Research On Type Synthesis Of Eight Planar Multiple Joint Assur Groups

With the research and application of various mechanism in the high-end equipment manufacturing industry more and more in-depth,low-level Assur group mechanism can not meet the needs of people for high-end machinery and equipment.Therefore,this dissertation takes the planar Assur groups with mult-joints as the research object,and conducts a comprehensive research on the Assur group type synthesis.This dissertation focuses on several key issues in type synthesis of planar Assur group with mult-joints,the comprehensive eigenvalue derivation of the number of Assur group,the topological expression of the Assur group and the isomorphism determination method,and the Assur group type synthesis.Through the analysis of the basic structure of the Assur group with mult-joints and the relationship between the structural parameters,the number synthesis formulas of the Assur group topological graph and contracted graph are derived,and the sequence of comprehensive eigenvalues of Assur group under 10-link is obtained by programming.The comprehensive results of the eight-link Assur groups with mult-joints number are listed in the dissertation.Expansion adjacency matrix of Assur group is constructed,which expresses the connection relationship between link-link and link to mult-joints,and the matrix is normalized according to the character of the matrix and the information contained,and the Assur group circuit information is obtained.Aiming at the isomorphism problem,a tree structure graph representing the Assur group is proposed,which consists of the root node,the layered node and the connecting line segment.On the basis of the tree structure graph of the Assur group,a node numerical arrangement rule is established,a node number sequence string is obtained,and the sequence is used as a criterion to perform isomorphism determination of the Assur group.The example proves that this method is not only suitable for the Assur group with mult-joints,but also for the isomorphic determination of the kinematic chain with mult-joints.The program design of Assur group isomorphism is realized,and the automatic identification of the structure with mult-joints is realized.Analyze the type of external kinematic pair in the contracted graph of the Assur group and its formation mode,and combine the comprehensive characteristic value sequence to synthesize the type of the Assur group;and further determine the connectivity of the contracted graph and the separability and isomorphism.The comprehensive results of the optimized Assur group of contracted graphs are obtained.Using the basic loop set theory,the rigid sub-chain identification method is used to discriminate the Assur group structure.According to the proposed binary member addition rule,the topological graph result of the 8-link Assur group with mult-joints is obtained.