Structural Synthesis of Baranov Trusses With Up to 13 Links

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Peng Huang ◽  
Huafeng Ding
Keyword(s):  
Open Problem ◽  
Structural Characteristics ◽  
Detection Algorithm ◽  
Synthesis Methods ◽  
Structural Synthesis ◽  
Topological Graphs ◽  
Systematic Method ◽  
Constraint Equations ◽  
Complete Set ◽  
Graph Form

The structural synthesis of Baranov trusses is still an open problem, although Baranov trusses are widely used in the design and analysis of mechanisms and robots. This paper proposes a systematic method for the structural synthesis of Baranov trusses. First, the definition review and the graph-form representations of Baranov trusses are proposed. Second, seven propositions on structural characteristics of Baranov trusses are concluded. Then, based on the set of constraint equations and a rigid subchain detection algorithm, a systematic method is presented to synthesize the complete set of Baranov trusses with a specified number of links. Finally, the synthesis results of contracted graphs (including valid and rigid contracted graphs) and topological graphs of Baranov trusses with up to 13 links are provided, and the synthesis methods and results between ours and the ones in the existing literature are compared and discussed in detail.

scholarly journals Structural Synthesis of Multi-Fingered Hands

2002 ◽  
Vol 124 (2) ◽  
pp. 272-276 ◽  
Author(s):  
Jyh-Jone Lee ◽  
Lung-Wen Tsai
Keyword(s):  
Degrees Of Freedom ◽  
Structural Characteristics ◽  
Human Hand ◽  
Functional Requirements ◽  
Structural Synthesis ◽  
Constraint Equations ◽  
Mechanical Hand ◽  
Force Closure ◽  
Systematic Enumeration ◽  
Mechanical Hands

The kinematic structure of a mechanical hand typically resembles the skeleton of a human hand and it is usually designed to emulate a subset of the functions of a human hand. This paper analyzes the structural characteristics associated with the functional requirements of a mechanical hand. Using the mobility criterion and force closure concept, constraint equations for structural synthesis of multi-fingered mechanical hands are derived. A procedure for systematic enumeration of the kinematic structures of mechanical hands is established. An atlas of feasible kinematic structures of multi-fingered hands having a mobility number ranging from 3 to 6 and contact degrees of freedom ranging from 1 to 5 is developed. Further, two theorems concerning the structural characteristics of mechanical hands are presented.

Automatic Structural Synthesis of Planar Multiple Joint Kinematic Chains

2013 ◽  
Vol 135 (9) ◽  
Author(s):  
Huafeng Ding ◽  
Weijuan Yang ◽  
Peng Huang ◽  
Andrés Kecskeméthy
Keyword(s):  
Degrees Of Freedom ◽  
Characteristic Number ◽  
Structural Synthesis ◽  
Topological Graph ◽  
Topological Graphs ◽  
Systematic Method ◽  
Joint Kinematic ◽  
Kinematic Chains ◽  
Mechanical Products ◽  
First Time

It is of great importance in the conceptual creative design of mechanical systems to synthesize as many feasible kinematic structures of mechanisms as possible. However, the methods for the structural synthesis of multiple joint kinematic chains are seldom addressed in literature even though they are widely used in various mechanical products. This paper proposes an automatic method to synthesize planar multiple joint kinematic chains. First, the bicolor topological graph and the bicolor contracted graph are introduced to represent the topological structures of multiple joint kinematic chains. Then, the characteristic number string of bicolor topological graphs is proposed and used to efficiently detect isomorphism in the synthesis progress. Finally, a systematic method for the synthesis of kinematic chains with one multiple joint is proposed, and the whole families of multiple joint kinematic chains with up to 16 links and all possible degrees of freedom are synthesized for the first time.

scholarly journals Sol-Gel Synthesis of the Double Perovskite Sr2FeMoO6 by Microwave Technique

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3876
Author(s):  
Jesús Valdés ◽  
Daniel Reséndiz ◽  
Ángeles Cuán ◽  
Rufino Nava ◽  
Bertha Aguilar ◽  
...  
Keyword(s):  
Particle Size ◽  
Hydrothermal Synthesis ◽  
Microwave Radiation ◽  
Structural Characteristics ◽  
Sol Gel ◽  
Synthesis Method ◽  
Double Perovskite ◽  
Synthesis Methods ◽  
X Ray ◽  
Sol Gel Synthesis

