scholarly journals Control Method for Realistic Motion in a Construction Tele-robotic System with a 3-DOF Parallel Mechanism

2003 ◽  
Vol 15 (4) ◽  
pp. 361-368 ◽  
Author(s):  
Dingxuan Zhao ◽  
◽  
Yupeng Xia ◽  
Hironao Yamada ◽  
Takayoshi Muto
Keyword(s):  
Parallel Mechanism ◽  
Control Method ◽  
Robotic System ◽  
Degree Of Freedom ◽  
Experimental Result ◽  
Parallel Mechanisms ◽  
High Quality ◽  
Link Mechanism ◽  
Acceleration Sensors ◽  
Parallel Link

In this study, we developed a construction tele-robotic system, which can be widely used, for example, for restoration works in damaged areas. The system consists of a servo-controlled construction robot, two joysticks for operations of the robot from a remote place and a 3-degree-of-freedom (DOF) parallel mechanism. An important problem to be solved in such a system is how to convey adequate presence of working area in a high quality to the operator. In this paper, we propose a control method of a 3-DOF parallel link mechanism to simulate the motion of the construction robot by using three acceleration sensors. The validity of this method has been confirmed experimentally. According to the experimental result, each motion of roll, pitch and heave of the construction robot can be simulated accurately by the 3-DOF parallel mechanisms.

Presentation of Realistic Motion to the Operator in Operating a Tele-operated Construction Robot

2002 ◽  
Vol 14 (2) ◽  
pp. 98-104 ◽  
Author(s):  
Dingxuan Zhao ◽  
◽  
Yupeng Xia ◽  
Hironao Yamada ◽  
Takayoshi Muto
Keyword(s):  
Visual Information ◽  
Control Method ◽  
Robotic System ◽  
Experimental Result ◽  
High Quality

In this study, a tele-operated construction robotic system was developed. An important problem to be solved in such a system is how the operator can feel the presence of working fields in a high quality. To solve the problem, in this paper, a new control method of employing the 3-DOF motion base is investigated to generate such a realistic motion as produced by a 6-DOF motion base. In order to confirm the validity of this control method, an evaluation experiment has been preformed. According to the experimental result, with both visual information and the motion of the robot, the operator on the 3-DOF motion base could feel the motion of not only roll, pitch and heave, but also surge, sway and yaw as well.

Precision and Dimensional Analysis about Parallel Mechanism Having Less Degree of Freedom Based on Differential Geometry

2014 ◽  
Vol 940 ◽  
pp. 509-512 ◽  
Author(s):  
De Xing Zheng ◽  
Bin Wang
Keyword(s):  
Differential Geometry ◽  
Dimensional Analysis ◽  
Parallel Mechanism ◽  
Structural Parameters ◽  
Maximum Error ◽  
Error Model ◽  
Degree Of Freedom ◽  
Vector Model ◽  
Parallel Mechanisms ◽  
Output Error

A 3-PUU parallel mechanism was studied, which can perform one-dimensional translation about z-axis and two-dimensional rotations about y-axis and x-axis. This paper shows the study about the precision analysis, the dimensional analysis and the synthesis problem of the parallel mechanism having less degree of freedom. First, the closed-loop vector model was built based on analyzing the branched-chains of 3-PUU, the pose error model was built through the differential geometry, and the error model of positive solutions was obtained which contains all the structural parameters errors. For the error of structural parameters given, the pose output error can be solved out by application of this model, the area of maximum error is found out. And the influence of pose output error was analyzed with postures changed. The dimensional analysis of 3-PUU was also done by this error model, and the reasonable selection of mechanism parameters was discussed. And then the rationality of structure dimensional design was discussed in this paper. Finally, this method also may be used in the dimensional analysis of other less freedom parallel mechanisms.

A 3-ṞPR Parallel Mechanism With Singularities That are Self-Motions

2010 ◽  
Vol 2 (3) ◽  
Author(s):  
Novona Rakotomanga ◽  
Ilian A. Bonev
Keyword(s):  
Parallel Mechanism ◽  
Control Strategies ◽  
Joint Space ◽  
Degree Of Freedom ◽  
Parallel Mechanisms ◽  
Active Joint ◽  
Cartesian Space ◽  
Three Degree Of Freedom

The Cartesian workspace of most three-degree-of-freedom parallel mechanisms is divided by Type 2 (also called parallel) singularity surfaces into several regions. Accessing more than one such region requires crossing a Type 2 singularity, which is risky and calls for sophisticated control strategies. Some mechanisms can still cross these Type 2 singularity surfaces through “holes” that represent Type 1 (also called serial) singularities only. However, what is even more desirable is if these Type 2 singularity surfaces were curves instead. Indeed, there exists at least one such parallel mechanism (the agile eye) and all of its singularities are self-motions. This paper presents another parallel mechanism, a planar one, whose singularities are self-motions. The singularities of this novel mechanism are studied in detail. While the Type 2 singularities in the Cartesian space still constitute a surface, they degenerate into lines in the active-joint space, which is the main result of this paper.

