The spacecraft micro-vibration restricts the smoothness of satellite-born pointing assembles, especially for space-based laser communication, it may cause more capacity loss. A precision shafting is often the key component, connecting the satellite and the optical antenna, and transferring micro-vibration from the satellite bus to the above payload. The oscillation characteristics of the Reaction Wheel(RW) subjected to mechanical tests was implemented via pairs of liner accelerometers and acquisition system, then the micro-vibration transfer property through shafting were studied. The results showed that the RW vibration standard deviation (STD) magnified about 5 times to 30mg~50mg in time domain after the mechanical test, the FFT analysis in frequency domain showed the vibration response frequency was spurious, but the main frequency of about 430Hz and 860Hz which matched the frequency multiplication of the frequency the RW bearing balls passing the point defects in the bearing inner part. The liner acceleration and angular velocity was almost direct ratio to the RW speed, and the RW tangential vibration seemed to be more sensitive to the speed. The space used precision shafting showed perfect attenuation for a high frequency angular vibration transferring, the attenuation ratio was about 70%.
The angular micro-vibration of a high resolution camera mounting on an agile satellite was achieved based on pairs of liner accelerometers alignment and numerical integration method. Three pairs of sensors were mounted at different portion of the satellite for studying the structure transfer character, including the Reaction Wheel (RW)interface, the camera interface and the camera tail. The results showed that the RW original micro-vibration standard deviation (STD) output acquired at the RW interference was 1.63μrad at RW 400rpm and increased to 2.43μrad when the RW speed up to 800rpm. When transferring from RW to the camera interface, the angular vibration response STD was attenuated to 0.31μrad@400rpm and 0.27μrad@800rpm, and finally to the camera tail the angular vibration response STD became 0.31μrad@400rpm and 0.30μrad@800rpm. We can see that the satellite-camera structure has a good attenuation effect on the micro-vibration, the output angular micro-vibration STD is about 0.31μrad with an input of 1.63μrad~2.43μrad. the stiffness of the camera is pretty good, ensuring that the micro-vibration STD difference between the camera flange and the camera tail is smaller 0.03μrad. In addition, we found that the FOGs useful bandwidth wasn’t insufficient when acquiring about 340Hz main frequency vibration signal in our case, even though a higher stiffness flange was recommended which connecting the FOG and camera.