scholarly journals Elastostatic Modeling and Shape Optimization of a 6-DOF Haptic Interface Device

2012 ◽  
Author(s):  
Stéphane Caro ◽  
Damien Chablat ◽  
Chao Chen
Keyword(s):  
Shape Optimization ◽  
Parallel Manipulator ◽  
Haptic Interface ◽  
Element Analysis ◽  
Stiffness Model ◽  
The Finite Element Analysis ◽  
Six Dof ◽  
The Masses ◽  
Six Degree Of Freedom ◽  
Interface Device

This paper deals with the shape optimization of a six degree-of-freedom haptic interface device. This six-dof epicyclic-parallel manipulator has all actuators located on the ground. A regular dexterous workspace is introduced to represent the mobility of user’s hand. Throughout this workspace, the deviation of the mobile platform is bounded to provide a better feeling to the user and the masses in motion are minimized to increase the transparency of the haptic device. The stiffness model is written using a virtual joint method and compared with the results obtained with the finite element analysis to be validated. Finally, the shape of the links are optimized in order to minimize the masses in motion while guaranteeing a given stiffness throughout the regular workspace of the mechanism.

The Analyse on Stiffness Model of 3-PPSR Flexible Parallel Robot

2014 ◽  
Vol 716-717 ◽  
pp. 1643-1647
Author(s):  
Yu Liang Luan ◽  
Wei Bin Rong ◽  
Li Ning Sun
Keyword(s):  
Finite Element ◽  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Parallel Robot ◽  
Force Balance ◽  
Element Analysis ◽  
Flexible Hinge ◽  
Stiffness Model ◽  
The Finite Element Analysis ◽  
The Mathematical Model

In order to achieve greater workspace motion, it’s designed a high aspect ratio 3-PPSR flexible parallel robot, driven by a piezoelectric motor, connected by flexible hinges, which has the advantages of simple structure, non singular, seamless, high motion precision. Because of the stiffness of the system directly affecting the motion accuracy, load bearing performance, according to the characteristics of high aspect ratio flexible hinge, It’s established the mathematical model of flexible hinge through finite element method. Using method of integral stiffness, conbined coordination equation with force balance equation, the flexible stiffness model of system is obtained. Finally, through using Ansys, it’s confirmed the validity of the theoretical model by comparing of the theoretical stiffness model results with the finite element analysis of the model results, to provide a reliable guarantee for optimization and analysis of kinematics and dynamics of flexible parallel robot.

Biomechanical Design of a Novel Six DOF Compliant Prosthetic Ankle-Foot 2.0 for Rehabilitation of Amputee

2017 ◽  
Author(s):  
Tan Thang Nguyen ◽  
Thanh-Phong Dao ◽  
Shyh-Chour Huang
Keyword(s):  
Strain Energy ◽  
Differential Evolution Algorithm ◽  
Maximum Energy ◽  
Element Analysis ◽  
Glass Fiber Reinforced Plastic ◽  
Glass Fiber Reinforced ◽  
Reinforced Plastic ◽  
The Finite Element Analysis ◽  
Six Dof ◽  
Deformation Stress

This paper develops a new design of a compliant prosthetic ankle-foot 2.0. The ankle-foot is a composite made of glass-fiber reinforced plastic (GFRP). The finite element analysis is used to evaluate the structural behavior of the ankle-foot, including the deformation, stress and strain energy. The Taguchi method is used to build a special orthogonal array. By using a differential evolution algorithm, the geometric parameters of the ankle-foot are determined. The result indicated that the optimal strain energy is improved approximately 155%. The maximum energy strain of 93.914 mJ is recognized. The results also revealed that the prosthetic ankle-foot is becoming more flexible due to the compliant ankle. Lastly, the prosthetic ankle-foot was proved to be effective for a human body up to 100 kg.

