Six degrees of freedom vibration transmissibility measurement of flexural opto-mechanical structures with 3-axis acceleration sensors

At an early stage of a high-resolution flexural opto-mechanical system design, it is essential to analyze its dynamic characteristics for assessing image quality due to environmental vibration, an experimental method to measure six degrees of freedom (6-DoFs) vibration transmissibility of flexural opto-mechanical structures is proposed in this article. A typical flexural opto-mechanical structure consists of an optical component, a mechanical component and several flexural modules. Using the developed method, optical and mechanical components are considered as rigid bodies. Two feature points which are uncoupled in motion are set in the components separately, and they can express 6-DoFs vibration of each component moderately. Several key points are set in each component too, and their vibrational accelerations are measured with 3-axis acceleration sensors firstly. Then, motion relations between the feature points and key points are established, 6-DoFs vibrational acceleration spectrums of the two feature points are analyzed, and 6-DoFs vibration transmissibility between them is calculated. Thirdly, the experiment is carried out for twenty times, and average 6-DoFs vibration transmissibility is calculated. Uncertainties of this method are discussed with numerical analysis and experiments.