The Study Of Automatic Type Synthesis Method Of Kinematic Chain

Automatic type synthesis of mechanism kinematic chain has been focus of many scholars, type synthesis method at present needs to be accompanied by a large number of isomorphism identification and detection of rigid sub chain. The isomorphism identification problem has not yet been proved to be P or NP, but in recent years due to the large number of efforts from the scholars of graph theory and mechanism, some scholars put forward some algorithms for isomorphism identification are effective. The rigid sub chain problems can be reduced to the subgraph isomorphism problem, is a problem of NPC, there is no polynomial time complexity algorithm for this problem, and compared with the isomorphism identification, the research of rigid sub chain detection algorithm has lagged behind other research isomorphism identification, resulting in kinematic chain type synthesis method is low efficient because of the rigid sub chain detection algorithm. Research on type synthesis chain therefore need pay more attention to the rigid sub chain problem.In this paper, a new description is given by reflecting loop informations of kinematic chain:prime product sequence, the sequence can not only reflect the loop vertex information but also the edge information. A new algorithm of a fast detection of rigid sub chain is based on combining the fundamental loops by some rules, and then generate a new data structure:stable configuration tree, traversing the tree, to detect the rigid sub chain. Improved the adjacency matrix using the primes represent vertex degree, weights, undirected edges, and directed edges of mixed graphs and then using dynamic modification of adjacency matrix for isomorphism identification,, and this algorithm can be used for isomorphism identification of mixed graphs.Finally, puts forward a new type synthesis method without rigid sub chain detection algorithm which can fill the gaps of the method of adding Assur group. This algorithm needs to convert the graph to a loop and some binary rods, detection of rigid sub chain, until all two rod superposition was completed, the complexity of the algorithm is polynomial. Some part of the one degree of freedom kinematic chain of 300 bars without rigid sub chain were given in the map. Developing the automatic type synthesis software by object oriented technology, and it will become a new for automatic type synthesis of mechanism kinematic chain.