scholarly journals Classification of a 3-RER Parallel Manipulator Based on the Type and Number of Operation Modes

2020 ◽  
pp. 1-17
Author(s):  
Xianwen Kong
Keyword(s):  
Parallel Manipulator ◽  
Operation Mode ◽  
Mode Analysis ◽  
Type Number ◽  
Systematic Classification ◽  
Operation Modes ◽  
Solid Foundation ◽  
And Control ◽  
The Impact

Abstract The type/number of operation modes of a parallel manipulator (PM) may vary with the link parameters of the PM. This paper presents a systematic classification of a 3-RER PM based on the type/number of operation modes. The 3-RER PM was proposed as a 4-DOF (degree-of-freedom) 3T1R PM in the literature. Using the proposed method, the classification of a PM based on the type/number of operation modes can be carried out in four steps, including formulation of constraint equations of the PM, preliminary classification of the PM using Gröbner Cover, operation mode analysis of all the types of PMs using primary decomposition of ideals, and identification redundant types of PMs. Classification of the 3-RER PM shows that it has 19 types. Besides the two 4-DOF 3T1R operation modes, different types of 3-RER PMs may have up to two more 3-DOF or other types of 4- DOF operation modes. This work is the first systematic study on the impact of link parameters on the operation modes of the 3-RER PM and provide a solid foundation for further research on the design and control of 3-RER PMs and other multi-mode (or reconfigurable) PMs.

Classification of a Class of 3-RER Parallel Manipulators Using Gröbner Cover and Primary Decomposition of Ideals

2019 ◽  
Author(s):  
Xianwen Kong
Keyword(s):  
Kinematic Chain ◽  
Parallel Manipulators ◽  
Polynomial Systems ◽  
Primary Decomposition ◽  
Type Number ◽  
Systematic Classification ◽  
Operation Modes ◽  
Moving Platform ◽  
The Impact

Abstract Recent studies have revealed that the type/number of operation modes of a parallel manipulator (PM) may vary with the link parameters of the PM. However, current research on the impact of link parameters on the type/number of operation modes of a PM is usually based on intuition. This paper deals with the systematic classification of a 3-RER PM. The 3-RER PM is composed of a base and a moving platform connected by three RER legs, each of which is a serial kinematic chain composed of a revolute (R) joint, a planar (E) joint and an R joint in sequence. The axes of the R joints on the base (or moving platform) are all parallel. At first, a set of constraint equations of the 3-RER PM is first derived. Then using a method called Gröbner cover to calculate the comprehensive Gröbner system of parametric polynomial systems, the 3-RER PM is classified into 21 types. The operation modes of all the types of 3-RER PMs are determined using primary decomposition of ideals. Besides the two 4-DOF (degree-of-freedom) 3T1R operation modes, different types of 3-RER PMs may have up to two more 3-DOF or other types of 4-DOF operation modes. This work is the first systematic study on the impact of link parameters on the operation modes of the 3-RER PM and will contribute to the design and control of 3-RER PMs and research on multi-mode (or reconfigurable) PMs.

Reconfiguration Analysis of a 2-DOF 3-4R Parallel Manipulator With Planar Base and Platform

2015 ◽  
Author(s):  
Xianwen Kong ◽  
Jingjun Yu ◽  
Duanling Li
Keyword(s):  
Parallel Manipulator ◽  
Operation Mode ◽  
Euler Parameter ◽  
Operation Modes ◽  
Minimum Number ◽  
Moving Platform ◽  
Multiple Operation ◽  
Motion Characteristics ◽  
Rolling Mode ◽  
And Control

This paper deals with a 2-DOF 3-4R parallel manipulator (PM) with planar base and platform — a novel PM with multiple operation mode (or disassembly-free reconfigurable PM) with minimum number of actuated joints. At first, a set of constraint equations of the 3-4R PM is derived with the orientation of the moving platform represented using a Euler parameter quaternion (also Euler-Rodrigues quaternion) and then solved using the algebraic geometry method. It is found that this 3-4R PM has six 2-DOF operation modes, including the two expected spherical translation mode and sphere-on-sphere rolling mode when the PM was synthesized. The motion characteristics of the moving platform are obtained using the kinematic interpretation of Euler parameter quaternions with certain number of constant zero components, which was presented in a recent paper by the first author of this paper, instead of the eigenspace based approach in the literature. The transition configurations, which are constraint singular configurations, among different operation modes are also presented. This work provides a solid foundation to the development and control of the 2-DOF 3-4R parallel manipulator (PM) with both 2-DOF spherical translation mode and 2-DOF sphere-on-sphere rolling mode.

