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A bio-inspired spider-like structure isolator for low-frequency vibration

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Applied Mathematics and Mechanics(English Edition) 2023年第8期44卷 1263-1286页

作者： Guangdong SUI Shuai hou Xiaofan ZHANG Xiaobiao SHAN Chengwei hou Henan SONG weijie hou Jianming LI State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China School of Astronautics Harbin Institute of TechnologyHarbin 150001China Yangtze River Delta HIT Robot Technology Research Institute Wuhu 241000Anhui ProvinceChina Tianjin Key Laboratory of Microgravity and Hypogravity Environment Simulation Technology Tianjin 300301China

This paper proposes a quasi-zero stiffness(QZS)isolator composed of a curved beam(as spider foot)and a linear spring(as spider muscle)inspired by the precise capturing ability of spiders in vibrating *** curved beam is simplified as an inclined horizontal spring,and a static analysis is carried out to explore the effects of different structural parameters on the stiffness performance of the QZS *** finite element simulation analysis verifies that the QZS isolator can significantly reduce the first-order natural frequency under the load in the QZS *** harmonic balance method(HBM)is used to explore the effects of the excitation amplitude,damping ratio,and stiffness coefficient on the system’s amplitude-frequency response and transmissibility performance,and the accuracy of the analytical results is verified by the fourth-order Runge-Kutta integral method(RK-4).The experimental data of the QZS isolator prototype are fitted to a ninth-degree polynomial,and the RK-4 can theoretically predict the experimental *** experimental results show that the QZS isolator has a lower initial isolation frequency and a wider isolation frequency bandwidth than the equivalent linear *** frequency sweep test of prototypes with different harmonic excitation amplitudes shows that the initial isolation frequency of the QZS isolator is 3 Hz,and it can isolate 90%of the excitation signal at 7 *** proposed biomimetic spider-like QZS isolator has high application prospects and can provide a reference for optimizing low-frequency or ultra-low-frequency isolators.

关键词： bionic isolation structure curved beam nonlinear stiffness quasi-zero stiffness(QzS) low-frequency vibration isolator

Gravity compensation method via magnetic quasi-zero stiffness combined with a quasi-zero deformation control strategy

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Science China(Technological Sciences) 2022年第8期65卷 1738-1748页

作者： Zhou Rui Zhou YiFan CHEN XueDong hou weijie WANG Chang WANG Hao JIANG Wei State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China Tianjin Key Laboratory of Microgravity and Hypogravity Environment Simulation Technology Tianjin Institute of Aerospace Mechanical and Electrical EquipmentTianjin 300301China Institute of Artificial Intelligence Huazhong University of Science and TechnologyWuhan 430074China

Gravity compensation refers to the creation of a constant supporting force to fully or partly counteract the gravitational force for ground verification to simulate the spacecraft dynamics in outer space with zero-or micro-gravity. Gravity compensation is usually implemented via a very low stiffness suspension/supporting unit, and a servo system in series is adopted to extend the simulation range to hundreds of millimeters. The error of suspension force can be up to tens of Newton due to the contact/friction in the suspension/supporting unit and the error of the force/pressure sensor. It has become a bottleneck for the ground verification of spacecraft guidance, navigation, and control systems with extreme requirements, such as tons of payload and fine thrust in sub-Newtons. In this article, a novel gravity compensation method characterized by quasi-zero stiffness plus quasi-zero deformation(QZS-QZD) is proposed. A magnetic negative stiffness spring in parallel with positive springs and aerostatic bearing is adopted to form a QZS supporting unit, and disturbance forces, such as contact or friction, can be eliminated. The deformation of the QZS supporting unit is measured via a displacement sensor, and the QZD control strategy is applied to guarantee the force error of gravity compensation to be less than sub-newtons and irrelevant to the payload. The principle of gravity compensation with QZS-QZD is analyzed, and performance tests on a prototype are carried out. The results show that when the spacecraft moves smoothly, the absolute force error is less than 0.5 N, the relative error of gravity compensation is less than 0.1%, and when collisions with other objects occur, the relative errors are 0.32% and 0.65%. The proposed method can significantly improve the gravity compensation accuracy in comparison with conventional approaches.

关键词： gravity compensation zero-gravity ground verification quasi-zero stiffness quasi-zero deformation

Communication simulation of on-board diagnosis network in high-speed Maglev trains

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Journal of Modern Transportation 2011年第4期19卷 240-246页

作者： Zhigang LIU Yunchang hou weijie FU School of Electrical Engineering Southwest Jiaotong University Chengdu 610031 China

The on-board diagnosis network is the nervous system of high-speed Maglev trains, connecting all controller sensors, and corresponding devices to realize the information acquisition and control. In order to study the on-board diagnosis network＇s security and reliability, a simulation model for the on-board diagnosis network of high-speed Maglev trains with the optimal network engineering tool （OPNET） was built to analyze the network＇s performance, such as response error and bit error rate on the network load, throughput, and node-state response. The simulation model was verified with an actual on-board diagnosis network structure. The results show that the model results obtained are in good agreement with actual system performance and can be used to achieve actual communication network optimization and control algorithms.