Dynamic Analysis and Control Research of a 3-DOF Hydraulic Driven Parallel Mechanism

2020 ◽  
Vol 13 (2) ◽  
pp. 156-170
Author(s):  
Bing Zhang ◽  
Saike Jiang ◽  
Ziliang Jiang ◽  
Jiandong Li ◽  
Kehong Zhou ◽  
...  
Keyword(s):  
Control System ◽  
Dynamic Model ◽  
Control Strategy ◽  
Parallel Mechanism ◽  
Control Method ◽  
Simulation Method ◽  
Euler Method ◽  
Parallel Mechanisms ◽  
Rigid Body Dynamic ◽  
And Control

Background: The parallel mechanism is widely used in motion simulators, parallel machine tools, medical equipment and other fields. It has advantages of high rigidity, stable structure and high carrying capacity. However, the control strategy and control method are difficult to study because of the complexity of the parallel mechanism system. Objective: The purpose of this paper was to verify the dynamic model of a hydraulic driven 3-DOF parallel mechanism and propose a compound control strategy to broaden the bandwidth of the control system. Methods: The single rigid body dynamic model of the parallel mechanism was established by the Newton Euler method. The feed forward control strategy based on joint space control with inverse kinematic was designed to improve the bandwidth and control precision. The co-simulation method based on MATLAB / SIMULINK and ADAMS was adopted to verify the dynamics and control strategy. Results: The bandwidth of each degree of freedom in the 3-DOF parallel mechanism was used to expand about 10Hz and the amplitude error was controlled below 5%. Conclusion: Based on the designed dynamic model and composite control strategy, the controlled accuracy of the parallel mechanism is improved and the bandwidth of the control system is broadened. Furthermore, the improvements can be made in aspects of control accuracy and real-time performance to compose more patents on parallel mechanisms.

Design of Statically Balanced Six-Degree-of-Freedom Parallel Mechanisms Based on Tensegrity System

2009 ◽  
Author(s):  
S. M. Mehdi Shekarforoush ◽  
Mohammad Eghtesad ◽  
Mehrdad Farid
Keyword(s):  
Parallel Mechanism ◽  
Degree Of Freedom ◽  
Parallel Mechanisms ◽  
Engineering Systems ◽  
Suitable Alternative ◽  
Tensegrity Systems ◽  
Six Degree Of Freedom

A parallel mechanism that is based on tensegrity system is studied in this article. Tensegrity systems are a suitable alternative for conventional engineering systems like mechanisms for some application. In this article, tensegrity mechanisms are classified into tensegrity mechanism with passive and active compliant components. Based on this classification, two types of six-degree-of-freedom parallel mechanism are proposed and kinematics and static of them are solved. The first type is the 6–6 tensegrity mechanism with passive compliant components and the second type is the 6-3 tensegrity mechanism with active compliant components.

Stiffness Analysis and Design of a Compact Modified Delta Parallel Mechanism

Robotica ◽  
2004 ◽  
Vol 22 (4) ◽  
pp. 463-475 ◽  
Author(s):  
Woo-Keun Yoon ◽  
Takashi Suehiro ◽  
Yuichi Tsumaki ◽  
Masaru Uchiyama
Keyword(s):  
Parallel Mechanism ◽  
Rotation Axis ◽  
Haptic Interface ◽  
Structural Stiffness ◽  
Parallel Mechanisms ◽  
Simple Method ◽  
Elastic Deformations ◽  
Stiffness Analysis ◽  
Analysis And Design ◽  
Parallel Link

In our previous work, we developed a compact 6-DOF haptic interface as a master device which achieved an effective manual teleoperation. The haptic interface contains a modified Delta parallel-link positioning mechanism. Parallel mechanisms are usually characterized by a high stiffness, which, however, is reduced by elastic deformations of both parts and bearings. Therefore, to design such a parallel mechanism, we should analyze its structural stiffness, including elastic deformations of both parts and bearings. Then we propose a simple method to analyze structural stiffness in a parallel mechanism using bearings. Our method is based on standard concepts such as static elastic deformations. However, the important aspect of our method is the manner in which we combine these concepts and how we obtain the value of the elasticity coefficient of a rotation axis in a bearing. Finally, we design a modified Delta mechanism, with a well-balanced stiffness, based on our method of stiffness analysis.

