Kinematic Characteristics and Dynamics Analysis of the Truss Tetrahedral Deployable Mechanism Unit

The tetrahedral deployable mechanism unit in the truss deployable antenna was analyzed and studied in this paper. The 3RR-3RRR truss tetrahedral deployable mechanism unit was taken as the research object, configuration and geometric characteristics of the mechanism unit were analyzed, based on the graph theory and screw theory, the screw constrained topology diagram were obtained and the degree of freedom (DOF) was analyzed, the result showed that it has only one DOF. Then, through the operation of the screws, velocities of the nodes and the rods were obtained, and the Jacobian matrix was also obtained, based on the screw derivative, accelerations of the nodes and the rods were calculated, and dynamic modeling of the tetrahedral deployable mechanism unit were built based on the principle of virtual work and Newton-Euler equation. Finally, a simulation model of the mechanism unit was built, the curves of velocities and accelerations of the nodes and rods and the driving force were obtained through the Adams and Matlab software, the correctness of theoretical analysis was verified by the simulation results. The research in this paper lays the foundation for the follow-up research and application of this tetrahedral deployable mechanism unit, and provides references for the kinematics and dynamics analysis of other space deployable mechanisms.