Dexterity Analysis of 3-RCR Parallel Robot Mechanism

2011 ◽  
Vol 464 ◽  
pp. 129-132
Author(s):  
Hai Zhen Chen ◽  
Zhong Yue Zou ◽  
Hong Peng Song
Keyword(s):  
Parallel Mechanism ◽  
Jacobian Matrix ◽  
Condition Index ◽  
Parallel Robot ◽  
Polar Coordinates ◽  
Matlab Software ◽  
The Future ◽  
Global Condition ◽  
Searching Method ◽  
Theory Foundation

Based on forward position equations of 3-RCR parallel mechanism, the Jacobian matrixes were obtained. The global condition index was gotten based on the Jacobian matrix. According to the global condition index and the polar coordinates boundary searching method, using MATLAB software, the dexterity atlases of the mechanism were gotten. Finally, the dexterity was analyzed. The research can provide theory foundation for study and application of parallel mechanism in the future.

Novel Design and Analysis of a Fully Decoupled 3-DOF Spherical Parallel Robot

2009 ◽  
Author(s):  
Dan Zhang ◽  
Fan Zhang
Keyword(s):  
Physical Meaning ◽  
Parallel Mechanism ◽  
Jacobian Matrix ◽  
Parallel Robot ◽  
Degree Of Freedom ◽  
Redundant Constraints ◽  
Rotational Motions ◽  
Three Degree Of Freedom ◽  
Novel Design

In this paper, we propose a unique, decoupled Three Degree-of-Freedom (DOF) parallel wrist. The condition required for synthesizing a fully isotropic parallel mechanism is obtained based on the physical meaning of the row vector in the Jacobian Matrix. Specifically, an over-constrained spherical 3-DOF parallel mechanism is presented and the modified structure, which avoids the redundant constraints, is also introduced. The proposed manipulator is capable of decoupled rotational motions around the x, y and z axes and contains an output angle that is equal to the input angle. Since this device is analyzed with the Jacobian Matrix, which is constant, the mechanism is free of singularity and maintains homogenous stiffness over the entire workspace.

scholarly journals Diseño cinemático de un robot paralelo 2-PRR

2020 ◽  
Vol 25 (3) ◽  
pp. 372-379
Author(s):  
Sebastián Durango Idárraga ◽  
Mariline C. Delgado Martínez ◽  
César A. Álvarez Vargas ◽  
Rubén D. Flórez Hurtado ◽  
Manuel A. Flórez Ruiz
Keyword(s):  
Condition Index ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Normalization Method ◽  
Dimensional Synthesis ◽  
Singular Configurations ◽  
Highly Sensitive ◽  
Global Condition ◽  
Specific Geometry ◽  
Workspace Design

In civil construction Abstract— This paper presents a dimensional synthesis for a 2-PRR planar parallel robot with a structural plane of symmetry. This robot can achieve the translation of the moving platform without changing the orientation, being useful for applications that require controlled positions with high rigidity. Because the performance of parallel robots is highly sensitive to their geometric parameters, many methodologies to state the dimensional synthesis has been developed. We used the method of Parameter - Finiteness Normalization Method (PFNM) to state the dimensional synthesis using Global Condition Index (GCI) and workspace ( ) design atlases. For the two, GCI and , designed atlases, it is not possible to maximize one of the indexes without diminishing the other one, which represents a design compromise. Also, we remark singular configurations that are coming from specific geometry or limit positions. The complete dimensional synthesis is also presented.

One Novel Isoconstrained Parallel Robot With Schoenflies-Motion

2013 ◽  
Author(s):  
Po-Chih Lee
Keyword(s):  
Parallel Mechanism ◽  
Jacobian Matrix ◽  
Parallel Robot ◽  
Singularity Analysis ◽  
Point Of View ◽  
Universal Joint ◽  
Small Motion ◽  
Robot Architecture ◽  
Pick And Place ◽  
Pick And Place Operation

The coupling between two opposite bars of the hinged parallelogram produces relative 1-DoF circular translation and the opposite bars can move but remain parallel. From the point of view of kinematics, a hinged parallelogram is equivalent to a prismatic pair for a small motion. On the basis of a special parallel mechanism with the limb architecture of type CPUh (C and P denote cylindrical and prismatic pairs; Uh indicates the pseudo-universal-joint having one revolute and one screw pairs with the intersecting axes), we provide one novel Schoenflies-motion isoconstrained CPaUh//CPaUh robot with only two limbs having the hinged parallelograms for the fast pick-and-place operation of the assembly and packaging applications. This type of robot is compact for not only its structure but also its actuation. The robot architecture and kinematics including inverse and forward solutions are studied. In addition, Jacobian matrix, singularity analysis and workspace are further discussed. It is hoped that the evaluations of such two-limb parallel mechanism can be useful for possible application in industry where pick-and-place motion and higher accuracy are required.

