A dual quaternion approach to efficient determination of the maximal singularity-free joint space and workspace of six-DOF parallel robots

2018 ◽  
Vol 129 ◽  
pp. 279-292 ◽  
Author(s):  
XiaoLong Yang ◽  
HongTao Wu ◽  
Bai Chen ◽  
Yao Li ◽  
SuRong Jiang
Keyword(s):  
Joint Space ◽  
Parallel Robots ◽  
Dual Quaternion ◽  
Maximal Singularity ◽  
Six Dof

Six-DOF parallel manipulators with maximal singularity-free joint space or workspace

Robotica ◽  
2013 ◽  
Vol 32 (3) ◽  
pp. 401-411 ◽  
Author(s):  
K. Y. Tsai ◽  
J. C. Lin ◽  
Yiting Lo
Keyword(s):  
Objective Function ◽  
Parallel Manipulators ◽  
Joint Space ◽  
Geometric Parameters ◽  
Important Criterion ◽  
Systematic Method ◽  
Complex Singularities ◽  
Maximal Singularity ◽  
Six Dof

SUMMARYSingularity-free workspace is a very important criterion for the design of manipulators, especially for parallel manipulators which are well known for their limited workspace and complex singularities. This paper studies geometric parameters and dexterity measures that affect the size of a singularity-free joint space and proposes methods for the development of 6-DOF Stewart–Gough parallel manipulators that have better singularity-free joint space. With a local dexterity measure as the objective function, a systematic method is employed to search for the design with a maximal singularity-free joint space. The related workspaces are also investigated. It is shown that the workspace is not proportional to the size of the joint space and that manipulators with a larger singularity-free workspace usually have relatively poor dexterity.

Computationally Efficient Inverse Dynamics of a Class of Six-DOF Parallel Robots: Dual Quaternion Approach

2018 ◽  
Vol 94 (1) ◽  
pp. 101-113 ◽  
Author(s):  
XiaoLong Yang ◽  
HongTao Wu ◽  
Yao Li ◽  
ShengZheng Kang ◽  
Bai Chen
Keyword(s):  
Inverse Dynamics ◽  
Parallel Robots ◽  
Dual Quaternion ◽  
Computationally Efficient ◽  
Six Dof

Wrench capabilities of planar parallel manipulators. Part I: Wrench polytopes and performance indices

Robotica ◽  
2008 ◽  
Vol 26 (6) ◽  
pp. 791-802 ◽  
Author(s):  
Flavio Firmani ◽  
Alp Zibil ◽  
Scott B. Nokleby ◽  
Ron P. Podhorodeski
Keyword(s):  
Parallel Manipulators ◽  
Joint Space ◽  
Linear Mapping ◽  
Redundant Manipulators ◽  
Task Space ◽  
Performance Indices ◽  
Study Case ◽  
And Performance ◽  
Planar Parallel Manipulators

SUMMARYThis paper is organized in two parts. In Part I, the wrench polytope concept is presented and wrench performance indices are introduced for planar parallel manipulators (PPMs). In Part II, the concept of wrench capabilities is extended to redundant manipulators and the wrench workspace of different PPMs is analyzed. The end-effector of a PPM is subject to the interaction of forces and moments. Wrench capabilities represent the maximum forces and moments that can be applied or sustained by the manipulator. The wrench capabilities of PPMs are determined by a linear mapping of the actuator output capabilities from the joint space to the task space. The analysis is based upon properly adjusting the actuator outputs to their extreme capabilities. The linear mapping results in a wrench polytope. It is shown that for non-redundant PPMs, one actuator output capability constrains the maximum wrench that can be applied (or sustained) with a plane in the wrench space yielding a facet of the polytope. Herein, the determination of wrench performance indices is presented without the expensive task of generating polytopes. Six study cases are presented and performance indices are derived for each study case.

Determination of Maximal Singularity-Free Workspace of Parallel Mechanisms Using Constructive Geometric Approach

2013 ◽  
pp. 307-314
Author(s):  
Mohammad Hadi Farzaneh Kaloorazi ◽  
Mehdi Tale Masouleh ◽  
Stéphane Caro ◽  
Behnam Mashhadi Gholamali
Keyword(s):  
Geometric Approach ◽  
Parallel Mechanisms ◽  
Maximal Singularity

Experimental results for the flexible joint cable-suspended manipulator of ICaSbot

Robotica ◽  
2013 ◽  
Vol 31 (6) ◽  
pp. 887-904 ◽  
Author(s):  
M. H. Korayem ◽  
M. Bamdad ◽  
H. Tourajizadeh ◽  
A. H. Korayem ◽  
R. M. Zehtab ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Experimental Tests ◽  
Parallel Robot ◽  
Joint Space ◽  
End Effector ◽  
Flexible Joint ◽  
Cable Robot ◽  
Six Dof ◽  
And Control ◽  
Computed Torque

SUMMARYIn this paper, design, dynamic, and control of the motors of a spatial cable robot are presented considering flexibility of the joints. End-effector control in order to control all six spatial degrees of freedom (DOFs) of the system and motor control in order to control the joints flexibility are proposed here. Corresponding programing of its operation is done by formulating the kinematics and dynamics and also control of the robot. Considering the existence of gearboxes, flexibility of the joints is modeled in the feed-forward term of its controller to achieve better accuracy. A two sequential closed-loop strategy consisting of proportional derivative (PD) for linear actuators in joint space and computed torque method for nonlinear end-effector in Cartesian space is presented for further accuracy. Flexibility is estimated using modeling and simulation by MATLAB and SimDesigner. A prototype has been built and experimental tests have been done to verify the efficiency of the proposed modeling and controller as well as the effect of flexibility of the joints. The ICaSbot (IUST Cable-Suspended robot) is an under-constrained six-DOF parallel robot actuated by the aid of six suspended cables. An experimental test is conducted for the manufactured flexible joint cable robot of ICaSbot and the outputs of sensors are compared with simulation. The efficiency of the proposed schemes is demonstrated.

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