Analysis And Simulation Of Energy Dissipation Mechanisms In Si-based Resonant Gyroscopes

Si-based resonant gyroscope is an important inertial device for measuring angle or angular velocity of a moving body,with the feature of small size,low power consumption,high reliability,low-cost,etc.And has been widely used in consumer electronics,aerospace,etc.Quality factor is a core parameter of these devices,which directly determine the sensitivity and reliability,and will be directly influenced by ambient pressure,material thermal elastic and anchor structure.Related achievements have been reported while there is little report on the comprehensive study of dissipation mechanisms in gyroscopes.Owing to the background above,we take the wheel angular vibratory gyroscope as research object.The structure and modal analysis has been given and the mechanics characteristic has been studied.The damping mechanisms in angular vibratory gyroscope has been comprehensively analyzed based on sufficient study of the structure,focusing on air damping,thermolelastic damping(TED)and anchor loss.Slide damping model of drive mode is created based on Coutte-flow model and Stokes-flow model,while squeeze damping model of sense mode is created by solving the Reynolds equation through the finitedifference method,and the results is validated by comparing with the FEA results.The feature of TED and anchor loss has been researched and FEA results has been given.The influence of these three dissipation mechanisms on the structure has been fully studied under different conditions.Results shows that at room temperature(25?),air damping is the major mechanism in the ambient pressure more than 1Pa,while TED and anchor loss become the major mechanism,which will limit the quality factor.The analytical model and simulation method in this paper will provide a theoretical reference for further research of MEMS structure.