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Subject Keyword Abstract Author
Computation of Stabilizing PI-PD Controllers

Nusret Tan
International Journal of Control, Automation, and Systems, vol. 7, no. 2, pp.175-184, 2009

Abstract : The PI-PD controller structure provides an excellent four-parameter controller for control of integrating, unstable and resonant processes to set point changes while the conventional PID controller has limitations in controlling such systems. In this paper, a graphical method for the computation of all stabilizing PI-PD controllers is given. The proposed method is based on plotting the stability boundary locus, which is a locus dependent on the parameters of the controller and frequency, in the parameter plane. The stability boundary loci are first obtained in the and planes and then it is shown that all the stabilizing values of the parameters of a PI-PD controller can be found. Compu-tation of stabilizing PI-PD controllers which achieve user specified gain and phase margins is also studied. The method is used to design robust PI-PD controllers for control systems with parametric un-certainties. A design procedure for interval control systems is proposed. Examples are given to show the benefit of the method presented.

Keyword : Gain margin, phase margin, PI-PD control, stabilization, uncertain systems.

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