A TORSIONAL NONRESONANT Z-AXIS MICROMACHINED GYROSCOPE WITH NON-RESONANT ACTUATION TO MEASURE THE ANGULAR ROTATION OF AN OBJECT

摘要

A gimbal-type torsional z-axis micromachined gyroscope with a non-resonant actuation scheme measures angular rate of an object with respect to the axis normal to the substrate plane (the z-axis). A 2 degrees-of-freedom (2-DOF) drive-mode oscillator is comprised of a sensing plate suspended inside two gimbals. By utilizing dynamic amplification of torsional oscillations in the drive-mode instead of resonance, large oscillation amplitudes of the sensing element is achieved with small actuation amplitudes, providing improved linearity and stability despite parallel-plate actuation. The device operates at resonance in the sense direction for improved sensitivity, while the drive direction amplitude is inherently constant within the same frequency band.