Displacement Analysis of a Six-DOF Parallel Manipulator With 3R3P and 4R2P Chains

1998 ◽  
Author(s):  
R. Kamra ◽  
D. Kohli ◽  
A. K. Dhingra
Keyword(s):  
Parallel Manipulator ◽  
Solution Procedure ◽  
Analysis Problem ◽  
Forward Displacement ◽  
Numerical Examples ◽  
Displacement Analysis ◽  
Tangent Method ◽  
Six Dof ◽  
Six Degree Of Freedom ◽  
Forward Displacement Analysis

Abstract This paper addresses the forward displacement analysis of a six degree of freedom platform manipulator which is actuated by three different configurations involving six chains with six joints in each chain. The displacement analysis problem involves finding all possible positions and orientations of the platform along with all the joint variables in response to the inputs supplied. The forward displacement analysis problem is solved using the “Suppressed Tangent method.” The proposed solution procedure is illustrated through three numerical examples. The first example deals with forward displacement analysis of a platform manipulator actuated by six 3R3P chains whereas the second and third examples deal with a manipulator actuated by five 3R3P and one 4R2P, and four 3R3P and two 4R2P chains respectively.

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.

Modeling and prototype experiment of a six-DOF parallel micro-manipulator with nano-scale accuracy

2014 ◽  
Vol 229 (14) ◽  
pp. 2611-2625
Author(s):  
Yi Dong ◽  
Feng Gao ◽  
Yi Yue
Keyword(s):  
Degrees Of Freedom ◽  
Experimental Result ◽  
Element Analysis ◽  
Six Degrees Of Freedom ◽  
Compliant Structure ◽  
Nano Scale ◽  
Stiffness Model ◽  
Micro Manipulator ◽  
Six Dof ◽  
The Relationship

This paper presents a high-accurate micro-manipulator featured with monolithic compliant structure, orthogonally arranged parallel mechanism and piezoelectric (PZT) actuation. 6-SPS mechanism is employed to provide six degrees of freedom (DOF), including three linear translations and three rotations. The kinematics and stiffness of the micro-manipulator is studied first in this paper. Then, the relationship between PZT nominal displacement and the end pose is derived. Aiming at achieving trajectories with nano-scale accuracy, a two-step strategy is proposed. Finite element analysis (FEA) is conducted to verify the kinematics and stiffness model. Finally, in order to demonstrate the performance of the micro-manipulator, experiments of typical trajectories are carried out. The experimental result shows that the proposed micro-manipulator is capable of achieving trajectories with nano-scale accuracy.

Stiffness Modeling and Analysis of Passive Four-Bar Parallelogram in Fully Compliant Parallel Positioning Stage

2011 ◽  
Vol 1 (1) ◽  
pp. 61-78 ◽  
Author(s):  
X. Jia ◽  
Y. Tian ◽  
D. Zhang ◽  
J. Liu
Keyword(s):  
Finite Element Analysis ◽  
Parallel Mechanism ◽  
Element Analysis ◽  
Modeling And Analysis ◽  
Stiffness Modeling ◽  
Stiffness Model ◽  
The Finite Element Analysis ◽  
Positioning Stage ◽  
Compliant Parallel Mechanism ◽  
Stiffness Variation

In order to investigate the influence of the stiffness of the compliant prismatic pair, a planar four-bar parallelogram, in a fully compliant parallel mechanism, the stiffness model of the passive compliant prismatic pair in a compliant parallel positioning stage is established using the compliant matrix method and matrix transformation. The influences of the constraints and the compliance of the connecting rods on the flexibility characteristics of the prismatic pair are studied based on the developed model. The relative geometric parameters are changed to show the rules of the stiffness variation and to obtain the demands for simplification in the stiffness modeling of the prismatic pair. Furthermore, the finite element analysis has been conducted to validate the analytical model.

Sensitivity Analysis in Shape Optimization Design for Pressure Vessel

1992 ◽  
Vol 114 (4) ◽  
pp. 428-432 ◽  
Author(s):  
L. Younsheng ◽  
L. Ji
Keyword(s):  
Sensitivity Analysis ◽  
Finite Element ◽  
Shape Optimization ◽  
Pressure Vessel ◽  
Optimization Design ◽  
Element Model ◽  
Element Analysis ◽  
Design Variables ◽  
The Finite Element Analysis ◽  
Derivatives Of

In this paper, sensitivity analysis for a finite element model during shape optimization design for a pressure vessel is discussed. The derivation is emphatically carried out for the derivatives of stiffness matrix and various load ranks with respect to design variables. Because the information resulting from the finite element analysis is fully utilized in this method, the programs are greatly simplified so that it becomes possible to carry out the shape optimization with comparatively more versatility. The conclusion is illustrated by an example.

