Loop-Structure Decomposition of Kinematic Chains, Application to Rigid Sub-Chain Detection

2007 ◽  
Author(s):  
Huafeng Ding ◽  
Zhen Huang
Keyword(s):  
New Method ◽  
Loop Structure ◽  
Kinematic Chains ◽  
Structure Synthesis ◽  
Computer Aided ◽  
Structure Decomposition ◽  
Isomorphism Identification

Rigid sub-chain detection and isomorphism identification are two of the most difficult problems in the computer aided structure synthesis of kinematic chains. Based on the array representation of the loops of kinematic chains, this paper first introduces two operations of loops. Then a new theory of structure decomposition of kinematic chains is proposed on the basis of the concept of the independent loop set. After that a new method grounded on the theory is proposed for rigid sub-chain detection. Finally, the optimized algorithm for structure decomposition is presented and the corresponding program for rigid sub-chain detection is developed as well.

scholarly journals An Algorithm for Identifying the Isomorphism of Planar Multiple Joint and Gear Train Kinematic Chains

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Yanhuo Zou ◽  
Peng He
Keyword(s):  
Equivalent Circuit Model ◽  
Gear Train ◽  
Analysis Method ◽  
Kinematic Chains ◽  
Mathematical Algorithm ◽  
Structure Synthesis ◽  
Mathematical Problems ◽  
Node Voltage ◽  
Isomorphism Identification ◽  
Weighted Adjacency Matrix

Isomorphism identification of kinematic chains is one of the most important and challenging mathematical problems in the field of mechanism structure synthesis. In this paper, a new algorithm to identify the isomorphism of planar multiple joint and gear train kinematic chains has been presented. Firstly, the topological model (TM) and the corresponding weighted adjacency matrix (WAM) are introduced to describe the two types of kinematic chains, respectively. Then, the equivalent circuit model (ECM) of TM is established and solved by using circuit analysis method. The solved node voltage sequence (NVS) is used to determine the correspondence of vertices in two isomorphism identification kinematic chains, so an algorithm to identify two specific types of isomorphic kinematic chains has been obtained. Lastly, some typical examples are carried out to prove that it is an accurate, efficient, and easy mathematical algorithm to be realized by computer.

Computer-Aided Edge Loop Theory of Kinematic Structure of Mechanisms and Its Applications

2009 ◽  
Author(s):  
Huafeng Ding ◽  
Jing Zhao ◽  
Qinchuan Li ◽  
Zhen Huang
Keyword(s):  
Efficient Method ◽  
Kinematic Structure ◽  
Computation Complexity ◽  
Topological Graphs ◽  
Kinematic Chains ◽  
Loop Theory ◽  
Computer Aided ◽  
Structure Decomposition ◽  
Edge Based ◽  
Selection Of

Based on the edge-based array representation of loops in the topological graphs of kinematic chains, this paper first proposes three arithmetic operations of loops. Then the concept of the independent loop set as well as it determination rules is introduced, and a new structure decomposition algorithm of kinematic chains is presented. Based on the algorithm, an automatic and efficient method for rigid subchain detection and driving pair selection of kinematic chains is proposed. Finally, an index is proposed to assess computation complexity of kinematic analysis with respect to different driving pair selections.

Isomorphism Identification of Planar Kinematic Chains Based on Characteristic Arrays and Computation

2012 ◽  
Vol 201-202 ◽  
pp. 263-266
Author(s):  
Ye Qin Shen ◽  
Chuan Yu Wu ◽  
Shi Fu Xu ◽  
Lei Zhang
Keyword(s):  
Great Improvement ◽  
Visual Basic ◽  
New Method ◽  
Kinematic Chains ◽  
Isomorphism Identification

At present, the research of isomorphism identification of planar kinematic chains has reached a great improvement, however, most of the methods are proved so complex, inefficient as well as unreliable that the research is hindered and restricted a lot. At the same time, especially with the appearance of the planar kinematic chains with multiple joints, there is less research about the methods. Hence, in the paper, based on the method of kinematic chains with characteristic arrays, one method of isomorphism identification of kinematic chains with single joint as well as multiple joints is proposed presently. What is more, a software based on this new method proposed is developed with Visual Basic. In the end of the paper, an example is analysed in detail with hand computation and this software, through which the method is proved simple, efficient as well as reliable.

