Dimensional synthesis method for wide-band waveguide iris filters

2010 ◽  
Vol 4 (9) ◽  
pp. 1256 ◽  
Author(s):  
Q.F. Zhang ◽  
Y.L. Lu
Keyword(s):  
Synthesis Method ◽  
Wide Band ◽  
Dimensional Synthesis

A New Approach for Exact/Approximate Point Synthesis of Planar Mechanisms

2005 ◽  
Author(s):  
Ahmad Smaili ◽  
Nadim Diab
Keyword(s):  
Synthesis Method ◽  
Dimensional Synthesis ◽  
Gradient Search ◽  
Planar Mechanisms ◽  
Simple Method ◽  
New Approach ◽  
Optimum Synthesis ◽  
Approximate Synthesis ◽  
Optimum Solution ◽  
Synthesis Approach

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.

The Dimensional Synthesis of Spatial Cable-Driven Parallel Mechanisms

2013 ◽  
Vol 5 (4) ◽  
Author(s):  
K. Azizian ◽  
P. Cardou
Keyword(s):  
Synthesis Method ◽  
Sufficient Condition ◽  
Nonlinear Program ◽  
Parallel Mechanisms ◽  
Dimensional Synthesis ◽  
End Effector ◽  
A Value ◽  
Null Value ◽  
Objective Value

This paper presents a method for the dimensional synthesis of fully constrained spatial cable-driven parallel mechanisms (CDPMs), namely, the problem of finding a geometry whose wrench-closure workspace (WCW) contains a prescribed workspace. The proposed method is an extension to spatial CDPMs of a synthesis method previously published by the authors for planar CDPMs. The WCW of CDPMs is the set of poses for which any wrench can be produced at the end-effector by non-negative cable tensions. A sufficient condition is introduced in order to verify whether a given six-dimensional box, i.e., a box covering point-positions and orientations, is fully inside the WCW of a given spatial CDPM. Then, a nonlinear program is formulated, whose optima represent CDPMs that can reach any point in a set of boxes prescribed by the designer. The objective value of this nonlinear program indicates how well the WCW of the resulting CDPM covers the prescribed box, a null value indicating that none of the WCW is covered and a value greater or equal to one indicating that the full prescribed workspace is covered.

Solution Region Synthesis Method for Six Positions Synthesis of 5-SS Spatial Linkage

2016 ◽  
Author(s):  
Jianyou Han ◽  
Guangzhen Cui ◽  
Junjie Hu
Keyword(s):  
Systematic Approach ◽  
Synthesis Method ◽  
Degree Of Freedom ◽  
Dimensional Synthesis ◽  
End Effector ◽  
Region Method ◽  
Solution Region ◽  
The One

This paper presents a systematic approach to perform the dimensional synthesis of spatial 5-SS (spherical-spherical) link-ages for six specified positions of the end-effector. The dimensional synthesis equations for a SS link are formulated and solved. We synthesize five SS links to connect the base and end-effector, and then obtain the one-degree-of-freedom spatial 5-SS linkage, which can move through six specified positions. We use the solution region method to build the planar solution region expressing the linkages, due to there are infinite linkages for six positions synthesis. It is convenient to select the linkages from the solution region for designers. The applicability of the proposed approach is illustrated by the example.

Fourier Methods for Kinematic Synthesis of Coupled Serial Chain Mechanisms

2005 ◽  
Vol 127 (2) ◽  
pp. 232-241 ◽  
Author(s):  
Xichun Nie ◽  
Venkat Krovi
Keyword(s):  
Low Cost ◽  
Synthesis Method ◽  
Path Following ◽  
Degree Of Freedom ◽  
Dimensional Synthesis ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Serial Chain ◽  
End Effectors ◽  
Serial Chains

