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Six million Q factor micro fused silica shell resonator with teeth-like tines released by femtosecond laser-assisted chemical etching

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Science China(Technological Sciences) 2024年第6期67卷 1923-1932页

作者： ZHAO Tao SHI Yan LU Kun XI Xiang wu xuezhong XIAO DingBang College of Intelligence Science and Engineering National University of Defense TechnologyChangsha410073China

The quality factor(Q factor)is a crucial performance parameter for *** this paper,a novel release method for highquality micro fused silica shell resonators with teeth-like tines with good surface morphology is *** method is based on femtosecond laser-assisted chemical ***,the optimal energy range of femtosecond laser modification is obtained through mechanism ***,the optimal parameters for a straight line and arc pattern are determined by optimizing the average output power,processing speed,and processing *** results demonstrate why edge breakage in rounded corners is easy under different ***,according to these conclusions,the processing is performed on a micro fused silica shell resonator with a Q factor exceeding 6 *** addition,subsurface damage is rare throughout the fabrication process,and the surface roughness of the released cross section reaches the nanometer *** improved Q factor helps suppress mechanical thermal noise and reduce zero bias and zero bias drift,constituting the primary method for enhancing the performance of the resonant gyroscope.

关键词： micro hemispherical resonator fused silica laser-assisted chemical etching quality factor

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Removal of the rate table:MEMS gyrocompass with virtual maytagging

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Microsystems & Nanoengineering 2023年第6期9卷 175-184页

作者： Tongqiao Miao Qingsong Li Liangqian Chen Junjian Li Xiaoping Hu xuezhong wu Wenqi wu Dingbang Xiao College of Intelligence Science and Technology National University of Defense TechnologyChangsha 410073China

High-performance micro-electro-mechanical system(MEMS)gyrocompasses for north-finding systems have been very popular for *** this paper,a MEMS north-finding system(NFS)based on virtual maytagging(VM)is presented for the first *** stark contrast to previous schemes of MEMS-based NFSs(e.g.,carouseling,maytagging)and the abandoning rate table,we developed a honeycomb disk resonator gyroscope(HDRG)and two commercial accelerometers for azimuth *** of the physical rotation of the integrated turntable in traditional NFSs,the vibratory working modes of the HDRG are rotated periodically with electronic control to reduce the uncertainty in the *** systematically analyzing the principle of NFSs with VM,we designed tests to verify the practicability at the sensor level.A bias instability of 0.0078°/h can be obtained during one day with VM in an *** also implemented comparative north-finding experiments to further check our strategy at the system *** accuracy in the azimuth can reach 0.204°for 5 min at 28.2°latitude with VM and 0.172°with *** results show that without any mechanical turning parts,VM technology makes it possible to develop high-precision handheld MEMS NFSs.

关键词： NFS virtual system

Modeling and Analysis of Mechanical Quality Factor of the Resonator for Cylinder Vibratory Gyroscope

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Chinese Journal of Mechanical Engineering 2017年第1期30卷 180-189页

作者： XI Xiang wu xuezhong wu Yulie ZHANG Yongmeng College of Mechatronics Engineering and Automation National University of Defense TechnologyChangsha 410073China

Mechanical Quality factor（Q factor） of the resonator is an important parameter for the cylinder vibratory gyroscope（CVG）. Traditional analytical methods mainly focus on a partial energy loss during the vibration process of the CVG resonator, thus are not accurate for the mechanical Q factor prediction. Therefore an integrated model including air damping loss, surface defect loss, support loss, thermoelastic damping loss and internal friction loss is proposed to obtain the mechanical Q factor of the CVG resonator. Based on structural dynamics and energy dissipation analysis, the contribution of each energy loss to the total mechanical Q factor is quantificationally analyzed. For the resonator with radius ranging from 10 mm to 20 mm, its mechanical Q factor is mainly related to the support loss, thermoelastic damping loss and internal friction loss, which are fundamentally determined by the geometric sizes and material properties of the resonator. In addition, resonators made of alloy 3J53 （Ni42CrTiA1）, with different sizes, were experimentally fabricated to test the mechanical Q factor. The theoretical model is well verified by the experimental data, thus provides an effective theoretical method to design and predict the mechanical Q factor of the CVG resonator.

关键词： mechanical Quality factor cylinder vibratory gyroscope energy loss

Design and Characterization of a Novel Z-axis Quartz Cross-fork Micromachined Gyroscope

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Chinese Journal of Mechanical Engineering 2011年第1期24卷 50-57页

作者： XIE Liqiang wu xuezhong LI Shengyi WANG Haoxu TAO Yi DONG Peitao College of Mechatronics Engineering andAutomation National University of Defense Technology Changsha 410073 China Engineering Institute of Engineering Corps PLA University of Science and Technology Nanjing 210007 China wuhan Ordnance N. C. O. Academy Wuhan 430075 China

