H∞ disturbance attenuation for uncertain mechanical systems with input delay

The paper deals with the robust H disturbance attenuation problem for uncertain mechanical systems with input delay. The parameter uncertainties for the mass, damping and stiffness matrices take an additive a priori norm-bounded form. The time delay for the input is time-invariant but has a known constant bound. A robust static H state-feedback controller is designed to attenuate the disturbance on the controlled output to a prescribed level for all admissible parameter uncertainties and input delay. The design approach is formulated in terms of the feasibility of certain delay-dependent linear matrix inequalities. A numerical example is employed to illustrate the effectiveness of the approach.