The Fundamental Research Of An Extendible Space Borne Truss Structure Radatsat-2

Because of the limit of cargo space in skyrockets, the antennas of satellites have to be folded to both sides within top of the body. Nowadays, the majority of antennas on the backwards on the satellites are supported by the extendible structure. This thesis is based on the RADARSAT2 support structures for a project from one certain astronomy research center, and showed the research of certain basic principles of this support structure.We firstly introduced the current development of the extendible structures both at home and abroad, studied the structure and problems in the working principle of unfolding process, and pointed out the possible chaos movement of this under actuated structure. To overcome this phenomenon, we introduced several researching principles in the nonlinear fields, and pointed out that rigidity constraints may be used to help eliminate chaos.Secondly, by using the Lagrange dynamic modeling theory, we made the modeling of one typical weightless underacted five-bar mechanism. Based on Wolf’s calculating theory of the maximum Lyapunov exponent, we made programs which can be used to get the maximum Lyapunov exponent by a limited time series. By changing the designed parameters of the rigid components, we successfully accomplished the elimination of chaos phenomenon of this mechanism.Then by the software ADAMS, we made simulations of 2 designed plans of the Radarsat-2 structure. Based on the dynamic model of the extendible structures, we give the derivation of unfolding order and the cause of singular form in these plans.At last, we pointed out the existed problems in this research and gave researching future of this problem.