A 2-DOF Translational Parallel Manipulator with Passive Universal Joints

2013 ◽  
Vol 278-280 ◽  
pp. 541-545
Author(s):  
Zeng Ming Li ◽  
Bin Bin Peng ◽  
Bao Gang Yang ◽  
Hao Yuan Chen
Keyword(s):  
Spatial Structure ◽  
Bearing Capacity ◽  
Parallel Manipulator ◽  
Simple Structure ◽  
Jacobian Matrix ◽  
Degree Of Freedom ◽  
Kinematics Analysis ◽  
High Stiffness ◽  
The Stability ◽  
Universal Joints

In the paper, a novel 2-DOF (degree of freedom) plane translational parallel manipulator with passive universal joints and three legs is presented. Firstly, the 2-DOF translational parallel manipulator which has the spatial structure and high bearing capacity in the direction perpendicular to the kinematics plane is described. Then, the kinematics analysis of the 2-DOF parallel manipulator, which include inverse and forward solutions, are studied in detail, and the Jacobian matrix of the parallel manipulator is also derived based on it. Lastly, to improve the stability and bearing capacity further, the symmetric mechanisms with four legs and passive universal joints are constructed by adding a leg in parallel. The proposed 2-DOF parallel manipulator not only has the simple structure, but high stiffness especially in the direction perpendicular to kinematics plane for its spatial arrangment and passive universal joints.

Parametric Design of a Spherical Eight-Bar Linkage Based on a Spherical Parallel Manipulator

2008 ◽  
Vol 1 (1) ◽  
Author(s):  
Gim Song Soh ◽  
J. Michael McCarthy
Keyword(s):  
Inverse Kinematics ◽  
Parallel Manipulator ◽  
Parametric Design ◽  
Degree Of Freedom ◽  
Kinematics Analysis ◽  
End Effector ◽  
Arbitrary Base ◽  
Three Degree Of Freedom ◽  
Spherical Parallel Manipulator

This paper presents a procedure that determines the dimensions of two constraining links to be added to a three degree-of-freedom spherical parallel manipulator so that it becomes a one degree-of-freedom spherical (8, 10) eight-bar linkage that guides its end-effector through five task poses. The dimensions of the spherical parallel manipulator are unconstrained, which provides the freedom to specify arbitrary base attachment points as well as the opportunity to shape the overall movement of the linkage. Inverse kinematics analysis of the spherical parallel manipulator provides a set of relative poses between all of the links, which are used to formulate the synthesis equations for spherical RR chains connecting any two of these links. The analysis of the resulting spherical eight-bar linkage verifies the movement of the system.

Design and analysis of a totally decoupled 3-DOF spherical parallel manipulator

Robotica ◽  
2010 ◽  
Vol 29 (7) ◽  
pp. 1093-1100 ◽  
Author(s):  
Dan Zhang ◽  
Fan Zhang
Keyword(s):  
Physical Meaning ◽  
Parallel Mechanism ◽  
Parallel Manipulator ◽  
Jacobian Matrix ◽  
Degree Of Freedom ◽  
Redundant Constraints ◽  
Rotational Motions ◽  
Spherical Parallel Manipulator

SUMMARYIn this paper, we propose a unique, decoupled 3 degree-of-freedom (DOF) parallel wrist. The condition required for synthesizing a fully isotropic parallel mechanism is obtained on the basis of 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. As this device is analyzed with the Jacobian matrix, the mechanism is free of singularity within its workspace and maintains homogenous stiffness over the entire workspace.

