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.

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.

A Novel Spherical Parallel Manipulator with Circular Guide

2013 ◽  
Vol 325-326 ◽  
pp. 1014-1018
Author(s):  
Hai Rong Fang ◽  
Zhi Hong Chen ◽  
Yue Fa Fang
Keyword(s):  
Inverse Kinematics ◽  
Parallel Manipulator ◽  
Degree Of Freedom ◽  
High Rigidity ◽  
Geometric Conditions ◽  
Spherical Parallel Manipulator

In this paper, a novel 3-degree-of-freedom (DOF) parallel manipulator that can perform three rotations around the remote centre is presented. The theory of screws and reciprocal screws is employed for the analysis of the geometric conditions. In particular, using circular guide to instead of R joints, so that has the advantage of enabling continuous 360° revolute around Z-axis. The inverse kinematics of mechanism is given and the workspace has a good performance. To compare with the machine constructed with traditional joints, it has the advantage of high rigidity and precision.

Experimental study and performance analysis on a new dehumidifier with outside evaporative cooling

2019 ◽  
Vol 148 ◽  
pp. 200-211 ◽  
Author(s):  
Xiaosong Cheng ◽  
Donggen Peng ◽  
Yonggao Yin ◽  
Shaohua Xu ◽  
Danting Luo
Keyword(s):  
Experimental Study ◽  
Performance Analysis ◽  
Evaporative Cooling ◽  
And Performance

Experimental study and performance analysis on high gradient insulators

2012 ◽  
Vol 24 (3) ◽  
pp. 563-566
Author(s):  
任成燕 Ren Chengyan ◽  
袁伟群 Yuan Weiqun ◽  
张东东 Zhang Dongdong ◽  
严萍 Yan Ping ◽  
王珏 Wang Jue ◽  
...  
Keyword(s):  
Experimental Study ◽  
Performance Analysis ◽  
High Gradient ◽  
And Performance

scholarly journals Performance evaluation of a 15 kWth biomass gasifier in downdraft and updraft operating modes: an experimental study

2018 ◽  
Vol 172 ◽  
pp. 06005
Author(s):  
K. Shanmuganandam ◽  
J. Anichai ◽  
V. Jayakumar
Keyword(s):  
Power Generation ◽  
Experimental Study ◽  
Performance Evaluation ◽  
Performance Analysis ◽  
Ambient Air ◽  
Producer Gas ◽  
Operating Modes ◽  
Feed Stock ◽  
Alternate Source ◽  
And Performance

Biomass gasifiers are equipment’s that can generate producer gas which is a renewable, alternate source of energy that can be employed for power generation and thermal applications. In this experimental study the gasifier is tested in updraft and downdraft modes and performance analysis was carried out. For both the studies, casuarina wood and ambient air were used as feed stock and gasification agent respectively. From the experimental analysis it was inferred that the performance of the biomass gasifier was higher in downdraft mode than updraft mode.

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.

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