Sampled-data non-linear H-infinity estimation and control

This paper considers the non-linear H-infinity estimation problem with samp led measurements and the non-linear H-infinity control problem with sampled measurement feedback where the control signal should be of a staircase typ e. Sufficient conditions are found that guarantee a prescribed level of dis turbance attenuation for all bounded energy disturbances. The global soluti ons of these problems are expressed in terms of solutions to Hamilton-Jacob i equations. A particular feasible selection of the injection gain that is based on a linearization of the estimator in the neighbourhood of the estim ated trajectory is proposed. The obtained results are demonstrated by a pra ctical example of vehicle attitude determination.