THE SYNTHESIS OF MECHANISM SYSTEMS USING A MECHANISM CONCEPT LIBRARY

2010 ◽  
Vol 34 (1) ◽  
pp. 151-163 ◽  
Author(s):  
Feng-Ming Ou ◽  
Hong-Sen Yan ◽  
Ming-Feng Tang

This paper presents an approach for synthesizing all possible mechanism systems of kinematic building blocks in a mechanism concept library. The kinematic building blocks are defined as SISO primitive mechanisms, and their serial and/or parallel combinations are expressed as corresponding out-trees based on graph representation. By representing the constructive building blocks as labeled vertices and their possible combination relationships as directed edges, the synthesis approach is developed by adopting graph enumeration theorem. An illustrative example of four kinematic building blocks, including two crank-rocker linkages and two slider-crank mechanisms, is provided to validate the presented approach. The result shows that all feasible mechanism systems can be obtained effectively by following the synthesis method and which provides more alternatives in the library during design or re-design of mechanisms.

Author(s):  
Maria Terushkin ◽  
Offer Shai

This paper introduces a novel way to augment the knowledge and methods of rigidity theory to the topological decomposition and synthesis of gear train systems. A graph of gear trains, widely reported in the literature of machine theory, is treated as a graph representation from rigidity theory—the Body-Bar graph. Once we have this Body-Bar graph, methods and theorems from rigidity theory can be employed for analysis and synthesis. In this paper we employ the pebble-game algorithm, a computational method which allows determination of the topological mobility of mechanisms and the decomposition of gear trains into basic building blocks—Body-Bar Assur Graphs. Once we gain the ability to decompose any gear train into standalone components (Body-Bar Assur Graphs), this paper suggests inverting the process and applying the same method for synthesis. Relying on rigidity theory operations (Body-Bar extension, in this case), it is possible to construct all of the Body-Bar Assur Graphs, meaning the building blocks of gear trains. Once we have these building blocks at hand, it is possible to recombine them in various ways, providing us with a topological synthesis method for constructing gear trains. This paper also introduces a transformation between the Body-Bar graph and other graph representations used in mechanisms, thus leaving room for the application of the proposed synthesis and decomposition method directly to known graph representations already used in machine theory.


2021 ◽  
Vol 891 ◽  
pp. 111-115
Author(s):  
Maradhana Agung Marsudi ◽  
Farah Fitria Sari ◽  
Pandu Mauliddin Wicaksono ◽  
Adinda Asmoro ◽  
Arif Basuki ◽  
...  

In this work, silver nanoparticles have been successfully synthesized using simple and environmentally friendly ‘green synthesis’ method using Indonesian wild honey as mediator. Particle count and size can be optimized by varying the silver nitrate precursor and honey concentration, with the help of sodium hydroxide as pH regulator. Based on X-ray diffraction (XRD) result, crystalline structure of Ag has been confirmed in sample with impurities from AgCl. Based on dynamic light scattering (DLS) and transmission electron microscopy (TEM) results, it was found that the smallest average particles size of AgNPs (117.5 nm from DLS and 11.1 nm from TEM) was obtained at sample with 5% w/v of honey and 0.5 mM of AgNO3.


Author(s):  
Ahmad Smaili ◽  
Nadim Diab

The aim of this article is to provide a simple method to solve the mixed exact-approximate dimensional synthesis problem of planar mechanism. The method results in a mechanism that can traverse a closed path with the choice of any number of exact points while the rest are approximate points. The algorithm is based on optimum synthesis rather than on precision position methods. Ant-gradient search is applied on an objective function based on log10 of the error between the desired positions and those generated by the optimum solution. The log10 function discriminates on the side of generating miniscule errors (on the order of 10−14) at the exact points while allowing for higher errors at the approximate positions. The algorithm is tested by way of five examples. One of these examples was used to test exact/approximate synthesis method based on precision point synthesis approach.


Author(s):  
Norbert Német ◽  
Ylenia Miele ◽  
Gábor Shuszter ◽  
Eszter L. Tóth ◽  
János Endre Maróti ◽  
...  

AbstractIn the past decade, much effort has been devoted to using chemical clock-type reactions in material design and driving the self-assembly of various building blocks. Urea-urease enzymatic reaction has chemical pH clock behavior in an unbuffered medium, in which the induction time and the final pH can be programmed by the concentrations of the reagents. The urea-urease reaction can offer a new alternative in material synthesis, where the pH and its course in time are crucial factors in the synthesis. However, before using it in any synthesis method, it is important to investigate the possible effects of the reagents on the enzymatic reaction. Here we investigate the effect of the reagents of the zeolite imidazole framework-8 (zinc ions and 2-methylimidazole) on the urea-urease reaction. We have chosen the zeolite imidazole framework-8 because its formation serves as a model reaction for the formation of other metal–organic frameworks. We found that, besides the inhibition effect of the zinc ions which is well-known in the literature, 2-methylimidazole inhibits the enzymatic reaction as well. In addition to the observed inhibition effect, we report the formation of a hybrid urease-zinc-2-methylimidazole hybrid material. To support the inhibition effect, we developed a kinetic model which reproduced qualitatively the experimentally observed kinetic curves.


