Modeling and experimental study of dynamic characteristics of the moment wheel assembly based on structural coupling

Abstract

The microvibration of the satellite moment wheel assembly (MWA) is an essential input for integrated simulation analysis of spacecraft microvibration, which forms the basis for spacecraft vibration suppression. Therefore, it is important to guarantee high-precision data from ground measurements of vibration sources for research into the stabilization accuracy of large space telescopes. In general, a coupled wheel-to-structure disturbance model is more representative of the real environment, and two aspects of the coupling need to be considered: coupling caused by insufficient MWA stiffness and coupling caused by the vibration source installation structure. Therefore, this paper presents the relevant work conducted on these two coupling aspects. First, this paper proposes the amplification factor coefficient, which considers structural coupling based on the classical vibration model of the MWA. The average error in this case could be within 5%. This approach could reduce the computational requirements without affecting the quality of the results. Additionally, as the mass of the MWA is greater and the disturbance output is more obvious. The structural coupling with the installation foundation is unavoidable. In this paper, the effects of installation stiffness on the disturbance measurements are analyzed based on the dynamic mass measurement method and quantitative impedance theory. Finally, based on the above theory, verification testing of the disturbance and transfer models of the MWA is performed and the test results are compared with the simulation results; it is shown that a level of accuracy within ±5% can be achieved.