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Novel method of constructing generalized Hoberman sphere mechanisms based on deployment axes

Xuemin SUN, Yan-An YAO, Ruiming LI

《机械工程前沿(英文)》 2020年 第15卷 第1期   页码 89-99 doi: 10.1007/s11465-019-0567-5

摘要: This study proposes a method of constructing type II generalized angulated elements (GAEs II) Hoberman sphere mechanisms on the basis of deployment axes that intersect at one point. First, the constraint conditions for inserting GAEs II into deployment axes to form a loop are given. The angle constraint conditions of the deployment axes are obtained through a series of linear equations. Second, the connection conditions of two GAEs II loops that share a common deployable center are discussed. Third, a flowchart of constructing the generalized Hoberman sphere mechanism on the basis of deployment axes is provided. Finally, four generalized Hoberman sphere mechanisms based on a fully enclosed regular hexahedron, arithmetic sequence axes, orthonormal arithmetic sequence axes, and spiral-like axes are constructed in accordance with the given arrangement of deployment axes that satisfy the constraint conditions to verify the feasibility of the proposed method.

关键词: deployable mechanism     type II generalized angulated elements     Hoberman sphere mechanism     deployment axes     constraint conditions    

Design and experiment of a novel pneumatic soft arm based on a deployable origami exoskeleton

《机械工程前沿(英文)》 2023年 第18卷 第4期 doi: 10.1007/s11465-023-0770-2

摘要: Soft arms have shown great application potential because of their flexibility and compliance in unstructured environments. However, soft arms made from soft materials exhibit limited cargo-loading capacity, which restricts their ability to manipulate objects. In this research, a novel soft arm was developed by coupling a rigid origami exoskeleton with soft airbags. The joint module of the soft arm was composed of a deployable origami exoskeleton and three soft airbags. The motion and load performance of the soft arm of the eight-joint module was tested. The developed soft arm withstood at least 5 kg of load during extension, contraction, and bending motions; exhibited bistable characteristics in both fully contracted and fully extended states; and achieved a bending angle of more than 240° and a contraction ratio of more than 300%. In addition, the high extension, contraction, bending, and torsional stiffnesses of the soft arm were experimentally demonstrated. A kinematic-based trajectory planning of the soft arm was performed to evaluate its error in repetitive motion. This work will provide new design ideas and methods for flexible manipulation applications of soft arms.

关键词: pneumatic soft arm     soft airbag     deployable origami exoskeleton     bistable characteristics     cargo-loading capacity    

基于Watt连杆的可重复使用运载火箭腿式可展开着陆机构——原理、原型设计和实验验证 Article

于海涛, 田保林, 闫振, 高海波, 张宏剑, 吴会强, 王英超, 石玉红, 邓宗全

《工程(英文)》 2023年 第20卷 第1期   页码 120-133 doi: 10.1016/j.eng.2022.05.015

摘要:

可重复使用运载火箭是降低太空运输成本的一种新途径。着陆机构是可重复使用运载火箭的重要组成部分,起到着陆支撑和吸收冲击的作用。本文提出了一种新型的可展开着陆机构(LDLM)。采用Watt-II型六杆机构,利用连杆变分法得到优选构型。本文建立了多目标优化范式,使得可展开着陆机构具有着陆支撑区域大、轻量化、连杆内力合理等优点,在此基础上,利用多目标遗传算法(NSGA-II)进化算法得到了可展开式着陆机构设计的最优尺寸参数。本文研制了全功能可重复使用运载火箭缩比样机,通过集成重力控制的展开方案促进展开动作,避免全范围驱动,采用双重锁紧机构提高展开状态时结构的可靠性,采用多级铝蜂窝缓冲器提供可靠的减震性能。实验结果表明,所提出的可展开式着陆机构能够提供快速平稳的展开(持续时间小于1.5 s),且对舱体的姿态扰动较小(偏航和俯仰波动小于6°)。此外,该机构在0.2 m自由落体测试中提供了足够的冲击衰减(加速度峰值小于10g)。所提出的可展开着陆机构可作为未来可重复使用运载火箭潜在的腿式起落架替代方案。

