Relative Motion Coupled Dynamic Modeling and Analysis of On-Orbit Servicing

This paper studies coupled relative orbit and attitude dynamic modeling when an on-orbit servicing spacecraft approaches and captures a target spacecraft.The attitude dynamic model of the servicing spacecraft with respect to the target is established.Taking into consideration the relative motion between the docking position and mass center of the target spacecraft as well as coupled motion between spacecraft attitude and docking position,coupled relative orbit and attitude dynamic model is established with the target in an arbitrary orbit.In-depth analysis of the coupled motion of the model is given.A nonlinear output feedback attitude control law is designed and numerical simulation for the coupled dynamic model and CW equation is performed to demonstrate the motion effect of the relative position between the docking points of the two spacecraft induced by motion coupling of orbit and attitude.