Reconfiguration Analysis of a Variable Degrees-of-Freedom Parallel Manipulator With Both 3-DOF Planar and 4-DOF 3T1R Operation Modes

2016 ◽  
Author(s):  
Xianwen Kong
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Operation Mode ◽  
Parallel Manipulators ◽  
Euler Parameter ◽  
Operation Modes ◽  
Moving Platform ◽  
Schönflies Motion ◽  
And Control

Reconfiguration analysis is essential for the design and control of multi-operation-mode parallel manipulators (PMs). This paper deals with the reconfiguration analysis of a variable-DOF (degrees-of-freedom) multi-operation-mode E/PPPR = PM, i.e. a PM with both 3-DOF planar operation mode and 4-DOF 3T1R (or Schönflies motion which has three translational DOF and 1 rotational DOF) operation mode. The axes of rotation of the moving platform in the 3-DOF planar operation mode are not parallel to the axes of rotation of the moving platform in the 4-DOF 3T1R operation mode. In the reconfiguration analysis, the orientation of the moving platform is represented using a Euler parameter quaternion (also Euler-Rodrigues quaternion). The reconfiguration analysis shows that the E/PPPR = PM has two 4-DOF 3T1R operation modes and two 3-DOF planar operation modes, including the two expected operation modes. The transition configurations between each pair of operation modes are also identified.

scholarly journals Measuring urban form: Overcoming terminological inconsistencies for a quantitative and comprehensive morphologic analysis of cities

2020 ◽  
pp. 239980832091044 ◽  
Author(s):  
Martin Fleischmann ◽  
Ombretta Romice ◽  
Sergio Porta
Keyword(s):  
Spatial Distribution ◽  
Quantitative Analysis ◽  
Urban Form ◽  
Large Scale ◽  
Global Scale ◽  
Urban Morphology ◽  
Systematic Classification ◽  
Social Patterns ◽  
The Impact

Unprecedented urbanisation processes characterise the Great Acceleration, urging urban researchers to make sense of data analysis in support of evidence-based and large-scale decision-making. Urban morphologists are no exception since the impact of urban form on fundamental natural and social patterns (equity, prosperity and resource consumption’s efficiency) is now fully acknowledged. However, urban morphology is still far from offering a comprehensive and reliable framework for quantitative analysis. Despite remarkable progress since its emergence in the late 1950s, the discipline still exhibits significant terminological inconsistencies with regards to the definition of the fundamental components of urban form, which prevents the establishment of objective models for measuring it. In this article, we present a study of existing methods for measuring urban form, with a focus on terminological inconsistencies, and propose a systematic and comprehensive framework to classify urban form characters, where ‘urban form character’ stands for a characteristic (or feature) of one kind of urban form that distinguishes it from another kind. In particular, we introduce the Index of Elements that allows for a univocal and non-interpretive description of urban form characters. Based on such Index of Elements, we develop a systematic classification of urban form according to six categories (dimension, shape, spatial distribution, intensity, connectivity and diversity) and three conceptual scales (small, medium, large) based on two definitions of scale (extent and grain). This framework is then applied to identify and organise the urban form characters adopted in available literature to date. The resulting classification of urban form characters reveals clear gaps in existing research, in particular, in relation to the spatial distribution and diversity characters. The proposed framework reduces the current inconsistencies of urban morphology research, paving the way to enhanced methods of urban form systematic and quantitative analysis at a global scale.

