A GPU homotopy path tracker and end game for mechanism synthesis

Detecting the existence of a crank in the Stephenson-Ш six-bar linkage is one of the most difficult problems encountered in the mechanism synthesis. Based on the model established for the circuit analysis of the Stephenson six-bar chains, through judging whether there is a dead-center position in the circuits of this linkage, this paper presents a new method for identifying the existence of a crank in the Stephenson-Ш six-bar linkage. Some examples are given to demonstrate the validity of this method.

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Redundantly actuated mechanism synthesis of the symmetrical unconstrained branched chain parallel mechanism

2015 7th International Conference on Modelling, Identification and Control (ICMIC) ◽

10.1109/icmic.2015.7409378 ◽

2015 ◽

Author(s):

Yanmin Liu ◽

Shihua Li ◽

Zhili Tian ◽

Jianhua Zhang

Keyword(s):

Parallel Mechanism ◽

Mechanism Synthesis ◽

Redundantly Actuated ◽

Branched Chain

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Design and Virtual Prototyping of Rehabilitation Aids

Volume 4: Design for Manufacturing Conference ◽

10.1115/detc97/dfm-4361 ◽

1997 ◽

Author(s):

Venkat Krovi ◽

Vijay Kumar ◽

G. K. Ananthasuresh ◽

Jean-Marc Vezien

Keyword(s):

Virtual Prototyping ◽

Assistive Devices ◽

Cad Model ◽

Mechanism Synthesis ◽

Design And Optimization ◽

Revolute Joints ◽

Synthesis Design ◽

Serial Chain

Abstract This paper presents a paradigm for virtual prototyping of a class of one-of-a-kind assistive devices that can be customized to the human user. This class consists of passive, articulated mechanical aids for manipulation that are physically coupled to the user. We address the mechanism synthesis, design and optimization and its evaluation in a virtual prototyping environment that consists of a CAD model of the product and a customized model of the human user. In addition, we develop the theory and methodology for designing planar serial chain mechanisms with revolute joints coupled by cable-pulley transmissions. As an illustrative example, we consider the design and prototyping of a customized feeding aid for quadriplegics.

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A Methodology for Compliant Mechanisms Design: Part I — Introduction and Large-Deflection Analysis

18th Design Automation Conference: Volume 2 — Geometric Modeling, Mechanisms, and Mechanical Systems Analysis ◽

10.1115/detc1992-0146 ◽

1992 ◽

Author(s):

A. Midha ◽

I. Her ◽

B. A. Salamon

Keyword(s):

Large Deflection ◽

Compliant Mechanisms ◽

Compliant Mechanism ◽

Companion Paper ◽

Computational Techniques ◽

Shooting Methods ◽

Mechanism Synthesis ◽

Calculation Algorithm ◽

Deflection Analysis ◽

Kinematic Properties

Abstract A broader research proposal seeks to systematically combine large-deflection mechanics of flexible elements with important kinematic considerations, in yielding compliant mechanisms which perform useful tasks. Specifically, the proposed design methodology will address the following needs: development of the necessary nomenclature, classification and definitions, and identification of the kinematic properties; categorization of mechanism synthesis types, both structurally as well as by function; development of efficient computational techniques for design; consideration of materials; and application and validation. Contained herein, in particular, is an introduction to the state-of-the-art in compliant mechanisms, and the development of an accurate chain calculation algorithm for use in the analysis of a large-deflection, cantilevered elastica. Shooting methods, which permit specification of additional boundary conditions on the elastica, as well as compliant mechanism examples are presented in a companion paper.

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Performance Quality, Sensitivity, and Tolerance Specification of Mechanisms

23rd Biennial Mechanisms Conference: Mechanism Synthesis and Analysis ◽

10.1115/detc1994-0217 ◽

1994 ◽

Author(s):

Kwun-Lon Ting ◽

Yufeng Long

Keyword(s):

Signal To Noise Ratio ◽

Rayleigh Quotient ◽

Sensitivity Index ◽

Signal To Noise ◽

Mechanism Synthesis ◽

Performance Quality ◽

Mechanical Assemblies ◽

Tolerance Specification ◽

Position Synthesis ◽

The Ideal

Abstract By employing Taguchi’s concept to mechanism synthesis, this paper presents the theory and technique to identify a robust design, which is the least sensitive to the tolerances, for mechanisms and to determine the tolerance specification for the best performance and manufacturability. The method is demonstrated in finite and infinitesimal position synthesis. The sensitivity Jacobian is first introduced to relate the performance tolerances and the dimensional tolerances. The Rayleigh quotient of the sensitivity Jacobian, which is equivalent to Taguchi’s signal to noise ratio, is then used to define the performance quality and a sensitivity index is introduced to measure the sensitivity of the performance quality to the dimensional tolerances for the whole system. The ideal tolerance specification is obtained in closed form. It shows how the tolerance specification affects the performance quality and that the performance quality can be significantly improved by tightening a key tolerance while loosening the others. The theory is general and the technique is readily adaptable to almost any form and type of mechanical system, including multiple-loop linkages and mechanical assemblies or even structures.

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A More Effective Formulation of the Path Generation Mechanism Synthesis Problem

23rd Biennial Mechanisms Conference: Mechanism Synthesis and Analysis ◽

10.1115/detc1994-0200 ◽

1994 ◽

Author(s):

Irfan Ullah ◽

Sridhar Kota

Keyword(s):

Objective Function ◽

Error Function ◽

Mathematical Optimization ◽

Optimization Methods ◽

Complex Nature ◽

Mechanism Synthesis ◽

Structural Error ◽

Crank Angle ◽

The Common ◽

Selection Of

Abstract Use of mathematical optimization methods for synthesis of path-generating mechanisms has had only limited success due to the very complex nature of the commonly used Structural Error objective function. The complexity arises, in part, because the objective function represents not only the error in the shape of the coupler curve, but also the error in location, orientation and size of the curve. Furthermore, the common introduction of timing (or crank angle), done generally to facilitate selection of corresponding points on the curve for calculating structural error, has little practical value and unnecessarily limits possible solutions. This paper proposes a new objective function, based on Fourier Descriptors, which allows search for coupler curve of the desired shape without reference to location, orientation, or size. The proposed objective function compares overall shape properties of curves rather than making point-by-point comparison and therefore does not requires prescription of timing. Experimental evidence is provided to show that it is much easier to search the space of the proposed objective function compared to the structural error function.

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