The effect of microwave radiation on the hydrothermal synthesis of the double perovskite Sr2FeMoO6 has been studied based on a comparison of the particle size and structural characteristics of products from both methods. A temperature, pressure, and pH condition screening was performed, and the most representative results of these are herein presented and discussed. Radiation of microwaves in the hydrothermal synthesis method led to a decrease in crystallite size, which is an effect from the reaction temperature. The particle size ranged from 378 to 318 nm when pH was 4.5 and pressure was kept under 40 bars. According to X-ray diffraction (XRD) results coupled with the size-strain plot method, the product obtained by both synthesis methods (with and without microwave radiation) have similar crystal purity. The Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) techniques showed that the morphology and the distribution of metal ions are uniform. The Curie temperature obtained by thermogravimetric analysis indicates that, in the presence of microwaves, the value was higher with respect to traditional synthesis from 335 K to 342.5 K. Consequently, microwave radiation enhances the diffusion and nucleation process of ionic precursors during the synthesis, which promotes a uniform heating in the reaction mixture leading to a reduction in the particle size, but keeping good crystallinity of the double perovskite. Precursor phases and the final purity of the Sr2FeMoO6 powder can be controlled via hydrothermal microwave heating on the first stages of the Sol-Gel method.

scholarly journals LAYERED DOUBLE HYDROXIDES: NANOMATERIALS FOR APPLICATIONS IN AGRICULTURE

2015 ◽  
Vol 39 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Luíz Paulo Figueredo Benício ◽  
Rejane Alvarenga Silva ◽  
Júnia Aparecida Lopes ◽  
Denise Eulálio ◽  
Rodrigo Morais Menezes dos Santos ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Layered Double Hydroxides ◽  
Slow Release ◽  
Structural Characteristics ◽  
Synthesis Methods ◽  
Double Hydroxides ◽  
Near Future

The current research aims to introduce Layered Double Hydroxides (LDH) as nanomaterials to be used in agriculture, with particular reference to its use as storage and slow release matrix of nutrients and agrochemicals for plant growing. Structural characteristics, main properties, synthesis methods and characterization of LDH were covered in this study. Moreover, some literature data have been reported to demonstrate their potential for storage and slow release of nitrate, phosphate, agrochemicals, besides as being used as adsorbent for the wastewater treatment. This research aims to expand, in near future, the investigation field on these materials, with application in agriculture, increasing the interface between chemistry and agronomy.

scholarly journals Structural synthesis of plane kinematic chain inversions without detecting isomorphism

2021 ◽  
Vol 12 (2) ◽  
pp. 1061-1071
Author(s):  
Jinxi Chen ◽  
Jiejin Ding ◽  
Weiwei Hong ◽  
Rongjiang Cui
Keyword(s):  
Mechanism Design ◽  
Adjacency Matrix ◽  
Synthesis Method ◽  
Kinematic Chain ◽  
Degree Of Freedom ◽  
Synthesis Methods ◽  
Creative Design ◽  
Structural Synthesis ◽  
Kinematic Chains

Abstract. A plane kinematic chain inversion refers to a plane kinematic chain with one link fixed (assigned as the ground link). In the creative design of mechanisms, it is important to select proper ground links. The structural synthesis of plane kinematic chain inversions is helpful for improving the efficiency of mechanism design. However, the existing structural synthesis methods involve isomorphism detection, which is cumbersome. This paper proposes a simple and efficient structural synthesis method for plane kinematic chain inversions without detecting isomorphism. The fifth power of the adjacency matrix is applied to recognize similar vertices, and non-isomorphic kinematic chain inversions are directly derived according to non-similar vertices. This method is used to automatically synthesize 6-link 1-degree-of-freedom (DOF), 8-link 1-DOF, 8-link 3-DOF, 9-link 2-DOF, 9-link 4-DOF, 10-link 1-DOF, 10-link 3-DOF and 10-link 5-DOF plane kinematic chain inversions. All the synthesis results are consistent with those reported in literature. Our method is also suitable for other kinds of kinematic chains.

SOLVING SPATIAL CONSTRAINTS WITH GLOBAL DISTANCE COORDINATE SYSTEM

2006 ◽  
Vol 16 (05n06) ◽  
pp. 533-547 ◽  
Author(s):  
LU YANG
Keyword(s):  
Coordinate System ◽  
Systematic Approach ◽  
Distance Geometry ◽  
Spatial Constraints ◽  
Constraint Equations ◽  
System A ◽  
Short Program ◽  
Complete Set ◽  
Point Line ◽  
Made In

A systematic approach making use of distance geometry to solve spatial constraints is introduced. We demonstrate how to create the constraint equations by means of a relevant distance coordinate system. A short program is made (in Maple) which implements the algorithm producing automatically a complete set of constraint equations for a given point-plane configuration. The point-line-plane configurations are converted into point-plane ones beforehand.

