Branch Identification of Geared Five-Bar Chains

1996 ◽  
Vol 118 (3) ◽  
pp. 384-389 ◽  
Author(s):  
Xiaohong Dou ◽  
Kwun-Long Ting
Keyword(s):  
Synthesis Problem ◽  
Input Condition ◽  
Computer Aided ◽  
Position Synthesis ◽  
Linkage Synthesis

This paper presents the method to identify the rotatability and branch condition in linkages containing simple geared five-bar chains. The method is subsequently extended to identify the existence of dead positions. When used in the computer aided linkage synthesis, the algorithm may effectively reduce the complexity of the finite position synthesis of geared five-bar linkages to the level similar to that of four-bar linkages. The algorithm is effective for any linkage inversion, any type of synthesis problem, any input condition, and any number of discrete positions. The method can be generalized to other serially connected multiloop linkages.

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.

Kinematic Mapping Based Evaluation of Assembly Modes for Planar Four-Bar Synthesis

2005 ◽  
Author(s):  
Hans-Peter Schro¨cker ◽  
Manfred L. Husty ◽  
J. Michael McCarthy
Keyword(s):  
Image Space ◽  
Synthesis Problem ◽  
New Method ◽  
Kinematic Mapping ◽  
Position Synthesis ◽  
Four Bar Linkage

This paper presents a new method to determine if two task positions used to design a four-bar linkage lie on separate circuits of a coupler curve, known as a “branch defect.” The approach uses the image space of a kinematic mapping to provide a geometric environment for both the synthesis and analysis of four-bar linkages. In contrast to current methods of solution rectification, this approach guides the modification of the specified task positions, which means it can be used for the complete five position synthesis problem.

Four-Bar Linkage Synthesis Methods for Two Precision Positions Combined With N Quasi-Positions

1995 ◽  
Author(s):  
John A. Mirth
Keyword(s):  
Synthesis Method ◽  
Synthesis Methods ◽  
Bounded Motion ◽  
Transmission Angle ◽  
Pass Through ◽  
Position Synthesis ◽  
Four Bar Linkage ◽  
Exact Positions ◽  
Linkage Synthesis

Abstract Mechanisms seldom need to pass through more than one or two exact positions. The method of quasi-position synthesis combines a number of approximate or “quasi” positions with two exact positions to design four-bar linkages that will produce a specified, bounded motion. Quasi-position synthesis allows for the optimization of some linkage characteristic (such as link lengths or transmission angles) by using the three variables that describe a single quasi-position. Procedures for circuit and transmission angle rectification are also easily incorporated into the quasi-position synthesis method.

Mobility of Stephenson Six-Bar Chains: Part I — Circuit and Circuit Defect

2004 ◽  
Author(s):  
Xiao-Ning Guo ◽  
Jin-Kui Chu
Keyword(s):  
Theoretical Basis ◽  
Difficult Problem ◽  
Computer Aided ◽  
Scheme Selection ◽  
Selection Of ◽  
Linkage Synthesis

Circuit defect is a fundamental and difficult problem in the process of linkage synthesis. In this paper, a Stephenson six-bar chain can be regarded as combination of a four-bar chain and a dyad. Base on the distance of two common joints shared by the four-bar chain and the dyad, the principle is elucidated and the model is established for circuit identification of Stephenson six-bar chains. The criteria and procedures to automatically identify the circuit and circuit defect of Stephenson six-bar chains are developed. The results provide theoretical basis and technical method for computer aided dimensional scheme selection of Stephenson six-bar mechanisms synthesis. In addition, the model for circuit identification can be directly used to solve the motion order defect that is often encountered in Stephenson six-bar mechanisms synthesis.

Six and Seven Position Triad Synthesis Using Continuation Methods

1994 ◽  
Vol 116 (2) ◽  
pp. 660-665 ◽  
Author(s):  
T. Subbian ◽  
D. R. Flugrad
Keyword(s):  
Finite Number ◽  
Continuation Method ◽  
Synthesis Problem ◽  
Continuation Methods ◽  
Path Generation ◽  
Motion Generation ◽  
Number Of Solutions ◽  
Position Synthesis

A continuation method is used for the synthesis of triads for motion generation with prescribed timing applications. The procedure is applied to solve both six and seven position synthesis problems. Triad Burmester curves are generated for the six position synthesis problem and an eight-bar mechanism is designed to illustrate the procedure. For the seven position synthesis problem, a finite number of solutions are obtained. A geared five-bar, seven position path generation example is considered.