The Analysis on the Singularity of a 3-TPT Parallel Robot

2011 ◽  
Vol 225-226 ◽  
pp. 903-906 ◽  
Author(s):  
Jian Ye Guo ◽  
Liang Zhao ◽  
Jia Shun Shi
Keyword(s):  
Parallel Mechanism ◽  
Position Control ◽  
Theoretical Foundation ◽  
Jacobian Matrix ◽  
Parallel Robot ◽  
Kinematics Analysis ◽  
Processing Track ◽  
Measure Index

This paper took a 3-TPT Parallel Robot as the object to study its singularity within the workspace. Firstly the kinematics equation of Parallel Robot was established according to the kinematics analysis and the Jacobian matrix of parallel mechanism could be obtained at the same time. Then the workspace of Parallel Robot was carried on the solution and the analysis. Finally the degree of operability was taken as the measure index to analyze the singularity of Parallel Robot within the workspace, and the results showed that this Parallel Robot does not have singular position. The analysis results of this paper have laid the theoretical foundation for the position control and processing track planning of this Parallel Robot.

Workspace Analysis and Performance Evaluation of a 6/6 Cable-Suspended Parallel Robot

2013 ◽  
Vol 655-657 ◽  
pp. 1114-1118
Author(s):  
Hui Zhou ◽  
Yi Cao ◽  
Jing Hu Yu ◽  
Gui Lan Chen ◽  
Qiang Wang ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Special Class ◽  
Screw Theory ◽  
Condition Index ◽  
Parallel Robot ◽  
Workspace Analysis ◽  
Global Condition ◽  
Moving Platform ◽  
And Performance ◽  
Velocity Transmission

This paper mainly addressed the workspace analysis and performance evaluation of a special class of the 6/6 cable-suspended parallel robot. Based on the screw theory and the static equilibrium, the Jacobian matrix of the cable -suspended parallel robot is constructed. The workspace volume is characterized as the set of points where the centroid of the moving platform can reach with tensions in all suspension cables for a constant orientation. This paper attempts to tackle some aspects of optimal design of this special class of the 6/6 cable-suspended parallel robot by addressing the variations of the workspace volume and the accuracy of the robot using different geometric configurations, different ratios and orientations of the moving platform. The global condition index is used as a performance index of a robot with respect to the force and velocity transmission over the whole workspace.

Workspace Analysis and Simulation of 3-PCR Parallel Mechanism

2010 ◽  
Vol 43 ◽  
pp. 137-141 ◽  
Author(s):  
Xiu Qing Hao ◽  
Zong Gang Xu ◽  
Kai Yun Cai
Keyword(s):  
Mathematical Model ◽  
Cross Section ◽  
Parallel Mechanism ◽  
Influence Factors ◽  
Polar Coordinates ◽  
Matlab Software ◽  
Conversion Method ◽  
Workspace Analysis ◽  
Coordinate Conversion ◽  
Design And Manufacture

Inverse position equations of 3-PCR parallel mechanism were obtained by coordinate conversion method, based on the influence factors to the workspace of parallel mechanism, workspace volume under a certain size was worked out with method of polar coordinates boundary searching. According to mathematical model, using MATLAB software, solid figure and cross-section diagram of the mechanism in a certain range of size were presented. Finally, characteristics of workspace were analyzed through diagrams. Workspace analysis can provide necessary preconditions for the design and manufacture of parallel mechanism.

