Based On The Array Of Virtual Mems Gyro Technology

With the excellent features of small volume, low weight ,low price, long life-span and easiness for volume-production, microgyros based on MEMS have a wide application prospect. However, few of them can be used in ultra-precision fields because of their low performance. So it is significant to develop a new method to improve the performance of microgyros not only for the development of this technology but also for enforcing the influence of our country in this field.A virtual gyro system based on gyro array technique is proposed. In this system, performance of microgyros is improved effectively in two aspects. First a microgyro with high Quality Factor in atmospheric pressure is designed and fabricated;then several microgyros of this kind form a gyro array whose drifts are compensated by a specifically designed Kalman filter.The main contents in this thesis are described as follows:(1). The basic principle, classes and core parts of Coriolis vibratory microgyro are described;an integrated design schemes is proposed.(2). Based on MEMS Garden, a microgyro with symmetrical decoupled structure is designed. The air damping in driving mode and detecting mode are both slide film damping. Test result shows that this gyro has high Quality Factor in atmospheric pressure.(3). Stochastic error model of microgyros and Allan variance modeling scheme are studied. The problem of how to apply the results extracted by Allan variance modeling scheme directly to stochastic error model is solved.(4). An optimal filter for virtual gyro system is designed based on Kalman theory. This filter is implemented in Matlab/Simulink software. The drifts data of three microgyros which have a bias stability character of 35 deg/hr are used to validate the filter. Experiment results prove to be satisfactory. The bias stability decreases to 0.15 deg/hr, which means that the drift performance of the gyro array increases by 233 times.