TYPE SYNTHESIS AND TYPE ANALYSIS OF 3T2R HYBRID MECHANISMS VIA GF SET

2017 ◽  
Vol 32 (4) ◽  
Author(s):  
Yi Cao ◽  
Hui Zhou ◽  
Youlei Qin ◽  
Kai Liu ◽  
Weixi Ji ◽  
...  
Keyword(s):  
Type Synthesis ◽  
Type Analysis ◽  
Gf Set ◽  
Hybrid Mechanisms

Type synthesis for 4-DOF parallel press mechanism using GF set theory

2015 ◽  
Vol 28 (4) ◽  
pp. 851-859 ◽  
Author(s):  
Jun He ◽  
Feng Gao ◽  
Xiangdun Meng ◽  
Weizhong Guo
Keyword(s):  
Set Theory ◽  
Type Synthesis ◽  
Gf Set

Type Synthesis of Parallel Mechanisms Having Two Rotations

2010 ◽  
Author(s):  
Feng Gao ◽  
Jialun Yang ◽  
Qiaode Jeffrey Ge
Keyword(s):  
Natural Law ◽  
Robotic Manipulators ◽  
Performance Criteria ◽  
Generalized Function ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Gf Set ◽  
End Effectors

In the last few decades, researchers have proposed a few different methods to synthesize parallel mechanisms. In this paper, we propose both the natural law for kinematic mobility and the generalized function sets (GF set for short) which are used for the type synthesis of parallel mechanisms, particularly for those having two rotations. The natural law for kinematic mobility lays the foundation for the algorithms of the intersection of GF sets. Moreover, the GF sets are used for describing the performance criteria of the end-effectors of robotic manipulators in a clear and systematic way, including the mechanisms having two rotations. Finally, several novel parallel mechanisms having two rotations have been illustrated to show the effectiveness of the proposed methodology.

Type Synthesis of Parallel Mechanisms Having the Second Class GF Sets and Two Dimensional Rotations

2010 ◽  
Vol 3 (1) ◽  
Author(s):  
Feng Gao ◽  
Jialun Yang ◽  
Qiaode Jeffrey Ge
Keyword(s):  
Generalized Function ◽  
Two Dimensional ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Gf Set ◽  
End Effectors

With the introduction of generalized function sets (GF set) to represent the characteristics of the end-effectors of parallel mechanisms, two classes of GF sets are proposed. The type synthesis of parallel mechanisms having the second class GF sets and two dimensional rotations, including 2-, 3-, and 4DOF parallel mechanisms, is investigated. First, the intersection algorithms for the GF sets are established via the axiom of two dimensional rotations. Second, the kinematic limbs with specific characteristics are designed according to the axis movement theorem. Finally, several parallel mechanisms having the second class GF sets and two dimensional rotations have been illustrated to show the effectiveness of the proposed methodology.

Study of hydrogenation of petroleum asphaltenes

1981 ◽  
Vol 46 (2) ◽  
pp. 409-418 ◽  
Author(s):  
Gustav Šebor ◽  
Salvador Reynoso ◽  
Milan Hájek ◽  
Otto Weisser ◽  
Jiří Mostecký
Keyword(s):  
Temperature Region ◽  
Catalytic Hydrogenation ◽  
Starting Material ◽  
Type Analysis ◽  
H Nmr ◽  
Petroleum Asphaltenes

Isolated petroleum asphaltenes were subjected to model thermal and catalytic hydrogenation experiments in the temperature region 300-450° C. The course of hydrogenation of the asphaltenes studied is discussed based on 1H-NMR type analysis of the starting material and the hydrogenation products.

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.

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