Micro-vibration modeling and analysis of single-gimbal control moment gyros

Micro-vibration modeling and analysis of single-gimbal control moment gyros (SGCMGs) are conducted in this study. Considering the rotation and support effect of the lowspeed gimbal, a nonlinear time-varying dynamic model for micro-vibration analysis of an SGCMG is established using the energy theorem. By considering the Hertzian contact, elastohydrodynamic lubrication, and surface waviness, the nonlinear supporting forces and moments of the angular contact ball bearings on the high-speed rotor and low-speed gimbal are derived, and accordingly, an iterative solution method is proposed. Based on a three-axis dynamic force measurement platform, the dynamic characteristics of a real SGCMG are tested to verify the rationality of the proposed micro-vibration model. Subsequently, the effects of unbalance mass, surface waviness amplitude, gimbal lock angle, and rotation angular speed of the gimbal on the threeaxis gimbal bearing transmission forces are discussed. The findings of this study provide insights for clarifying the micro-vibration characteristics and provide a theoretical basis for the working state design and structural optimization of SGCMGs. (c) 2022 Elsevier B.V. All rights reserved.