Abstract:

Five vibration isolators are installed on the spatial five vertices of rigid body for the light-weight design demand of fiber optical gyroscope (FOG) strapdown inertial navigation system (SINS). The elastic center and eccentricity of the vibration damping system are calculated based on elastic center theory, and the addictive fifth isolator makes the eccentricity from centroid of Inertial measurement unit to elastic center decrease to 1.42mm. The solution to eliminate coupling vibration is discussed, and the coupling vibration among angular vibrations can't be eliminated because there is inertial principal axis excursion, but the coupling vibration between linear and angular vibrations can be eliminated by means of adjusting structure mass distribution or isolators’ stiffness ratio. The vibration impact response of SINS is calculated by using the finite element method and the results show that both two kinds of optimization methods achieve good vibration decouple effects and angular vibrations caused by linear impaction reduce by about 29~100 times.

Key words: Fiber optical gyroscope, Strapdown inential navigation, Isolator, Coupling vibration