6-DOF wheeled parallel robot and its automatic type synthesis method

For the synthesis of the required type about the multi-robot coordination system in industrial transportation, this paper presents a novel method in which each robot in the coordinated task is viewed as a branched chain of an equivalent parallel robot (EPR), which is converted into a problem for type synthesis of parallel robots. A theoretic method is proposed to represent the kinematic features of the mechanism’s end-effector and its position and pose in the world coordinate system. The basic concept of a robotic characteristic (C) set is given, and the corresponding algorithm is analyzed. Based on the theory of C set, the concrete steps for type synthesis of EPR are presented by analyzing the characteristics of its branched chains, and many EPR groups with end kinematic features for the C sets of the operational tasks are obtained. Then three translational (3T) operational requirements that can be extended to other degrees of freedom (DOF) are adopted, and the DOF of homogeneous and heterogeneous EPR are analyzed using screw theory. Finally the validation of the method is demonstrated by Adams, which shows that the two groups are able to complete the task.

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Method for the Creation of a Six Bar Linkage to Simultaneously Carry Two Rigid Bodies Through Four Coordinated Positions

Volume 4: 36th Mechanisms and Robotics Conference, Parts A and B ◽

10.1115/detc2012-70013 ◽

2012 ◽

Author(s):

Ronald A. Zimmerman

Keyword(s):

Synthesis Method ◽

Rigid Bodies ◽

Type Synthesis ◽

Linkage Mechanism ◽

Center Point ◽

Seat Cushion ◽

The Creation ◽

Linkage Synthesis

A method for the creation of a six bar linkage with two ground pivots to simultaneously carry two rigid bodies through four coordinated positions was invented and is described and illustrated herein. Type synthesis was used to identify possible linkage classes and specific types of possible six bar linkages. A linkage synthesis method which superimposes three Burmester center point curves to create a six bar linkage mechanism with two ground pivots, to carry two coupled rigid bodies simultaneously through four specified, coordinated positions was developed and is demonstrated. An extension of the method to carry two non-coupled rigid bodies through four positions is indicated. This method was invented in the process of developing a 2nd row automotive truck seat, which is used as an example to illustrate the procedure. A six bar linkage which carries an automotive truck seat back and seat cushion through four coordinated positions is shown.

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Type Synthesis of 3-DOF Translational Parallel Manipulators Based on Atlas of DOF Characteristic Matrix

Volume 2: 30th Annual Mechanisms and Robotics Conference, Parts A and B ◽

10.1115/detc2006-99321 ◽

2006 ◽

Author(s):

Jingjun Yu ◽

Jian S. Dai ◽

Xin-Jun Liu ◽

Shusheng Bi ◽

Guanghua Zong

Keyword(s):

System Theory ◽

Lie Group ◽

Synthesis Method ◽

Parallel Manipulators ◽

Complete Classification ◽

Characteristic Matrix ◽

Type Synthesis ◽

Lie Group Theory ◽

Low Degree ◽

New Type

Low-degree-of-freedom (Low-DOF) parallel manipulators (PMs) have drawn extensive interest, particularly in type synthesis in which two main approaches were established in the reciprocal screw system theory and Lie group theory. This paper aims at proposing a new type synthesis method to complementing the above methods. For this purpose, the concept of the DOF characteristic matrix, originated from displacement subgroup and displacement submanifold, is proposed. A new but general approach based on the atlas of DOF Characteristic Matrix is addressed for both exhaustive classification and type synthesis of low-DOF PMs. Compared to the method based on Lie group, the proposed approach is prone to construct an orthogonal structure and easy to realize the complete classification and exhaustive enumeration of a class of low-DOF PM. In order to verify the effectiveness of the proposed method, type synthesis of Translational PMs (TPMs) particularly in ones with an orthogonal structure is performed, resulting in some novel orthogonal TPMs.

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Type Synthesis and Application of Gear Linkage Transplanting Mechanisms Based on Graph Theory

Transactions of the ASABE ◽

10.13031/trans.13200 ◽

2019 ◽

Vol 62 (2) ◽

pp. 515-528

Author(s):

Liang Sun ◽

Yuzhu Zhou ◽

Xuan Chen ◽

Chuanyu Wu

Keyword(s):

Graph Theory ◽

Structural Characteristics ◽

Synthesis Method ◽

Kinematic Chain ◽

Gear Train ◽

Type Synthesis ◽

Linkage Mechanism ◽

Topological Graph ◽

Labeled Graphs ◽

Motion Characteristics

Abstract. Type synthesis is an important step when designing innovations in mechanisms. To overcome the limitation of traditional gear train transplanting mechanisms in realizing a specific trajectory, a swinging linkage mechanism is introduced into the design of the transplanting mechanism. To design a crop-transplanting gear linkage mechanism (GLM), an automatic synthesis method based on graph theory is proposed in this article. First, the numbers of loops, links, joints and other parameters, along with unlabeled graphs, are calculated based on the structural characteristics of the GLM. The labeled graphs that correspond to the kinematic chain (KC) are then obtained by thickening the edges of the unlabeled graphs, and physically reasonable labeled graphs are derived from identification of the structural rationality of the corresponding structures. Based on the relative motion characteristics of the input and output links of the transplanting mechanisms, criteria for screening the gear linkage mechanisms represented by the labeled graphs are formulated, and the labeled graphs that are suitable for transplanting are calculated to enrich the configurations of the transplanting mechanisms. Finally, two examples are tested to verify the effectiveness of the proposed type synthesis method. Keywords: Gear linkage, Screening, Topological graph, Transplanting mechanism, Type synthesis.

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Automated Type and Modular Dimensional Synthesis of Planar Linkages

Volume 2: 34th Annual Mechanisms and Robotics Conference, Parts A and B ◽

10.1115/detc2010-28540 ◽

2010 ◽

Author(s):

Marti´n A. Pucheta ◽

Alberto Cardona

Keyword(s):

Synthesis Method ◽

Path Following ◽

Graph Representation ◽

Dimensional Synthesis ◽

Type Synthesis ◽

Automated Method ◽

Initial Graph ◽

Closed Chain ◽

Planar Linkages ◽

Synthesis Stage

We present an automated method for type and dimensional synthesis of planar linkage mechanisms. In the kinematic problem, a graph representation called initial graph is given to the parts to move. The type synthesis stage consists of an exhaustive subgraph search of the initial graph inside the graphs taken from a previously enumerated atlas of mechanisms. Each alternative resulting from the type synthesis is dimensioned using the Precision Position Method and Genetic Algorithms: the closed-chain topology is decomposed into single-open chains of two and three links programmed as dyad and triad modules; these modules are executed to compute all the significant dimensions of the linkage. Using this type and dimensional synthesis method, a fast generation and evaluation of many mechanisms can be done in few minutes using a desktop personal computer. The enumeration of mechanisms for a path following task, including eight-bar solutions, illustrates the whole design process.

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