Lumped parameter analytic modeling and behavioral simulation of a 3-DOF MEMS gyro-accelerometer

Abstract

Anewanalyticalmodelofa3-degree-of-freedom (3-DOF) gyro-accelerometer system consisting of a 1-DOF drive and 2-DOF sense modes is presented. The model con- structs lumped differential equations associated with each DOF of the system by vector analysis. The coupled differen- tialequationsthusestablishedaresolvedanalyticallyfortheir responsesinboththetimeandfrequencydomains.Consider- ing these frequency response equations, novel device design conceptsarederivedbyforcingthesensephasetozero,which leadstoacertainrelationshipbetweenthestructuralfrequen- cies, thereby causing minimization of the damping effect on the performance of the system. Furthermore, the feasi- bility of the present gyro-accelerometer structure is studied using a unique discriminatory scheme for the detection of both gyro action and linear acceleration at their events. This scheme combines the formulated settled transient solution of the gyro-accelerometer with the processes of synchronous demodulation and filtration, which leads to the in-phase and quadrature components of the system's output signal. These two components can be utilized in the detection of angu- lar motion and linear acceleration. The obtained analytical results are validated by simulation in a MATLAB/Simulink environment, and it is found that the results are in excellent agreement with each other.