A new H-infinity filter design for linear time delay systems

A new delay-dependent H-infinity filtering design is proposed for linear, c ontinuous, time-invariant systems with time delay. The obtained filter is o f the Luenberger observer type. The design guarantees that the H-infinity-n orm of the system, relating the exogenous signals to the estimation error, is less than a prescribed level. The filter is based on the application of a newly derived version of the bounded real lemma for time-delayed systems. This novel approach is compared, via an example, with another solution tha t appears in the literature.