Application of Taguchi Method on the Tolerance Design of a Four-Bar Function Generation Mechanism

2005 ◽  
Author(s):  
Fu-Chen Chen ◽  
Hsing-Hui Huang
Keyword(s):  
Taguchi Method ◽  
Control Factor ◽  
Tolerance Design ◽  
Initial Value ◽  
Function Generator ◽  
Function Generation ◽  
Manufacturing Tolerance ◽  
Structural Error ◽  
Experimental Errors ◽  
The Mean

The purpose of this paper is to use the Taguchi method on the tolerance design of a four-bar function generator in order to obtain the structural error that is insensitive to variations in manufacturing tolerance and joint clearance. The contribution of each control factor to the variations was also examined to further determine if the tolerance of the factor should be tightened to improve the precision of the mechanism. From the study of the four-bar function generator, it was revealed that the control factor B had the most significant effect on the variation of the structural errors. These were closely followed by factors E, C and D. On the whole, experimental errors contributed only 2.69% to the structural errors, much smaller than the contribution by individual factors, indicating that the design of the experiments was appropriate and the results were highly reliable. By tightening the tolerance, it is apparent that the mean of structural errors is reduced by 0.227 and the change in variance is 69.81% of the initial value, i.e. a reduction of 30.19%.

A SIMPLE APPROACH FOR THE TOLERANCE DESIGN OF WATT-I TYPE SIX-BAR HINGE MECHANISM USING TAGUCHI METHOD

2006 ◽  
Vol 13 (02) ◽  
pp. 157-169 ◽  
Author(s):  
FU-CHEN CHEN ◽  
YIH-FONG TZENG
Keyword(s):  
Taguchi Method ◽  
Signal To Noise Ratio ◽  
Control Factor ◽  
Tolerance Design ◽  
Manufacturing Tolerance ◽  
Response Table ◽  
Product Variation ◽  
Key Dimensions ◽  
Relationship Of

This paper uses the Taguchi method on the tolerance design of a hinge mechanism with the aim of obtaining a design that is insensitive to variations in manufacturing tolerance and joint clearance. The contribution of each control factor in the mechanism to the variations was also quantified. From the analysis of the response table and diagram, it was concluded that the dimension r1, r2, r4 and β had a significant effect on the quality of the mechanism, contributing a total of 82.36% to product variation and were consequently named the key dimensions. The tolerance of these factors must therefore be tightened to improve the quality of the mechanism. Through a series of confirmation experiments, it was revealed that tightening the tolerance resulted in an increase in the S/N (signal to noise) ratio by 1.851 db and a reduction in product variation by 19.25% from the original 80.75%. The proposed method does not require complex mathematical derivatives, but simply the input and output relationship of the system. The method proposed in this study can be applied to all types of mechanism.

Tolerance Design for Four-Bar Function Generating Mechanisms with Joint Clearances Using Taguchi Method

2010 ◽  
Vol 118-120 ◽  
pp. 517-521 ◽  
Author(s):  
Xian Zhen Huang ◽  
Yi Min Zhang ◽  
Hao Lu ◽  
Le Tang ◽  
He Li
Keyword(s):  
Taguchi Method ◽  
Design Parameters ◽  
Tolerance Design ◽  
Function Generator ◽  
Function Generation ◽  
Joint Clearances ◽  
Generation Mechanisms ◽  
Sensitivity Maps

This paper presents a method for tolerance design of four-bar function generating mechanisms with joint clearances using Taguchi method. Based on previous studies made by other researchers, we propose a model to quantify the effects of uncertain factors on the accuracy of four-bar function generating mechanisms. Taguchi’s approach is applied to select the optimal tolerance ranges for the design parameters of function generation mechanisms. Sensitivity maps are plotted to provide an insight to the effects of parameter errors on the performance variances of four-bar function generating mechanisms. To illustrate the efficiency of the proposed methodology, the tolerance design of a four-bar function generator with joint clearances is discussed.

Taguchi-fuzzy-based approach for the sensitivity analysis of a four-bar function generator

2006 ◽  
Vol 220 (9) ◽  
pp. 1413-1421 ◽  
Author(s):  
F-C Chen ◽  
H-H Huang
Keyword(s):  
Sensitivity Analysis ◽  
Fuzzy Logic ◽  
Taguchi Method ◽  
Performance Index ◽  
Control Factor ◽  
Maximum Displacement ◽  
Function Generator ◽  
Control Factors ◽  
The Mean ◽  
Key Dimensions

This article aims to use the Taguchi method coupled with fuzzy logic on the tolerance sensitivity analysis of a four-bar function generator. Experiments designed by the Taguchi method were carried out for obtaining the mean and the maximum displacement variations of the function generator. By converting these two variations into a multiple performance index by means of fuzzy logic, the effect of each control factor on the mechanism quality was further analysed. The Taguchi method coupled with fuzzy logic was used to systematically analyse the effect of individual control factors on the displacement variations of a four-bar function generator from which the key dimensions were identified.