关键词: 可重复使用运载火箭(RLV)     可展开机构     优化设计    

Practical optimization of deployable and scissor-like structures using a fast GA method

M. SALAR, M. R. GHASEMI, B. DIZANGIAN

《结构与土木工程前沿(英文)》 2019年 第13卷 第3期   页码 557-568 doi: 10.1007/s11709-018-0497-z

摘要: This paper addresses practical sizing optimization of deployable and scissor-like structures from a new point of view. These structures have been recently highly regarded for beauty, lightweight, determine behavior, proper performance against lateral loads and the ability of been compactly packaged. At this time, there is a few studies done considering practical optimization of these structures. Loading considered here includes wind and gravity loads. In foldable scissor-like structures, connections have a complex behavior. For this reason, in this study, the authors used the ABAQUS commercial package as an analyzer in the optimization procedure. This made the obtained optimal solutions highly reliable from the point of view of applicability and construction requirements. Also, to do optimization task, a fast genetic algorithm method, which has been recently introduced by authors, was utilized. Optimization results show that despite less weight for aluminum models than steel models, aluminum deployable structures are not affordable because they need more material than steel structures and cause more environmental damage.

关键词: optimization     scissor-like structures     deployable structures     genetic algorithm     ABAQUS    

中国空间可展开结构——进展与趋势

马小飞, 李团结, 马静雅, 王治易, 史创, 郑士昆, 崔琦峰, 李潇, 刘凡, 郭宏伟, 刘立武, 王作为, 李洋

《工程(英文)》 2022年 第17卷 第10期   页码 207-219 doi: 10.1016/j.eng.2022.04.013

摘要:

可展开空间结构技术是一种实现航天器结构构型的方法,尤其是用于具有展开和折叠功能的空间结构。进入轨道后,空间结构从整流罩中释放、展开并定位。随着通信、遥感和导航卫星技术的发展,空间可展开结构已经成为空间科学和技术的前沿研究课题。本文总结了中国空间可展开结构的研究现状和发展趋势,包括:空间大型网状天线、空间太阳翼、深空探测用可展开结构等。从可展开机构设计、索膜结构找形方法、动力学分析、可靠性的环境适应性分析和验证等角度阐述了空间可展开结构的关键技术。最后,阐明了网状天线、太阳翼、可展开机构以及在轨调整、组装和建造等领域的未来技术发展和趋势。

关键词: 空间可展开结构,网状天线,太阳翼,深空探测    

“天问一号”火星探测中的大折展比形状记忆可展开子系统 Article

曾成均, 刘立武, 杜洋, 于淼, 辛晓洲, 刘天珍, 许培磊, 闫俣, 张豆, 戴雯煦, 兰鑫, 张风华, 王林林, 万雪, 边文凤, 刘彦菊, 冷劲松

《工程(英文)》 2023年 第28卷 第9期   页码 49-57 doi: 10.1016/j.eng.2023.01.005

摘要:

“天问一号”火星探测器在深冷的太空环境中经过七个月的飞行到达火星轨道后,迫切需要对其局部状态和周围环境进行监测。针对这一问题,我们开发了一种具有大折展比的形状记忆聚合物复合材料柔性可展开子系统(SMPC-FDS),其包含一个摄像头和两个温度遥测点,用于监测火星轨道器的局部状态和深空环境。在此,我们将报告 SMPC-FDS 的开发、测试和成功应用情况。在到达火星遥感轨道之前,SMPC-FDS 被设计为具有高刚度的折叠状态,在到达火星轨道之后,它处于具有大包络的展开状态。从折叠状态到展开状态的转换是通过电加热形状记忆聚合物复合材料(SMPC)实现的,在这一过程中,SMPC-FDS 上的摄像头可以从多个角度捕捉轨道器的局部状态。此外,在通电过程中,SMPC-FDS上的温度遥测点可提供环境温度和SMPC温度变化的反馈信息。通过模拟火星在轨环境,从材料性能、结构动力学性能、热真空展开可行性等方面全面验证了SMPC-FDS的工程可靠性。自2020年7月23日“天问一号”火星探测器发射以来,已成功地从SMPC-FDS上的遥测点获取了其周围温度环境的科学数据,并拍摄了轨道器在轨状态照片。