Research on Kinematic Chain Isomorphism Identification Method Based on the Standardization Adjacent Matrix

2010 ◽  
Vol 43 ◽  
pp. 514-518 ◽  
Author(s):  
Mao Zhong Ge ◽  
Jian Yun Xiang ◽  
Yong Kang Zhang
Keyword(s):  
Graph Theory ◽  
Kinematic Chain ◽  
New Method ◽  
Kinematic Chains ◽  
Identification Method ◽  
Isomorphism Identification

In order to solve a baffling problem of kinematic chain isomorphism identification, proceeded from the isomorphism’s principles of graph theory, a new method for detecting isomorphism among planar kinematic chains using the standardization adjacent matrix is presented in this paper. The general course of adjacent matrix standardization processing and numbering principle of node are introduced, the implementation of this new method is illustrated with an example, it is showed that this new method can be accurately and effectively performed.

Feature Edge Extraction Via Angle-Based Edge Collapsing and Recovery

2018 ◽  
Vol 18 (2) ◽  
Author(s):  
Soji Yamakawa ◽  
Kenji Shimada
Keyword(s):  
Adverse Effects ◽  
Computer Aided Design ◽  
Region Growing ◽  
New Method ◽  
Small Radius ◽  
Edge Extraction ◽  
Line Segments ◽  
Computer Aided ◽  
Downstream Processes ◽  
Aided Design

This paper presents a new method for extracting feature edges from computer-aided design (CAD)-generated triangulations. The major advantage of this method is that it tends to extract feature edges along the centroids of the fillets rather than along the edges where fillets are connected to nonfillet surfaces. Typical industrial models include very small-radius fillets between relatively large surfaces. While some of those fillets are necessary for certain types of analyses, many of them are irrelevant for many other types of applications. Narrow fillets are unnecessary details for those applications and cause numerous problems in the downstream processes. One solution to the small-radius fillet problem is to divide the fillets along the centroid and then merge each fragment of the fillet with nonfillet surfaces. The proposed method can find such fillet centroids and can substantially reduce the adverse effects of such small-radius fillets. The method takes a triangulated geometry as input and first simplifies the model so that small-radius, or “small,” fillets are collapsed into line segments. The simplification is based on the normal errors and therefore is scale-independent. It is particularly effective for a shape that is a mix of small and large features. Then, the method creates segmentation in the simplified geometry, which is then transformed back to the original shape while maintaining the segmentation information. The groups of triangles are expanded by applying a region-growing technique to cover all triangles. The feature edges are finally extracted along the boundaries between the groups of triangles.

scholarly journals A NEW METHOD FOR QUANTIFICATION OF REGENERATED BONE TISSUE ON X-RAY IMAGES OF ELONGATED BONES

2011 ◽  
Vol 22 (3) ◽  
pp. 183 ◽  
Author(s):  
Aneta Gądek ◽  
Leszek Wojnar ◽  
Maciej Tęsiorowski ◽  
Barbara Jasiewicz
Keyword(s):  
External Fixator ◽  
Theoretical Background ◽  
New Method ◽  
Ilizarov Method ◽  
Bone Lengthening ◽  
X Ray ◽  
Internal Part ◽  
Computer Aided Analysis ◽  
Computer Aided ◽  
The Moment

A new method for quantification of bone regenerate on the basis of computer-aided analysis of digitized Xray images is presented and its applicability in bone lengthening using Ilizarov method is demonstrated. In contrary to classical methods the internal part of the bone image is taken into consideration instead of the bone edges. Theoretical background of this concept is presented and experimentally verified. Experimental results show that the method proposed allows us for assessment of the bone regenerate, precise choice of the moment of external fixator removal as well as prediction of abnormalities in the osteogenesis process (excluding overall decalcification). However, the rules of interpretation of the results are not discussed in details.

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