Operation Mode Analysis of Joint Heating about Solar Collectors and Ground Source Heat Pump

2013 ◽  
Vol 805-806 ◽  
pp. 52-57
Author(s):  
Yue Ren Wang ◽  
Xiao Zhang ◽  
Yong Qiang Fang
Keyword(s):  
Heat Pump ◽  
Operation Mode ◽  
Mode Analysis ◽  
Ground Source Heat Pump ◽  
Solar Collectors ◽  
System Operation ◽  
Heating Systems ◽  
Operation Efficiency ◽  
Ground Source ◽  
The Impact

From the viewpoint of improving heating quality and saving energy, the paper proposes the use of Joint Heating Systems about Solar Collectors and Ground Source Heat Pump (JHSSCGSHP). The typical architecture in Shenyang is analyzed about dynamic simulation by the use of JHSSCGSHP. MATLAB is used to operate comparative analysis of simulation. It focuses on the impact of water temperature of inlet and outlet of heat pump systems in different series of separate heating of ground source heat pump and JHSSCGSHP. Thus the influence of the system operation efficiency based on different operation modes is compared.

scholarly journals ІДЕНТИФІКАЦІЯ ТА КЛАСИФІКАЦІЯ ГЛОБАЛЬНИХ ВИКЛИКІВ

2020 ◽  
pp. 36-44
Author(s):  
М. С. Татар
Keyword(s):  
Social Economic ◽  
Practical Significance ◽  
Interstate Relations ◽  
Systematic Classification ◽  
Probability Of Occurrence ◽  
Global Challenge ◽  
Global Challenges ◽  
The Impact

Global challenges complex affect the system of international relations, interstate relations, the nature of interaction between economic entities within the state and between economic entities of different states, requiring a radical transformation and modification of the modern global system and the actions of its actors. The aim of the research is to identification, classification of global challenges by strength of impact and probability of occurrence to further determine their impact on the economic entities behavior and the formation of relationships between them. The subject of the research is the global challenges, the strength of their impact and the probability of occurrence and change in time. The methods of the research: logical-substantive method, method of comparison, methods of induction and deduction, analysis and synthesis. The hypothesis of the research. There is a need to identify and classify global challenges to further determination of their impact on the nature of behavior and the system of relationships of economic entities in the context of global challenges. The statement of basic materials. The concepts of global challenge, global problem, global risk, global crisis, global catastrophe are considered. It is proposed to consider the global challenge as a situation facing a large number of people who are not able to solve it on their own in an adequate time and they need to join efforts to solve it, which can create a global threat that will result in global problems, risks, crises and catastrophes, and be an incentive for global positive change. The classification of global challenges is proposed, which includes geopolitical, social, economic, biological, demographic, climatic, technological, informational, cultural. The originality and practical significance of the research lies in the systematic classification of global challenges in order to further determination of the impact of each group of global challenges on changes in both interstate relations and the nature of interaction between individual entities. Conclusions and perspectives of further research. The proposed by the author classification of global challenges on the basis of the annotated critical analysis of scientific literature, which is presented by 7 groups of global challenges such as geopolitical, social, economic, biological, demographic, climatic, technological, informational, cultural – will be the basis for global challenges impact determining on the nature of behavior and the system of relationships of economic entities in the context of global challenges.

Reconfiguration of a 3-(rR)PS Metamorphic Parallel Mechanism Based on Complete Workspace and Operation Mode Analysis

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Latifah Nurahmi ◽  
Dongming Gan
Keyword(s):  
Parallel Mechanism ◽  
Operation Mode ◽  
Mode Analysis ◽  
Finite Point ◽  
Constraint Equations ◽  
Revolute Joints ◽  
Operation Modes ◽  
Identification Approach ◽  
Moving Platform ◽  
Mode A

