scholarly journals Design and Analysis of a Wire-Driven Parallel Mechanism for Low-Gravity Environment Simulation

2014 ◽  
Vol 6 ◽  
pp. 810606 ◽  
Author(s):  
Weifang Wang ◽  
Xiaoqiang Tang ◽  
Zhufeng Shao ◽  
Jiping Yang ◽  
Wangmin Yi
Keyword(s):  
Parallel Mechanism ◽  
Quality Index ◽  
Parallel Manipulator ◽  
Force Distribution ◽  
The Moon ◽  
Low Gravity ◽  
Wire Tension ◽  
Environment Simulation ◽  
The Wire ◽  
And Control

Traditional simulation mechanisms are unable to meet the simulation requirements of spacecraft launcher in low-gravity environment, like in the Moon. Based on the advantages of wire-driven parallel mechanism, a 6-DOF low-gravity environment simulation device with eight wires is designed in this paper. Firstly, the configuration and dimensional design of this wire-driven parallel mechanism are carried out. To operate and control the wire-driven parallel mechanism, a force distribution algorithm is introduced and the workspace is analyzed. Then, an evaluation index named quality index is established in order to study the performance of the wire-driven parallel manipulator in its workspace and reasonable tension is obtained after analyzing the influence on quality index caused by different wire tension.

Experimental Research on Force/Position Control of a Wire-Driven Parallel Rehabilitative Robot

2011 ◽  
Vol 138-139 ◽  
pp. 68-73 ◽  
Author(s):  
Ke Yi Wang ◽  
Fang Chao Ma ◽  
Meng Hao ◽  
Li Xun Zhang ◽  
Pan Liu
Keyword(s):  
Position Control ◽  
Parallel Robot ◽  
Force Balance ◽  
Robot System ◽  
End Effector ◽  
Wire Tension ◽  
Parallel Control ◽  
The Wire ◽  
And Control ◽  
Force Balance Equation

During rehabilitative training, a 3-DOF wire-driven parallel robot driven was designed to coordinate and control the trainer pelvis movement. Based on the force balance equation of the end-effector, the stiffness problem about the robot system was analyzed and one kind of force/position parallel control strategy was proposed that the position loop would realize the end-effector motion trajectory, and the force loop would control the wire tension. The experimental results have shown that the robot systematic stiffness is related with the wire tension and can be changed to realize the compliance control of the robot system by adjusting the wire tension.

Simulation and Experiment of Wire Tensions for Wire-Driven Parallel Manipulator

2013 ◽  
Vol 694-697 ◽  
pp. 2779-2782
Author(s):  
Yi Xin Chen ◽  
Sui Lu Yue ◽  
Qi Lin ◽  
Zhao Wang
Keyword(s):  
Nonlinear Programming ◽  
Multiple Solutions ◽  
Parallel Manipulator ◽  
Programming Model ◽  
Optimal Solution ◽  
Wire Tension ◽  
Nonlinear Programming Model ◽  
Simulation And Experiment ◽  
Simulation Results ◽  
The Wire

For the multiple solutions of wire tensions to wire-driven parallel manipulator, the paper presents a wire tension optimization program based on the penalty function. After building a nonlinear programming model and simulating in MATLAB, the optimal solution of wire tensions under the minimal preload is calculated. Compared with the simulation results and experimental results, it shows that the wire tensions in experiment are relatively stable and the trends are overall consistent with the simulation results. The study lays a foundation for selecting the suitable preload for the wire-driven parallel manipulator.

scholarly journals The impact of air quality on its Baidu index: grey model analysis

2021 ◽  
Author(s):  
Leping Tu ◽  
Yan Chen
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Quality Index ◽  
Air Quality Index ◽  
Grey Correlation ◽  
Convolution Model ◽  
Grey Correlation Analysis ◽  
And Control ◽  
The Impact ◽  
The Relationship

Abstract To investigate the relationship between air quality and its Baidu index, we collect the annual Baidu index of air pollution hazards, causes and responses. Grey correlation analysis, particle swarm optimization and grey multivariate convolution model are used to simulate and forecast the comprehensive air quality index. The result shows that the excessive growth of the comprehensive air quality index will lead to an increase in the corresponding Baidu index. The number of search for the causes of air quality has the closest link with the comprehensive air quality index. Strengthening the awareness of public about air pollution is conducive to the improvement of air quality. The result provides a reference for relevant departments to prevent and control air pollution.

scholarly journals EVALUATION AND SELECTION OF THE METHOD FOR CONTROL SYSTEM THE WIRE TENSION IN CUT-OUT ELECTRIC EROSION MACHINES

2021 ◽  
pp. 47-50
Author(s):  
M. N. Buza ◽  
N. O. Butusov ◽  
A. S. Voronin ◽  
A. G. Alekhin
Keyword(s):  
Control System ◽  
Wire Tension ◽  
Electric Erosion ◽  
The Wire ◽  
Selection Of

Variants of the electrode tension mechanism in an electric erosion machine are considered in order to ensure a quick change of the electrode thread and the required degree of tension.

Interaction Between Wire and Ingot in Wiresaw Slicing

1999 ◽  
Author(s):  
Fuqian Yang ◽  
J. C. M. Li ◽  
Imin Kao
Keyword(s):  
Finite Element ◽  
Contact Zone ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Bending Stiffness ◽  
Mechanical Interaction ◽  
Wire Tension ◽  
Cutting Zone ◽  
The Wire

Abstract The deformation of the wire in the wiresaw slicing process was studied by considering directly the mechanical interaction between the wire and the ingot. The wire tension on the upstream is larger than on the downstream due to the friction force between the wire and the ingot. The tension difference across the cutting zone increases with friction and the span of the contact zone. The pressure in the contact zone increases from the entrance to the exit if the wire bending stiffness is ignored. The finite element results show that the wire bending stiffness plays an important role in the wire deformation. Higher wire bending stiffness (larger wire size) generates higher force acting onto the ingot for the same amount of wire deformation, which will leads to higher material removal rate and kerf loss. While larger wire span will reduce the force acting onto the ingot for a given ingot displacement in the direction perpendicular to the wire.

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