Workspace analysis and verification of cable-driven parallel mechanism for wind tunnel test

2016 ◽  
Vol 231 (6) ◽  
pp. 1012-1021 ◽  
Author(s):  
Xiaoguang Wang ◽  
Yunbo Hu ◽  
Qi Lin
Keyword(s):  
Wind Tunnel ◽  
Parallel Mechanism ◽  
Aerodynamic Force ◽  
Wind Tunnel Test ◽  
Special Kind ◽  
Parallel Robot ◽  
System Construction ◽  
Vector Projection ◽  
Workspace Analysis ◽  
Projection Strategy

Cable-driven parallel mechanism is a special kind of parallel robot in which traditional rigid links are replaced by actuated cables. This provides a new suspension method for wind tunnel test, in which an aircraft model is driven by a number of parallel cables to fulfil 6-DOF motion. The workspace of such a cable robot is limited due to the geometrical and unilateral force constraints, the investigation of which is important for applications requiring large flight space. This paper focuses on the workspace analysis and verification of a redundant constraint 6-DOF cable-driven parallel suspension system. Based on the system motion and dynamic equations, the geometrical interference (either intersection between two cables or between a cable and the aircraft) and cable tension restraint conditions are constructed and analyzed. The hyperplane vector projection strategy is used to solve the aircraft’s orientation and position workspace. Moreover, software ADAMS is used to check the workspace, and experiments are done on the prototype, which adopts a camera to monitor the actual motion space. In addition, the system construction is designed by using a built-in six-component balance to measure the aerodynamic force. The results of simulation and tests show a good consistency, which means that the restraint conditions and workspace solution strategy are valid and can be used to provide guidance for the cable-driven parallel suspension system’s application in wind tunnel tests.

Feasibility investigation of large-scale model suspended by cable-driven parallel robot in hypersonic wind tunnel test

2016 ◽  
Vol 231 (13) ◽  
pp. 2375-2383 ◽  
Author(s):  
Xiaoguang Wang ◽  
Miaojiao Peng ◽  
Zhenghong Hu ◽  
Yueshi Chen ◽  
Qi Lin
Keyword(s):  
Wind Tunnel ◽  
Large Scale ◽  
Cfd Simulation ◽  
Aerodynamic Force ◽  
Wind Tunnel Test ◽  
Special Kind ◽  
Parallel Robot ◽  
Scale Model ◽  
Hypersonic Wind Tunnel ◽  
Large Scale Model

Cable-driven parallel robot is a special kind of robot, which is actuated by cables. It is already applied in the low speed wind tunnel to get aerodynamic measurement of aircraft model, and the aircraft pose could be adjusted by changing the cable length. Whether it can be used in hypersonic wind tunnel still needs further discussion. This paper presents the dynamics and aerodynamics analysis of a large-scale model supported by 6-DOF cable-driven parallel robot to investigate the feasibility of this special kind of suspension system in hypersonic wind tunnel. The description of this setup with a X-51A-like model is given, and then based on the system dynamic equations, aerodynamic force and stiffness matrix are derived. In the simulation, properties of dynamics and aerodynamics are mainly concerned. A typical shock tunnel with flow duration of about 100 milliseconds is taken as an example, and results show that the system is stable enough to meet the fundamental static wind tunnel test. From the cable tension variation under impact load and the sensitivity analysis, it is likely accessible to derive the aerodynamic forces. Compared with the sting suspension method, cable-driven parallel robot has the priority of higher inherent frequency and more flexible degrees. The interference to the flow field induced by cables is also preliminarily proved to be small by the CFD simulation, which can be acceptable and corrected. Researches conducted show the feasibility of cable-driven parallel robot’s application in hypersonic wind tunnel.

