Sensitivity analysis of an in-plane MEMS vibratory gyroscope

This paper aims to put forward a detailed sensitivity analysis of an in-plane MEMS gyroscope with respect to various performance criteria that are very critical for use of the sensor in different applications ranging from platform stabilization to micro UAVs. Sensitivity analysis involves selecting key design parameters and critical performance criteria and studying the effect of variation of each design parameter on each of the performance criteria. The five key design parameters of the MEMS gyro are the drive stiffness k _d , sense stiffness k _s , drive mass m _d , sense mass m _s and the sense damping coefficient C _s . The four critical gyro performance criteria selected are scale factor, bandwidth, resolution and dynamic range. The influence of variations in different geometric dimensions of the structure on the design parameters of the gyro is also established. The critical geometric dimensions are identified that are then suitably modified allowing faster convergence of the design to meet the desired performance specifications. This study is relevant on two counts (1) the fine tuning of the design to meet all the desired performance criteria with minimum variation in geometric dimensions and with no change in the footprint of the sensor die and (2) the influence of geometric dimensional variations induced during the fabrication of the MEMS gyro structure.