H ∞ control for flexible spacecraft with time-varying input delay

This paper is concerned with H∞ control problem for flexible spacecraft with disturbance and time-varying control input delay. By constructing an augmented Lyapunov functional with slack variables, a new delay-dependent state feedback controller is obtained in terms of linear inequality matrix. These slack variables can make the design more flexible, and the resultant design also can guarantee the asymptotic stability and H∞ attenuation level of closed-loop system. The effectiveness of the proposed design method is illustrated via a numerical example.