Thermal effect on performance of micromachined hemispherical gyroscope

Abstract

The thermal effect on performance of micromachined hemispherical vibratory gyroscope subjected to environment temperature change was investigated comprehensively in this paper. Firstly, the structure and principle of typical micromachined hemispherical gyroscope were introduced, and its advantages over other micromachined gyroscopes were demonstrated Taking a typical micromachined hemispherical gyroscope as a model, then, the analysis of modes was implemented under varying environment temperature ranging from -40°C to 120°C, and the relation between resonant frequency shift and temperature change was given based on the reference temperature of 20°C. The results showed that all order resonant frequencies decreased when environment temperature increased, and the high order frequency shifted more than the low order frequency. Finally, the reference state was chosen when the micromachined hemispherical gyroscope was driven at the driving resonant frequency and at room temperature of 20°C, and the sensing vibration amplitude presented the angular rate output. The sensing vibration amplitudes were calculated with the angular rate input from 0/s to π/s and environment temperature changing from -40°C to 120°C, and it concluded that temperature change can seriously degrade the angular rate output.