Solving stiffness and deformation of a 3-UPU parallel manipulator with one translation and two rotations

Robotica ◽  
2011 ◽  
Vol 29 (6) ◽  
pp. 815-822 ◽  
Author(s):  
Bo Hu ◽  
Yi Lu
Keyword(s):  
Elastic Deformation ◽  
Stiffness Matrix ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Jacobian Matrix ◽  
Stiffness Modeling ◽  
Special Orientation ◽  
Universal Joints

SUMMARYThe stiffness modeling and elastic deformation of 3 degrees of freedom, 3-universal joints–prismatic pairs–universal joints (UPU) parallel manipulator (PM) with one translation and two rotations are studied. First, the constraint wrenches are derived corresponding to the special orientation of universal joints in each of the UPU legs. Second, the elastic deformation of active legs produced by these active forces and constrained wrenches are derived. Third, a 6 × 6 Jacobian matrix is derived from constraint and active forces, and the statics is solved. Finally, the stiffness matrix of 3-UPU PM is established and its elastic deformation is solved.

A novel 4-RRCR parallel mechanism based on screw theory and its kinematics analysis

2012 ◽  
Vol 227 (9) ◽  
pp. 2039-2048 ◽  
Author(s):  
Sheng Guo ◽  
Congzhe Wang ◽  
Haibo Qu ◽  
Yuefa Fang
Keyword(s):  
Parallel Mechanism ◽  
Jacobian Matrix ◽  
Screw Theory ◽  
Degree Of Freedom ◽  
Forward Kinematics ◽  
Kinematics Analysis ◽  
Elimination Method ◽  
Direct Kinematics

In this article, a novel 4-RRCR parallel mechanism is introduced based on screw theory, and its kinematics and singularity are studied systematically. First, the degree of freedom analysis is performed using the screw theory. The formulas for solving the inverse and direct kinematics are derived. Second, a recursive elimination method is proposed to solve the Jacobian matrix based on the algebra operation of reciprocal product. Then, three kinds of singularity, i.e. limb, platform, and actuation singularities are analyzed. Finally, the analysis proves that the proposed mechanism possesses two advantages of simple forward kinematics and no platform singularity.

scholarly journals Kinematics Simulation of Gough-Stewart Parallel Manipulator by Using Simulink Package in Matlab Software

2019 ◽  
Vol 27 (2) ◽  
pp. 10-20
Author(s):  
Hassan Mohammed Alwan ◽  
Riyadh Ahmed Sarhan
Keyword(s):  
Theoretical Model ◽  
Parallel Manipulator ◽  
Degree Of Freedom ◽  
Kinematics Analysis ◽  
Matlab Software ◽  
Kinematics Simulation ◽  
Moving Platform ◽  
Position And Orientation ◽  
Six Degree Of Freedom ◽  
Forward Equations

The Gough Stewart Robotic manipulator is a parallel manipulator with six-degree of freedom, which has six equations of Kinematics (Inverse and forward), with six variables (Lengths, Position, and Orientation). In this work derived the inverse equations, which used to compute the lengths of the linkages and its changes depended on the position and orientation of the platform's center, then derived the forward equations to calculate the position and orientation of the moving platform in terms of the lengths. This theoretical model of the kinematics analysis of the Gough Stewart has been built into the Simulink package in Matlab to obtain the lengths, position, and orientation for the manipulator at any time of motion. The input parameters (Position and Orientation) in inverse blocks compared with the output parameters (Position and Orientation) in the forward blocks, which show good results.

scholarly journals A Six Degree of Freedom Epicyclic-Parallel Manipulator

2012 ◽  
Vol 4 (4) ◽  
Author(s):  
Chao Chen ◽  
Thibault Gayral ◽  
Stéphane Caro ◽  
Damien Chablat ◽  
Guillaume Moroz ◽  
...  
Keyword(s):  
Inverse Kinematics ◽  
Parallel Manipulator ◽  
Degree Of Freedom ◽  
Kinematics Analysis ◽  
End Effector ◽  
Six Dof ◽  
Six Degree Of Freedom

A new six-dof epicyclic-parallel manipulator with all actuators allocated on the ground is introduced. It is shown that the system has a considerably simple kinematics relationship, with the complete direct and inverse kinematics analysis provided. Further, the first and second links of each leg can be driven independently by two motors. The serial and parallel singularities of the system are determined, with an interesting feature of the system being that the parallel singularity is independent of the position of the end-effector. The workspace of the manipulator is also analyzed with future applications in haptics in mind.

