Design of Centralized PI/PID Controller: Interaction Measure Approach

Controller designs of multivariable systems are always difficult due to interactions and coupling between inputs and outputs. Control system design involves input/output (IO) selection, that is, decisions on the number, the place, and the type of actuators and sensors. The choice of inputs and outputs affects the performance, complexity, and cost of the control system. In most of the multivariable systems controllers are designed by decomposing multi-loop systems into a number of equivalent single loops and design of a controller for each loop is performed. The success of controller depends on the input output pairing as it decides the structure of the controller. In this paper design rules and tuning procedure of the controller for multivariable process with delay time are discussed without decomposing multivariable system. An example, for which the proposed method of design of multivariable controller is employed to show its effectiveness.