共查询到18条相似文献,搜索用时 187 毫秒
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新型并联机床的力/运动传递各向同性性能及其分布 总被引:4,自引:1,他引:3
以并联机器人机构为原型的并联机床,其力/运动传递各向同性性能是随其运动平台的位姿变化而变化的。本文应用并联机器人机构学理论,提出基于6-SPS并联三维平台机构的新型6自由度并联机床的力/运动传递各向同性性能评价指标,并给出这些指标在定位姿工作空间内的分布情况,这对该结构形式的并联机床的设计及其任务规划和控制有重要意义。 相似文献
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以一种新型3-TPT三自由度并联机床为研究对象,建立了该机床的运动学正、反解方程,推导出了该机床的雅可比矩阵及其雅可比逆矩阵,并在此基础上运用Matlab软件对该机床的奇异性及平稳性进行了研究,计算出了该机床雅可比矩阵行列式的绝对值表达式,仿真出了该机床各驱动杆的伸缩速度变化曲线,研究结果表明:该机床具有运动平稳、不存在奇异形位等优点。该研究为并联机床结构最优化设计及性能分析提供了一定的理论依据。 相似文献
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提出了一种具有2个转动自由度的空间并联机构。一个垂直于定平台的沿Z方向的转动,另一个方向平行于定平台且方向随着机构的运动而不断变化。根据约束螺旋理论分析了该机构分支的运动螺旋和约束螺旋,并计算了自由度,对其输入原件选取的合理性进行了判断。用D-H法建立各分支连杆坐标系,建立机构的位置方程。 相似文献
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螺旋理论以其几何概念清楚,物理意义明确,表达形式简单等优势,常被用于分析机构的自由度。按照传统的G-K(Grubler-Kutzbach)公式,能较容易地计算出串联机构的自由度,而对于一些特殊机构,尤其是含有闭环子链的复杂并联机构,往往无法便捷、正确地求解其自由度。为解决以上问题,以一种拓扑结构为[3-R(4S)1-RUPU]+R型的Delta并联机器人为研究对象,对其4S闭环子链进行了等效运动副螺旋系的求解,并判别了机构的局部自由度以及公共约束;利用修正的G-K公式,分别对原机构和等效后的机构进行了自由度的验证。结果表明:两种情形下的自由度数均为4,且自由度的性质为3平移1旋转,与实际设计相符。 相似文献
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基于螺旋理论3-PSS并联机构运动特性分析 总被引:1,自引:0,他引:1
基于螺旋理论,分析了一种新的3-PSS并联机构的运动特性.首先将该机构的一个分支拆分成两个串联机构,分别建立了动平台的螺旋运动方程;接着根据结构特点,找到机构的运动约束关系;再根据反螺旋理论中的运动和约束力的关系,得出该机构始终受到三个线性无关的力偶约束力,最终从理论上证明3-PSS并联机构只能有三个平动自由度.结论极大地简化了该机构的其它特性分析,同时该方法对其它少自由度并联机构运动特性分析具有一定借鉴意义. 相似文献
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以三平动非对称冗余驱动(3-2SPS)并联机床机构为研究对象,并对该机构进行工作空间和运动学分析。建立该机构的位置反解模型,并得到带约束条件的位置反解运动方程,利用边界数值搜索法,确定并联机构的工作空间。采用Matlab曲线拟合[1]确定杆长变化与动平台运动位姿关系方程,以此分析冗余驱动滑块位于不同位置状态下,每个杆长的速度、加速度。研究结果为3-2SPS非对称冗余驱动并联机构的实际应用提供了理论依据。 相似文献
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文章提出了一种新的三自由度混联机床构型,基于Solidworks建立其三维实体模型.利用误差独立作用原理,建立了误差分析数学模型.通过矩阵分析方法结合运动学徽分方程,分析了并联机床静态误差,得到固定平台校链点位里误差、驱动杆长度误差与运动平台位里误差的映射关系,并对机构误差在工作空间内的分布规律进行了仿真,为混联机床的误差补偿提供了理论基础. 相似文献
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M. Geldart P. Webb H. Larsson M. Backstrom N. Gindy K. Rask 《International Journal of Machine Tools and Manufacture》2003,43(11):1107-1116
The current trend within the Tool and Die manufacturing sector is to machine components directly from hardened material using high speed 5-axis machining. This has been driven by the increasing requirements for cost competitiveness and lead-time reduction. Significant research effort has been applied to the optimisation of the process with factors such as tooling and machining strategies being considerably improved. However, the underlying structures of the machine tools used have remained unchanged and still consist of a serial kinematic chain. One of the standard justifications for the development of machines designed around parallel kinematic chains is that they should exhibit inherently greater stiffness, have higher axis accelerations and be capable of generating significantly higher cutting forces than conventional serial machines. This suggests that they should be ideally suited to the direct manufacture of tools and dies from hardened material.The comparison of different machine tool types is a complex and difficult process, particularly when their structures are fundamentally different. This paper describes an approach used to compare the performance of three very different types of machines. The technique uses two parameters; surface finish and geometric accuracy to assess the relative performance of different machine tools when cutting hardened material. The method is used to compare a serial kinematic 5-axis machining centre, a serial kinematic 3-axis machining centre and a parallel kinematic 6-axis machining centre.The results of the comparison are presented in this paper and show that all the machine tools performed to an equal standard for materials with a hardness of 54HRc but for very hard materials, 62HRc, the parallel kinematic machine out performed the serial machine tools. 相似文献
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对并联机床进行动态性能分析有着重要意义。应用工程分析软件,建立了一种三自由度并联机床整机的有限元模型,对整机进行了模态分析,提取了整机前十阶固有频率和振型。为了解各阶频率对机床动载荷的响应情况,在模态分析的基础上对整机进行了谐响应分析,得到了动平台、球铰、滑鞍等关键部位的频率位移响应曲线。分析结果表明,机床的第2阶和第4阶固有频率对机床动态性能影响最大。球铰结合部为机床结构中薄弱环节,由此提出了机床结构优化设计建议,将球形铰链更换为虎克铰链,从而提高了机床的动态性能。 相似文献
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To benefit from the advantages of parallel kinematic machines (PKM) in industrial applications an efficient kinematic calibration
is of particular importance. In this paper a new approach for kinematic calibration of PKM is presented that has been developed
and successfully tested on a hexapod at the IWM Dresden. The approach particularly respects the concept of simple design that
aims at a cost-effective and economic over-all solution. Aspects of calibration that are in many cases not explicitly accounted
for are considered. A simple and robust double-ball-bar (DBB) is used for data acquisition while continuously moving the platform
on a specific trajectory in 6 degrees of freedom (dof). The measuring trajectory is optimized to ensure the identifiability
of kinematic parameters, respecting their sensitivity and orthogonality in the workspace. Parameter identification is based
on Genetic algorithms with customized genetic operators as well as real and simulated measurements. A significant rise of
motion accuracy was obtained in the whole workspace.
We would like to thank the German Research Foundation (DFG) for their kind support. 相似文献
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