Robust H∞ control of uncertain systems with time‐varying state and control input delays

In this paper, a new method for robust H
∞
controller of uncertain systems with time‐varying state and control input delays is proposed. A sufficient condition, which is dependent on the maximum value of the time derivative of time‐varying delay, is also presented for the existence of H
∞
controller. The proposed controller not only stabilizes closed‐loop uncertain systems but also guarantees a prescribed H
∞
norm bound of the closed‐loop transfer matrix from the disturbance to controlled output. Furthermore, we propose a new robust stability criterion to decide the allowed maximum bound of plant uncertainty which still can be stabilized by proposed robust controller. An example given illustrates the availability of the proposed design method.