Coupling analysis on relative motion of spacecraft attitude and orbit model based on dual quaternion

Coupling effect between the spacecraft attitude and orbit influences relative motion of the spacecraft a lot, also influences control. Thus the couple characteristics should be studied before controller design. In this paper, we used relative motion model which is built based on dual quaternion, to analysis coupling effect. We proposed a new method-parameters analysis method, that is, the parameters in the coupling term were changed successively, solved the above dynamics equation, get the curves and the laws of the relative motion parameters generated by coupling terms. Based above, we designed control law to prove the coupling impact on control effect. Simulations have been done with the coupling model and the classic model of the relative motion respectively. The results show that coupling effect seriously affects the attitude and orbit of relative motion, especially the attitude influences the orbit motion a lot. In order to make the orbit and attitude control simultaneously, we must consider the coupling effect and coordinated characteristic during the controller design.