Research On Design Method And Control Technology Of Quadrature Frequency-modulated MEMS Vibratory Gyroscope

Microelectromechanical gyroscope is an indispensable part in the fields of navigation and guidance,intelligent robot,portable electronic equipment and so on,for its characteristics of low cost,small volume,low power consumption and easy portability.Compared with amplitude-modulated(AM)gyroscope,frequency-modulated(FM)gyroscope has the advantages of wider input range,better scale factor linearity and temperature stability.Because of its large capacitance area and adjustable electrodes,the multi-ring-disk structure has always been the research hotspot of MEMS gyroscope.On this basis,a radially pleated disk resonator is designed in this paper.The numerical analysis of the FM gyroscope,the frequency adjustment technology and the control system of quadrature frequency-modulated(QFM)gyroscope prototype are studied.The main contents are as follows:1.The FM gyroscope is modeled in detail,and the frequency output models under free vibration,open-loop operation and QFM operation are analyzed.Their dynamic equations are solved by slowly varying envelope approximation method.On this basis,in order to improve the temperature stability of orthogonal frequency output,Frequency differential operation is introduced.2.The radially pleated disk resonator is designed,and its mode simulation and parameter calculation are carried out by COMSOL and Matlab.The simulation and calculation results show that the Q of the radially pleated disk resonator is 3.66 times higher than that of the common multi-ring-disk resonator without changing the Coriolis coupling factor.3.A coupling model of frequency adjustment based on electrostatic rectification is established,and the coupling effect between off-axis tuning and in-axis tuning observed in experiment is explained.Under this guidance,the modal frequency difference of mode of the radially pleated disk resonator is adjusted from 10.88 Hz to less than5 m Hz.4.Based on the FPGA digital circuit,the control system of QFM gyroscope is designed,and the gyro prototype is built.The performance of the prototype with single QFM operation or double QFM differential operation is experimentally characterized and compared.