The invention provides a
satellite flexible attitude dynamics modeling method considering the change of the
mass center of a whole
satellite, and the model is used for simulating the on-
orbit flexible attitude behavior of the
satellite. The method comprises the following steps: establishing an
inertial coordinate system Oi, an orbital coordinate
system Oo, a star coordinate
system Ob and a sailboard coordinate
system Of; establishing an attitude motion equation Eq.1 of a whole
satellite system, an equation Eq.2 of flexible vibration of the sailboard and an attitude motion equation Eq.3 of the sailboard relative to a central body, wherein the Eq.1, Eq.2 and Eq.3 consider the influence of the
mass center change of the whole satellite and the flexible vibration of the large sailboard; and calculating a direction cosine matrix RoI of the
centroid orbital coordinate system, a direction cosine matrix RsI of the star coordinate system, an attitude conversion matrix Rso of the star coordinate system relative to the
centroid orbital coordinate system and an Euler angle, and taking the Euler angle as
attitude control input. According to the satellite attitude dynamics calculation method considering the satellite
centroid change and the sailboard elastic deformation in real time, the problem that the instantaneous centroid change cannot be simulated in an existing attitude dynamics
algorithm is solved.