A New Methodology for an Optimal Shape Design

2011 ◽  
Vol 61 ◽  
pp. 43-54 ◽  
Author(s):  
W. El Alem ◽  
A. El Hami ◽  
Rachid Ellaia
Keyword(s):  
Structural Optimization ◽  
Shape Optimization ◽  
Geometric Modeling ◽  
High Performance ◽  
Optimization Problems ◽  
Continuous Optimization ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Optimization Methodology ◽  
Continuous Optimization Problems

The aim of this paper is to study the implementation of an efficient and reliable methodology for shape optimization problems where the objective function and constraints are not known explicitly and are dependent on the Finite Element Analysis (FEA). It is based on the Simultaneous Perturbation Stochastic Approximation (SPSA) method for solving unconstrained continuous optimization problems. We also propose Penalty SPSA (PSPSA) for solving constrained optimization problems, the constraints are handled using exterior point penalty functions within an algorithm that combines SPSA and exact penalty transformations. This paper presents a new structural optimization methodology that combines shape optimization, geometric modeling, FEA and PSPSA method to successfully optimize structural optimization problems. Several tests have been performed on some well known benchmark functions to demonstrate the robustness and high performance of the suggested methodology. In addition, an illustrative two-dimensional structural problem has been solved in a very efficient way. The numerical results demonstrate the robustness and high performance of the suggested methodology for structural optimization problems.

Stiffness Modeling and Analysis of Passive Four-Bar Parallelogram in Fully Compliant Parallel Positioning Stage

2013 ◽  
pp. 59-75
Author(s):  
X. Jia ◽  
Y. Tian ◽  
D. Zhang ◽  
J. Liu
Keyword(s):  
Finite Element Analysis ◽  
Parallel Mechanism ◽  
Element Analysis ◽  
Modeling And Analysis ◽  
Stiffness Modeling ◽  
Stiffness Model ◽  
The Finite Element Analysis ◽  
Positioning Stage ◽  
Compliant Parallel Mechanism ◽  
Stiffness Variation

In order to investigate the influence of the stiffness of the compliant prismatic pair, a planar four-bar parallelogram, in a fully compliant parallel mechanism, the stiffness model of the passive compliant prismatic pair in a compliant parallel positioning stage is established using the compliant matrix method and matrix transformation. The influences of the constraints and the compliance of the connecting rods on the flexibility characteristics of the prismatic pair are studied based on the developed model. The relative geometric parameters are changed to show the rules of the stiffness variation and to obtain the demands for simplification in the stiffness modeling of the prismatic pair. Furthermore, the finite element analysis has been conducted to validate the analytical model.

TriRhino: a five-DOF hybrid serial-parallel manipulator with all rotating axes being continuous: stiffness analysis and experiments

2020 ◽  
pp. 1-15
Author(s):  
Yundou Xu ◽  
Fan Yang ◽  
Zhenghe Xu ◽  
Jiantao Yao ◽  
Yulin Zhou ◽  
...  
Keyword(s):  
Structural Design ◽  
Parallel Manipulator ◽  
Element Analysis ◽  
Great Ability ◽  
Stiffness Analysis ◽  
The Real ◽  
Hybrid Manipulator ◽  
The Finite Element Analysis ◽  
Measurement Results ◽  
Structural Parts

Abstract This paper studies the stiffness and experiment of a five-degree-of-freedom hybrid, serial-parallel, manipulator, with all rotating axes being continuous: TriRhino. First, the motion principle of the hybrid manipulator is introduced and the structural design is presented. Next, the stiffness analysis of the hybrid manipulator is carried out. Specifically, a stiffness test, based on prototype and loading device, is performed, proving that the real stiffness is lower than that obtained by the finite element analysis. Following, the main geometric parameters, involving error, are determined, while the real values of the parameters with error are identified, through performed calibration experiments. Finally, the measurement results show that the positioning accuracy of the manipulator is significantly improved, after kinematic calibration. Moreover, machining experiments on a workpiece show the great ability of the proposed manipulator, in machining parts with curved surface, thus great application prospects, in the machining of structural parts with complex surfaces, are quite realistic.

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