The integral-inequality method is a new way of tackling the delay-dependent stabilization problem for a linear system with time-varying state and input delays: x˙(t)=Ax(t)+A1x(t-h1(t))+B1u(t)+B2u(t-h2(t)). In this paper, a new integral inequality for quadratic terms is first established. Then, it is used to obtain a new state- and input-delay-dependent criterion that ensures the stability of the closed-loop system with a memoryless state feedback controller. Finally, some numerical examples are presented to demonstrate that control systems designed based on the criterion are effective, even though neither (A,B1) nor (A+A1,B1) is stabilizable.

Delay-dependent stabilization of linear systems with time-varying state and input delays