Torsional nonresonant z-axis micromachined gyroscope with non-resonant actuation to measure the angular rotation of an object

A MEMS gyroscope comprising:

• a three-mass structure comprised of two gimbals and a sensing plate, a first one of the two gimbals comprising a passive gimbal which contains the sensing plate, the passive gimbal executing large oscillation amplitudes by amplifying small amplitude oscillations of a second one of the two gimbals comprising a driven active gimbal;
• and
• parallel-plate actuators dynamically coupled to the active gimbal, the actuation range of the parallel-plate actuators being narrow to minimize nonlinear force profile applied to the two gimbals and to minimize instability of the gyroscope.

A method of operating a MEMS-based inertial torsional z-axis surface-micromachined gyroscope with non-resonant actuation to measure the angular rotation of an object comprising:

• driving a torsional 2-DOF drive-mode oscillator at nonresonance comprised of an active gimbal and passive gimbal in a flat operational frequency band to amplify small oscillation amplitudes of a driven active gimbal, to minimize the nonlinear force profile and minimize instability due to actuation of the active gimbal, while substantially eliminating any mode-matching requirement;
• and
• sensing torsional oscillation at resonance of a sensing plate coupled to the torsional 2-DOF drive-mode oscillator.

An improvement in a method of operating a MEMS gyroscope comprising:

• driving two gimbals of a three-mass structure comprised of two gimbals and a sensing plate with parallel-plate actuators dynamically coupled to the active gimbal, in which the actuation range of the parallel-plate actuators are narrow to minimize nonlinear force profile applied to the two gimbals and to minimize instability of the gyroscope;
• and
• dynamically amplifying small amplitude oscillations of the driven active gimbal to generate large oscillation amplitudes of the passive gimbal.