The existing researches on quartz gyroscope mainly focus on the structure design of the tuning fork, which aim at obtaining a better vibration characterization. However, the fabrication of complicated structure is a challenge for present processes, and the imperfect fabrication process seriously affects the performances of the sensors. In this paper, a novel quartz cross-fork structure micromachined gyroscope is proposed. The sensor has a simple structure in x-y plane of quartz crystal. Unlike other quartz gyroscopes, the proposed gyroscope is based on shear stress detection to sense Coriolis’ force rather than normal stress detection. This feature can simplify the sensing electrode patterns and miniaturize the structure easily. Then the mechanical analysis of the structure is discussed. In order to obtain high sensitivities and uniform characteristics between different structures, the sensing beam is designed to be tapered, and the taper should be appreciably greater than 1°. This scheme is validated by finite element analysis software. The dynamic characteristic of the structure is analyzed by lumped parameter model. The dynamic stress in the beam and the detection sensitivity are deduced to optimize the structure parameter of gyroscope. Finally, the gyroscope is fabricated by quartz anisotropic wet etching. The prototype is characterized as follows. The drive mode frequency is 13.38 kHz, and the quality factor is about 900 in air. The scale factor is 1.45 mV/（（°） s –1 ） and the nonlinearity is 3.6% in the dynamic range of ±200°/s. Process and test results show that the proposed quartz gyroscope can achieve a high performance at atmosphere pressure. The research can simplify the fabrication of the quartz gyroscope, and is taken as a novel method for the design of quartz gyroscope.

关键词： quartz gyroscope cross-fork dynamic analysis Coriolis’ force

Precision Balance Method for Cupped Wave Gyro Based on Cup-bottom Trimming

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Chinese Journal of Mechanical Engineering 2012年第1期25卷 63-70页

作者： TAO Yi XI Xiang XIAO Dingbang TAN Yingqi CUI Hongjuan wu xuezhong College of Mecha tronics Engineering and Automation National University of Defense TechnologyChangsha 410073China wuhan Ordnance N.C.O.Academy Wuhan 430075China Department of Mechatronics Engineering Zhuhai CollegeJilin UniversityZhuhai 519041China

The mechanical balance process is the key process to eliminate the quadrature error and improve the performance of the cupped wave gyro. The conventional mechanical balance method for cupped wave gyro based on cup-wall trimming requires high control accuracy of trimming quantity, which increases the production cost and decreases the fabrication efficiency in large extent. However, it is hard to reach the high balance accuracy with the natural frequency split of mHz grade by using the conventional method. In this paper, the lumped mass dynamic model of the cupped wave gyro is built by discretization method, and the effects of different position trimming on the natural frequency are analyzed. It is pointed out that trimming off a tiny quantity of material from cup-wall causes large variation of the natural frequency is the main reason for the low accuracy of the conventional mechanical balance method. Then, a precision balance method for cupped wave gyro based on cup-bottom trimming is presented and the entire procedures of this method are given. The static balance process and dynamic balance process of the precision balance method are simulated by the finite element software. The simulation result shows that the precision balance method based on cup-bottom trimming brings less additional natural frequency split in the static balance process, minimizes the natural frequency split to mHz grade and rectify the angle of mode offset to 0.1° grade in the dynamic balance process, furthermore, the method decreases the requirement for control accuracy of trimming quantity evidently. The research work provides references for structure optimization design and balance process plan of the cupped wave gyro.

关键词： cupped wave gyro precision balance trimming modal analysis natural frequency split

Model of NBTI combined with mobility degradation

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Journal of Semiconductors 2018年第12期39卷 141-146页

作者： xuezhong wu Chenyue Ma Shucheng Gao Xiangbin Li Fu Sun Lining Zhang Xinnan Lin The Shenzhen Key Lab of Advanced Electron Device and Integration ECE PKUSZ College of Electronic Science and Technology Shenzhen University

The mobility degradation induced by negative bias temperature instability(NBTI) is usually ignored in traditional NBTI modeling and simulation, resulting in overestimation of the circuit lifetime, especially after longterm operation. In this paper, the mobility degradation is modeled in combination with the universal NBTI *** coulomb scattering induced by interface states is revealed to be the dominant component responsible for mobility degradation. The proposed mobility degradation model fits the measured data well and provides an accurate solution for evaluating coupling of NBTI with HCI(hot carrier injection) and SHE(self-heating effect), which indicates that mobility degradation should be considered in long-term circuit aging simulation.

关键词： NBTI mobility degradation aging simulation algorithm hot carrier injection self-heating effect coupling

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光悬浮微粒子旋转特性研究

中国科学:技术科学 2023年第8期53卷 1351-1359页

作者：曾凯蒲俊吉吴宇列肖定邦吴学忠国防科技大学智能科学学院长沙410073

悬浮光机械系统将微粒子悬浮在空中,较好地隔绝了环境噪声,在诸多精密测量及量子科学领域都发挥着重要作用.利用圆偏振激光驱动微粒子自旋,可以进行扭矩测量、气体辨识及真空摩擦等方面的研究.本文基于光悬浮微粒子旋转动力学模型,搭建... 详细信息