关键词: 空间可展开结构     形状记忆聚合物复合材料     火星探测     温度遥测     在轨展开    

Theory and method of mechanism system design

Huijun ZOU, Qinghua LIANG, Qing ZHANG

《机械工程前沿(英文)》 2010年 第5卷 第4期   页码 399-411 doi: 10.1007/s11465-010-0116-8

摘要: Conceptual design is the most critical and creative phase of design. Recently, increasing attention has been directed to supporting conceptual-level computer aided creative design and its theories and methodologies. Specifically, for conceptual design of mechanical products, this paper presents a novel function solving model for mechanical product design and highlights the importance of systematic synthesis to achieve creative design. Then it builds a framework as a function-effect-process-action- mechanisms (FEPAM) mapping process, which enables creative design on the basis of conceiving different action schemes. After that, several key points are elaborated including 1) representing and decomposition methods of functions and motion behaviors; 2) action scheme representing method based on network plan techniques; and 3) variation and creation methods based on action scheme transformations.

关键词: mechanism system creative design     process model     function solving model     process action procedure     mechanisms knowledge base     principle of mechanism system composition    

Formation mechanism and modeling of surface waviness in incremental sheet forming

《机械工程前沿(英文)》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0679-1

摘要: Improving and controlling surface quality has always been a challenge for incremental sheet forming (ISF), whereas the generation mechanism of waviness surface is still unknown, which impedes the widely application of ISF in the industrial field. In this paper, the formation mechanism and the prediction of waviness are both investigated through experiments, numerical simulation, and theoretical analysis. Based on a verified finite element model, the waviness topography is predicted numerically for the first time, and its generation is attributed to the residual bending deformation through deformation history analysis. For more efficient engineering application, a theoretical model for waviness height is proposed based on the generation mechanism, using a modified strain function considering deformation modes. This work is favorable for the perfection of formation mechanism and control of surface quality in ISF.

关键词: surface waviness     incremental sheet forming     numerical simulation     formation mechanism     deformation history    

Autogenous healing mechanism of cement-based materials

《结构与土木工程前沿(英文)》   页码 948-963 doi: 10.1007/s11709-023-0960-3

摘要: Autogenous self-healing is the innate and fundamental repair capability of cement-based materials for healing cracks. Many researchers have investigated factors that influence autogenous healing. However, systematic research on the autogenous healing mechanism of cement-based materials is lacking. The healing process mainly involves a chemical process, including further hydration of unhydrated cement and carbonation of calcium oxide and calcium hydroxide. Hence, the autogenous healing process is influenced by the material constituents of the cement composite and the ambient environment. In this study, different factors influencing the healing process of cement-based materials were investigated. Scanning electron microscopy and optical microscopy were used to examine the autogenous healing mechanism, and the maximum healing capacity was assessed. Furthermore, detailed theoretical analysis and quantitative detection of autogenous healing were conducted. This study provides a valuable reference for developing an improved healing technique for cement-based composites.

关键词: autogenous healing     cement-based materials     healing mechanism     aggregation effect    

Optimal design of a linkage–cam mechanism-based redundantly actuated parallel manipulator

《机械工程前沿(英文)》 2021年 第16卷 第3期   页码 451-467 doi: 10.1007/s11465-021-0634-6

摘要: A redundantly actuated parallel manipulator (RAPM) with mixed translational and rotational degrees of freedom (DOFs) is challenged for its dimensionally homogeneous Jacobian modeling and optimal design of architecture. In this paper, a means to achieve redundant actuation by adding kinematic constraints is introduced, which reduces the DOFs of the end-effector (EE). A generic dimensionally homogeneous Jacobian is developed for this type of RAPMs, which maps the generalized velocities of three points on the EE to the joint velocities. A new optimization algorithm derived from this dimensionally homogeneous Jacobian is proposed for the optimal design of this type of RAPMs. As an example, this paper presents a spatial RAPM involving linkages and cam mechanisms. This RAPM has 4 DOFs and 6 translational actuations. The linkage lengths and the position of the universal joints of the RAPM are optimized based on the dimensionally homogeneous Jacobian.

