Study On Key Technologies Of A Novel Fused Silica Micro Hemispherical Resonator Gyroscope

As the core device of inertial navigation system,micro hemispherical resonator gyroscope?MHRG?is one of the vibratory gyroscopes based on Coriolis effect of elastic wave,which has broad application in military and civil fields.The western countries have imposed strict embargo policies on this technology and product.Therefore,carrying on an independent research is the only choice for high performance MHRG in China.In order to achieve high performance for MHRG,it is necessary to have a high transduction efficiency and good manufacturability.Fused silica?FS?micro shell resonator is primarily miniaturized from the macroscopic hemispherical resonator.The radial electrodes and out-of-plane electrodes have been defined for the MHRG.At present,it is limited for the MHRG to have the above advantages simultaneously.A novel FS MHRG is proposed in this dissertation.Sensitivity amplification structures are designed along the shell edge for high transduction efficiency and sensitivity.The out-of-plane electrodes has a simple process and uniform capacitive gaps.This dissertation focuses on the structure design and fabrication of high precision FS MHRG,particularly for structural design and optimization,fabrication process and micro-assembly of MHRG.The main contents of this dissertation are as follows:1.The MHRG with sensitivity amplification structures is presented in this paper.The architecture of device with out-of-plane electrode is designed and compared with the reported MHRG.The dynamic model is derived based on Lagrange method.The principle of out-of-plane drive and detection,out-of-plane driving efficiency and detection efficiency,sensitivity and scale factor of MHRG are analyzed.The performance parameters of MHRG are demonstrated and the dominant factors for the improvement of performance are studied.2.The method of structure design and optimization based on PSO is proposed for the MHRG with sensitivity amplification structures.The parametrical model of micro shell resonator is built.Finite element method?FEM?is presented to analyze the dynamics performance of MHRG and the effects of dominant factors on Q-factor are studied.FEM is used to demonstrate the effect of structure parameters on the dynamic parameters.Finally,the structure design and optimization are performed based on the local version of particle swarm optimization.3.The process of micro blow torching with whirling platform and femtosecond ablation is presented to fabricate the MHRG with sensitivity amplification structures for high symmetry.The micro blow torching with whirling platform is creatively proposed for the fabrication of shell structure with high symmetry.Then the sensitivity amplification structures are released high efficiently and precisely with femtosecond laser ablation.The metallized resonator is bonded with out-of-plane electrodes by using the precision micro-assembly.The high vacuum package is performed for the MHRG based on metal packages.4.Fabrication imperfections of the MHRG with sensitivity amplification structures are analyzed and the electrostatic tuning using out-of-plane electrodes is presented to eliminate the frequency split.According to the sources of fabrication imperfection,the parametrical model of MHRG with fabrication imperfection is built and effect of fabrication imperfection on MHRG is analyzed.The electrostatic stiffness tuning is presented with out-of-plane electrodes based on the equivalent model of MHRG.FEM simulation and experiment are used to verify the frequency tuning theory.5.Performance testing is performed for the MHRG with sensitivity amplification structures.The MHRG is operated in force-rebalance mode,which demonstrates a scale factor?SF?of 0.107V/?°/s?with a full-scale range 200°/s,an angle random walk?ARW?of 0.099°/h^1/2,a bias instability of 0.46°/h and temperature coefficient of zero bias of6.19°/h/? without any temperature compensation.