【作者】 王雄；

【导师】 李圣怡；

【作者基本信息】 国防科学技术大学 ， 机械工程， 2012， 博士

【摘要】 摇摆质量微陀螺采用了轴对称的傅科摆结构和沿中性面对称的棒状振动质量结构，其驱动模态和检测模态为轴对称弹性体的正交降阶模式。该微陀螺具有工作模态固有频率相同（无需模态匹配）、惯性质量大、灵敏度高等突出优点，具有成为可批量生产的高性能微陀螺的潜质。国外摇摆质量微陀螺的研究得到长足发展，但对我国进行产品和技术封锁。因此，开展摇摆质量微陀螺技术研究，对我国高性能微陀螺技术研究具有重要的战略意义。国外对摇摆质量微陀螺技术的研究主要集中在谐振结构改善、加工工艺优化和测控方法创新等方面，很少涉及到其结构设计理论。本文设计了一款摇摆质量微陀螺，采用全差分的静电激励和电容检测的工作模式。利用MEMS加工技术、传统精密机械加工技术和高精度对准粘接技术完成微陀螺原理样机的制造。摇摆质量微陀螺制造工艺简单，成本低，具有批量生产的潜力。本文围绕摇摆质量微陀螺的结构设计理论、能量损耗机理、动态特性分析、MEMS加工工艺和原理样机验证开展研究，主要研究内容如下：1．设计了一种全差分摇摆质量微陀螺的总体结构，分析了微陀螺在工作模态谐振时的力学特性，提出一种计算微陀螺工作模态固有频率的数值方法和解析模型；建立了微陀螺接口电容、驱动力矩和反馈力矩等电学特性的理论模型；根据力学特性和电学特性的分析结果，获得了微陀螺工作模态固有频率的参数化解析模型，为微陀螺的结构设计提供理论依据。2．系统研究了摇摆质量微陀螺的能量损耗机理。分别推导了微陀螺各种能量损耗机理（Q值）的理论模型，其中包括空气压膜阻尼、支撑损耗、热弹性阻尼、基底能量损耗和表面能量损耗等。研究结果表明：大气条件下，空气压膜阻尼对微陀螺Q值的影响最显著，微陀螺必须进行真空封装；真空封装后，支撑损耗对微陀螺Q值的影响较大。为了提高微陀螺的Q值，必须尽可能地增大支撑结构与谐振结构之间的厚度比。3．研究了摇摆质量微陀螺的动态特性。推导了微陀螺哥氏力矩的理论模型，建立了微陀螺的动力学微分方程，分别获取了驱动系统和检测系统振动位移的稳态响应。根据Q值理论模型和稳态响应结果，求得了微陀螺结构灵敏度的解析模型。通过分析不同参数对结构灵敏度的影响机理，对微陀螺的谐振结构进行了优化设计，确定了微陀螺的结构参数。4．研究了摇摆质量微陀螺的加工工艺。根据微陀螺的结构特征，将其加工工艺分解为硅微结构、玻璃基板（含金属电极）、质量棒和支撑装置等四部分。分别研究了硅微结构、玻璃基板的MEMS加工工艺，设计了一种基于预埋掩膜各向异性湿法腐蚀为主的单晶硅加工工艺，并利用紫外激光划片工艺完成玻璃基板通孔的加工。优化了微陀螺的组装工艺，制作出微陀螺样机，并利用金属管壳焊接技术实现了微陀螺的真空封装。5．摇摆质量微陀螺样机的原理验证。研制了摇摆质量微陀螺专用的模态测试电路和信号测控电路，对微陀螺样机进行了模态测试和哥氏力信号测试。测试结果初步验证了本文所提出的微陀螺结构设计理论、能量损耗机理、动态特性、结构参数优化方法的正确性以及制造工艺的可行性。更多还原

【Abstract】 The Rocking Mass Micro-Gyroscope (RMG) adopts an axisymmetric Foucaultpendulum vibratory structure and a centrosymmetric rocking mass post, whoseoperational modes are the perpendicular degeneration modes of the axisymmetric elasticbody. RMG has some important advantages, such as equal natural frequency of theoperational modes without modes matching, large inertia mass, high sensitivity, andthus has the potential to be the high performance microgyroscope which can befabricated in batches. The study on RMG has been greatly developed abroad, but therelated products and technologies are forbidden by the western countries. Therefore,researching the RMG technologies to improve our microgyroscope technologies is ofgreat importance.The study on RMG technology abroad mainly focused on vibratory structureimproving, fabrication process optimizing, and control method innovating, hardlyinvolved its structure design theory. In this dissertation, we explore a novel rockingmass microgyroscope, which operates based on the method of entirely differentialelectrostatic force actuating and capacitance sensing. The prototype of RMG isfabricated by MEMS process, traditional precision mechanical machining and precisionadherence technologies. RMG has the advantages as simple fabrication process, highprecision, low cost, and also has the potential to be fabricated in batches.In this dissertation, we present the structure design theory, energy loss mechanism,dynamics analysis, MEMS fabrication process, and performance test of the micro-gyroscope. The main content includes:1. The differential whole structure of RMG is designed, the mechanics of itsvibratory structure are analyzed, and the natural frequency analytical model of itsoperational modes is deduced. The theoretical models of the microgyroscope’s interfacecapacitance, actuating momentum, and feedback momentum are also deduced. Based onthe analyzed mechanics and electrics results of the microgyroscope, the detailed naturalfrequency analytical model of its operational modes are derived to provide thetheoretical basis for its structure design.2. All the energy loss mechanisms of RMG are studied, and their theoretical modelof vibratory damping (Q-factors) are respectively deduced, including squeeze-film airdamping, support loss, thermoelastic damping, energy loss of the base, and surface loss.The squeeze-film air damping will badly restrain the Q-factors of the microgyroscope inatmospheric air, and the microgyroscope must be packaged in low vacuum. The supportloss will mainly affect the Q-factors of the microgyroscope in vacuum, and the ratio ofthe thickness between the support structure and the vibratory structure must be designedas larger as possible to improve its Q-factors. 3. The dynamic characteristic of RMG is studied. The Coriolis momentumtheoretical model of the microgyroscope are deduced, then the dynamic differentialequations are built, and the steady-state responses of the actuating mode and sensingmode are derived finally. The analytical model of the structural sensitivity of themicrogyroscope is derived, based on its Q-factor theoretical model and steady-stateresponse results. The whole structure of RMG is optimized, and the parameters of thevibratory structure are achieved, by analyzing the influences of different parameters onthe structural sensitivity.4. The fabrication process of RMG is studied. Based on the strucaturalcharacteristics of RMG, the fabrication process is divided into four parts, such as siliconstructure, Pyrex base (including metal electrodes), rocking mass post, and supportingpart. The MEMS fabrication processes of the silicon structure and Pyrex base arestudied respectively, a kind of single crystal silicon anisotropic wet etching processbased on pre-buried mask method is designed, and the hole in the center of the Pyrexbase is fabricated by using the UV laser dicing technology. The assembly process ofRMG is optimized, and then the prototype is fabricated and encapsulated in low vacuumby using metal tube welding technology. Finally, the operational modes of theprototypes in atmospheric air and in vacuum are characterized respectively.5. The RMG prototype is theoretically validated. The special mode test circuit andCoriolis siginal test circuit of RMG are designed and fabricated. The mode frequencyresponse curves and Coriolis signal of RMG prototype are tested. The tested resultsindicate that: the structure design theory, energy loss mechanism, dynamics theory,and structural parameter optimization method in this dissertation are valid; the MEMSfabrication processes are feasible.更多还原