Research On Dynamic Calibration System For MHD Micro-angular Vibration Sensor

The high-precision attitude orientation of effective payloads such as satellite platforms and remote sensing systems can be seriously affected by the micro-angular vibration of the on-orbit satellite,and thus effective measurement and control are required.The magneto-hydrodynamic(MHD)micro-angular vibration sensor is a novel micro-angular vibration measuring component for effective payloads in space applications.With the advantages of high bandwidth,low noise and small size,it can be used to measure satellite micro-angular vibration,which has micro-amplitude and wide-band characteristics.The complex sensitivity of MHD micro-angular vibration sensor is an important parameter to evaluate its dynamic performance.In order to ensure the accuracy of the sensor measuring the angular vibration information,an absolute dynamic calibration method using laser interferometer was proposed.The major work in this paper are listed as follows.1.First,according to the micro-amplitude and wide-band measurement characteristics of MHD micro-angular vibration sensor,as well as the small-size and high-efficiency demand of the calibration system,an absolute calibration method with high-precision and wide-band measurement capability was selected.A homodyne laser interferometer was combined with an angular retro-reflector,and an angular vibration calibration method of single-frequency sinusoidal excitation was applied.A sinusoidal approximation methodwas used to process the dynamic calibration results.Furthermore,a dual beam structurewas used to improve the measurement resolution of laser interference.2.Second,the principle error of the dynamic calibration system was analyzed,and the overall scheme and key elements was designed.To ensure the accuracy of the wide-band angular vibration excitation and avoid the integral structure resonance,two experimental clamps were designed and the structural stress simulations were carried out.Moreover,the calibration system was built and the automatic calibration testing software was compiled,where the dynamic calibration efficiency of the sensor was effectively improved.3.The dynamic calibration experiments of sensitivity amplitude and phase shift of the MHD micro-angular vibration sensor were accomplished.The results indicate that the established laser interference calibration device can calibrate the complex sensitivity of the MHD micro-angular vibration sensor under the small-angle vibration in wide frequency range.The calibratable angular vibration frequency range of the laser interference dynamic calibration device is 25?1000 Hz,and the angular velocity range of that is 0.060 ? 7590 mrad/s.The expanded uncertainties of the sensitivity amplitude and phase shift of the calibration system for the MHD micro-angular sensor are 0.48%,1.48°in the frequency range of 25?500 Hz,and 2%,5.43°in the frequency range of 500?1000 Hz(k = 2).