Synthesis of planar kinematic chains with prismatic pairs based on a similarity recognition algorithm

2021 ◽  
pp. 1-13
Author(s):  
Rongjiang Cui ◽  
Zhizheng Ye ◽  
Shifu Xu ◽  
Chuan-yu Wu ◽  
Liang Sun
Keyword(s):  
Recognition Algorithm ◽  
Synthesis Process ◽  
Synthesis Methods ◽  
Structural Synthesis ◽  
Kinematic Chains

Abstract The structural synthesis of planar kinematic chains (KCs) with prismatic pairs (P-pairs) is the basis of innovating mechanisms containing P-pairs. In literature, only a little research has been carried out to synthesize planar KCs with P-pairs. Moreover, these synthesis methods for KCs with P-pairs involve all possible combinations of edges, resulting in a large number of isomorphic KCs and a low synthesis efficiency. In this study, our previous similarity recognition algorithm is improved and applied to synthesize planar KCs with P-pairs. Only a small number of isomorphic KCs are generated in the synthesis process, and the synthesis efficiency is greatly enhanced. Our method is applied to synthesize 9-link 2-DOF, 10-link 1-DOF, and 11-link 2-DOF KCs with one and two P-pairs. Our synthesis results are consistent with those of the existing literature. The present work is helpful to design mechanisms with P-pairs and can be extended to mechanisms with other types of kinematic pairs.

Discussion of Hwang and Chen's constraint equations to eliminate order, circuit and branch defects for the paper: Defect-free synthesis of Stephenson-III motion generators, published in Journal of Mechanical Engineering Science, 2008; 222: 2485–2494

2019 ◽  
Vol 234 (5) ◽  
pp. 1130-1134
Author(s):  
Wen-Yi Lin
Keyword(s):  
Mechanical Engineering ◽  
Optimization Algorithms ◽  
Synthesis Method ◽  
Synthesis Methods ◽  
Engineering Science ◽  
Function Generation ◽  
Constraint Equations ◽  
Optimum Synthesis

Many studies to find solutions for the optimum synthesis problems of linkage mechanisms for path, motion or function generation have appeared in the literature. However, their main focus has been on the development of optimization algorithms or synthesis methods without the handling of the defect problems or only with consideration of the same assembly mode. Hwang and Chen's pioneering work proposed a defect-free optimum synthesis method with constraint equations to eliminate order, circuit and branch defects for Stephenson III six-bar motion generators. However, their proposed constraint equations for the three types of defects are incomplete or not clear enough. In this discussion, we not only examine these faults but also offer the correct and complete constraints to eliminate the three types of defects.

Relative Dynamic Stiffness Testing and Vibration Suppression Technology for the Complete Set of High-Precision CNC

2012 ◽  
Vol 430-432 ◽  
pp. 1636-1640
Author(s):  
Feng Tao Wang ◽  
Bin Zhang ◽  
Yang Yang Zhang ◽  
Xing Hai Fu ◽  
Liu Hai He
Keyword(s):  
Cutting Force ◽  
High Precision ◽  
Vibration Suppression ◽  
Structural Characteristics ◽  
Dynamic Stiffness ◽  
Vibration Resistance ◽  
Complete Set ◽  
Spindle Vibration

This thesis proposed a method of testing the relative dynamic stiffness for the whole machine of the high-precision CNC. That is to cut the specimen, then to test the cutting force in all directions and the spindle vibration of the actual processing respectively. It can determine the relative dynamic stiffness of the machine. According to testing results of the relative dynamic stiffness and the structural characteristics of the machine, it can make a program to restrain the suppression vibration. Comparing the dynamic stiffness before vibration suppression and after, vibration resistance of the machine significantly has been improved which validate the effectiveness of the program.

Mobility analysis and structural synthesis of a class of spatial mechanisms with coupling chains

Robotica ◽  
2015 ◽  
Vol 34 (11) ◽  
pp. 2467-2485 ◽  
Author(s):  
Wen-ao Cao ◽  
Huafeng Ding ◽  
Ziming Chen ◽  
Shipei Zhao
Keyword(s):  
Structural Analysis ◽  
Parallel Mechanisms ◽  
Mobility Analysis ◽  
Structural Synthesis ◽  
Systematic Method ◽  
General Methodology ◽  
Spatial Mechanisms ◽  
Analysis And Synthesis

SUMMARYThis paper presents a systematic method for dealing with mobility analysis and structural synthesis of a class of important spatial mechanisms with coupling chains, which involve more complex coupling relations than spatial parallel mechanisms. First, an approach to the establishment of the motion screw equation of the class of mechanisms is derived. Then, a general methodology for mobility analysis along with detection of rigid substructures is proposed based on the motion screw equation. Third, the principle of structural synthesis of the class of mechanisms is established on the basis of the method of mobility analysis. Finally, some novel spatial mechanisms with coupling chains are synthesized, illustrating the effectiveness of the method. The study of the paper will benefit structural analysis and synthesis of more complex spatial mechanisms with coupling chains.

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