Authors: P. Febina Beevi; T.K. Sunil Kumar; Jeevamma Jacob
Addresses: Electrical Engineering Department, NIT Calicut, 673601 Kerala, India ' Electrical Engineering Department, NIT Calicut, 673601 Kerala, India ' Electrical Engineering Department, NIT Calicut, 673601 Kerala, India
Abstract: This paper addresses the problem of design of a two degree of freedom (2-DOF) PID controller for time delay systems. The proposed approach is to design 2-DOF PID controller using a novel method which combines model order reduction, approximate model matching (AMM) concepts as well as optimisation techniques. The conventional PID controllers are usually in 1-DOF structure. The problem of finding the parameters of the 2-DOF PID controller is formulated as that of obtaining the solution of a set of non-homogeneous linear equations. The proposed method not only ensures the stability of the closed loop system with a 2-DOF PID controller but also satisfies the required performance criteria. The developed method does not pose any restriction either on the order of the model or on the structure/order of the controller transfer function. Moreover, this method is computationally simple and easy to implement. Simulation results demonstrate the effectiveness of the proposed method.
Keywords: approximate model matching; model; model order reduction; non-homogeneous linear equations; optimisation techniques; performance criteria; stability; time delay; transfer function; 2-DOF PID controller.
International Journal of Intelligent Systems Technologies and Applications, 2018 Vol.17 No.1/2, pp.123 - 135
Received: 13 Apr 2017
Accepted: 25 May 2017
Published online: 03 May 2018 *