Stabilization of Free-Flying Under-Actuated Mechanisms in Space

Under-actuated mechanisms provide low cost automation and can overcome actuator failures. These mechanisms are particularly useful for space applications mainly because of their less weight and lower power consumption. In space under-actuation could be effectively introduced in large space structures and robot manipulators. Such mechanisms would however be difficult to control because of the fewer number of actuators in the system. In this paper, we formulate the dynamics of open chain under-actuated mechanisms in space using Hamilton´s canonical equations. Next, we develop a theorem that provides us with sufficient conditions for the asymptotic stabilty of autonomous systems. We use this asymptotic stability theorem to verify the efficacy of control strategies that we develop to stabilize our under-actuated system to equilibrium manifolds. Simulation results provide support to our theoretical claims.