General Mobility Identification and Rectification of Watt Six-Bar Linkages

2007 ◽  
Author(s):  
Kwun-Lon Ting ◽  
Changyu Xue ◽  
Jun Wang ◽  
Kenneth R. Currie
Keyword(s):  
Linkage Analysis ◽  
Mobility Analysis ◽  
Computer Aided ◽  
Analysis And Synthesis ◽  
General Mobility

Mobility identification is a common problem encountered in linkage analysis and synthesis. Mobility of linkages refers to the problems concerning branch defect, full rotatability, singularities, and order of motion. By introducing the concept of stretch rotation, the paper shows the existence of a hidden five-bar loop in a Watt six-bar linkage and how it affects the formation of branches, sub-branches, as well as the whole mobility of the entire linkage. The paper presents the first methodology for a fully automated computer-aided complete mobility analysis of Watt six-bar linkages.

Mobility Identification of a Group of Single Degree-of-Freedom Eight-Bar Linkages

2010 ◽  
Author(s):  
Jun Wang ◽  
Kwun-Lon Ting
Keyword(s):  
Linkage Analysis ◽  
Range Of Motion ◽  
Configuration Space ◽  
Mobility Analysis ◽  
Joint Rotation ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Computer Aided ◽  
Analysis And Synthesis ◽  
First Time

This paper presents the first complete and automated mobility identification method for a group of single-DOF planar eight-bar linkages and thus represents a breakthrough on the recognition and understanding of complex linkage mobility. The mobility identification in this paper refers to the configuration space, the range of motion, and configuration recognition. It is a troublesome problem encountered in any linkage analysis and synthesis. The problem becomes extremely confusing with complex multiloop linkages. The proposed approach is simple and straightforward. It recognizes that the loop equations are the mathematical fundamentals for the formation of branches, sub-branches, and other mobility issues of the entire linkage. The mobility information is then extracted through the discriminant method. The paper presents complete answers to all typical mobility issues, offers the mathematical insight as well as explanation on the effects of multiple loops via joint rotation space, and casts light for treating the mobility problems of other complex linkages. The merits of the discriminant method for mobility identification are clarified and examples are employed to showcase the proposed method. The computer-aided automated mobility analysis of eight-bar linkages is made possible for the first time.

A Program for Computer Aided Energy Analysis and Synthesis

1981 ◽  
Vol 14 (2) ◽  
pp. 2875-2880
Author(s):  
T. Ohi ◽  
H. Itoh ◽  
K. Ono ◽  
K. Kokuryo ◽  
Y. Torita ◽  
...  
Keyword(s):  
Energy Analysis ◽  
Computer Aided ◽  
Analysis And Synthesis

Construction, Mobility Analysis and Synthesis of Polyhedra With Articulated Faces

2013 ◽  
Vol 6 (1) ◽  
Author(s):  
Thierry Laliberté ◽  
Clément Gosselin
Keyword(s):  
Physical Models ◽  
Single Type ◽  
Mobility Analysis ◽  
Analysis And Synthesis ◽  
Articulated Mechanisms ◽  
Mechanical Arrangement

The concept of polyhedra with articulated faces is investigated in this paper. Polyhedra with articulated faces can be described as polyhedral frameworks, whose faces are constrained to remain planar. A mechanical arrangement based on a single type of component is proposed for the construction of the polyhedra. Then, the determination of their infinitesimal and full-cycle mobility is addressed. In some cases, they are rigid structures while in others they are articulated mechanisms. Finally, examples are given, using simulation and physical models, and several new families of articulated polyhedra are synthesized.

Unified Mobility Identification and Rectification of Six-Bar Linkages

2009 ◽  
Author(s):  
Kwun-Lon Ting ◽  
Jun Wang ◽  
Changyu Xue
Keyword(s):  
Special Form ◽  
Simple Explanation ◽  
Input Output ◽  
Mobility Analysis ◽  
Joint Rotation ◽  
Input Condition ◽  
Computer Aided ◽  
Unified Method

This paper offers a unified method for a complete and unified treatment on the mobility identification and rectification of any planar and spherical six-bar linkages regardless the linkage type and the choice of the input, output, or fixed links. The method is based on how the joint rotation spaces of the four-bar loop and a five-bar loop in a Stephenson six-bar linkage interact each other. A Watt six-bar linkage is regarded as a special form of Stephenson six-bar linkage via the stretch and rotation of a four-bar loop. The paper offers simple explanation and geometric insights for the formation of branch (circuit), sub-branch, and order of motion of six-bar linkages. All typical mobility issues, including branch, sub-branch, and type of motion under any input condition can be identified and rectified with the proposed method. The method is suitable for automated computer-aided mobility identification. The applicability of the results to the mobility analysis of serially connected multiloop linkages is also discussed.

