Robust stability condition for a class of time-delay plants with uncertainty

Abstract

In this paper, we consider the robust stability condition for single-input/single-output time-delay plants with new class of uncertainties. First of all, we define a class of uncertainties to be considered. The necessary and sufficient robust stability condition for time-delay plants with such class of uncertainties is presented. The relation between the time-delay plant and the nominal time-delay plant to satisfy the robust stability condition is clarified. By using this relation, we will show the necessary and sufficient robust stability condition for the time-delay plant with varying number of right half plane poles.

The Parameterization of All Disturbance Observers for Time-Delay Plants

“…In many dynamical systems such as biological systems, chemical systems, metallurgical processing systems, nuclear reactors, pneumatic and hydraulic systems with long transmission lines, and electrical networks, the presence of a time delay is quite common and often leads to poor performance and instability of a control system [16][17][18][19][20][21][22][23][24][25]. This implies that if we design a control system that considers the time delay in the plant, then in some cases, the control system is unstable and has poor performance.…”