悬浮光机械系统将微粒子悬浮在空中,较好地隔绝了环境噪声,在诸多精密测量及量子科学领域都发挥着重要作用.利用圆偏振激光驱动微粒子自旋,可以进行扭矩测量、气体辨识及真空摩擦等方面的研究.本文基于光悬浮微粒子旋转动力学模型,搭建了真空光悬浮及旋转实验装置,对悬浮粒子的平均转速和转速波动进行了研究.结果表明,影响光力矩的激光功率越强,激光偏振态越接近圆偏振光,粒子的平均转速则越大.但影响粒子平均转速的主要因素是阻尼力矩,通过降低环境气压以减小粒子的旋转阻尼,其平均转速可大幅提升.通过调控这些实验参数,约4μm直径的球霰石微球在环境气压为0.1 Pa时被驱动至3.93 MHz转速.但在低气压环境下,微粒子的热运动也变得明显,从而导致悬浮粒子的等效激光功率随着热运动而变化,进而使得粒子的转速波动也随着气压的下降而增大.本文首创性地对比了相同气压不同转速下的转速波动,进一步说明了粒子热运动对转速波动的影响规律.此外,本文还研究了不同气压下转速相对波动的变化规律,这为光悬浮转子在陀螺仪领域的潜在应用奠定了基础.这些研究结果对于提升光悬浮系统已有应用以及开拓新领域均有重要意义.

关键词：悬浮光机械系统光致旋转超快旋转转速稳定性

全角模式半球谐振陀螺的阻尼误差修调与补偿技术研究

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机械工程学报 2022年第16期58卷 145-152页

作者：张勇猛郭锞琛孙江坤余升肖定邦吴学忠国防科技大学智能科学学院长沙410073

半球谐振陀螺具有精度高、可靠性好、抗干扰能力强等诸多优点,是最具性能潜力的哥氏振动陀螺之一。工作在力平衡模式下的半球谐振陀螺虽然具有极高的检测精度,但其动态性能受到控制系统的限制,难以充分发挥半球谐振陀螺性能优势。而工... 详细信息

半球谐振陀螺具有精度高、可靠性好、抗干扰能力强等诸多优点,是最具性能潜力的哥氏振动陀螺之一。工作在力平衡模式下的半球谐振陀螺虽然具有极高的检测精度,但其动态性能受到控制系统的限制,难以充分发挥半球谐振陀螺性能优势。而工作在全角模式下的半球谐振陀螺兼具大量程和高动态范围,并且拥有稳定的标度因数,是未来发展的重点。然而,在全角模式下,高精度的半球谐振陀螺对其结构误差更为敏感,其加工过程中的结构不对称,尤其是阻尼不对称,将会对陀螺的测量精度产生严重影响。针对全角模式下阻尼误差的影响进行研究,提出全角模式下的谐振子阻尼修调方案,利用等效电阻尼降低了谐振子周向的阻尼不对称程度,并且设计了阻尼补偿方案,将陀螺阻尼误差引起的漂移由原先的0.0316°/s降低至了0.0051°/s,进一步提升了陀螺的测量精度。

关键词：全角模式半球谐振陀螺振动陀螺阻尼修调阻尼误差补偿

用超声衰减谱测量层状双金属氢氧化物粒度分布的方法

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高等学校化学学报 2024年第3期45卷 55-63页

作者：张明峰吴博侯光昊周蕾王学重北京石油化工学院新材料与化工学院恩泽生物质精细化工北京市重点实验室北京102617

层状双金属氢氧化物(LDHs)作为一种性能优良的非贵金属电催化剂,在提高析氧反应速率、降低制氢成本等方面具备巨大优势,其粒度大小直接影响催化活性位点的有效暴露面积和本征结构,很大程度上决定了LDHs电催化析氧反应的活性时间和催化效... 详细信息

层状双金属氢氧化物(LDHs)作为一种性能优良的非贵金属电催化剂,在提高析氧反应速率、降低制氢成本等方面具备巨大优势,其粒度大小直接影响催化活性位点的有效暴露面积和本征结构,很大程度上决定了LDHs电催化析氧反应的活性时间和催化效率.因此,实现对LDHs粒度分布的在线检测对LDHs的合成控制与活性提升具有重要意义.根据LDHs粒度小、形貌特殊的特点,本文建立了一种基于超声衰减谱在线测量其在悬浮体系中粒度分布(PSD)的方法,该方法在LDHs粒度表征领域的应用尚属首次.利用超声衰减谱法对LDHs悬浮体系粒度分布进行测量的最大难点是传统ECAH模型需要首先已知难以获得的体系分散相和连续相的物性参数.本文采用主成分分析(PCA)结合误差反向传播(BP)神经网络建立了预测模型,并引入遗传算法(GA)对模型进行优化,解决了超声衰减谱法的难点,通过CoFeAl-LDH悬浮体系进行了验证.结果表明,PCA-GA-BP神经网络能有效对LDHs在悬浮体系中的粒度分布进行在线预测,预测值与真实值的峰形重合度高,峰高偏差小,两者的均方误差MSE为0.1497,模型拟合优度R2=0.9768,说明该方法可作为在线测量LDHs粒度分布的有效方式.

关键词：层状双金属氢氧化物超声衰减谱粒度分布在线检测 BP神经网络遗传算法