scholarly journals Design and performance analysis of a 3-RRR spherical parallel manipulator for hip exoskeleton applications

2017 ◽  
Vol 4 ◽  
pp. 205566831769759 ◽  
Author(s):  
Soheil Sadeqi ◽  
Shaun P Bourgeois ◽  
Edward J Park ◽  
Siamak Arzanpour
Keyword(s):  
Experimental Study ◽  
Performance Analysis ◽  
Inverse Kinematics ◽  
Parallel Manipulator ◽  
Jacobian Matrix ◽  
Kinematics Analysis ◽  
Normal Gait ◽  
Sensitivity Indices ◽  
And Performance ◽  
Spherical Parallel Manipulator

This paper presents the design and performance analysis and experimental study of a 3-RRR spherical parallel manipulator in the context of hip exoskeleton applications. First, the mechanism’s inverse kinematics analysis and Jacobian matrix development are revisited. Manipulability, dexterity, and rotational sensitivity indices are then evaluated for two different methods of attachment to the human body. The superior attachment method in terms of these performance measures is indicated, and an experimental study based on the selected method is conducted; the experiment involves testing the capability of a 3-RRR manipulator’s end-effector in tracking the motions experienced by a human hip joint during normal gait cycles. Finally, the results of the experimental study indicate that the manipulator represents a feasible hip exoskeleton solution providing total kinematic compliance with the human hip joint’s 3-degree-of-freedom motion capabilities.

Forward kinematics analysis of parallel mechanisms with restricted workspace

2014 ◽  
Vol 229 (14) ◽  
pp. 2561-2572 ◽  
Author(s):  
Mingchao Geng ◽  
Tieshi Zhao ◽  
Chang Wang ◽  
Yuhang Chen ◽  
Erwei Li
Keyword(s):  
Jacobian Matrix ◽  
Search Method ◽  
Degree Of Freedom ◽  
Forward Kinematics ◽  
Parallel Mechanisms ◽  
Kinematics Analysis ◽  
Iterative Search ◽  
Newton Raphson ◽  
Equivalent Method ◽  
Quasi Newton

The iterative search method (Newton-Raphson or Quasi-Newton) is an important numerical method for solving the forward kinematics problem of parallel mechanisms. But there may be a failure when the iterative search method solves the forward kinematics problems of a class of mechanisms, whose workspace is restricted. The extreme displacement singularity in the limbs is one reason for the workspace restriction. An equivalent method is proposed to remove the extremely displacement singularity in the limbs, and the forward kinematics solutions of two representative 6 degree of freedom mechanisms are given to illustrate the mechanism equivalence. For the coupled fewer degree of freedom mechanisms, the coupled motion is another reason for the workspace restriction. The virtual mechanism method and modified Jacobian matrix method are applied to solve the forward kinematics problems of this class of mechanisms. Numerical examples are given to validate the theories proposed above.

Design and Kinematics Analysis of a New Two DOF Tilter

2012 ◽  
Vol 591-593 ◽  
pp. 674-678
Author(s):  
Hai Dong Wang ◽  
Bing Heng Yang ◽  
Kai Zhang ◽  
Yu Quan Bi
Keyword(s):  
Bearing Capacity ◽  
High Precision ◽  
Coordinate Transformation ◽  
Pitch Angle ◽  
Parallel Manipulator ◽  
Kinematics Analysis ◽  
Kinematic Simulation ◽  
Configuration Theory ◽  
Moving Platform ◽  
Branched Chains

According to the configuration theory of the parallel manipulator with a few degree of freedom (DOF), the paper adopted 2PSU-U mechanism to design a new parallel tilter with 2 DOF, which has such advantages as strong bearing capacity, high precision and kinematic decoupling. It used the coordinate transformation to establish the position and velocity equations of the tilter, and also used the instance to make kinematic simulation, whose result indicated that the roll and pitch angle of the moving platform can vary according to the set motion law by driving two sliders of the main moving branched chains.

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