关键词： Maglev trains diagnosis network OPNET communication simulation

基于不同加工工艺的微孔节流空气静压轴承的特性研究

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机床与液压 2024年第7期52卷 123-128,133页

作者：于贺春寇新俊侯玮杰刘海腾李广平张国庆王文博中原工学院机电学院河南郑州450007 天津航天机电设备研究所天津300301 天津市微低重力环境模拟技术重点实验室天津300301

随着超精密加工技术和地面微低重力仿真的发展,相关产业对空气静压轴承的性能要求越来越高。由于传统的孔式节流器其结构特点不能完全满足实际使用的需要,节流孔直径与气膜间隙同一数量级的微孔节流空气静压轴承因其良好的刚度和承载特... 详细信息

随着超精密加工技术和地面微低重力仿真的发展,相关产业对空气静压轴承的性能要求越来越高。由于传统的孔式节流器其结构特点不能完全满足实际使用的需要,节流孔直径与气膜间隙同一数量级的微孔节流空气静压轴承因其良好的刚度和承载特性,越来越受到关注。但在微孔节流器的发展过程中,微孔的加工工艺却限制了其推广应用。针对目前常用的三类微孔加工工艺,进行了理论仿真研究,通过建立不同加工工艺轴承仿真模型,运用双向流固耦合仿真方法,对比分析了基于不同加工工艺的微孔节流空气静压轴承的动静态特性。研究结果表明:锥孔类轴承承载性能优于其他两类,但耗气量大且在小间隙时刚度较差;薄壁直孔类轴承承载性能稍逊,但在大间隙下轴承刚度较佳;嵌套类轴承承载性能较差,但在小间隙下轴承刚度较大且耗气量较低。

关键词：空气静压轴承超精密加工微低重力仿真微孔节流静动态特性

Quantum-Resistant Multi-Feature Attribute-Based Proxy Re-Encryption Scheme for Cloud Services

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工程与科学中的计算机建模(英文) 2024年第1期138卷 917-938页

作者： Jinqiu hou Changgen Peng weijie Tan Hongfa Ding State Key Laboratory of Public Big Data College of Computer Science and TechnologyGuizhou UniversityGuiyang550025China Key Laboratory of Advanced Manufacturing Technology Ministry of EducationGuizhou UniversityGuiyang550025China College of Information Guizhou University of Finance and EconomicsGuiyang550025China

Cloud-based services have powerful storage functions and can provide accurate ***,the question of how to guarantee cloud-based services access control and achieve data sharing security has always been a research *** the attribute-based proxy re-encryption(ABPRE)schemes based on number theory can solve this problem,it is still difficult to resist quantum attacks and have limited expression *** address these issues,we present a novel linear secret sharing schemes(LSSS)matrix-based ABPRE scheme with the fine-grained policy on the lattice in the ***,to detect the activities of illegal proxies,homomorphic signature(HS)technology is introduced to realize the verifiability of ***,the non-interactivity,unidirectionality,proxy transparency,multi-use,and anti-quantum attack characteristics of our system are all ***,it can efficiently prevent the loss of processing power brought on by repetitive authorisation and can enable precise and safe data sharing in the ***,under the standard model,the proposed learning with errors(LWE)-based scheme was proven to be IND-sCPA secure.

关键词： Lattice learning with errors attribute-based proxy re-encryption linear secret sharing schemes

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微低重力试验多孔青铜气浮转台研制

哈尔滨工业大学学报 2023年第1期55卷 82-88页

作者：张晓峰路阳侯玮杰王利桐李鹏谷金峰先进陶瓷与加工技术教育部重点实验室(天津大学) 天津300354 天津市微低重力环境模拟技术重点实验室天津300301

在微低重力环境模拟中,为降低涡流干扰力矩,设计了基于多孔青铜节流器的气浮转台系统。首先,在止推轴承选型中,对局部多孔质节流器和全多孔质节流器进行了对比分析,发现在气膜厚度20μm条件下,全多孔质节流器承载能力比局部多孔质节流器... 详细信息

在微低重力环境模拟中,为降低涡流干扰力矩,设计了基于多孔青铜节流器的气浮转台系统。首先,在止推轴承选型中,对局部多孔质节流器和全多孔质节流器进行了对比分析,发现在气膜厚度20μm条件下,全多孔质节流器承载能力比局部多孔质节流器高40%,因此设计选择全多孔节流器形式;然后,分析了在不同供气压力、不同材料渗透率下,气浮转台止推轴承及径向轴承的承载能力和刚度特性,发现选择较小的材料渗透率能够获得更高的气膜刚度,为气浮转台的结构设计提供了依据。最终研制的气浮转台采用开式止推轴承形式,节流器使用自研的多孔青铜材料,通过精密加工技术,使得加工前后的渗透率保持近似不变。试制成功的气浮转台回转精度小于0.8μm,150 kg负载下,未出现气锤自激振动现象。气浮转台系统的最大干扰力矩为9×10^(-4) m。该气浮转台系统不仅可用于微低重力试验,还可应用于超精密加工等领域。

