Dynamic Analysis of Satellite Antenna System with Joint Clearance and Reflector Flexibility

Abstract

A methodology for modeling and analysis of satellite antenna systems is presented considering the effects of the joint clearance and reflector flexibility in the system. The joint clearance model is established based on a thorough geometric description of the eccentricity vector. The contact-impact forces are evaluated based on a Hertz contact theory and a modified Coulomb’s friction law. The fixed-interface component-mode synthesis method and Lagrange’s equations are used to achieve a lower-order dynamic model by modal truncation. Furthermore, in the process of dynamic modeling, the changes of topology were expressed as constraint variations; namely, adding or deleting the variable structure constraint in the dynamic model. Finally, the multibody dynamics of satellite antenna are analyzed by considering a flexible reflector with ideal and nonideal joints. Thus, the simulation results can predict the dynamic characteristics of satellite attitude and antenna pointing with the effects of clearance and reflector flexibility. The conclusions have important theoretical and significant practical engineering value in the analysis and control of satellite antenna pointing accuracy.