A Method for Adjustable Planar and Spherical Four-Bar Linkage Synthesis

2004 ◽  
Vol 127 (3) ◽  
pp. 456-463 ◽  
Author(s):  
Boyang Hong ◽  
Arthur G. Erdman
Keyword(s):  
Synthesis Method ◽  
New Method ◽  
Spherical Form ◽  
Numerical Example ◽  
Input And Output ◽  
Special Cases ◽  
Position Synthesis ◽  
Four Bar Linkage ◽  
Linkage Synthesis

This paper describes a new method to synthesize adjustable four-bar linkages, both in planar and spherical form. This method uses fixed ground pivots and an adjustable length for input and output links. A new application of Burmester curves for adjustable linkages is introduced, and a numerical example is discussed. This paper also compares a conventional synthesis method (nonadjustable linkage) to the new method. Nonadjustable four-bar linkages provide limited solutions for five-position synthesis. Adjustable linkages generate one infinity of solution choices. This paper also shows that the nonadjustable solutions are special cases of adjustable solutions. This new method can be extended to six position synthesis, with adjustable ground pivots locations.

Finite Position Synthesis Using the Image Curve of a Spherical Four-Bar Motion

1992 ◽  
Vol 114 (1) ◽  
pp. 55-60 ◽  
Author(s):  
R. M. C. Bodduluri ◽  
J. M. McCarthy
Keyword(s):  
Minimization Problem ◽  
Image Space ◽  
Synthesis Problem ◽  
Numerical Examples ◽  
Distance Error ◽  
Normal Distance ◽  
Position Synthesis ◽  
The Given

This paper presents an approach to the finite position synthesis of spherical four-bar linkages that unites traditional precision theory with recent results in approximate position synthesis. This approach maps the desired positions to points in an image space, and the motion of the coupler of a spherical four-bar to a curve. The synthesis problem then becomes one of finding the image curve that passes through the given positions (precision position synthesis) or as close as possible (approximate position synthesis), the solution of which is obtained by minimizing the normal distance error. Nonbranching constraints are incorporated into the minimization problem to give the designer control over the type of the linkage synthesized. Numerical examples are presented for five, six, and ten positions.

scholarly journals Computer-aided synthesis of spherical and planar 4R linkages for four specified orientations

2019 ◽  
Vol 10 (1) ◽  
pp. 309-320 ◽  
Author(s):  
Guangming Wang ◽  
Hao Zhang ◽  
Xiaoyu Li ◽  
Jiabo Wang ◽  
Xiaohui Zhang ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Poor Performance ◽  
Program Package ◽  
Synthesis Problem ◽  
Analytic Geometry ◽  
Spherical Trigonometry ◽  
Calculation Methods ◽  
Orientation Task ◽  
Computer Aided ◽  
Type Classification

Abstract. According to the burmester theory, an infinite number of spherical or planar 4R linkages for a specific four-orientation task can be synthesized, but most of the linkage solutions calculated by this method are invalid because of motion defect, poor performance and others. In order to improve the synthesis efficiency, a program package based on Matlab is developed to find a satisfied linkage solution automatically and quickly. Firstly, the calculation on circle points and the center points based on the burmester theory in spherical problems is introduced. Secondly, the calculation methods of linkage defect discrimination, linkage type classification, linkage performance evaluation and solutions visualization based on the theory of spherical trigonometry are presented respectively. Thirdly, the synthesis calculation of program package is extended to the planar 4R linkage based on the theory of planar analytic geometry. Finally, the examples of the spherical synthesis problem and the planar synthesis problem based on solutions map are introduced to test the program package, the result proves this program package is effective and flexible.

scholarly journals Computer Aided Design of Useful Spherical Watt I Six-Bar Linkages

2013 ◽  
Author(s):  
Kaustubh H. Sonawale ◽  
Alex Arredondo ◽  
J. Michael McCarthy
Keyword(s):  
Computer Aided Design ◽  
Design Procedure ◽  
Software System ◽  
Open Chain ◽  
Kinematic Synthesis ◽  
Computer Aided ◽  
Tolerance Zones ◽  
Task Specification ◽  
Position Synthesis ◽  
Aided Design

This paper presents a software system for the kinematic synthesis of useful spherical Watt I six-bar linkages that can guide a body through five task positions. The design procedure begins with the specification of a spherical 3R open chain that reaches five specified task positions. The six-bar linkage is designed by constraining the 3R spherical chain to the topology of a Watt I spherical six-bar linkage. The CAD software SolidWorks is used to specify the 3R chain and the five spherical task positions. We describe the SolidWorks Add-In MechGen that reads the SolidWorks data and generates candidate linkages. Included in the task specification are tolerance zones that allow random adjustments to the task positions to search for defect-free linkages. An example is provided that demonstrates the five position synthesis of a useful spherical Watt I six-bar linkage.

Sign in / Sign up

Export Citation Format

Share Document