Joint Rotation Space of Five-Bar Linkages

1992 ◽  
Author(s):  
Kwun-Lon Ting ◽  
J. H. Shyu
Keyword(s):  
Extensive Study ◽  
Degree Of Freedom ◽  
Joint Rotation ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
The Relationship

Abstract Unlike single degree of freedom linkages, the rotatability at a joint of a five-bar linkage is affected by the rotatability at another joint. Unless the linkage has full rotatability, the allowable inputs of a five-bar linkage are related. This article, by taking the interrelationship between the rotatability of two input angles into consideration, presents the most extensive study on the rotatability of five-bar linkages. The joint rotation space of a five-bar linkage is the region between the singular curves which represent the relationship between the input angular positions of the linkage at singular positions. By distinguishing five-bar linkages into C-C (crank-crank), C-R (crank-rocker), and R-R (rocker-rocker) types, there are totally nine C-C types, four C-R types and four R-R types of joint rotation space in classes I and II five-bar linkages. The results in this paper are essential for understanding the basic mobility and limitation of five-bar linkages. One may also find them useful in manipulators or multi-loop linkages which have a five-bar chain as the major or minor structure. The results are also applicable to spherical five-bar linkages.

scholarly journals Simulation Analysis of One Degree of Freedom Motion of Electromagnetic Spherical Joint based on Maxwell

2021 ◽  
Vol 2085 (1) ◽  
pp. 012014
Author(s):  
Haoran Wang ◽  
Fucong Liu ◽  
Sai Lou
Keyword(s):  
Mathematical Model ◽  
Simulation Analysis ◽  
Lagrange Equation ◽  
Degree Of Freedom ◽  
Spherical Joint ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Structure And Motion ◽  
The Mathematical Model ◽  
The Relationship

Abstract In order to improve the stiffness of the spherical joint of the robot, reduce the difficulty of manufacturing and the complexity of the control system, this paper proposed a method of spherical joint and digital drive of the robot based on the electromagnetic principle. Firstly, introduces the structure and motion principle of the spherical joint of the robot, establishes the mathematical model of the spherical joint and establishes the dynamic model according to the second Lagrange equation. after that, the relationship between the number of ampire-turns of the electromagnet on the spherical joint, the attitude Angle of the rotor and the force of the rotor was obtained by simulating the single degree of freedom of the joint based on Ansys maxwell and Matlab, which provided a basis for the realization of the digital drive of the spherical joint.

Branch Identification of Spherical Six-Bar Linkages

2016 ◽  
Author(s):  
Liangyi Nie ◽  
Jun Wang ◽  
Kwun-Lon Ting ◽  
Daxing Zhao ◽  
Quan Wang ◽  
...  
Keyword(s):  
Range Of Motion ◽  
Degree Of Freedom ◽  
Joint Rotation ◽  
Single Degree Of Freedom ◽  
Complex Issue ◽  
Single Degree ◽  
Identification Method ◽  
Spatial Linkages ◽  
Spherical Linkages

Branch (assembly mode or circuit) identification is a way to assure motion continuity among discrete linkage positions. Branch problem is the most fundamental, pivotal, and complex issue among the mobility problems that may also include sub-branch (singularity-free) identification, range of motion, and order of motion. Branch and mobility complexity increases greatly in spherical or spatial linkages. This paper presents the branch identification method suitable for automated motion continuity rectification of a single degree-of-freedom of spherical linkages. Using discriminant method and the concept of joint rotation space (JRS), the branch of a spherical linkage can be easily identified. The proposed method is general and conceptually straightforward. It can be applied for all linkage inversions. Examples are employed to illustrate the proposed method.

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.

Estimation of Hysteretic Energy of MDOF Structures Based on Equivalent SDOF Systems

2007 ◽  
Vol 340-341 ◽  
pp. 435-440
Author(s):  
Hong Nan Li ◽  
Feng Wang ◽  
Zhao Hui Lu
Keyword(s):  
Ground Motions ◽  
Estimation Method ◽  
Degree Of Freedom ◽  
Energy Relation ◽  
Energy Estimation ◽  
Single Degree Of Freedom ◽  
Hysteretic Energy ◽  
Single Degree ◽  
Energy Demands ◽  
The Relationship

It is important for obtaining the relationship between seismic energies of single degree-of-freedom (SDOF) systems and multiple degree-of-freedom (MDOF) structures in engineering. In this paper, the formula of hysteretic energy between the MDOF structures and equivalent SDOF systems is developed. Here is also presented the procedure for estimating hysteretic energy of MDOF structures subjected to severe ground motions employing the energy relation equation based on equivalent SDOF systems. Eight examples for two regular and six irregular MDOF structures show that the procedure to obtain the hysteretic energy demands of MDOF structures may be used as a simple and effective energy estimation method.

Kinematic comparison of single degree-of-freedom robotic gait trainers

2021 ◽  
Vol 159 ◽  
pp. 104258
Author(s):  
Jeonghwan Lee ◽  
Lailu Li ◽  
Sung Yul Shin ◽  
Ashish D. Deshpande ◽  
James Sulzer
Keyword(s):  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Robotic Gait
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