Kinematic analysis and design of a novel 6-degree of freedom parallel robot

2014 ◽  
Vol 229 (2) ◽  
pp. 291-303 ◽  
Author(s):  
DU Hui ◽  
GAO Feng ◽  
PAN Yang
Keyword(s):  
Set Theory ◽  
Kinematic Analysis ◽  
Parallel Mechanism ◽  
Design Methodology ◽  
Parallel Robot ◽  
End Effector ◽  
Analysis And Design ◽  
Velocity Models ◽  
Reachable Workspace ◽  
Rotational Motions

A novel 3-UP3R parallel mechanism with six degree of freedoms is proposed in this paper. One most important advantage of this mechanism is that the three translational and three rotational motions are partially decoupled: the end-effector position is only determined by three inputs, while the rotational angles are relative to all six inputs. The design methodology via GF set theory is brought out, using which the limb type can be determined. The mobility of the end-effector is analyzed. After that, the kinematic and velocity models are formulated. Then, workspace is studied, and since the robot is partially decoupled, the reachable workspace is also the dexterous workspace. In the end, both local and global performances are discussed using conditioning indexes. The experiment of real prototype shows that this mechanism works well and may be applied in many fields.

Problems Regarding Singularities Analysis of a 3-RRR Parallel Mechanism

2014 ◽  
Vol 658 ◽  
pp. 569-574 ◽  
Author(s):  
Florentin Buium ◽  
Cezar Duca ◽  
Dumitru Leohchi
Keyword(s):  
Parallel Mechanism ◽  
Scientific Literature ◽  
Parallel Robot ◽  
Principal Mechanism ◽  
Working Quality

The paper presents some authors results regarding working quality inside workspace of a 3 DoF, 3 RRR planar parallel mechanism, used as parallel robot structure. Namely we deal with singularities avoidance inside workspace as is wide known in scientific literature this represents a major disadvantages of these mechanisms. To this purpose, the configuration determinant notion has been used as principal mechanism work parameter.

Static Analysis for a Novel 6-(P-2P-S) Parallel Robot

2009 ◽  
Vol 69-70 ◽  
pp. 580-584 ◽  
Author(s):  
D.F. Zhang ◽  
Feng Gao
Keyword(s):  
Carrying Capacity ◽  
Simple Structure ◽  
Jacobian Matrix ◽  
Parallel Robot ◽  
Singular Value ◽  
Force Transmission ◽  
Practical Application ◽  
Positioning Device ◽  
Orientation Parameters ◽  
Orientation Workspace

A novel 6-(P-2P-S) parallel robot is put forward. With the characters of some movement decoupling on the orthogonal pose, the robot can be used as the macro manipulator of the macro/micro dual driven robots. The macro manipulator as a high-precision positioning device, it is significant for the practical application and drive train design to research statics. First, the force Jacobian matrix is deduced, which is related to the orientation parameters. Then based on the Jacobian matrix singular value decomposed characteristic, the static force transmission evaluation indicators Kf and Km are defined. Finally, considering structure constraints and parameters, the distribution of evaluation indicators in the orientation workspace is drawn, which provide the theoretical base for the design and applications of the robot. Because of the characters of simple structure, high carrying capacity, less motion inertia, good manufacturability, the 6-(P-2P-S) parallel macro manipulator has been designed.

scholarly journals Simulation of a rotating strong gravity that reverses time

2021 ◽  
pp. 7-16
Author(s):  
Yoshio Matsuki ◽  
Petro Bidyuk
Keyword(s):  
Angular Momentum ◽  
Gravitational Field ◽  
Momentum Density ◽  
Polar Coordinates ◽  
Energy Tensor ◽  
Stress Energy Tensor ◽  
Strong Gravity ◽  
The Past ◽  
Stress Energy ◽  
The Future

In this research we simulated how time can be reversed with a rotating strong gravity. At first, we assumed that the time and the space can be distorted with the presence of a strong gravity, and then we calculated the angular momentum density of the rotating gravitational field. For this simulation we used Einstein’s field equation with spherical polar coordinates and the Euler’s transformation matrix to simulate the rotation. We also assumed that the stress-energy tensor that is placed at the end of the strong gravitational field reflects the intensities of the angular momentum, which is the normal (perpendicular) vector to the rotating axis. The result of the simulation shows that the angular momentum of the rotating strong gravity changes its directions from plus (the future) to minus (the past) and from minus (the past) to plus (the future), depending on the frequency of the rotation.

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