Large Amplitude Linear Drive Quadruple Mass Gyroscope

Abstract

Coriolis vibratory gyroscope drive amplitude of 16 $\upmu\mathrm{m}$ is demonstrated with $+30$ ppm frequency shift nonlinearity. Here, MEMS quadruple mass gyroscope (QMG) mechanical flexures are specifically designed to separate spurious modes without affecting linear operation of gyroscope drive over large amplitudes. A simulated frequency change of $+480$ ppm was initially predicted, however, when electrostatically driven at large amplitudes comb drive and sense tips begin to introduce spring softening reducing nonlinearity to $+30$ ppm. Careful consideration was also taken to electrostatically tune as-fabricated frequency mismatch without further exacerbating nonlinearity. Angle random walk (ARW) versus drive amplitude is plotted with a demonstrated $8\times$ improvement compared to similar quadruple mass gyroscopes.