Disturbance observer-based sliding mode control for spacecraft non-cooperative rendezvous
Kai Zhang, Guang‐Ren Duan, Ming-Da Ma · 2016
The problem of autonomous rendezvous with a non-cooperative spacecraft target is investigated in this paper. A fully nonlinear spacecraft rendezvous dynamical model is established in the line of sight coordinate frame, further, with considering the gravity difference term, the rendezvous system is modeled as an uncertain nonlinear system. As a stepping-stone, a second-order disturbance observer is introduced to estimate the uncertain terms. Then, with the observed information, a sliding mode controller is proposed to stabilize the uncertain nonlinear system. For asymptotic convergence, it is only required that the second derivatives of uncertain terms are locally Lipschitz. Finally, simulations are conducted on the fully nonlinear rendezvous dynamical model and results are presented to show fine performance of the proposed control schemes.