Performance of a Silicon-on-Insulator MEMS gyroscope with digital force feedback

This paper presents development efforts and laboratory test data for a Silicon-on-Insulator (SOI) Micro Electro Mechanical System (MEMS) vibratory angular rate sensor intended for wide dynamic range and harsh environment applications, such as those experienced by hypervelocity and small diameter missiles and munitions. The SOI angular rate sensor (gyroscope), utilizes advantages offered from the mass and feature sizes achieved by Deep Reactive Ion Etching (DRIE). This particular effort focused on developing a symmetric device design, along with multi-bit sigma-delta force-feedback control, to increase dynamic range and reduce susceptibility to environmental parameters, including temperature, vibration, and sustained Z-axis acceleration loading. The rate sensing performance of these devices in both open-loop and closed-loop configurations has been characterized in the laboratory and a unit has been flight-tested on a prototype hypervelocity missile.