Farhad Kiani - Dept. of Mechanical Engineering University of Yazd, Yazd, Iran
Mohammad Bozorg - Dept. of Mechanical Engineering University of Yazd, Yazd, Iran

This paper deals whit computation of the robust performance domain of PID controller for time delay systems with uncertain coefficients .Using equivalent theorem for stabilizing and robust performance and combining it with minimum distance function, robust performance domain will be obtained for all of these coefficients. This task contains two stages. First, delay parameter is assumed fix, then the change domain of the uncertain coefficients existing in the controller and plant are obtained. Second, using delay parameter change, change domain of this coefficient is obtained according to robust performance domain.

Time Delay, PID Controllers, Minimum Distance Approach, Uncertain Parameters