Mobility analysis and structural synthesis of a class of spatial mechanisms with coupling chains

Robotica ◽  
2015 ◽  
Vol 34 (11) ◽  
pp. 2467-2485 ◽  
Author(s):  
Wen-ao Cao ◽  
Huafeng Ding ◽  
Ziming Chen ◽  
Shipei Zhao
Keyword(s):  
Structural Analysis ◽  
Parallel Mechanisms ◽  
Mobility Analysis ◽  
Structural Synthesis ◽  
Systematic Method ◽  
General Methodology ◽  
Spatial Mechanisms ◽  
Analysis And Synthesis

SUMMARYThis paper presents a systematic method for dealing with mobility analysis and structural synthesis of a class of important spatial mechanisms with coupling chains, which involve more complex coupling relations than spatial parallel mechanisms. First, an approach to the establishment of the motion screw equation of the class of mechanisms is derived. Then, a general methodology for mobility analysis along with detection of rigid substructures is proposed based on the motion screw equation. Third, the principle of structural synthesis of the class of mechanisms is established on the basis of the method of mobility analysis. Finally, some novel spatial mechanisms with coupling chains are synthesized, illustrating the effectiveness of the method. The study of the paper will benefit structural analysis and synthesis of more complex spatial mechanisms with coupling chains.

scholarly journals Okkam - advanced morphological approach as method for computer aided innovation (CAI)

2019 ◽  
Vol 298 ◽  
pp. 00120 ◽  
Author(s):  
Dmitry Rakov
Keyword(s):  
High Performance ◽  
Solution Space ◽  
Engineering Systems ◽  
Performance Potential ◽  
Computer Aided ◽  
Morphological Approach ◽  
Analysis And Synthesis ◽  
Systems Requirements ◽  
Requirement Changes ◽  
Selection Of

This paper presents the use of Advanced Morphological Approach based for analysis, generation and synthesis of new engineering solutions as part CAI (computer-aided innovation). CAI is developing as a response to the higher demands of science and industry to the innovative level of new products. The developed approach and a software Okkam is to create a sequence of operations, comparison and selection of rational variants set by means of a series of successive procedures. The specifics of structural synthesis consist of the discreteness of variables, the presence of conditionally logical limitations and the need to work with multiple conflicting criteria. Key objective is to find a solution space with the potential to fulfil the top level engineering systems requirements. Usage of cluster analysis, set theory, set of rules allows to identify the clusters of innovative systems combining high performance potential with robustness regarding requirement changes and design uncertainties. Implementation of the approach is demonstrated by the example of the analysis and synthesis of communications devices. These studies verify the weighty potential of the pro-posed approach compared to present methods.

Full Rotatability of Stephenson Six-Bar and Geared Five-Bar Linkages

2008 ◽  
Author(s):  
Kwun-Lon Ting ◽  
Jun Wang ◽  
Changyu Xue ◽  
Kenneth R. Currie
Keyword(s):  
Linkage Analysis ◽  
Degree Of Freedom ◽  
Comprehensive Treatment ◽  
Joint Rotation ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Input And Output ◽  
Difficult Condition ◽  
Center Position ◽  
Analysis And Synthesis

Full rotatability identification is a problem frequently encountered in linkage analysis and synthesis. The full rotatability of a linkage is referred to a linkage in which the input may complete a full revolution without the possibility of encountering a dead center position. In a complex linkage, the input rotatability of each branch may be different. This paper presented a unified and comprehensive treatment for the full rotatability identification of six-bar and geared five-bar linkages disregard the choice of input and output joints or fixed link. A simple way to identify all dead center positions and the associated branches is discussed. Special attention and detail discussion is given to the more difficult condition with the input given through a link or joint not in the four-bar loop or on a gear-link. A branch without a dead center position has full rotatability. Using the concept of joint rotation space, the branch of each dead center position, and hence the branch without a dead center position can be identified easily. The proposed method is simple and conceptually straightforward and the process can be automated easily. It can be extended to any other single-degree-of-freedom complex linkages.

Full Rotatability and Singularity of Six-Bar and Geared Five-Bar Linkages

2010 ◽  
Vol 2 (1) ◽  
Author(s):  
Kwun-Lon Ting ◽  
Jun Wang ◽  
Changyu Xue ◽  
Kenneth R. Currie
Keyword(s):  
Linkage Analysis ◽  
Comprehensive Treatment ◽  
Not Given ◽  
Joint Rotation ◽  
Difficult Condition ◽  
Continuous Rotation ◽  
Center Position ◽  
Analysis And Synthesis

Full rotatability identification is a problem frequently encountered in linkage analysis and synthesis. The full rotatability of a linkage refers to a linkage, in which the input may complete a continuous rotation without the possibility of encountering a dead center position. In a complex linkage, the input rotatability of each branch may be different. This paper presents a unified and comprehensive treatment for the full rotatability identification of six-bar and geared five-bar linkages, regardless of the choice of input joints or reference link. A general way to identify all dead center positions and the associated branches is discussed. Special attention and detail discussion is given to the more difficult condition, in which the input is not given through a joint in the four-bar loop or to a gear link. A branch without a dead center position has full rotatability. Using the concept of joint rotation space, the branch of each dead center position, and hence, the branch without a dead center position can be identified. One may find the proposed method to be generally and conceptually straightforward. The treatment covers all linkage inversions.

The Spatial Linkage Analysis and Synthesis of the Vector Fitting Method

2012 ◽  
Vol 268-270 ◽  
pp. 1231-1238
Author(s):  
You Liang Xu
Keyword(s):  
Linkage Analysis ◽  
Unit Vector ◽  
New Method ◽  
Analysis And Design ◽  
Vector Fitting ◽  
The Core ◽  
Design Variables ◽  
Fitting Method ◽  
Analysis And Synthesis ◽  
Core Idea

Put forward a new method of spatial linkage analysis and synthesis of the vector fitting. The core idea is: all components available in mechanisms can be represent by one or one group of vectors, all vectors are transformed from unit vector, and the mechanism is a assemblage of those vectors. Because of kinematic variables (position, direction, changing when moving ) and design variables (shape, size, unchanging when moving ) is been properly separated which can improve the efficiency of analysis and calculation. The example shows that the method is efficient, and can be used both in the analysis and design of the mechanism.

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