Two types of micromachined vibratory gyroscopes

Abstract

Micromachined vibratory gyroscopes (MVG) can be classified into two broad types, angle gyroscopes (or Type I) and rate gyroscopes (or Type II). Gyroscopes of the first type measure orientation angles directly, while gyroscopes of the second type measure rotational rate. Most MVG implementations to date are found exclusively in the angular rate measuring variety. This paper introduces a unified approach for description of MVGs, discusses design challenges, and introduces designs and experimental results demonstrating MVGs of both types. We demonstrate that even though challenging, Type I devices can be implemented using conventional micromachining technologies. This type of micromachined devices is new, unexplored, and may potentially enable high performance micro-scale gyros. Low-grade Type II gyroscopes have been already commercially successful. We summarize our results on Type II wide-bandwidth gyro concept and demonstrate that inherent robustness against parameter variation can be effectively achieved structurally, shifting the complexity from the control electronics to the structural design of Type II MVGs