Kinematic Design and Topological Characteristics of a nT1R-type Reconfigurable Parallel Mechanism

2019 ◽  
pp. 2379-2389
Author(s):  
Huiping Shen ◽  
Yingchun Zhao ◽  
Guanglei Wu ◽  
Ke Xu
Keyword(s):  
Parallel Mechanism ◽  
Kinematic Design ◽  
Topological Characteristics

scholarly journals Kinematic design of a translational parallel mechanism based on sub-kinematic chain determined workspace superposition

2021 ◽  
pp. 095440622110046
Author(s):  
Huiping Shen ◽  
Yinan Zhao ◽  
Guanglei Wu ◽  
Ju Li ◽  
Damien Chablat
Keyword(s):  
Parallel Mechanism ◽  
Kinematic Chain ◽  
Inverse Kinematic ◽  
Parallel Mechanisms ◽  
Kinematic Modeling ◽  
Symbolic Model ◽  
Kinematic Design ◽  
Decoupled Motion ◽  
Topological Characteristics ◽  
Kinematic Solution

This paper presents the kinematic design of a translational parallel mechanism (PM) named Vari-Orthoglide by means of the workspace superposition, according to the sub-kinematic chain (SKC) based PM composition principle. The main topological characteristics of the manipulator with two SKCs under study, such as the position and orientation (POC) characteristics, degree of freedom (DOF) and coupling degree are analyzed, which turns out that the coupling degree equals to 1, implying the partially decoupled motion. With the topological characteristics based kinematic modeling principle, a symbolic model of the kinematics is established to derive its symbolic direct and inverse kinematic solutions. Based upon the direct kinematic solution, the workspaces for the two SKCs can be efficiently found. Moreover, the singularity loci are identified for finding the singularity-free workspace, where a regular workspace is fitted as the task workspace as expected. The presented work shows an approach to design translational parallel mechanisms considering motion decoupling and regular workspace, applicable to other types of parallel mechanisms.

scholarly journals Type Synthesis of 1T2R Parallel Mechanisms Using Structure Coupling-Reducing Method

2019 ◽  
Vol 32 (1) ◽  
Author(s):  
Haitao Liu ◽  
Ke Xu ◽  
Huiping Shen ◽  
Xianlei Shan ◽  
Tingli Yang
Keyword(s):  
Explicit Form ◽  
Parallel Mechanism ◽  
Analytic Solutions ◽  
Forward Kinematics ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Real Time Control ◽  
Time Control ◽  
Topological Characteristics ◽  
Zero Coupling

Abstract Direct kinematics with analytic solutions is critical to the real-time control of parallel mechanisms. Therefore, the type synthesis of a mechanism having explicit form of forward kinematics has become a topic of interest. Based on this purpose, this paper deals with the type synthesis of 1T2R parallel mechanisms by investigating the topological structure coupling-reducing of the 3UPS&UP parallel mechanism. With the aid of the theory of mechanism topology, the analysis of the topological characteristics of the 3UPS&UP parallel mechanism is presented, which shows that there are highly coupled motions and constraints amongst the limbs of the mechanism. Three methods for structure coupling-reducing of the 3UPS&UP parallel mechanism are proposed, resulting in eight new types of 1T2R parallel mechanisms with one or zero coupling degree. One obtained parallel mechanism is taken as an example to demonstrate that a mechanism with zero coupling degree has an explicit form for forward kinematics. The process of type synthesis is in the order of permutation and combination; therefore, there are no omissions. This method is also applicable to other configurations, and novel topological structures having simple forward kinematics can be obtained from an original mechanism via this method.

scholarly journals Topological Design of an Asymmetric 3-Translational Parallel Mechanism With Zero Coupling Degree and Motion Decoupling

2018 ◽  
Author(s):  
Huiping Shen ◽  
Chengqi Wu ◽  
Damien Chablat ◽  
Guanglei Wu ◽  
Ting-li Yang
Keyword(s):  
Parallel Mechanism ◽  
Design Theory ◽  
Analytical Formula ◽  
Inverse Kinematic ◽  
Topology Design ◽  
Kinematic Chains ◽  
Topological Design ◽  
Decoupled Motion ◽  
Topological Characteristics ◽  
Zero Coupling

In this paper a new asymmetric 3-translational (3T) parallel manipulator, i.e., RPa(3R) 2R+RPa, with zero coupling degree and decoupled motion is firstly proposed according to topology design theory of parallel mechanism (PM) based on position and orientation characteristics (POC) equations. The main topological characteristics such as POC, degree of freedom and coupling degree are calculated. Then, the analytical formula for the direct and inverse kinematic are directly derived since coupling degree of the PM is zero. The study of singular configurations is simple because of the independence of the kinematic chains.

Dexterity Analysis of 6-dof 3-urps Parallel Mechanism

2012 ◽  
Vol 591-593 ◽  
pp. 754-757
Author(s):  
Hong Li Yun ◽  
Xiao Na Song
Keyword(s):  
Condition Number ◽  
Parallel Mechanism ◽  
Three Dimensional ◽  
Inverse Solution ◽  
Kinematics Analysis ◽  
Characteristic Analysis ◽  
Kinematic Design ◽  
Ps I

The kinematics analysis is carried out on a kind of 3-urps parallel mechanism (pm) with 6-dof. The positional inverse solution and Jacobean matrixes which is used to analyze the dexterity of mechanism are derived. Condition number is used as evaluating indicator of dexterity in this article, and its’ three-dimensional graphs are drawn when this mechanism in different attitudes. It is indicated that dexterity of moving is excelled than the rotary movement’s for this pm. The optimum dexterity can be obtained in the center of mechanism’s workroom, which can be applied to further characteristic analysis and kinematic design of mechanisms.

Kinematic design of 3-URU pure rotational parallel mechanism to perform precise motion within a large workspace

Meccanica ◽  
2010 ◽  
Vol 46 (1) ◽  
pp. 89-100 ◽  
Author(s):  
Syamsul Huda ◽  
Yukio Takeda ◽  
Shuta Hanagasaki
Keyword(s):  
Parallel Mechanism ◽  
Kinematic Design

scholarly journals A Translational Three-Degrees-of-Freedom Parallel Mechanism With Partial Motion Decoupling and Analytic Direct Kinematics

2020 ◽  
Vol 12 (2) ◽  
Author(s):  
Huiping Shen ◽  
Damien Chablat ◽  
Boxiong Zeng ◽  
Ju Li ◽  
Guanglei Wu ◽  
...  
Keyword(s):  
Parallel Mechanism ◽  
Design Theory ◽  
Degrees Of Freedom ◽  
Analytic Solutions ◽  
Inverse Kinematic ◽  
Kinematic Modeling ◽  
Topological Design ◽  
Prismatic Joints ◽  
Topological Characteristics ◽  
Three Degrees Of Freedom

Abstract According to the topological design theory and the method of parallel mechanism (PM) based on position and orientation characteristic (POC) equations, this paper studied a three-degrees-of-freedom (3-DOF) translational PM that has three advantages, i.e., (i) it consists of three fixed actuated prismatic joints, (ii) the PM has analytic solutions to the direct and inverse kinematic problems, and (iii) the PM is of partial motion decoupling property. First, the main topological characteristics, such as the POC, degree-of-freedom, and coupling degree, were calculated for kinematic modeling. Thanks to these properties, the direct and inverse kinematic problems can be readily solved. Further, the conditions of the singular configurations of the PM were analyzed, which corresponds to its partial motion decoupling property.

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