摘要: |
可展机构既可展开至指定构型用于工作,也可收拢以便于运输,在航天和建筑等领域具有广阔的应用前景。本文提出并设计了一种以Bennett过约束机构为基本组成单元的可展机构,该机构的工作形面可拟合柱面,且具有全部杆件可紧凑折叠成一束的收拢构型。对Bennett机构进行了几何描述,并分析其运动学特性;利用剪式机构实现了单元机构的组合连接,保证了设计关键点准确位于目标参数曲面上,计算了所设计的可展机构的展收比;对机构的运动学及动力学性能进行了仿真分析,验证了所提出的设计,为后续的样机研制提供了理论依据。验证结果表明:本文提出的Bennett过约束机构单元组合简单、形面拟合精度高、刚度大,能够很好地应用于该圆柱面天线的设计。该研究对航天可展机构的设计分析具有参考价值。 |
关键词: 可展机构 Bennett机构 柱面拟合 运动学分析 |
DOI:10.15982/j.issn.2095-7777.2017.04.005 |
分类号: |
基金项目:国家自然科学基金重点资助项目(51635002);青年科学基金资助项目(51605011) |
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Design and Analysis of Approximate Cylindrical Deployable Mechanism with Bennett Linkages |
YANG Jiaxin, LV Shengnan, DING Xilun
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School of Mechanical Engineering & Automation, Beihang University, Beijing 100081, China
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Abstract: |
Deployable mechanisms can be deployed to the designated configuration for work,and can also be folded for facilitating transportation. It has broad application prospects in space,architecture,and other fields. A deployable mechanism is presented, which uses the Bennett over-constraint mechanism as a basic element. Working surface of the mechanism can be fitted to cylindrical surface. Meanwhile,all bars of the mechanism can be compactly folded into a bundle configuration. Firstly,geometric description of the Bennett mechanism is analyzed,and its kinematic characteristics are discussed. Secondly,combination of unit mechanism is realized by using the scissors linkage,ensuring that the design key points are accurately located on the target surface. Finally,kinematics and dynamic performances of the mechanism are simulated, validating the proposed design and providing theoretical fundamental for the follow-up prototype development.The Bennett over-constraint mechanism in this paper is simple and have high precision and rigidity,which can be well applied to the cylindrical surface of the antenna design. This study is of great value to the design and analysis of aerospace deployable mechanism. |
Key words: deployable mechanism Bennett linkages cylindrical surface kinematics analysis simulation |