Single degree-of-freedom coupled serial chain (SDCSC) mechanisms are a class of mechanisms that can be realized by coupling successive joint rotations of a serial chain linkage, by way of gears or cable-pulley drives. Such mechanisms combine the benefits of single degree-of-freedom design and control with the anthropomorphic workspace of serial chains. Our interest is in creating articulated manipulation-assistive aids based on the SDCSC configuration to work passively in cooperation with the human operator or to serve as a low-cost automation solution. However, as single-degree-of-freedom systems, such SDCSC-configuration manipulators need to be designed specific to a given task. In this paper, we investigate the development of a synthesis scheme, leveraging tools from Fourier analysis and optimization, to permit the end-effectors of such manipulators to closely approximate desired closed planar paths. In particular, we note that the forward kinematics equations take the form of a finite trigonometric series in terms of the input crank rotations. The proposed Fourier-based synthesis method exploits this special structure to achieve the combined number and dimensional synthesis of SDCSC-configuration manipulators for closed-loop planar path-following tasks. Representative examples illustrate the application of this method for tracing candidate square and rectangular paths. Emphasis is also placed on conversion of computational results into physically realizable mechanism designs.

Dimensional Synthesis of Open Path Generator of Four-Bar Mechanisms Using the Haar Wavelet

2015 ◽  
Vol 137 (8) ◽  
Author(s):  
Jianwei Sun ◽  
Wenrui Liu ◽  
Jinkui Chu
Keyword(s):  
Synthesis Method ◽  
Haar Wavelet ◽  
Characteristic Dimension ◽  
Dimensional Synthesis ◽  
Open Path ◽  
Actual Mechanism ◽  
Mechanism Parameter ◽  
Relationship Of ◽  
Parameter Values ◽  
Internal Relationship

This paper presents a synthesis method for the open path generation of a four-bar mechanism using the Haar wavelet. The synthesis method utilizes the wavelet transform and normalization to extract the wavelet output feature parameters (WOFP) of the open path. Analysis of the WOFP reveals a particular characteristic: for the same four-bar mechanism, not only do variations of the mechanism origin and angles and the proportional scaling of the linkage lengths have no influence on the details of the WOFP but the same holds true for the position of the point that generates the coupler curve. Based on this finding, a numerical atlas database comprises 192,596 groups of basic dimensional types was established and a method of matching recognition was proposed as well. According to the internal relationship of the wavelet characteristic dimension parameters (WCDP), the actual mechanism parameter values and position parameters of an objective four-bar mechanism can be calculated. Four examples are presented to verify the accuracy and practicality of the proposed theory.

Automated Type and Modular Dimensional Synthesis of Planar Linkages

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.

Kinematic Analysis and Synthesis of the Knotting Mechanisms Can be Used in the Production of Handmade Carpet: A Case Study

2005 ◽  
Vol 219 (9) ◽  
pp. 987-1005 ◽  
Author(s):  
M Topalbekiroğlu
Keyword(s):  
Structural Characteristics ◽  
Complex Structure ◽  
Synthesis Method ◽  
Production Method ◽  
Human Hand ◽  
Functional Requirements ◽  
Dimensional Synthesis ◽  
New Production ◽  
Analysis And Synthesis

The weaving process in a handmade carpet contains independent knots, which have a complex structure. A new production method, mechanism, or machine for producing knots in handmade carpets has not been developed since thousands of years. They are still woven by human hand. Two different types of knots are used to form handmade carpets, which are called as the Turkish (Gördes knot) and the Persian (Sehna knot) knots. In this article, the conceptual design and dimensional synthesis for mechanisms used to produce these knots are studied. To generate all-acceptable one-degree of freedom (DOF) and two-DOF planar knotting mechanism, a systematic methodology is presented. First, the functional requirements of the knotting mechanism are established according to the problem statement. Some of the functional requirements of the knotting mechanism are then translated into the structural characteristics of mechanism. On the basis of the requirements and the structural considerations, the unwanted mechanism is screened out. Finally, two different mechanisms are developed for the knotting mechanism and their dimensions are determined by dimensional synthesis method.

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