Experimental Studies on Aerodynamic Characteristics of Pantograph System According to the Pantograph Cover Configurations for High Speed Train

2011 ◽  
Author(s):  
Yeongbin Lee ◽  
Minho Kwak ◽  
Kyu Hong Kim ◽  
Dong-Ho Lee
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Aerodynamic Drag ◽  
Aerodynamic Force ◽  
Experimental Studies ◽  
Wind Tunnel Test ◽  
Aerodynamic Characteristics ◽  
Experimental Models ◽  
High Speed Train ◽  
Drag And Lift

In this study, the aerodynamic characteristics of pantograph system according to the pantograph cover configurations for high speed train were investigated by wind tunnel test. Wind tunnel tests were conducted in the velocity range of 20∼70m/s with scaled experimental pantograph models. The experimental models were 1/4 scaled simplified pantograph system which consists of a double upper arm and a single lower arm with a square cylinder shaped panhead. The experimental model of the pantograph cover is also 1/4 scaled and were made as 4 different configurations. It is laid on the ground plate which modeled on the real roof shape of the Korean high speed train. Using a load cell, the aerodynamic force such as a lift and a drag which were acting on pantograph system were measured and the aerodynamic effects according to the various configurations of pantograph covers were investigated. In addition, the total pressure distributions of the wake regions behind the panhead of the pantograph system were measured to investigate the variations of flow pattern. From the experimental test results, we checked that the flow patterns and the aerodynamic characteristics around the pantograph systems are varied as the pantograph cover configurations. In addition, it is also found that pantograph cover induced to decrease the aerodynamic drag and lift forces. Finally, we proposed the aerodynamic improvement of pantograph cover and pantograph system for high speed train.

1030 Development of Wind Tunnel Test Technique for Evaluation of Tail Car Oscillation Caused by Aerodynamic Force in High-Speed Train

2007 ◽  
Vol 2007.82 (0) ◽  
pp. _10-30_
Author(s):  
Ken-taro NAKAGAWA ◽  
Ryo NOMURA ◽  
Hideki KAWAMOTO ◽  
Kazuto NAKAI ◽  
Hirofumi YAMAMORI
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Aerodynamic Force ◽  
Wind Tunnel Test ◽  
High Speed Train ◽  
Test Technique

Analysis about the Work Space of a 3-RPR Parallel Mechanism Based Wind Tunnel Experiment Platform

2015 ◽  
Vol 741 ◽  
pp. 646-650
Author(s):  
Yong Jin Hu ◽  
Wen Jia Chen ◽  
Lu Yang Li ◽  
Jian Zhang ◽  
Zi Yan Shao
Keyword(s):  
Wind Tunnel ◽  
Parallel Mechanism ◽  
Wind Tunnel Test ◽  
Wind Tunnel Experiment ◽  
Work Space ◽  
Experiment Platform ◽  
Test Platform ◽  
Dimensional Parameters ◽  
Position Solution ◽  
The Impact

This paper introduces the characteristics of a 3-RPR parallel mechanism based on the wind tunnel experiment platform, makes use of the constraint condition of the inverse position solution of the structure, and uses MATLAB software to draw images of their work space and analyze the impact of the dimensional parameters of wind tunnel platform on the scope of work space, and it provides a theoretical basis for the design and practical of wind tunnel test platform.

Quantification of aerodynamic forces for truss bridge-girders based on wind tunnel test and kriging surrogate model

2021 ◽  
pp. 136943322199249
Author(s):  
Huan Li ◽  
Xuhui He ◽  
Liang Hu ◽  
Guoji Xu
Keyword(s):  
Wind Tunnel ◽  
Surrogate Model ◽  
High Speed ◽  
Aerodynamic Force ◽  
Wind Tunnel Test ◽  
Geometric Parameters ◽  
Bridge Girders ◽  
Kriging Surrogate Model ◽  
Bridge Girder ◽  
Truss Bridge

This study presents an investigation to quantify the aerodynamics of truss bridge-girders via wind tunnel test and kriging surrogate model. Currently, the conventional methods documented in design specifications only take into consideration the mean drag force at null attack angle. To gain an in-depth understanding on the aerodynamics of truss bridge-girders, experiments on simplified bridge-girder models with various geometric parameters were carried out in uniform flow. A total of 15 truss bridge-girder models with aspect ratio (the ratio of width to height) B/D = 1.0, 1.3, 1.6, 1.9, and 2.2, solidity ratio (the ratio of projected to envelope areas) Φ = 0.20, 0.25, 0.30, 0.35, and 0.40, and two typical truss topologies (Warren and Pratt trusses) were examined in the most concerned range of wind angle of attack α = [–6°, 6°]. These truss bridge-girder models cover most of the high-speed railway bridges widely used in China. Experimental results show that the truss topology has limited effects on the aerodynamics of truss bridge-girders, whereas the effects of α, B/D, and Φ are significant. Based on these wind tunnel results, the ordinary kriging surrogate model was utilized to approximate the aerodynamics of truss bridge-girders. In using this model, aerodynamic force values for test cases can be interpolated with zero variance and uncertainties in unsampled design zones where geometric parameters can be quantified with Gaussian variance.

