“…In this frame, the x, y, and z components are referred to as radial direction, tangential direction, and normal direction, respectively. Considering space perturbation, the linear C-W equation [9,26] describes the relative dynamic motion between the deputy spacecraft and the chief spacecraft and is as follows: We define system state as ( ) [ , , , , , ] T t x y z x y z = q , and the relative motion equation in (1) can be written into the following state-space model.…”