Author(s):  
Marti´n A. Pucheta ◽  
Alberto Cardona

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.


Author(s):  
Weifeng Huang ◽  
Matthew I. Campbell

This paper presents a graph synthesis approach to planar N-bar mechanisms with revolute (R), prismatic (P), and RP (pin-in-slot) joints. This novel graph synthesis method extends the enumeration to define the possible topologies for mechanisms with any mix of R-, P-, and RP-joints. Each topology is explicitly defined as a graph which can be viewed and simulated within an online kinematic simulator. This method successfully produces the same number of topologies for 6, 8, 10, and 12-bar revolute joint mechanisms as those shown in the existing literature. It explicitly calculates all topologies for 6, 8, and 10 bars with a mix of the three joint-types.


2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Bergen Helms ◽  
Kristina Shea

Computational design synthesis aims to iteratively and automatically generate solution spaces of standard and novel design alternatives to support the innovation process. New approaches are required to generate alternative solutions at the function and behavior level as well as to ease the computational modeling of design knowledge. This paper introduces the approach of object-oriented graph grammars for the computational synthesis of product models based on a Function–Behavior–Structure (FBS) representation. The approach combines the advantages of a generic and systematic design method with a highly computable graph representation and object-oriented concepts. Through this combination, advances in terms of extendibility, efficiency, and flexible formalization of declarative and procedural engineering knowledge are achieved. Validation of the method is given through the synthesis of hybrid powertrains. The generation of hybrid powertrain solution spaces is shown, especially focusing on the impact of an evolving vocabulary, or building blocks, for synthesis. Future work includes integrating search methods in the synthesis process along with quantitative evaluation using simulation methods.


2005 ◽  
Vol 20 (10) ◽  
pp. 2613-2617 ◽  
Author(s):  
Jason S. Tresback ◽  
Alexander L. Vasiliev ◽  
Nitin P. Padture

Using a unique combination of template-based synthesis methods involving anodization, electroplating, and selective oxidation, we have synthesized engineered metal–oxide–metal (MOM) heterojunction nanowires in the Au–SnO2–Au and Au–NiO–Au systems for possible use in nanoelectronics. The template-based synthesis method used here is generic, and it has the potential to provide control over the structure and characteristics of the resulting MOM nanowires. By virtue of their heterojunction structure, MOM nanowires have the potential to overcome some of the drawbacks associated with all-oxide nanowire building blocks, and they present a rare opportunity to measure directly fundamental functional properties of nanoscale oxides.


Author(s):  
Elad Hahn ◽  
Offer Shai

In the field of structural synthesis of mechanisms several synthesis methods have been developed using different approaches. One of the more interesting approaches was that of bottom-up construction via the combination of modular structural groups, known as Assur groups. This approach is combined with new graph representations of mechanisms taken from rigidity theory, capable of representing all the different types of planar and spatial mechanisms. With the strong mathematical base of rigidity theory, a new synthesis method is proposed based on Assur groups, which are reformulated in terms of graph theory and renamed Assur Graphs. Using a single universal construction rule, Assur Graphs of different types and of any number of links are constructed, creating a complete set of building blocks for the synthesis of feasible mechanisms. As its name implies, the single universal construction is applicable for mechanisms of all types of joints and links, for planar or spatial motion.


Author(s):  
Christine Rotinat-Libersa ◽  
Belen Solano

In this paper, we present the different steps towards the development of miniature compliant bending joint and gripper with high mechanical performances. These low encumbrance structures (5 mm cross-section) should deliver, with few actuation force, a large output displacement (90° bending, and 60° jaws opening respectively) under large output loads. Firstly, we describe the theoretical studies that have been investigated in order to optimally dimension these structures. For the bending joint, the design has been inspired from the literature and optimized. For the gripper, a non-intuitive design has been generated using a multi-objective optimal synthesis method. Finally, these compliant structures have been prototyped, and characterized. As an applicative example, they have been integrated into the end-effector of a surgical instrument. Despite the limited output load performances obtained (12.5 mN.m output torque with a 2.1 N actuation force, and 0.2 N gripping force respectively), these new building blocks demonstrate the ability of millimeter-size robotic devices further miniaturization.


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