Analysis and Optimum Synthesis of Planar Mechanisms With Clearances and Tolerances Using Interval Analysis

2006 ◽  
Author(s):  
Nadim Diab ◽  
Ahmad Smaili
Keyword(s):  
Interval Analysis ◽  
Optimization Approach ◽  
Membership Functions ◽  
Optimization Scheme ◽  
Planar Mechanisms ◽  
Fuzzy Membership Functions ◽  
Optimum Synthesis ◽  
Gradient Based ◽  
Joint Clearances

This paper presents an interval analysis based approach for analysis and optimization of planar mechanisms including the effect of link lengths tolerances and joint clearances. Mathematical models describing the effect of the mechanical errors on the desired output parameters of the mechanism are derived, followed by the commissioning of an ant-gradient based optimization scheme to find the maximum possible deviations in them. A new optimization approach is also devised to design a four bar mechanism with “minimal” sensitivity to clearances and tolerances. An analysis case study is presented and the results are displayed in the form of fuzzy membership functions and compared with results obtained using a similar approach. An example on optimum synthesis of a four-bar mechanism with joint clearances and link tolerances for hybrid exact/approximate points trajectory is also presented. Insights based on the assessment of the results are introduced.

scholarly journals SUM NORMAL OPTIMIZATION OF FUZZY MEMBERSHIP FUNCTIONS

2002 ◽  
Vol 10 (04) ◽  
pp. 363-384 ◽  
Author(s):  
DAN SIMON
Keyword(s):  
Fuzzy Logic ◽  
Membership Function ◽  
Optimization Problem ◽  
Fuzzy Membership ◽  
Optimization Approach ◽  
Membership Functions ◽  
Fuzzy Logic Systems ◽  
Fuzzy Membership Functions ◽  
Normal Constraint ◽  
Logic System

Given a fuzzy logic system, how can we determine the membership functions that will result in the best performance? If we constrain the membership functions to a certain shape (e.g., triangles or trapezoids) then each membership function can be parameterized by a small number of variables and the membership optimization problem can be reduced to a parameter optimization problem. This is the approach that is typically taken, but it results in membership functions that are not (in general) sum normal. That is, the resulting membership function values do not add up to one at each point in the domain. This optimization approach is modified in this paper so that the resulting membership functions are sum normal. Sum normality is desirable not only for its intuitive appeal but also for computational reasons in the real time implementation of fuzzy logic systems. The sum normal constraint is applied in this paper to both gradient descent optimization and Kalman filter optimization of fuzzy membership functions. The methods are illustrated on a fuzzy automotive cruise controller.

Evolutionary Based Optimal Synthesis of Four-Bar Mechanisms

2003 ◽  
Author(s):  
D. Koladiya ◽  
P. S. Shiakolas ◽  
J. Kebrle
Keyword(s):  
Optimization Techniques ◽  
Optimization Approach ◽  
Path Generation ◽  
Planar Mechanisms ◽  
Function Generation ◽  
Novel Technique ◽  
Optimum Synthesis ◽  
Design Variables ◽  
Accuracy Level ◽  
And Function

Graphical and analytical syntheses have been well applied to path, motion and function generation of planar mechanisms. Optimization techniques in common, require “good initial guesses” and do not necessarily converge to a solution. This paper presents a methodology to synthesize mechanisms employing an evolutionary optimization approach technique known as Differential Evolution. The initial bounds for the design variables are defined automatically using a newly developed and novel technique called the Geometric Centroid of Precision Points. Optimum synthesis of four-bar linkages for path generation with user defined accuracy level at required precision points is discussed.

scholarly journals Toward Decentralised Sanitary Sewage Collection Systems: A Multiobjective Approach for Cost-Effective and Resilient Designs

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1886
Author(s):  
Arezoo Zahediasl ◽  
Amin E. Bakhshipour ◽  
Ulrich Dittmer ◽  
Ali Haghighi
Keyword(s):  
Treatment Plant ◽  
Drainage System ◽  
Cost Effective ◽  
Optimization Approach ◽  
Hydraulic Design ◽  
Multiobjective Approach ◽  
Layout Generation ◽  
Plant Allocation ◽  
Problem Solving Process

In recent years, the concept of a centralized drainage system that connect an entire city to one single treatment plant is increasingly being questioned in terms of the costs, reliability, and environmental impacts. This study introduces an optimization approach based on decentralization in order to develop a cost-effective and sustainable sewage collection system. For this purpose, a new algorithm based on the growing spanning tree algorithm is developed for decentralized layout generation and treatment plant allocation. The trade-off between construction and operation costs, resilience, and the degree of centralization is a multiobjective problem that consists of two subproblems: the layout of the networks and the hydraulic design. The innovative characteristics of the proposed framework are that layout and hydraulic designs are solved simultaneously, three objectives are optimized together, and the entire problem solving process is self-adaptive. The model is then applied to a real case study. The results show that finding an optimum degree of centralization could reduce not only the network’s costs by 17.3%, but could also increase its structural resilience significantly compared to fully centralized networks.

scholarly journals Intuitionistic Fuzzy Laplacian Twin Support Vector Machine for Semi-supervised Classification