Kinematic Synthesis of a Geared Five-Bar Function Generator

1971 ◽  
Vol 93 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Arthur G. Erdman ◽  
George N. Sandor
Keyword(s):  
Computer Program ◽  
Closed Form ◽  
Complex Numbers ◽  
Function Generator ◽  
Kinematic Synthesis ◽  
Numerical Examples ◽  
Function Generation ◽  
Structural Error ◽  
Dependent Variables ◽  
Angular Displacements

A general closed form method of planar kinematic synthesis, using complex numbers to represent link vectors, is applied to the synthesis of a geared five-bar linkage for function generation. Equations are derived and a computer program is developed to yield several solutions. Angular displacements of the input, a cycloidal crank, and the output, a simple follower, are used as linear analogs of the independent and the dependent variables, respectively. A method is demonstrated for six precision conditions (three first, three second-order precision conditions). Numerical examples are included, and the structural error of these geared five-bars are compared to that of optimized four-bar linkages generating the same functions.

scholarly journals Electrical stimulator with mechanomyography-based real-time monitoring, muscle fatigue detection, and safety shut-off: a pilot study

2020 ◽  
Vol 65 (4) ◽  
pp. 461-468
Author(s):  
Jannatul Naeem ◽  
Nur Azah Hamzaid ◽  
Amelia Wong Azman ◽  
Manfred Bijak
Keyword(s):  
Muscle Fatigue ◽  
Real Time ◽  
Isometric Force ◽  
Mean Square ◽  
Clear Indication ◽  
Initial Value ◽  
Cord Injury ◽  
The Mean ◽  
Electrical Stimulator ◽  
Fatigue Detection

AbstractFunctional electrical stimulation (FES) has been used to produce force-related activities on the paralyzed muscle among spinal cord injury (SCI) individuals. Early muscle fatigue is an issue in all FES applications. If not properly monitored, overstimulation can occur, which can lead to muscle damage. A real-time mechanomyography (MMG)-based FES system was implemented on the quadriceps muscles of three individuals with SCI to generate an isometric force on both legs. Three threshold drop levels of MMG-root mean square (MMG-RMS) feature (thr50, thr60, and thr70; representing 50%, 60%, and 70% drop from initial MMG-RMS values, respectively) were used to terminate the stimulation session. The mean stimulation time increased when the MMG-RMS drop threshold increased (thr50: 22.7 s, thr60: 25.7 s, and thr70: 27.3 s), indicating longer sessions when lower performance drop was allowed. Moreover, at thr70, the torque dropped below 50% from the initial value in 14 trials, more than at thr50 and thr60. This is a clear indication of muscle fatigue detection using the MMG-RMS value. The stimulation time at thr70 was significantly longer (p = 0.013) than that at thr50. The results demonstrated that a real-time MMG-based FES monitoring system has the potential to prevent the onset of critical muscle fatigue in individuals with SCI in prolonged FES sessions.

scholarly journals On Riemann—Liouville and Caputo Fractional Forward Difference Monotonicity Analysis

Mathematics ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1303
Author(s):  
Pshtiwan Othman Mohammed ◽  
Thabet Abdeljawad ◽  
Faraidun Kadir Hamasalh
Keyword(s):  
Time Scale ◽  
Initial Value Problems ◽  
Mean Value ◽  
Mean Value Theorem ◽  
Discrete Fractional Calculus ◽  
Initial Value ◽  
Forward Difference ◽  
The Mean ◽  
Monotonicity Analysis ◽  
Monotonicity Results

Monotonicity analysis of delta fractional sums and differences of order υ∈(0,1] on the time scale hZ are presented in this study. For this analysis, two models of discrete fractional calculus, Riemann–Liouville and Caputo, are considered. There is a relationship between the delta Riemann–Liouville fractional h-difference and delta Caputo fractional h-differences, which we find in this study. Therefore, after we solve one, we can apply the same method to the other one due to their correlation. We show that y(z) is υ-increasing on Ma+υh,h, where the delta Riemann–Liouville fractional h-difference of order υ of a function y(z) starting at a+υh is greater or equal to zero, and then, we can show that y(z) is υ-increasing on Ma+υh,h, where the delta Caputo fractional h-difference of order υ of a function y(z) starting at a+υh is greater or equal to −1Γ(1−υ)(z−(a+υh))h(−υ)y(a+υh) for each z∈Ma+h,h. Conversely, if y(a+υh) is greater or equal to zero and y(z) is increasing on Ma+υh,h, we show that the delta Riemann–Liouville fractional h-difference of order υ of a function y(z) starting at a+υh is greater or equal to zero, and consequently, we can show that the delta Caputo fractional h-difference of order υ of a function y(z) starting at a+υh is greater or equal to −1Γ(1−υ)(z−(a+υh))h(−υ)y(a+υh) on Ma,h. Furthermore, we consider some related results for strictly increasing, decreasing, and strictly decreasing cases. Finally, the fractional forward difference initial value problems and their solutions are investigated to test the mean value theorem on the time scale hZ utilizing the monotonicity results.

