Input-output synchronization for bias drift reduction of MEMS gyroscopes

MEMS vibratory gyroscopes ideally possess uncoupled components on their orthogonal drive and sense axes. Asymmetries in the structure of the device, caused by manufacturing non-idealities and device wear, introduce unwanted dynamic interactions between the sense and drive axes. These interactions often lead to the transfer of energy from the drive axis to the sense axis in the absence of any external perturbation. The transferred energy (leakage) appears as a time-accumulating bias drift on the measurement signal on the sense axis, resulting in error to the sensor output. This paper describes the application of an input-output controller to compensate for non-ideal interdependencies of drive and sense axes for vibratory gyroscopes in order to reduce the bias drift in the sense axis.