2021 ◽  
Author(s):  
Jia-Bin Zhou ◽  
Yan-Qin Bai ◽  
Yan-Ru Guo ◽  
Hai-Xiang Lin
Keyword(s):  
Support Vector Machine ◽  
Negative Impact ◽  
Twin Support Vector Machine ◽  
Fuzzy Membership ◽  
Support Vector ◽  
Membership Functions ◽  
Fuzzy Membership Functions ◽  
Intuitionistic Fuzzy ◽  
Benchmark Datasets ◽  
The Impact

AbstractIn general, data contain noises which come from faulty instruments, flawed measurements or faulty communication. Learning with data in the context of classification or regression is inevitably affected by noises in the data. In order to remove or greatly reduce the impact of noises, we introduce the ideas of fuzzy membership functions and the Laplacian twin support vector machine (Lap-TSVM). A formulation of the linear intuitionistic fuzzy Laplacian twin support vector machine (IFLap-TSVM) is presented. Moreover, we extend the linear IFLap-TSVM to the nonlinear case by kernel function. The proposed IFLap-TSVM resolves the negative impact of noises and outliers by using fuzzy membership functions and is a more accurate reasonable classifier by using the geometric distribution information of labeled data and unlabeled data based on manifold regularization. Experiments with constructed artificial datasets, several UCI benchmark datasets and MNIST dataset show that the IFLap-TSVM has better classification accuracy than other state-of-the-art twin support vector machine (TSVM), intuitionistic fuzzy twin support vector machine (IFTSVM) and Lap-TSVM.

OPTIMIZATION OF COMPOSITE AIRCRAFT STRUCTURES IN CONSIDERATION OF POSTBUCKLING BEHAVIOR

2010 ◽  
Vol 10 (04) ◽  
pp. 905-916 ◽  
Author(s):  
FERNASS DAOUD ◽  
MIRCEA CALOMFIRESCU
Keyword(s):  
Fiber Orientation ◽  
Load Level ◽  
Nonlinear Finite Element ◽  
Postbuckling Behavior ◽  
Optimization Scheme ◽  
Cross Sectional ◽  
Stiffened Composite Panels ◽  
Gradient Based ◽  
Element Approach ◽  
Composite Skins

An approach is presented to determine the design that minimizes the weight in consideration of the postbuckling behavior of stiffened composite panels. Since, due to computational expense, for optimization purposes a nonlinear finite element approach is not appropriate, a semianalytical approach is implemented in the EADS MAS software LAGRANGE. A gradient-based optimization scheme is employed to determine the ply thicknesses and fiber orientation of the composite skins and the cross-sectional areas of the stiffeners. Strength and stability constraints are used. Based on two examples of different complexity, weight savings are shown to be due to the fact, that skin buckling is allowed above a certain load level.

A method for automatic generation of fuzzy membership functions for mobile device’s characteristics based on Google Trends

2013 ◽  
Vol 29 (2) ◽  
pp. 510-517 ◽  
Author(s):  
Aitor Almeida ◽  
Pablo Orduña ◽  
Eduardo Castillejo ◽  
Diego López-de-Ipiña ◽  
Marcos Sacristán
Keyword(s):  
Automatic Generation ◽  
Google Trends ◽  
Fuzzy Membership ◽  
Membership Functions ◽  
Fuzzy Membership Functions

Fuzzy membership functions of procurement selection criteria

2002 ◽  
Vol 20 (3) ◽  
pp. 285-296 ◽  
Author(s):  
S. Thomas Ng ◽  
Duc Thanh Luu ◽  
Swee Eng Chen ◽  
Ka Chi Lam
Keyword(s):  
Selection Criteria ◽  
Fuzzy Membership ◽  
Membership Functions ◽  
Fuzzy Membership Functions

scholarly journals Optimal Component Sizing for Peak Shaving in Battery Energy Storage System for Industrial Applications

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2048 ◽  
Author(s):  
Rodrigo Martins ◽  
Holger Hesse ◽  
Johanna Jungbauer ◽  
Thomas Vorbuchner ◽  
Petr Musilek
Keyword(s):  
Energy Storage ◽  
Storage System ◽  
Energy Storage System ◽  
Optimization Approach ◽  
Battery Energy Storage System ◽  
Peak Shaving ◽  
Battery Energy Storage ◽  
Battery Energy ◽  
Power Capability

Recent attention to industrial peak shaving applications sparked an increased interest in battery energy storage. Batteries provide a fast and high power capability, making them an ideal solution for this task. This work proposes a general framework for sizing of battery energy storage system (BESS) in peak shaving applications. A cost-optimal sizing of the battery and power electronics is derived using linear programming based on local demand and billing scheme. A case study conducted with real-world industrial profiles shows the applicability of the approach as well as the return on investment dependence on the load profile. At the same time, the power flow optimization reveals the best storage operation patterns considering a trade-off between energy purchase, peak-power tariff, and battery aging. This underlines the need for a general mathematical optimization approach to efficiently tackle the challenge of peak shaving using an energy storage system. The case study also compares the applicability of yearly and monthly billing schemes, where the highest load of the year/month is the base for the price per kW. The results demonstrate that batteries in peak shaving applications can shorten the payback period when used for large industrial loads. They also show the impacts of peak shaving variation on the return of investment and battery aging of the system.

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