New designs of micromachined vibrating rate gyroscopes with decoupled oscillation modes

This paper reports on new vibrating comb-drive rate gyroscope designs featuring decoupling of the actuation and the detection mode. Analytical calculations as well as FEM and system simulations are carried and the main drawbacks of these sensors are investigated which are especially the frequency mismatch of the two oscillation modes, the insufficient bandwidth and the effects of levitation. Concepts and simulations of electrostatically controlling both the resonance frequency and the bandwidth are presented. Within these concepts no mechanical balancing of the devices is required and thus calibration costs are reduced. Simulations of a new quasi-rotating rate gyroscope show, that a resolution of 0.1°/s is possible at a bandwidth of 50 Hz with 6 mm³ sensor area only and that the effects of levitation are actually compensated