The Estimation of the Efficiency of Sampling, with Special Reference to Sampling for Yield in Cereal Experiments

1935 ◽  
Vol 25 (4) ◽  
pp. 545-577 ◽  
Author(s):  
F. Yates ◽  
I. Zacopanay
Keyword(s):  
Standard Deviation ◽  
Special Reference ◽  
Analysis Of Variance ◽  
Sampling Methods ◽  
Cereal Crops ◽  
Loss Of Information ◽  
Preliminary Discussion ◽  
Experimental Errors ◽  
Series Of Experiments ◽  
The Mean

The estimation of the experimental yields of cereal crops by sampling methods is considered in the light of results of eighteen experiments which were harvested by these methods at Rothamsted and its associated centres. The harvesting results of the Crop-Weather series of experiments are also included.A preliminary discussion of the interpretation of the analysis of variance as applied to sampling results is given, and an expression is found for the loss of information arising out of sampling. The results of the discussion are applicable to all types of sampling carried out on replicated experiments.The sampling and experimental errors of all the experiments have been calculated. The variation between sampling units in the same subplot (usually between l/100th and l/200th acre) was found to be such as would arise if each metre length of row had a standard deviation (about the plot mean) of the order of 25–30 per cent. of the mean yield.

NOTE ON THE VLASOV EQUATION FOR PLASMAS

1963 ◽  
Vol 41 (12) ◽  
pp. 1960-1966 ◽  
Author(s):  
Ta-You Wu ◽  
M. K. Sundaresan
Keyword(s):  
Distribution Function ◽  
Fourier Transform ◽  
Vlasov Equation ◽  
Hermite Polynomials ◽  
Infinite Matrix ◽  
Mean Square ◽  
Initial Value ◽  
Positive Ions ◽  
The Mean ◽  
The Fourier Transform

The linearized Vlasov equation is solved as an initial value problem by expanding (the Fourier components of) the distribution function in a series of Hermite polynomials in the momentum, with coefficients which are functions of time. The spectrum of frequencies is given by the eigenvalues of an infinite matrix. All the frequencies ω are real, extending from small values of order ω2 = k2(u22), where (u22) is the mean square velocity of the positive ions (of mass M), to [Formula: see text], where ω1, (u12) are the plasma frequency and mean square velocity of the electrons (of mass m). The classic work of Landau solves the Vlasov equation for (the Fourier transform of) the potential for which he obtains the "damping", whereas Van Kampen and the present writers solve the equation for (the Fourier transform of) the distribution function itself. While the present work gives results equivalent to those of Van Kampen, the method is simpler and in fact elementary.

Time course of the bronchoconstriction induced by inhaled histamine and methacholine

1983 ◽  
Vol 54 (3) ◽  
pp. 821-826 ◽  
Author(s):  
A. Cartier ◽  
J. L. Malo ◽  
P. Begin ◽  
M. Sestier ◽  
R. R. Martin
Keyword(s):  
Flow Resistance ◽  
Time Course ◽  
Recovery Phase ◽  
Base Line ◽  
Prolonged Action ◽  
Initial Value ◽  
Pulmonary Flow ◽  
The Mean

Eleven asthmatic subjects inhaled doubling concentrations of histamine until a near sixfold increase in total pulmonary flow resistance had been reached. This last concentration (C6) of histamine and methacholine was administered on two subsequent separate visits. Specific lung conductance (sGL) dropped to 18.6 +/- 7.9 (SD) and 19.1 +/- 10.3% of initial value after histamine and methacholine, respectively (NS). Whereas the peak action occurred in a similar interval (1–4 min), the mean duration of the subsequent plateau, defined as values of sGL within 20% of the maximum fall was 16.8 +/- 9.8 min for histamine and 74.6 +/- 53.7 min for methacholine (P less than 0.01). The recovery phase from the end of the plateau to base line lasted 25.5 +/- 14.4 min for histamine and 56.7 +/- 38.3 min for methacholine (P less than 0.01). The duration of plateau and recovery phases were not linked with base-line sGL, maximum fall in sGL, or C6. We conclude that for the same induced bronchoconstriction methacholine has a more prolonged action than histamine.

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