The Research And Design Of Micromachined Gyroscope With Full Decoupled

Micromachined gyroscopes are typical micro inertial sensors developed withMEMS(Micro-electro-mechanical System) technologies. They have received more andmore attention because of extensive prospects in the field of military equipments,industrial automation, entertainment devices and so on.Through the studies of error factors for current micromachined gyroscopes, this thesispresents a tuning fork micromachined gyroscope with full decoupled which was fabricatedby silicon bulk microprocessing technology. It works in the atmospheric environment. Inorder to achieve the full decoupling of drive and sense modes and maintain a highdetection sensitivity in such a bandwidth, it uses a symmetrical tunning fork structure. Ittakes the electromagnetic drive mode by comparing with other modes. Considering theamplitude of testing quality, damping coefficient, capacitance sensitivity and other factors,it selected the sense mode with changing combs’overlap length. The finite element modalof the micromachined gyroscope was analysed in the static case to study its verticaldisplacement in the natural state, anti-overload and decoupled performance.The micromachined gyroscope’s simplified dynamic modal was built based on theentity structure. It was used to discuss the relationship between the drive frequency, thesense frequency, the Q value, the driving force and the sensitivity and bandwidth. Theimpact of the elastic beam’s size parameters on the modal has been anaslysed by thestructural dynamic FEA method. It provided a theoretical basis’for design of such sensors.A special case which can realize the modes matching was selected for modal and harmonicresponse analysis. According to the micromachined gyroscope’s frequency responsecurves in damped or undamped condition, the inpact of air damping on the performancewas obtained, and the sustained dynamic characteristis could be predicted. Then the trendof capacitance sensitivity in different frequency difference and the overall performance ofmicromachined gyroscope was analysed by the way of comparing.The theories and results obtained in this thesis are very useful both in the theory andapplication for the research and design of tuning fork micromachined gyroscope with full decoupled. the method and thinking will be of great value to other kinds ofmicromachined gyroscope．...