Design and workspace analysis of a 3-degree-of-freedom parallel swivel head with large tilting capacity

2015 ◽  
Vol 231 (10) ◽  
pp. 1838-1849 ◽  
Author(s):  
Jiangzhen Guo ◽  
Dan Wang ◽  
Rui Fan ◽  
Wuyi Chen
Keyword(s):  
Machine Tool ◽  
Parallel Mechanism ◽  
Degree Of Freedom ◽  
Parallel Mechanisms ◽  
Spherical Joint ◽  
Hybrid Machine Tool ◽  
Tilting Angle ◽  
Workspace Analysis ◽  
Hybrid Machine ◽  
Orientation Workspace

Traditional parallel mechanisms are usually characterized by small tilting capability. To overcome this problem, a 3-degree-of-freedom parallel swivel head with large tilting capacity is proposed in this article. The proposed parallel swivel head, which is structurally developed from a conventional 3-PRS parallel mechanism, can achieve a large tilting capability by means of structural improvements. First, a modified spherical joint with a maximum tilting angle of ±120° is devised to diminish the physical restrictions on the orientation workspace. Second, a UPS typed leg is introduced for the sake of singularity elimination. The superiority of the proposed parallel swivel head is theoretically proved by investigations of singularity-free orientation workspace and then is experimentally validated using a prototype fabricated. The theoretical and experimental results illustrate that the proposed parallel swivel head has a large tilting capacity and thus can be used as swivel head for a hybrid machine tool which is designed to be capable of realizing both horizontal and vertical machining.

Workspace Analysis of New Type Parallel Mechanism with Serial Input

2011 ◽  
Vol 308-310 ◽  
pp. 2114-2119 ◽  
Author(s):  
Peng Lin Jing ◽  
Zhi You Feng
Keyword(s):  
Parallel Mechanism ◽  
Inverse Kinematic ◽  
Parallel Mechanisms ◽  
Constraint Force ◽  
Workspace Analysis ◽  
Inverse Solutions ◽  
New Type ◽  
Parallel Link ◽  
Branched Chain ◽  
The Impact

A new 4 DOF parallel mechanism with serial input limb is presented ——2UPS-RPU parallel mechanism, the limb with serial input is a less contrained active branched-chain,the number of its DOF is less than six,that is to say,the limbs not only transmitting driving force but also constraint force at the same time.Compared with traditional parallel mechanisms,the mechanism with serial input has greater number of DOF than the number of limbs and don’t lose the property of parallel mechanism. The inverse solutions to positions of the mechanism are modeled by inverse kinematic analysis in this paper, then the constraint conditions are established according to factors influencing the workspace of parallel mechanism,such as the limits of the hinge angle and the parallel link length.The workspace of 2UPS-RPU parallel mechanism can be obtained by using exetreme-boundary numerical algorithm in Matlab,the volume of workspace can be quantified by means of computation,and analyzing the impact of rod length ,circumradius of moving and fixed platform and motion pair rotation angle on the workspace.

Type Synthesis of 3-DOF Rotational Parallel Mechanisms With No Intersecting Axes

2012 ◽  
Author(s):  
Ziming Chen ◽  
Wen-ao Cao ◽  
Zhen Huang
Keyword(s):  
Parallel Mechanism ◽  
Screw Theory ◽  
Degree Of Freedom ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Constraint Force ◽  
New Approach ◽  
Spherical Parallel Mechanism ◽  
Rotational Motions

Parallel mechanisms which can realize three rotational motions are very important in the parallel mechanism family. Not the same with the traditional spherical parallel mechanism, a new kind of 3-DOF (degree of freedom) rotational parallel mechanism with no intersecting axes (RPMNIA) are proposed in this paper. This kind of rotational parallel mechanisms have the advantages of easy manufacturing. A new approach using the screw theory and the subchain theory is proposed to design the branches with only one constraint force and some new one-force-branches are found. Using these new branches, a group of 3-DOF rotational parallel mechanisms without intersecting axes are synthesized.

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