Abstract
Control on lirations of a tether system is studied by employing a crawler mass, which is necessary to inspect and recover any damage on tether. The model consists of a mother satellite and a subsatellite connected through tether and a crawler mass moving on tether. The model is a simple one, the satellites and crawler are assumed to be particles and mass and flexibility of tether are neglected. The mission function algorithm is employed for the control and feedback algorithm is confirmed. Results of numerical analysis show sufficient performance of the control of librational motion of the tether system employed with the crawler mass.