller matrix for diagonalization whereas using the diagonal elements for satisfying other control objectives, the present method simplifies it for possible wider application. The proposed method is outlined, the controller is designed using this approach and its closed loop performance has been evaluated using simulation. Even though the plant has substantial open loop coupling and non-negligible delay, the closed loop system with the designed controller was found to exhibit good set-point tracking, good decoupling and adequate disturbance rejection properties.