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

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.

2013 ◽  
Vol 456 ◽  
pp. 146-150
Author(s):  
Zhi Jiang Xie ◽  
Jun Zhang ◽  
Xiao Bo Liu

This paper designed a kind of parallel mechanism with three degrees of freedom, the freedom and movement types of the robot are analyzed in detail, the parallel mechanisms Kinematics positive and inverse solutions are derived through using the vector method. And at last its workspace is analyzed and studied systematically.


Author(s):  
Ame´lie Jeanneau ◽  
Just Herder ◽  
Thierry Laliberte´ ◽  
Cle´ment Gosselin

This paper first presents the concept and the fabrication of a new type of compliant rolling joint which combines the advantages of compliant mechanisms with those of rolling link mechanisms. In this joint, flexible bands create the necessary constraints to enforce a rolling movement between two links. Then, the rapid prototyping techniques used for the compliant rolling joint fabrication are described. The kinematics of one application of this joint in a 3-DOF planar parallel mechanism are then presented. A semigraphical method was used to find the solutions to the inverse kinematic problem. Finally, the workspace analysis and the velocity equations are presented.


Author(s):  
Wei Ye ◽  
Yuefa Fang ◽  
Sheng Guo ◽  
Haibo Qu

In this paper, the motion equivalent chain method is proposed and then applied to the type synthesis of a class of 2R2T parallel mechanism. The equivalent serial chains are synthesized for a specific 2R2T motion pattern based on screw theory. Feasible limb structures that provide a constraint couple and a constraint force are enumerated according to the reciprocity of the twist and wrench systems. Several motion equivalent single loop chains are constructed with the equivalent serial chains. Using motion equivalent single loop chains to replace the equivalent serial chains, a class of 2R2T parallel mechanisms is obtained based on the foundation of motion equivalent single loop chain structures.


2001 ◽  
Vol 13 (5) ◽  
pp. 488-496 ◽  
Author(s):  
Noriaki Ando ◽  
◽  
Masahiro Ohta ◽  
Kohei Gonda ◽  
Hideki Hashimoto

This paper describes the research results on telemicromanipulation systems for microlevel tasks. Because of its better manipulation precision, stiffness and speed characteristics, the parallel mechanism micromanipulator was chosen to compose our systems. First, the kinematic analysis of our original manipulator mechanism is performed. Then, the structure of our parallel manipulator, control scheme, and experimental results are shown. Position accuracy and device control characteristics are analyzed and the feasibility of the use of parallel mechanisms for micromanipulator is then discussed. A parallel manipulator motion is restricted by 3 factors: mechanical limits of the passive joints, collision between links and actuators limitations. Results of the numerical workspace analysis considering the above factors are shown. We are proposing the use of dual manipulators for implementing improved real manipulation systems. The first kinematics and workspace analysis of dual systems using the VR simulator are also shown.


2011 ◽  
Vol 201-203 ◽  
pp. 1907-1912
Author(s):  
Rong Jiang Cui ◽  
Zong He Guo ◽  
Zi Xun Yin ◽  
Song Song Zhu

First, the branched-chain of parallel mechanism was Classified according to reciprocal screw theory. Then, the introduction of variable topology mechanism theory, with the characteristics of parallel mechanisms themselves, the definition and basic variable topology means of variable topology parallel mechanism were given. With evolutionary theory, the method to design lower-mobility parallel mechanisms of non-asymmetric was proposed based on variable topology mechanism theory .Taking 3-RPS as ideal mechanism and topology synthesis was carried out, besides 2-RPS mechanism were analyzed. The introduction of variable topology mechanism theory provided a theoretical basis and innovative approaches for the synthesis configuration of Lower-mobility parallel mechanisms of non-asymmetric.


2013 ◽  
Vol 373-375 ◽  
pp. 2136-2142 ◽  
Author(s):  
Rui Fan ◽  
Huan Liu ◽  
Dan Wang

A spatial 3-DOF translational parallel mechanism is analyzed. Its inverse kinematic model is established. The section view of the workspace of the parallel mechanism is presented via boundary search method under the defined constraints. Considering the workspace volume as the optimization object, the relationship between structural parameters and workspace volume is obtained and the structural parameters to be optimized are determined. Finally, the optimization configuration of the mechanism is obtained. The results show that the volume of the workspace increases 1.55 times as much as the original volume, which lay the foundation for the architecture design.


2012 ◽  
Vol 522 ◽  
pp. 659-662
Author(s):  
Zhao Xin Meng ◽  
Xiao Gang Lei ◽  
Chao Mei Zhang

The planar 3-DOF parallel mechanism was developed as a part of the pushing device for the wood sawing. Using closed vector polygon method to make positive movement analysis of the mechanism, establish the positive solution mathematical model. It provided the theory bases for the error analysis and control algorithm of the planar 3-DOF parallel mechanism.


2008 ◽  
Vol 389-390 ◽  
pp. 246-251 ◽  
Author(s):  
Ping Zou ◽  
H.R. Qiu ◽  
Shan Min Gao ◽  
Ming Hu

This paper presents a new type of drill grinder based on a special universal joint. The special universal joint is composed of a parallel mechanism with three legs as the inputs. One can rotate as a spindle; other two legs can drive a moving platform and make a drill point get an accurate position in workspace. Due to the simple mechanical structure comparing the grinder with the existing conventional CNC cutting tool grinders, it should be easy for the grinder to manufacture at a low cost. In addition, inverse kinematic equations of the special type of universal joint are derived.


2021 ◽  
Author(s):  
Xianwen Kong

Abstract A 3-UPU translational parallel mechanism (TPM) is one of typical TPMs. Several types of 3-UPU TPMs have been proposed in the literature. Despite comprehensive studies on 3-UPU TPMs in which the joint axes on the base and the moving platform are coplanar, only a few 3-UPU TPMs with a skewed base and moving platform have been proposed. However, the impact of link parameters on singularity loci of such TPMs has not been systematically investigated. The advances in computing CGS (comprehensive Gröbner system) or Gröbner cover of parametric polynomial systems provide an efficient tool for solving this problem. This paper presents a systematic classification of 3-UPU TPMs, especially those with a skewed base and moving platform, based on constraint singularity loci. First, the constraint singularity equation of a 3-UPU TPM is derived. To simplify this equation, the coordinate frame on the base (or moving platform) is set up such that the centers of three U joints are located on different coordinate axes. Using Gröbner Cover, the 3-UPU TPMs are classified into 20 types based on the constraint singularity loci. Finally, a novel 3-UPU TPM is proposed. Unlike most of existing 3-UPU TPMs which can transit to two or more 3-DOF operation modes at a constraint singular configuration, the proposed 3-UPU TPM can only transit to one general 3-DOF operation mode in a constraint singular configuration. The singularity locus divides the workspace of this 3-UPU TPM into two constraint singularity-free regions. This work provides a solid foundation for the design of 3-UPU TPMs and a starting point for the classification of a general 3-UPU parallel mechanism.


Robotica ◽  
2004 ◽  
Vol 22 (4) ◽  
pp. 463-475 ◽  
Author(s):  
Woo-Keun Yoon ◽  
Takashi Suehiro ◽  
Yuichi Tsumaki ◽  
Masaru Uchiyama

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.


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