Sampled-data non-linear H∞ estimation and control

This paper considers the non-linear H-infinity estimation problem with sampled measurements and the non-linear H-infinity control problem with sampled measurement feedback where the control signal should be of a staircase type. Sufficient conditions are found that guarantee a prescribed level of disturbance attenuation for all bounded energy disturbances. The global solutions of these problems are expressed in terms of solutions to Hamilton-Jacobi equations. A particular feasible selection of the injection gain that is based on a linearization of the estimator in the neighbourhood of the estimated trajectory is proposed. The obtained results are demonstrated by a practical example of vehicle attitude determination.