A New VRFT Approach for IMC-PID Feedback-Feedforward Controller Design based on Robustness

Abstract

This paper presents, design of feedback-feedforward controllers based on Internal Model Controller (IMC) strategy using data based Virtual Reference Feedback Tuning (VRFT) approach. For minimum phase discrete systems, some VRFT approaches have been proposed to design IMC based PID controllers in the literature. However, the approaches determine whether the system is robust or not. In this paper, a new VRFT approach is investigated. The IMC based PID controllers are designed by scaling controller tuning parameters for specified robustness in addition of non-measurable disturbance signal. Different control structures, based on feedback and feedback plus feedforward and IMC filter, are evaluated both concerning regulatory and servo control. The simulation results show that, the proposed method enhance the performance for feedforward structures with filter based on same degree of robustness in terms of Integral Square Error (ISE), Total Variance (TV), VRFT Objective Function (JVR).