H-infinity filtering design for uncertain nonlinear systems under sampled measurements

This paper considers the problem of nonlinear H-infinity filtering for samp led-data systems with nonlinear time-varying parameter uncertainty. The aim is to design a digital filter such that the ratio of the energy of the est imation errors to the energy of the exogenous inputs is minimized or guaran teed to be less than or equal to a prescribed value for all admissible unce rtainties. A nonlinear bounded real lemma for sampled-data systems with non linear time-varying parameter uncertainty is provided. Based on this nonlin ear bounded real lemma, the robust H-infinity filtering problem is solved i n terms of both continuous and discrete Hamilton-Jacobi equations.