An experimental testbed to simulate space manipulators GNC

The space environment is very demanding and every mission requires careful assessment and preparation. This is especially true when operations are rather challenging as in the case of a multibody spacecraft and grasping mission. Therefore, the design and set-up of specific ground simulation techniques is mandatory in order to define and study the control law strategies to be later applied in orbit. The paper depicts the experimental activities carried out at the University of Rome “La Sapienza” to experimentally simulate planar, controlled operations of orbiting manipulators. The architecture of the set-up, including the choice for limiting the friction, is discussed. Hardware selection and assembly issues, with reference to performance expected by simulation set-up, are detailed. Special attention is devoted to the kinematic state determination and trajectory reconstruction, to be obtained by sensors and devices located onboard the manipulators and validated by external means like webcams, which become a part of the simulation testbed itself. Relevant performance of each subsystem is described, and verified in robust closed loop grasping maneuvers. A second application of the same set-up, which is also helpful and currently used in formation flying studies, is introduced.