Development of Starfish-Shaped Two-Ring Microelectromechanical Systems (MEMS) Vibratory Ring Gyroscope with C-Shaped Springs for Higher Sensitivity

Abstract

Microelectromechanical Systems (MEMS) vibratory gyroscopes are one of the integral inertial sensors of the inertial measurement unit (IMU). The usage of MEMS vibratory gyroscopes as inertial sensors has risen enormously in many applications, from household to automotive, smartphones to space applications, smart gadgets to military applications, and so on. This paper presents the mathematical modelling and initial development of the starfish structure with C-shaped springs for a MEMS vibratory ring gyroscope (VRG). The symmetric design methodology of VRGs corroborates higher sensitivity, mode matching, good thermal stability, better resolution, and shock resistance in extreme conditions. The proposed VRG has been designed and investigated using ANSYSTM software. This novel design incorporates a two-ring structure, with inner and outer rings, and with 16 C-shaped springs. The outer ring’s radius is 1000 μm and the whole VRG structure is supported by the outer eight small square pillars. The gyroscope structure’s wine-glass mode driving and sensing resonant frequencies were recorded at 51.50 kHz and 52.16 kHz. The mode mismatch between driving and sensing resonant frequency was measured at 0.66 kHz, which is relatively low compared to the other structures of vibratory gyroscopes. The proposed design provides high shock absorption with higher sensitivity for space applications for the control and manoeuvring of mini satellites for space applications.

Keywords

• MEMS
• starfish
• vibratory ring gyroscope
• mode matching
• space applications
• IMU