Digital type synthesis method of twin parallel mechanisms and several novel manipulators

2021 ◽  
Vol 155 ◽  
pp. 104103
Author(s):  
HongPeng Chu ◽  
ShuYang Shi ◽  
YuLin Zhou
Keyword(s):  
Synthesis Method ◽  
Parallel Mechanisms ◽  
Type Synthesis

Force Analysis and Mechanical Design of a Novel 3-DOF Parallel Mechanism

2018 ◽  
Author(s):  
Dongsheng Zhang ◽  
Yundou Xu ◽  
Jiantao Yao ◽  
Yulin Zhou ◽  
Yongsheng Zhao
Keyword(s):  
Degrees Of Freedom ◽  
Mechanical Design ◽  
Synthesis Method ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Constraint Force ◽  
Hybrid Manipulator ◽  
Rotational Degrees Of Freedom ◽  
Motion Characteristics ◽  
Alternative Designs

Parallel mechanisms (PMs) with two rotational degrees-of-freedom (DOF) and one translational DOF (2R1T) have gained much attention in recent years. In this paper, different from type synthesis method, inner properties of PMs (motion characteristics, type of joints and arrangement way of joints) are used to deduce PMs; and two novel 3-DOF PMs are presented using this method. Aiming at 2UPU/SP PM, the constraint force/torque generated on the moving platform (MP) are analysed; here, P, U and S denote prismatic, universal and spherical joints, respectively. The driving force and the constraint force/torque are drawn, which show good distribution of the constraint wrench. After that, a novel 5-DOF hybrid manipulator is constructed on the basis of the 2UPU/SP PM; according to different demands, two alternative designs of the 5-DOF hybrid manipulator are presented. The study in this paper will enhance the research applications of the 2UPU/SP PM.

scholarly journals Research for a novel class of translational spatial multi-loop coupled mechanisms: Type synthesis and kinematic analysis

2018 ◽  
Vol 10 (8) ◽  
pp. 168781401879702 ◽  
Author(s):  
Shuang Zhang ◽  
Jingfang Liu ◽  
Huafeng Ding
Keyword(s):  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Synthesis Method ◽  
Future Application ◽  
The Novel ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Split Method ◽  
New Synthesis ◽  
The Family

A novel type synthesis method for a class of spatial multi-loop coupled mechanisms with translational degrees of freedom is proposed in the paper. The novel class of spatial multi-loop coupled mechanisms has a stable topology layout which consists of three branches and three coupled chains. The basic idea of the new structural synthesis method lies at replacing the inputs of one mechanism by the outputs of another, thereby combining several mechanisms, where the topology split method for the topological layout and corresponding degree of freedom splitting principle are provided. The synthesis of the target mechanism is transformed into synthesis of corresponding serial and parallel mechanisms thereby, and a class of spatial multi-loop coupled mechanisms is synthesized. To validate the new synthesis method and to present a theoretical basis for future application, kinematic analysis of a single translational mobility (1T) spatial multi-loop coupled mechanism and a symmetrical two translational degrees of freedom (2T) spatial multi-loop coupled mechanism is performed. This article enriches the family of the spatial mechanisms for further instructing the study of spatial multi-loop coupled mechanisms.

Type Synthesis of Three-DOF Translational Parallel Mechanisms

2003 ◽  
Author(s):  
Jingjun Yu ◽  
Shusheng Bi ◽  
Guanghua Zong ◽  
Tieshi Zhao ◽  
Zhen Huang
Keyword(s):  
Degrees Of Freedom ◽  
Screw Theory ◽  
Synthesis Method ◽  
Reciprocal Relationship ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Constraint Forces ◽  
Novel Synthesis ◽  
Spatial Translation ◽  
Made In

This paper presents a simple but effective type synthesis method for spatial parallel mechanisms with three translational degrees of freedom based on the screw theory. Firstly all possible connecting-chain structures of three-DOF parallel mechanisms are enumerated. According to the reciprocal relationship between screw constraint forces and the motion screw, a novel synthesis method is presented. By using this method, type synthesis for three-DOF translational parallel mechanisms has been made in a systematic and detailed way. As a result, some novel parallel mechanisms generating spatial translation have been obtained. To verify the significance of type synthesis for this kind of mechanism, the paper also gives a concrete application instance, which is used for a micromanipulator for manipulating the bio-cells.

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 A New Method for Type Synthesis of 2R1T and 2T1R 3-DOF Redundant Actuated Parallel Mechanisms with Closed Loop Units

2020 ◽  
Vol 33 (1) ◽  
Author(s):  
Yongquan Li ◽  
Yang Zhang ◽  
Lijie Zhang
Keyword(s):  
Closed Loop ◽  
Screw Theory ◽  
Line Graph ◽  
Degree Of Freedom ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Allocation Criteria ◽  
Grassmann Line Geometry ◽  
Moving Platform ◽  
Atlas Method

Abstract The current type synthesis of the redundant actuated parallel mechanisms is adding active-actuated kinematic branches on the basis of the traditional parallel mechanisms, or using screw theory to perform multiple getting intersection and union to complete type synthesis. The number of redundant parallel mechanisms obtained by these two methods is limited. In this paper, based on Grassmann line geometry and Atlas method, a novel and effective method for type synthesis of redundant actuated parallel mechanisms (PMs) with closed-loop units is proposed. Firstly, the degree of freedom (DOF) and constraint line graph of the moving platform are determined successively, and redundant lines are added in constraint line graph to obtain the redundant constraint line graph and their equivalent line graph, and a branch constraint allocation scheme is formulated based on the allocation criteria. Secondly, a scheme is selected and redundant lines are added in the branch chains DOF graph to construct the redundant actuated branch chains with closed-loop units. Finally, the branch chains that meet the requirements of branch chains configuration criteria and F&C (degree of freedom & constraint) line graph are assembled. In this paper, two types of 2 rotational and 1 translational (2R1T) redundant actuated parallel mechanisms and one type of 2 translational and 1 rotational (2T1R) redundant actuated parallel mechanisms with few branches and closed-loop units were taken as examples, and 238, 92 and 15 new configurations were synthesized. All the mechanisms contain closed-loop units, and the mechanisms and the actuators both have good symmetry. Therefore, all the mechanisms have excellent comprehensive performance, in which the two rotational DOFs of the moving platform of 2R1T redundant actuated parallel mechanism can be independently controlled. The instantaneous analysis shows that all mechanisms are not instantaneous, which proves the feasibility and practicability of the method.

scholarly journals Type Synthesis of Fully-Decoupled Three-Rotational and One-Translational Parallel Mechanisms

10.5772/62684 ◽  
2016 ◽  
Vol 13 (2) ◽  
pp. 79 ◽  
Author(s):  
Yi Cao ◽  
Hai Chen ◽  
Youlei Qin ◽  
Kai Liu ◽  
Shuyi Ge ◽  
...  
Keyword(s):  
Parallel Mechanisms ◽  
Type Synthesis
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