Configuration synthesis and unfolding stiffness characteristics analysis of a truss antenna connecting mechanism based on URU-RR-URU hexagonal deployable unit

Abstract

• A method of configuration synthesis of deployable connecting mechanism is proposed. • Simulation analysis method is used to determine the stiffness of the driving spring. • The motion principle of the modular mechanism based on URU-RR-URU unit is simulated. • Two deployable mechanisms are compared and discussed. • A prototype with high deployment rate is developed and experiments are conducted. The networking connection mechanism between deployable units is the key to realize large deployable antennas. Considering the RRR-RR-SRS and URU-RR-URU hexagonal deployable units, a method of configuration synthesis for deployable antenna connecting mechanism is proposed. First, according to the hexagonal and triangular combined units’ division of the parabolic reflector and based on screw theory, a method of configuration synthesis for connecting mechanism of a modular mechanism is proposed, and two modular mechanisms are obtained. Next, the motion principle of the modular mechanism, based on a spring actuation URU-RR-URU unit, is simulated, while simulation analysis method is used to determine the spring stiffness . The structure composition, motion characteristics and deployment rate of the two mechanisms are compared and analyzed. Finally, the modular deployable mechanism, able of complete folding, is selected, while the unit prototype and one-circle modular prototype are developed for validation experiments regarding the correctness of the presented theoretical analysis. The results provide a theoretical basis for the design and application of the supporting mechanism of large deployable antennas with high deployment rate.