关键词: redundant actuation     parallel manipulator     linkage–cam mechanism     Jacobian     optimal design    

Cryogenic minimum quantity lubrication machining: from mechanism to application

《机械工程前沿(英文)》 2021年 第16卷 第4期   页码 649-697 doi: 10.1007/s11465-021-0654-2

摘要: Cutting fluid plays a cooling–lubrication role in the cutting of metal materials. However, the substantial usage of cutting fluid in traditional flood machining seriously pollutes the environment and threatens the health of workers. Environmental machining technologies, such as dry cutting, minimum quantity lubrication (MQL), and cryogenic cooling technology, have been used as substitute for flood machining. However, the insufficient cooling capacity of MQL with normal-temperature compressed gas and the lack of lubricating performance of cryogenic cooling technology limit their industrial application. The technical bottleneck of mechanical–thermal damage of difficult-to-cut materials in aerospace and other fields can be solved by combining cryogenic medium and MQL. The latest progress of cryogenic minimum quantity lubrication (CMQL) technology is reviewed in this paper, and the key scientific issues in the research achievements of CMQL are clarified. First, the application forms and process characteristics of CMQL devices in turning, milling, and grinding are systematically summarized from traditional settings to innovative design. Second, the cooling–lubrication mechanism of CMQL and its influence mechanism on material hardness, cutting force, tool wear, and workpiece surface quality in cutting are extensively revealed. The effects of CMQL are systematically analyzed based on its mechanism and application form. Results show that the application effect of CMQL is better than that of cryogenic technology or MQL alone. Finally, the prospect, which provides basis and support for engineering application and development of CMQL technology, is introduced considering the limitations of CMQL.

关键词: cryogenic minimum quantity lubrication (CMQL)     cryogenic medium     processing mode     device application     mechanism     application effect    

Review on mechanism and process of surface polishing using lasers

Arun KRISHNAN, Fengzhou FANG

《机械工程前沿(英文)》 2019年 第14卷 第3期   页码 299-319 doi: 10.1007/s11465-019-0535-0

摘要: Laser polishing is a technology of smoothening the surface of various materials with highly intense laser beams. When these beams impact on the material surface to be polished, the surface starts to be melted due to the high temperature. The melted material is then relocated from the ‘peaks to valleys’ under the multidirectional action of surface tension. By varying the process parameters such as beam intensity, energy density, spot diameter, and feed rate, different rates of surface roughness can be achieved. High precision polishing of surfaces can be done using laser process. Currently, laser polishing has extended its applications from photonics to molds as well as bio-medical sectors. Conventional polishing techniques have many drawbacks such as less capability of polishing freeform surfaces, environmental pollution, long processing time, and health hazards for the operators. Laser polishing on the other hand eliminates all the mentioned drawbacks and comes as a promising technology that can be relied for smoothening of initial topography of the surfaces irrespective of the complexity of the surface. Majority of the researchers performed laser polishing on materials such as steel, titanium, and its alloys because of its low cost and reliability. This article gives a detailed overview of the laser polishing mechanism by explaining various process parameters briefly to get a better understanding about the entire polishing process. The advantages and applications are also explained clearly to have a good knowledge about the importance of laser polishing in the future.

关键词: laser polishing     surface roughness     process parameters     mechanism    

Creation and integration mechanism of instrumentation flexible developing system

Xiaoli XU, Qiushuang LIU

《机械工程前沿(英文)》 2011年 第6卷 第2期   页码 235-240 doi: 10.1007/s11465-011-0122-5

摘要:

To solve many key technical problems during the development of modern instrumentation system integration and provide a new mode and fundamental technical equipment for the research and development (R&D) of modern instrumentation products, based on the concept of an instrumentation flexible developing system (IFDS), this paper discusses the creation and open flexible integration mechanism, perfects the integrated supporting environment and integrated system of the flexible interconnection, and constructs the new flexible integrated system. Based on the operation mechanism of the modern instrumentation developing system and the research and optimization of the rapid integration design method, the paper emphasizes the dynamic integrating method of multiple types of knowledge in a modern instrument R&D system, to effectively utilize the rich integrated resource and achieve rapid integration of the system. Applications show that the new IFDS can improve the integration level and efficiency of R&D of the modern instrumentation system, enforce the reliability of the system, shorten the R&D period, and reduce the development costs.

