Research On Error Characteristic Of Microminiature MEMS Gyroscope

MEMS gyroscope has the advantages of small size, low weight and high reliability. Its applications in both military and civil field are expanding. But limited by performance, MEMS gyroscope is mostly used in the field of medium-low precision navigation. The effective method for increasing available accuracy of MEMS gyroscope is error analysis, modeling and compensation, which is one of the research focuses currently. In this paper, error characteristic of MEMS gyroscope is researched.Building simulation model of MEMS gyroscope is the foundation of error characteristic research. The modeling grade is discussed. Advantages and disadvantages of four simulation models which included the ANSYS finite element analysis software model, the equivalent circuit model, the VHDL-AMS model and the SIMULINK model are comparatively analyzed. Four simulation models are established and the validity of these models is demonstrated by simulation.Based on the established model, the mechanical-thermal noise, temperature characteristic and quadrature error are researched. To resolve the problem that band-limited filter can not reduce the mechanical-thermal noise effectively, the mechanical-thermal noise is studied by correlation filter theory, and the followed simulation results show that correlation filter can decrease the effects of the mechanical-thermal noise effectively. In order to study the influence of temperature change on the performance of MEMS gyroscope, an analysis method combining ANSYS with SIMULINK is presented. The simulation of a micro quartz tuning fork gyroscope indicates the validity of the presented analysis method. The least square method and BP neural network are proposed to compensate gyro bias drift, and restrain gyro bias drift quite well. Quadrature error characteristic which are induced by mechanical coupling is researched by parameter averaging method, quantitative relation between quadrature error and structure parameters of MEMS gyroscope is drived, and a new avenue of researching quadrature error is provided.In order to further improve the ability of suppressing noise and environment interference, closed-loop detection system model is established, and the simulation comparison is made with open-loop detection system. The simulation results show that closed-loop detection system has better competence to suppress noise and environment interference, and its performance is superior to open-loop detection system.By the research on modeling, the mechanical-thermal noise, temperature characteristic and quadrature error, the mechanism of error characteristic is clarified, and the foundation is laid for more reasonable modeling and compensation. It is significant to improve performance of MEMS gyroscope for practical applications.