Design,Simulation And Optimization Of Doubly-decouped MEMS Gyroscope

Micro-electro-mechanical system(MEMS)gyroscope is a kind of sensor to measure the angular velocity or angular displacement.After decades of development,the performance of the MEMS gyroscope continues to improve and the system is gradually integrated through the advancement of device structure,processing circuit and control algorithm.2)From the two aspects of the dynamic equation and finite element analysis of the gyro,the thesis analyzes and simulates the frame gyro structure previously used by the research team and the double-coupled gyro structure of the new design.The double decoupling structure is obviously superior to the traditional frame gyro structure in suppressing the coupling displacement of the detection direction.The finite element simulation experiments show that the detection coupling displacement of the double decoupling structure is compared with the frame type when the working resonance frequency and the driving displacement are approximately equal.The gyro is reduced by approximately 36.67 times.At the same time,the driving and detecting beam structure of the double-decoupled gyro structure is optimized.The original low-frequency XY plane coupling mode(resonance frequency 5698.6Hz)is improved to work by the connection of the internal and external double anchor zone straight beam and the optimization of the coupling beam parameters.The resonant frequency is more than 10 times,and the Z-direction interference mode is also significantly optimized compared with the frame structure.The measured results of the double-decoupled gyro performance of the completed film have better zero-bias repeatability and noise characteristics compared with the frame type gyro.In addition,this thesis conducts static finite element analysis on the non-ideal decoupling performance of gyro and innovatively proposes a trapezoidal decoupling connection structure,which effectively reduces the rotational stress to the detection mass rotation.The effect of finite element analysis shows that this new structural design will suppress 71.3%of the rotation error.(c)Further,the structural design of a dual-mass tuning fork gyro is preliminarily studied,and in order to eliminate the low-order(low-frequency)non-working mode of-the micro-mechanical gyroscope,the adaptability and impact resistance of the micro-mechanical gyro environment The effect is to introduce the working mode optimization of the tuning fork double decoupling structure gyro by introducing a clever central anchor lever structure in the detection direction.The first mode of the optimized micromachined gyroscope is to drive the reverse working mode(6538.5Hz),the second mode is to detect the reverse working mode(6575Hz),the third mode is to drive the isotropic vibration mode(7749.8Hz),and the natural frequency difference from the closest detecting working mode is 1174.8Hz.The fourth-order vibration mode is the detection of the isotropic vibration mode(8813.1Hz),and the modal resonance frequency is significantly higher than that of the same mode(5914.5Hz)when the lever structure is not designed,making it much higher than The working mode frequency ensures that the lowest two-order mode of the gyro is the driving and detecting working mode,so that the gyro system is not interfered by the low frequency random vibration.3)A new orthogonal suppression electrode design scheme for the gate capacitance structure is proposed.Compared with the general comb-tooth structure orthogonal suppression electrode,the static stiffness is completely linear for the detection direction.At the same time,in order to further suppress the rotation error of the double decoupled gyro,this thesis innovatively proposes a new type of gate capacitance result rotation error suppression electrode,and conducts electricity-physics through the ANSYS multiphysics coupling simulation "Multi-physics" module.The field coupling simulation shows that the simulation results show that the suppression of the rotation error by approximately 14%can be achieved with a suitable voltage position setting of 4V.