Angular-velocity tracking with unknown dynamics for satellite rendezvous and docking

Abstract

Autonomous satellite on-orbit servicing is a very challenging task when the satellite to be serviced is tumbling and has an unknown dynamics model. This paper addresses an adaptive control approach which can be used to assist the control of a servicing satellite to rendezvous and dock with a tumbling satellite whose dynamics model is unknown. A proximity-rendezvous and docking operation can be assumed to have three steps: 1) pre-dock alignment, 2) soft docking and latching/locking-up, and 3) post-docking stabilization. The paper deals with the first and third steps. Lyapunovbased tracking law and adaptation law are proposed to guarantee the success of the nonlinear control procedures with dynamics uncertainties. A dynamics simulation example is presented to illustrate the application of the proposed control approach. Simulation results demonstrated that the adaptive control method can successfully track any required angular velocity trajectory even when the dynamics model of the target satellite is unknown.

Rendezvous Approach Guidance for Uncooperative Tumbling Satellites

“…Diao et al, used a Lyapanov-based tracking law to match angular velocities, and then defined an adaptive controller to stabilize the system right after docking [18].…”