Bias Contribution Modeling for a Symmetrical Micromachined Coriolis Vibratory Gyroscope

This paper establishes a bias contribution model for a micromachined Coriolis vibratory gyroscope (MCVG). Eight bias sources, including stiffness imbalance, mass imbalance, and oscillation of the sense mode itself with their contributions, were analyzed and calculated. The calculation methods for key parameters, such as coupling stiffness, coupling damping, and offsets of center of mass based on the established process imperfection model, are presented in detail. Finally, the total bias of the MCVG is measured with an error of 18% compared with the theoretically calculated bias using the model. The acceptable error range of the bias model provides a solution to predict the bias behavior in the design stage before the costly fabrication.