Minimal realization of dynamically balanced lumped mass WA gyroscope: dual foucault pendulum

Abstract

We report a new type of MEMS rate integrating gyroscope. The Dual Foucault Pendulum (DFP) gyroscope consists of two dynamically equivalent, mechanically coupled proof masses, oscillating in anti-phase motion, creating a dynamically balanced resonator with x-y symmetry in frequency and damping. Phase synchronization is established by mechanical coupling of the two proof masses, whereas quadrature suppression is achieved by four differential shuttle pairs placed in-between. Dual axis tuning fork behavior provides vibration immunity and anchor loss mitigation, resulting in a Qfactor over 100,000 on both modes at a center frequency of 2.7 kHz. Whole angle mechanization is demonstrated by FPGAbased closed loop control of the gyroscope, showing a scale factor variation of 22 ppm RMS over 2 hours of measurement. We believe Dual Foucault Pendulum is the minimal realization of a dynamically balanced lumped mass whole angle (WA) gyroscope.