关键词: modern instrumentation developing     flexible interconnection     flexible integration mechanism     rapid integration system     dynamic integrating method    

Mechanism and characterization of microplastic aging process: A review

《环境科学与工程前沿(英文)》 2023年 第17卷 第8期 doi: 10.1007/s11783-023-1700-6

摘要:

● Methods for estimating the aging of environmental micro-plastics were highlighted.

关键词: Microplastics     Aging     Degradation     Characterization     Mechanism    

Design of a novel side-mounted leg mechanism with high flexibility for a multi-mission quadruped earth

《机械工程前沿(英文)》 2023年 第18卷 第2期 doi: 10.1007/s11465-022-0740-0

摘要: Earth rover is a class of emerging wheeled-leg robots for nature exploration. At present, few methods for these robots’ leg design utilize a side-mounted spatial parallel mechanism. Thus, this paper presents a complete design process of a novel 5-degree-of-freedom (5-DOF) hybrid leg mechanism for our quadruped earth rover BJTUBOT. First, a general approach is proposed for constructing the novel leg mechanism. Subsequently, by evaluating the basic locomotion task (LT) of the rover based on screw theory, we determine the desired motion characteristic of the side-mounted leg and carry out its two feasible configurations. With regard to the synthesis method of the parallel mechanism, a family of concise hybrid leg mechanisms using the 6-DOF limbs and an L1F1C limb (which can provide a constraint force and a couple) is designed. In verifying the motion characteristics of this kind of leg, we select a typical (3-UPRU&RRRR)&R mechanism and then analyze its kinematic model, singularities, velocity mapping, workspace, dexterity, statics, and kinetostatic performance. Furthermore, the virtual quadruped rover equipped with this innovative leg mechanism is built. Various basic and specific LTs of the rover are demonstrated by simulation, which indicates that the flexibility of the legs can help the rover achieve multitasking.

关键词: design synthesis     parallel mechanism     hybrid leg mechanism     screw theory     quadruped robot    

标题 作者 时间 类型 操作

Novel method of constructing generalized Hoberman sphere mechanisms based on deployment axes

Xuemin SUN, Yan-An YAO, Ruiming LI

期刊论文

Design and experiment of a novel pneumatic soft arm based on a deployable origami exoskeleton

期刊论文

基于Watt连杆的可重复使用运载火箭腿式可展开着陆机构——原理、原型设计和实验验证

于海涛, 田保林, 闫振, 高海波, 张宏剑, 吴会强, 王英超, 石玉红, 邓宗全

期刊论文

Practical optimization of deployable and scissor-like structures using a fast GA method

M. SALAR, M. R. GHASEMI, B. DIZANGIAN

期刊论文

中国空间可展开结构——进展与趋势

马小飞, 李团结, 马静雅, 王治易, 史创, 郑士昆, 崔琦峰, 李潇, 刘凡, 郭宏伟, 刘立武, 王作为, 李洋

期刊论文

“天问一号”火星探测中的大折展比形状记忆可展开子系统

曾成均, 刘立武, 杜洋, 于淼, 辛晓洲, 刘天珍, 许培磊, 闫俣, 张豆, 戴雯煦, 兰鑫, 张风华, 王林林, 万雪, 边文凤, 刘彦菊, 冷劲松

期刊论文

Theory and method of mechanism system design

Huijun ZOU, Qinghua LIANG, Qing ZHANG

期刊论文

Formation mechanism and modeling of surface waviness in incremental sheet forming

期刊论文

Autogenous healing mechanism of cement-based materials

期刊论文

Optimal design of a linkage–cam mechanism-based redundantly actuated parallel manipulator

期刊论文

Cryogenic minimum quantity lubrication machining: from mechanism to application

期刊论文

Review on mechanism and process of surface polishing using lasers

Arun KRISHNAN, Fengzhou FANG

期刊论文

Creation and integration mechanism of instrumentation flexible developing system

Xiaoli XU, Qiushuang LIU

期刊论文

Mechanism and characterization of microplastic aging process: A review

期刊论文

Design of a novel side-mounted leg mechanism with high flexibility for a multi-mission quadruped earth

期刊论文