共查询到14条相似文献,搜索用时 46 毫秒
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柔索牵引并联机构的静刚度分析 总被引:5,自引:1,他引:5
对柔索牵引并联机构的静刚度进行分析,推导静刚度的一般理论计算公式。结果表明,柔索牵引并联机构的静刚度矩阵可分解为两项:k1是动平台位姿变化产生的静刚度,与索张力相关;k2是索的位形变化产生的静刚度。柔索牵引的完全约束定位机构(Completely restrained positioning mechanism,CRPM)或过约束定位机构(Redundantly restrained positioning mechanism,RRPM),其静刚度主要取决于k2,仅与索的弹性性能和索力作用的雅可比矩阵相关,而与索张力的大小无关。对于柔索牵引的欠约束定位机构(Incompletely restrained positioning mechanism,IRPM),由于柔索悬链线的影响,其静刚度不仅与索的弹性性能和雅可比矩阵相关,而且与索张力的大小有关。通过一平面3自由度RRPM的算例和代表IRPM的500m口径球面射电望远镜馈源悬索支撑系统的静刚度比较分析,证明了关于静刚度理论计算模型的有效性。 相似文献
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基于方位特征集设计理论,提出一种动平台能实现三平移动一转动并联机器人机构.根据方位特征方程分析机构的拓扑结构特性,通过杆长约束条件建立运动学方程模型并完成正逆解分析,根据雅可比矩阵确定了发生奇异位形的运动条件.进一步研究了机构的动平台操作空间形状与转动灵活性,同时,根据单一变量法分析结构参数对操作空间的影响,建立操作空间最大化优化模型,运用搜索速度快、全局搜索能力强的天牛须搜索算法进行了尺度优化.结果表明,该机构具有较大的、几何形状规则的工作空间,转动能力强.优化后的尺寸参数为该操作手的应用设计提供了理论依据. 相似文献
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具有力触觉反馈主从操作的检测装置是提升核主泵螺栓在线检测准确率、避免核辐射健康损害的有效手段.针对核主泵中空螺栓检测超声探头三平移一转动的深孔运动特征,基于方位特征集并联机构拓扑综合方法,构造了一种新型4-HSOC{-Ri1//Ri2(-P(4R))//Ri3⊥Ri4-}力触觉主端并联操作机构;以矢量方程法求解了该机构正逆运动学,并进行了工作空间、运动特性分析和仿真;对应从端深孔检测作业特征进行了工作空间匹配分析和实验验证.该主端力触觉并联机构具有对称折叠性和良好的动平台转动能力,适用于竖向深孔扫查作业,契合从端核主泵螺栓检测装置检测需求,为核主泵螺栓检测装置对孔、扫查任务及主从端运动匹配提供了理论基础. 相似文献
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大型射电望远镜悬索馈源支撑系统静刚度分析 总被引:1,自引:0,他引:1
针对大射电望远镜(LT)悬索支撑系统特殊的结构形式,对6索组成的馈源支撑系统的静刚度进行分析。首先,对舱索系统静平衡方程沿馈源舱运动方向上求导,同时考虑到悬索刚度随其应力变化而呈现几何非线性的特点,给出了馈源支撑系统静刚度的公式。其次,在上面结果的基础上,分析了一个定点位置下馈源舱在外界扰动下的振动情况,通过与大型射电望远镜50 m室外模型振动试验结果相比较,说明了静刚度求解方法的有效性。最后,给出了大型射电望远镜50m模型馈源舱运动空间边缘的悬索应力与馈源支撑系统刚度的关系。 相似文献
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柔索驱动并联机器人动力学建模与数值仿真 总被引:4,自引:0,他引:4
柔索驱动并联机器人采用柔索代替连杆作为驱动元件,并结合了并联机构和柔索驱动的优点。500 m口径大射电望远镜(Five-hundred meter aperture spherical radio telescope, FAST)粗调系统通过6根索长的协调变化使馈源舱作跟踪射电源的6自由度运动,其工作特点与并联机器人类似,因此可被看作柔索驱动并联机器人。基于此,根据FAST 5 m缩比试验模型,首先应用悬链线解析表达式推导出柔索两端固定时索端拉力与索长之间的关系,用于求解特定长度的驱动柔索对处于某一位姿的馈源舱的作用力。其次,对该舱索系统进行逆运动学分析,采用拉格朗日方程建立柔索驱动并联机器人的逆动力学模型。最后,针对FAST 5 m缩比模型的设计方案进行动力学仿真,数值结果表明该动力学建模是合理的。 相似文献
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Jin Zhenlin School of Mechanical Engineering Yanshan University Qinhuangdao ChinaGao Feng Hebei University of Technology 《机械工程学报(英文版)》2002,15(4):298-302
The unique design for a novel 6-SPS parallel 3-dimensional platform manipulator with an orthogonal configuration is investigated. The layout feature of the parallel manipulator is described. Its force/motion transmission capability evaluation criteria are presented. At the orthogonal configuration, the criteria and the relationships between the criteria and the link lengths are analyzed, which is important since it can provide designer a piece of valuable information about how to choose the linear actuators. From the analysis of the results it is shown that the force/motion transmission capabilities of the parallel manipulator are characterized by isotropy at the orthogonal configuration. The manipulator is particularly suitable for certain applications in 6-DOF micromanipulators and 6-axis force/moment transducers. 相似文献