scholarly journals Workspace Analysis and Optimization of 3-PUU Parallel Mechanism in Medicine Base on Genetic Algorithm

2015 ◽  
Vol 9 (1) ◽  
pp. 214-218 ◽  
Author(s):  
Yongchao Hou ◽  
Yang Zhao
Keyword(s):  
Genetic Algorithm ◽  
Inverse Kinematics ◽  
Parallel Mechanism ◽  
Three Dimensional ◽  
Parallel Robot ◽  
Search Method ◽  
Configuration Design ◽  
Optimization Analysis ◽  
Workspace Analysis ◽  
Promising Application

A novel 3-PUU parallel robot was put forward, on which kinematic analysis was conducted to obtain its inverse kinematics solution, and on this basis, the limitations of the sliding pair and the Hooke joint on the workspace were analyzed. Moreover, the workspace was solved through the three dimensional limit search method, and then optimization analysis was performed on the workspace of this parallel robot, which laid the foundations for the configuration design and further analysis of the parallel mechanism, with the result indicated that this type of robot was equipped with promising application prospect. In addition that, the workspace after optimization can meet more requirements of patients.

Analysis on Metamorphic of the Cable-Driven Parallel Mechanism in Wind Tunnel Test

2013 ◽  
Vol 336-338 ◽  
pp. 1196-1203
Author(s):  
Qing Lin Chen ◽  
Qi Lin
Keyword(s):  
Wind Tunnel ◽  
Parallel Mechanism ◽  
Wind Tunnel Test ◽  
Kinematics And Dynamics ◽  
High Angle ◽  
High Angle Of Attack ◽  
New Methods ◽  
Methods Of Calculation ◽  
Metamorphic Mechanism ◽  
Metamorphic Mechanisms

The workspace is limited in the fixed parameters of cable-driven parallel mechanism and interference often happens between cables and surfaces of actuator. The fundamental basis of metamorphic mechanisms is addressed in accordance with the design, kinematics and dynamics, as well as the compliant metamorphic mechanisms. Metamorphic structure was applied to the cable-driven parallel mechanism. The more adaptive metamorphic mechanism is the full mobile hinge, which provided whole workspace of the frame. Through adding the adaptive hinge, the workspace was extended. The new methods of distant to detect interference between cables and faces of actuator was discussed and applied to a 6 DOF cable-driven parallel mechanism. Comparing with other methods of calculation of interference, it showed more accurate and provided a function to metamorphic control. The volume of interference was coherent and the force of cable was smoother to control when testing the high angle of attack.

Wind Tunnel Test on Wind-Induced Aerodynamic Force of Transmission Tower

2014 ◽  
Vol 578-579 ◽  
pp. 427-431
Author(s):  
Wen Shan Shan ◽  
Bo Li ◽  
Jing Bo Yang ◽  
Yang Liu
Keyword(s):  
Wind Tunnel ◽  
Power Transmission ◽  
Aerodynamic Force ◽  
Wind Tunnel Test ◽  
Force Balance ◽  
Test Results ◽  
Transmission Tower ◽  
Balance Test ◽  
Shape Coefficient ◽  
Wind Speeds

Wind-induced aerodynamic force is the important parameter for transmission tower design. Based on force balance test, the tower and cross arm of typical 500kV power transmission tower have been investigated in wind tunnel using three wind speeds considering Reynolds effect. The test results show that the shape coefficient keeps the same at different wind speed, which means that Reynolds effect on transmission tower can be ignored. Then, the shape coefficients of tower and cross arm are provided.

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