Structure Design And Analysis Of An Anti Overload Dual-mass MEMS Gyroscope

Micromechanical gyroscope is a sensor which uses Coriolis effect to measure the external angular rate signal.It has the advantages of small size,low cost,low power consumption and high reliability.It is widely used in the field of positioning and navigation and military equipment.In recent years,as an inertial device of guided projectile,it will also be an important development direction.Because the launching overload of the guided projectile is very large,the adaptability requirement of anti high overload environment is put forward.In this paper,a dual-mass micromechanical gyroscope structure is designed,and its structural performance,mechanical properties and anti overload ability are analyzed and verified.The main research contents are as follows:（1）Based on the analysis of the working principle,overload impact principle and structure failure mechanism of the micromechanical gyroscope,the layout scheme of the double mass block anti overload structure is determined,and the structure design and parameter calculation of the elastic beam structure,mechanical coupling mechanism,drive detection mechanism and buffer stop anti overload mechanism of the micromechanical gyroscope are carried out.（2）The structural and mechanical properties of the designed dual mass micromechanical gyroscope are simulated and analyzed.The modal analysis shows that the frequency of the in-phase mode of the dual mass micromechanical gyroscope is higher than that of the reverse mode and separation is realized;the anti overload capacity of the structure in three directions is16800g,15200g,20000g through the anti overload performance analysis;and through the vibration characteristics analysis,gravity analysis and thermal analysis The structural performance and strength are verified by the solid coupling analysis.（3）The whole double mass micromechanical gyroscope is analyzed at the system level.The theoretical calculation of structure quality factor,sensitivity,bandwidth and thermo mechanical noise is carried out.The drive module,detection module,signal processing module and anti overload module with buffer stop mechanism are established.Through the modulation and demodulation of input signal,the conversion of angular rate to electrical signal is realized The total sensitivity of the double mass block micro gyroscope is 3.18×10^-4pF/（o/s）,and the anti overload performance meets the design requirements.（4）Finally,the process design is carried out,including process plan,process flow,lithography layout,as well as packaging plan and process,which provides conditions for the subsequent production of the prototype.The above research results can provide reference for the structural design,performance analysis and manufacturing of the micromachined gyroscope with shock resistance.