Abstract This paper focuses on the reconfiguration of a 3-(rR)PS metamorphic parallel mechanism based on complete workspace and operation mode analysis. The mechanism consists of three (rR)PS legs, and each (rR) joint is composed of two perpendicular revolute joints. One of the (rR) joint axes can be reconfigured continuously, which allows the mechanism to exhibit three distinct configurations. Initially, the constraint equations are derived by using algebraic geometry approach, and the primary decomposition is computed for the three configurations. It reveals that the 3-(rR)PS metamorphic parallel mechanism can exhibit one up to two operation modes among three configurations. When the second axes of the three (rR) joints intersect at a finite point and not coplanar, the 3-(rR)PS metamorphic parallel mechanism has only one operation mode. If the second axes of the three (rR) joints are coplanar, the 3-(rR)PS metamorphic parallel mechanism has two operation modes. It is shown that both operation modes have the same motion type, namely, 1T2R motion. However, to realize the same trajectories in both operation modes, the moving platform will have different orientations. Hence, the orientation workspaces of both operation modes are characterized and the axodes are used to compare the instantaneous motion of the moving platform when passing through the same trajectories. Based on these results, an identification approach is introduced to identify which operation mode a given mechanism pose belongs to and this provides a useful method for trajectory planning.

Reconfiguration Analysis of a Two Degrees-of-Freedom 3-4R Parallel Manipulator With Planar Base and Platform1

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Xianwen Kong ◽  
Jingjun Yu ◽  
Duanling Li
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Euler Parameter ◽  
Operation Modes ◽  
Minimum Number ◽  
Moving Platform ◽  
Multiple Operation ◽  
Motion Characteristics ◽  
Rolling Mode ◽  
And Control

This paper deals with a 2-DOF (degrees-of-freedom) 3-4R parallel manipulator (PM) with planar base and platform—a novel PM with multiple operation modes (or disassembly free reconfigurable PM) that can use the minimum number of actuated joints. At first, a set of constraint equations of the 3-4R PM are derived with the orientation of the moving platform represented using a Euler parameter quaternion (also Euler–Rodrigues quaternion) and then solved using the algebraic geometry method. It is found that this 3-4R PM has six 2-DOF operation modes, including the two expected spherical translation mode and sphere-on-sphere rolling mode when the PM was synthesized. The motion characteristics of the moving platform are obtained using the kinematic interpretation of Euler parameter quaternions with certain number of constant zero components, which was presented in a recent paper by the first author of this paper, instead of the eigenspace-based approach in the literature. The transition configurations, which are constraint singular configurations, among different operation modes are also presented. This work provides a solid foundation to the development and control of the 2-DOF 3-4R PM with both 2-DOF spherical translation mode and 2-DOF sphere-on-sphere rolling mode.

scholarly journals Operation Modes Comparison of a Reconfigurable 3-PRS Parallel Manipulator Based on Kinematic Performance

2016 ◽  
Author(s):  
Siddharth Maraje ◽  
Latifah Nurahmi ◽  
Stéphane Caro
Keyword(s):  
Parallel Manipulator ◽  
Screw Theory ◽  
Operation Mode ◽  
Algebraic Approach ◽  
Transmission Efficiency ◽  
Force Transmission ◽  
Operation Modes ◽  
Transmission Index ◽  
Prismatic Joints ◽  
Kinematic Mapping

The 3-PRS parallel manipulator with different arrangements of prismatic joints is called a reconfigurable 3-PRS parallel manipulator in this paper. The three prismatic joints in PRS limbs are attached to the base with an angle α between the horizontal plane of the base and their directions. Based on [1], the manipulator has identical operation modes, namely x0 = 0 and x3 = 0 for any value of α. Accordingly, this paper presents in more details the performance evaluation of these operation modes by using the output transmission index (OTI) and the constraint transmission index (CTI). The OTI and CTI determine the force transmission efficiency and the constraining ability of the manipulators, respectively. Initially, the determination of the number and types of operation modes of the 3-PRS parallel manipulator is recalled. The computation is carried out by using an algebraic approach, namely the Study kinematic mapping. In each operation mode, the actuation wrenches and the constraint wrenches are obtained based on the Screw theory. Then, the OTI and CTI are traced in the orientation workspace of the manipulator for different values of angle α. Furthermore, the singularity conditions are analysed corresponding to the values of OTI and CTI.

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