Modelling and control of orbit relative motion in small satellites

This work develops a multi-input multi-output robust controller to compensate the effects of atmospheric drag perturbations in the orbit tracking to be performed by small low altitude satellites. In particular, it is shown an approach for computing a H_∞ controller for the singular case when orbit dynamics are formulated through a relative motion model The problem captures some features related with other complex aerospace applications (space structure vibration, complex aircraft) so main contributions are offered from: the modelling methodology, the procedures for disturbance analysis and the proposed approach for robust control synthesis.