Research on angular vibration measurement system based on heterodyne interference

Abstract

In order to accurately evaluate the dynamic performance of inertial devices, this paper proposed an angular vibration test system and method for inertial devices based on heterodyne interference technology. This system is mainly composed of the angular vibration excitation device and the angular vibration measurement device. By installing an angular reflector on the swing table, the dual-frequency laser interferometer (DFLI) can measure the real-time angle value of the swing table, then obtain its amplitude-frequency characteristics with the Fast Fourier Transform algorithm . The experimental results show that the test system can measure angular vibrations exceeding 1000 Hz. Furthermore, the frequency bandwidth of an interferometric fiber optic gyroscope (IFOG) fabricated in our laboratory is evaluated by the angular vibration test system aforementioned, and its cut-off frequency is measured as 375 Hz. Finally, a comprehensive theoretical analysis has been implemented to investigate the uncertainty factors in the DFLI of this system.