关键词：多孔青铜多孔质节流器多孔质气体轴承气浮转台微低重力试验

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二体绳系卫星系统冲击效应动力学与试验研究

中国空间科学技术 2023年第1期43卷 53-62页

作者：段富成张慧博侯玮杰秦晓刚吴霞杨生胜河北工业大学机械工程学院天津300401 哈尔滨工程大学机电工程学院哈尔滨150001 天津市微低重力环境模拟技术重点实验室天津300301 真空技术与物理国家级重点实验室兰州730000

为了研究冲击效应对二体绳系卫星系统动力学特性的影响,开展了基于绝对节点坐标法的柔性绳索模型及绳系卫星系统运动特性分析研究。首先介绍了绝对节点坐标法柔索模型的建立过程,并进行了动力学仿真实验,在仿真时充分考虑了柔索的轴向... 详细信息

为了研究冲击效应对二体绳系卫星系统动力学特性的影响,开展了基于绝对节点坐标法的柔性绳索模型及绳系卫星系统运动特性分析研究。首先介绍了绝对节点坐标法柔索模型的建立过程,并进行了动力学仿真实验,在仿真时充分考虑了柔索的轴向刚度矩阵、弯曲刚度矩阵以及质量矩阵,可在不增加计算量的同时保留系绳真实特性。最后,搭建了三自由度的二体绳系卫星地面模拟试验系统,在规格为20 m×30 m的大型气浮平台上开展了试验验证,对末尾释放阶段和初始回收阶段系绳的张力以及子星的运动状态进行了分析。验证结果表明:地面模拟试验与仿真实验相比,系绳张力误差均在5%以内,验证了该建模方法的有效性和所搭建的试验系统的可靠性,同时为绳系卫星的未来发展和地面试验的进一步展开奠定了基础。

关键词：绝对节点坐标法绳系卫星动力学建模冲击效应试验验证

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心脏磁共振在心脏淀粉样变性中的应用进展

心血管病学进展 2023年第9期44卷 796-799页

作者：侯为洁龚艳君北京大学第一医院心内科北京100034

心脏淀粉样变性(CA)是指大量淀粉样纤维沉积于心肌细胞外间质,影响心脏结构与功能的一种严重疾病,随着病程进展,最终发展为严重的难治性心力衰竭。CA发病率低,目前诊断不足,且与肥厚型心肌病、高血压心脏病、主动脉瓣狭窄等引起心肌肥... 详细信息

心脏淀粉样变性(CA)是指大量淀粉样纤维沉积于心肌细胞外间质,影响心脏结构与功能的一种严重疾病,随着病程进展,最终发展为严重的难治性心力衰竭。CA发病率低,目前诊断不足,且与肥厚型心肌病、高血压心脏病、主动脉瓣狭窄等引起心肌肥厚的疾病难以鉴别。心脏磁共振具有无创、软组织分辨率高、无电离辐射等优势,其中心肌延迟强化、T1 mapping、细胞外间质容积、T2 mapping、心脏磁共振特征跟踪以及弥散张量成像在CA的临床诊断、疾病分层和预后评估中有重要作用。现就心脏磁共振在CA中的应用进展做一综述。

关键词：心脏磁共振心脏淀粉样变性心肌延迟强化 Native T1 细胞外间质容积 T2 mapping 心脏磁共振特征跟踪弥散张量成像

基于CiteSpace的大学与高中物理衔接研究的计量分析

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物理通报 2022年第10期51卷 15-18页

作者：陈善珂侯伟杰邵渭泉青岛大学物理科学学院山东青岛266000

通过CiteSpace软件对中国知网收录的294篇大学与高中物理衔接相关文献的作者、机构、关键词、研究热点等进行统计分析,揭示国内大学与高中物理衔接研究的研究现状与发展趋势,并通过文献分析得出结论:在新高考改革和新课标提出的背景下,... 详细信息

通过CiteSpace软件对中国知网收录的294篇大学与高中物理衔接相关文献的作者、机构、关键词、研究热点等进行统计分析,揭示国内大学与高中物理衔接研究的研究现状与发展趋势,并通过文献分析得出结论:在新高考改革和新课标提出的背景下,研究大学与高中物理衔接可以帮助高校教师解决物理教学中的难题,也可以对高中教师在教学实践中培养学生的核心素养提供帮助.

关键词：大学与高中物理衔接 CiteSpace 高考改革核心素养