A Robust Angular Rate Sensor Utilizing 2:1 Auto-Parametric Resonance Excitation

This paper presents a single-axis angular rate sensor that is robust to variations in its operating voltage and frequencies. The sensor is developed to overcome the shortcomings of conventional mode-matched Micromachined Vibratory Gyroscopes in open loop operations, namely narrow frequency bandwidths and unstable scale factors. The developed sensor utilizes inherent forcing and inertial nonlinearities from electrostatic forces and fabrication imperfections to auto-parametrically excite the sense mode via 2:1 auto-parametric resonance, which yields a broader bandwidth frequency response for the sensor's sense mode. The experimental results demonstrated -3 dB frequency bandwidth of 500 Hz, a scale factor of 50 mu V/degrees/s, and a dynamic range of +/- 330 degrees/s.