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具有大位置空间的3自由度并联机构运动性能分析 总被引:5,自引:1,他引:4
提出一种具有较大位置空间的3自由度并联机构,该机构为Tricept机构的变异型,结构特点是将Tricept机构中的被动支链与三条主动支链之一相集成,且主动关节的三条轴线彼此垂直并汇交于一点。对机构的位置空间、运动灵活度及刚度特性进行分析,给出表征尺度参数改变与机构运动性能变化关系的图形描述。分析表明,对于不同的尺度参数组合以及较小的胡克铰、球铰的极限转角,机构动平台均可获得较大的位置空间;位置空间的中部区间占整个位置空间体积值较大,且在该区间内动平台具有较好的运动灵活度及刚度特性。给出的图形描述较全面地表征尺度参数与机构运动性能之间的关系,可用于机构性能的进一步分析与运动学设计。 相似文献
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DESIGN FEATURES OF A PARALLEL TESTING PLATFORM FOR SIMULATING KINEMATIC CHARACTERISTICS OF HIP JOINT
To simulate the movement of a human during daily activities, such as walking, running, squatting, and kneeling, a novel parallel hip joint simulator whose key movement component is a 3SPS + 1PS parallel manipulator with four degrees of freedom (DOF) was proposed. SPS denotes the spherical-prismatic-spherical leg, and PS denotes the prismatic-spherical leg where only the prismatic joint is actuated and hence underlined. Firstly, the formulae for solving the inverse kinematics of the 3SPS + 1PS parallel manipulator were derived based on the unit quaternion method. Then, the parallel hip joint simulator was designed and finally developed by means of constructing the mechanical module, control module, hydraulic loading module, and data transmission module. In addition, three linear actuators are driven by the scheduled inverse displacement trajectories to enable the moving platform to output rotations about the Z-, Y-, and X-axes for representing flexion/extension, abduction/adduction, and external/internal rotations of the human hip joint. Simultaneously, the hydraulic loading module represents the dynamic loading as described by ISO 14242 Part-1 acting on the hip joint during the kinematic experiment. The kinematic experiment and dynamic loading experiment show that the fitting curves of the experimental results are consistent with the designed movement and loading trajectories. All these illustrate that the developed 3SPS + 1PS parallel hip joint simulator with effective design of all modules can substantially represent the designed movement and loading trajectories. The developed hip joint simulator can provide more reliable tribology test data for artificial prosthesis of hip joint. 相似文献
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