Gyroscopes, which measure rotational rate or angle, are widely used in applications ranging widely from navigation and vehicle stabilization to applications in consumer electronics, such as image stabilization and gaming. Due to their small size, cost, weight, and power consumption, MEMS gyroscopes in particular have expanded the boundaries of gyroscope technology, enabling many of the current applications which would be impossible or prohibitively expensive with macro-scale gyroscopes.
However, despite their many advantages, MEMS gyroscopes suffer from high short-term noise and long-term offset drift compared to their macro-scale counterparts. Research in the past decade has managed to improve the performance of MEMS gyroscopes by several orders of magnitude, so that high-end MEMS gyroscopes are beginning to compete with lower-end macro-scale gyroscopes.
However, due to industry pressure to incorporate increasing numbers of sensors on the same die while maintaining low prices, the die size allocated to gyroscopes is steadily decreasing. The challenge is to maintain the performance increase seen over the past years despite decreasing die size. One approach to achieving these seemingly contradictory goals is to take advantage of high resonator quality factor (Q), mode-matched operation, and large drive displacement to improve performance despite small resonator volume. This necessitates, however, a thorough understanding of several nonlinear effects which arise through the combination of high Q, mode-matched operation, and large drive displacement
This dissertation describes the design of a small-volume, high-Q disk resonator gyroscope (DRG) and two nonlinearities (cubic and parametric) which emerge at large drive displacements.The implications for both rate and rate-integrating modes of operationare discussed.
September 30, 2015
Nitzan, S. H. (2015). Nonlinear Effects in High-Q Disk Resonator Gyroscopes. United States: University of California, Davis.