新型大工作空间并联机构及其性能研究

【作者】 叶冬明；

【导师】 李开明；

【作者基本信息】 南京理工大学 ， 机械制造及其自动化， 2012， 硕士

【摘要】 为了并联机构顺利地应用于工作实际,设法使其向具有结构简单、工作空间大、控制容易等特点方向发展的相关研究越来越受到人们的关注本文用附加一个冗余滑动的方法构建一种新型三平动大工作空间并联机构。并开展构型优化、位置解析、奇异性、承载能力特性、刚度建模等相关研究。首先根据该型机构的组成和结构特点,利用矢量法建立机构的位置正解和反解方程以及速度雅可比矩阵,利用速度雅可比对机构的奇异性进行分析。其次在考虑伸缩杆伸缩范围、球铰链转角限制及杆件干涉等约束时,搜索出机构可达工作空间边界。并以工作空间体积为评价指标,分析机构基本参数对工作空间的影响,找出影响工作空间的敏感因素,对实现机构大工作空间进行详细论述。接着应用机构学理论求出机构的力雅可比矩阵,定义承载能力性能指标,描绘该指标在工作空间内的分布情况,分析机构的力承载能力特性,为机构应用提供指导。结合机构的雅可比矩阵,建立机构的整体刚度与单伸缩杆刚度模型。求得各向刚度在工作空间的分布情况。提出面平均刚度总体性能评价指标,并分析机构的结构参数对刚度的影响情况。为提高并联机构的性能,进行结构的改进提供理论依据。更多还原

【Abstract】 In order to make the parallel manipulators successfully apply in practical, the research which developed to simple structure, large workspace, easy control and other characters has been paid more and more attention.In this paper, we construct a new three translational parallel mechanism with large workspace by attaching a redundant sliding method. And carry out related researches about the configuration optimization, position analysis, singularity, bearing capacity, stiffness and so on.Firstly, according to this type of manipulator’s composition and structural characteristics, use the vector method to establish the forward and inverse solutions and velocity Jacobian matrix and analyze its singularity.Secondly, considering the constraint of the range of the adjustable stem, the limit of the spherical joint’s angle and the interference of the member, search the machine’s reachable workspace. Put forward the workspace volume as the evaluation index, analyze the basic parameters on the influence of workspace, find out the sensitive factors, and discuss how to realize the large workspace in detail.Finally, use the theory of mechanism to find out the Jacobian matrix of force, define the performance index of bearing capacity, depict the index’s distribution in the workspace, and analyze the capacity characteristic of force bearing. Combined the Jacobian matrix, establish the stiffness model of the whole body and the single adjustable stem. Seek the distribution of the stiffness in workspace. Present the overall performance evaluation index of the average stiffness, and analyze the manipulator’s structure parameters on the influence of the stiffness. Provide theoretical basis for improving the performance of the parallel manipulator and the structure.更多还原