NONLINEAR CONTROL OF TETHERED SATELLITE SYSTEM OSCILLATIONS

The control of in-plane transversal vibrations of a tethered satellite system by means of a longitudinal force exerted by subsatellite thrus ts is analysed. A one-mode model is derived for describing the inplane dynamics of such a system. On the basis of this model, two different nonlinear (and simple to be implemented) control laws are proposed for the stabilization of the tethered satellite system. The Liapunov stab ility theory is used to show the global asymptotic stability of the st ation-keeping phase of the tethered satellite system, subjected to eit her control laws. The effectiveness of the proposed control laws is sh own by means of both analytical arguments and simulation runs.