共查询到19条相似文献,搜索用时 171 毫秒
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用邻接矩阵判断含复铰平面运动链同构和拓扑对称的新方法 总被引:3,自引:0,他引:3
提出了含复铰平面运动链同构和拓扑对称性判断的邻接矩阵方法。通过适当地定义运动链的邻接矩阵,在结构特征相同的情况下,比较两运动链邻接矩阵的结构,即可完成同构判断。通过邻接矩阵可得到构件或铰链点的广度优先生成树,比较生成树的结构特征,即可确定构件或铰链点的拓扑对称关系。研究表明,该方法具有简便、可靠、计算工作量小和便于用计算机处理等特点。 相似文献
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Manoj Kumar Lohumi Aas Mohammad Irshad Ahmad Khan 《Journal of Mechanical Science and Technology》2012,26(12):4041-4046
The problem of isomorphism among kinematic chains and their derived mechanism has been a hot area of research from last several years. The researchers so far have proposed many methods which are mainly based on characteristic polynomial and some code based methods to test the isomorphism among kinematic chains. In this present communication a hierarchical clustering based computerized method is proposed for the above said problem and it is tested for planar kinematic chains upto twelve links without any counter examples. In this method a hierarchical clustering algorithm is also developed for the identification of distinct mechanism derived from kinematic chains. In this method kinematic chains are represented in the form of weighted squared shortest path distance matrix and this matrix is further transformed in the form of tree or dendrogram with the help of hierarchical clustering algorithm. This algorithm directly gives the number of distinct mechanism derived from a given kinematic chain. The cophenetic correlation coefficient of dendrogram is used as an index for isomorphism identification among kinematic chains. The proposed method is efficient and accurate and only one matrix for a given kinematic chain is developed for the determination of distinct mechanisms. This method is successfully examined for one degree of freedom, 6, 8, 10, 12 links planar kinematic chains, 9 links two degree of freedom and 10 links three degree of freedom planar kinematic chains. The computer algorithm for the proposed method has been proposed which can easily be converted into a computer program. These results are useful for designers to detect isomorphism in mechanisms derived from kinematic chains and duplication among kinematic chains. 相似文献
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同构识别在机构类型综合中占有重要位置。本文在对含高副平面运动链分析的基础上,提出了含高副平面运动链支路码的概念,并提出了一种用计算机对含高副和不含高副的平面运动链均适用的同构识别方法。该方法不受运动链杆数和自由度数的限制,且速度快、计算量少。经大量实例计算,该方法行之有效 相似文献
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用拓扑特性矩阵辨识运动链的同构体及机架变换研究 总被引:3,自引:4,他引:3
基于运动链的基本环路及环路中构件、运动副的互相连接关系,建立了描述平面和空间运动链及机构的拓扑特性矩阵,对平面、空间运动链及机构的同构体辨识问题进行了研究。由于拓扑特性矩阵较常用于同构体辨识的邻接矩阵、关联矩阵等矩阵的元素少,而且可以通过比较拓扑特性矩阵的对应行列的元素直接进行同构体的辨识,因此,应用拓扑特性矩阵辨识同构体是更简便和高效的。给出了应用拓扑特性矩阵辨识同构体的方法、步骤及流程图,并给出了较典型的辨识例子(包括空间运动链),证明了该方法的正确性和高效性。同时还应用拓扑特性矩阵对运动链的机架变换问题进行了研究。 相似文献
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利用邻接矩阵的幂序列进行运动链和机构的同构判定 总被引:4,自引:1,他引:3
从同构的图论意义出发,提出了一个新的运动链结构不变量,进而提出了利用邻接矩阵的幂序列进行运动链同构判定的方法。它与现有的其他方法相比,具有直观、简便和显明图论依据的特点,且该方法不仅可以实现运动链的同构判定,而且可以成功地判定一般图的同构。在此基础上,本文最后给出了从同一运动链中识别出不同机构的两个方法。 相似文献
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SONG Li HUANG Yong CHENG Ling Department of Mechanical Engineering Xiangtan University Xiangtan China 《机械工程学报(英文版)》2006,(4)
The adjacent matrix method for identifying isomorphism to planar kinematic chain with multiple joints and higher pairs is presented. The topological invariants of the planar kinematic chain can be calculated and compared by adjacent matrix. The quantity of calculation can be reduced effectively using the several divisions of bars and the reconfiguration of the adjacent matrix. As two structural characteristics of adjacent matrix, the number of division and division code are presented. It can be identified that two kinematic chains are isomorphic or not by comparing the structural characteristics of their adjacent matrixes using a method called matching row-to-row. This method may be applied to the planar linkage chain too. So, the methods of identifying isomorphism are unified in the planar kinematic chain that has or hasn't higher pairs with or without multiple joints. And it has some characters such as visual, simple and convenient for processing by computer, and so on. 相似文献
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STUDYONISOMORPHISMOFPLANARKINEMATICCHAINSSTUDYONISOMORPHISMOFPLANARKINEMATICCHAINSLiWenhui;ZouHuijun;CaoZhikui(ShanghaiJiaoto... 相似文献
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针对目前空间机构结构描述和分析方法存在的不足,提出了基于约束函数和邻接矩阵的新方法。根据空间机构运动副的约束特征,定义了向量形式的空间机构运动副特征参数——约束函数及以约束函数为元素的空间机构特征参数矩阵——运动链邻接矩阵;分析了约束函数的性质;运用运动副约束函数和运动链邻接矩阵对空间机构的拓扑结构进行了描述和分析。结果表明,运动副约束函数适用于包括变拓扑结构的各类运动副,能综合描述运动副类型、级别、自由度、方位、性质等信息及其变化的情况;运动链邻接矩阵适用于各类机构的非瞬时描述与分析,能广泛描述运动链的构件数、运动副数目、类型、级别、方位、性质、机构类别、自由度、空间布局等诸多信息;示例证明了约束函数和邻接矩阵描述分析空间机构的直观性、有效性和简便性。基于约束函数和邻接矩阵的解决方案为空间机构的描述和分析提供了一种新的途径和方法。 相似文献