Utilization of mechanical quadrature in silicon MEMS vibratory gyroscope to increase and expand the long term in-run bias stability

摘要

A method for self-compensation of the bias draft of the quadrature signal of a gyroscope. The method is a combination of a variety of sub-methods, which can include quadrature compensation, can be used to achieve the highest possible stability. The calibration methods include a temperature self-sensing algorithm utilizing the drive-mode resonance frequency for calibration of thermal drift in the mechanical parameters of the system, a sideband-ratio approach for direct detection of mechanical drive-mode amplitude, modifying the AC and DC components of the amplitude gain control (AGC) for improved stability, and an approach for compensation of thermal drift in the sense-mode pick off system by utilizing mechanical quadrature. By using some or all of the four methods of calibration above, the highest level of long term in-run bias stability can be achieved.