Design of 2df imc controller

Abstract

The Internal model control (IMC) relies on the mathematical model of the process to be controlled. In IMC we can achieve accurate control only if the control systems contain (either implicitly or explicitly) some mathematical representation of the process to be controlled. In this report we analyze about automatic process control, basic principle behind imc, and design 2df imc controller. The 1df imc controller is good for set point tracking. But in case of disturbance rejection the time to settle is too high. In this case we use 2df imc controller. One controller is used for set point tracking and another is used for disturbance rejection. Two degree of freedom imc controller is always not use full. 2df imc controller is not use full for Process having frequency response initially low and then high. So before designing the controller for the process, we have to check and compare with the 1df output and then we should design controller for the process. In case of 1df controller, we design filter parameter as our requirement to track the set point. Set point Controller is designed in such a way that it cancels out poles and zeroes of the process. So the controller is very good for set point tracking. But for the process having disturbance lag it is not useful. If we design the 1df controller for disturbance rejection it is not good for set point tracking. So we have to use another degree of freedom. In our study we analyze different principle of designing the 2df imc controller and advantage of this over 1df controller.