Design and Analysis of Extremely Low-Noise MEMS Gyroscopes for Navigation

Abstract:

Inertial measurement sensors that include three gyroscopes and three accelerometers are key elements of inertial navigation systems. Miniaturization of these sensors is desirable to achieve low manufacturing cost, high durability, low weight, small size, and low energy consumption. However, there is a tradeoff between miniaturization of inertial sensors and their performance. Developing all the necessary components for navigation using inertial sensors in a small volume requires major redesign and innovation in these sensors.

The main goal of this research is to identify, analyze and optimize parameters that limit the performance of miniaturized inertial gyroscopes and provide comprehensive design guidelines for achieving multi-axis navigation-grade MEMS gyroscopes.

In this research, two different structures are considered for low-noise MEMS gyroscopes:
1) shell gyroscopes in yaw direction, and 2) a novel super sensitive stacked (S3) gyroscopes for pitch and roll directions.

Extensive analysis conducted throughout this research provided insight into ways to significantly improve gyroscopes design, structure, fabrication, and assembly and helped fabricate resonators with Qs as high as 10 million (the highest reported Q in MEMS resonators). Noise performance of gyroscopes based on these designs decreased by about two orders of magnitude, representing one of the best noise performances reported for a MEMS gyroscope.