A Robust Tolerance Design Method Based on Fuzzy Quality Loss

2006 ◽  
Vol 1 (1) ◽  
pp. 101-105 ◽  
Author(s):  
Yan-long Cao ◽  
Jian Mao ◽  
Jiang-xin Yang ◽  
Zhao-tong Wu ◽  
Li-qun Wu
2011 ◽  
Vol 421 ◽  
pp. 634-639
Author(s):  
Yi Feng Wang ◽  
Heng Zhang ◽  
Yan Long Cao ◽  
Jiang Xin Yang

This paper introduces a computer-aided concurrent tolerance design system based on real manufacturing resources (CATFM), which can ensure the optimal robust tolerance and consider real manufacturing resource owned by the factory. Firstly, the concurrent tolerance design model which can get balance between quality and cost utilizing Taguchi's quality loss function is proposed. Then the principle of concurrent tolerancing is concisely depicted through analyzing the overall structure of the system, and the design method is described in detail. Finally, an example is adopted to illustrate the proposed system.


1999 ◽  
Author(s):  
Chang-Xue (Jack) Feng ◽  
Ravi Balusu

Abstract Tolerance design bridges design and manufacturing. Concurrent design of tolerances and manufacturing processes may ensure the manufacturability, reduce the manufacturing and other related costs, decrease the number of fraction nonconforming (or defective rate), and shorten the production lead time. Since process capability indices relate tolerance specifications to manufacturing process capabilities, it is quite natural to apply them to concurrent design of tolerances and processes. As process shifts often exist in a manufacturing process, using Cp does not yield a good estimation of fraction nonconforming. Index Cpk does not precisely measure process shift either, but Cpm does. Therefore, this research compares the applications of Cp, Cpk and Cpm based on a numerical example of non-linear mechanical tolerance synthesis. In addition, the Taguchi quality loss function is used together with the manufacturing cost as the objective function.


2020 ◽  
Vol 10 (4) ◽  
pp. 1435 ◽  
Author(s):  
Guodong Sa ◽  
Zhenyu Liu ◽  
Chan Qiu ◽  
Jianrong Tan

With the increase of the working frequency of the array antenna, tolerance design has become increasingly important. The state-of-art tolerance design methods mainly deal with the position tolerance of the discrete elements. However, the geometric errors of the whole array have resulted from two aspects: (1) the position errors of the discrete elements and (2) the form errors of the continuous reflection plate. To optimize the position tolerance and flatness simultaneously, a hybrid tolerance design method is proposed. First, the relation between the performance of the array antenna and hybrid tolerances was determined based on the second order Taylor expansion. Then the expectation and variance of the performance were derived. Finally, the hybrid tolerances were optimized and the performance of the antenna was improved. Simulation results proved the effectiveness and efficiency of the proposed hybrid tolerance design method.


2019 ◽  
Vol 9 (16) ◽  
pp. 3216 ◽  
Author(s):  
Ci He ◽  
Shuyou Zhang ◽  
Lemiao Qiu ◽  
Xiaojian Liu ◽  
Zili Wang

To increase the reliability and accuracy of tolerance design, more and more research works are considering not only orientation and position deviations; they are also forming errors in tolerance modeling. As a direct cause of form errors in industrial mass production, the processing features of the machining system degrade over time. Under the Industry 4.0 paradigm, an assembly tolerance design method based on Skin Model Shape is proposed to take the effect of degrading processing features into consideration. A continuous-time multi-dimensional Markov process is trained through maximum likelihood estimation based on the nodal sampling point set on the machined surface. Degradation of the machined surface is modeled based on the joint probability distribution of nodal displacements. Assembly force constraints and assembly entity constraints are applied to spatial assembly simulations. Tolerance synthesis takes the manufacturing cost and assembling probability as design objectives. A design example of the rotary feed component in a five-axis machine tool is proposed for explanation and verification.


2014 ◽  
Vol 687-691 ◽  
pp. 4996-4999
Author(s):  
Zhang Rong

With the constraints on manufacturing capacity, the satisfaction of product performance and the cost of manufacture are contradictory, the problem between high-performance and low-cost must be solved at the period of design and manufacture for product. To solve this problem, the product loss model has been analyzed, the parameterized and non-parameterized model of anticipant losses has been researched, with concurrent design, in connection with the product with multiple correlated assembly functional dimensions, the relation function between quality loss and process dimension tolerance has been provided, the concurrent tolerance design mathematical model based on lowest-cost and quality loss has been established. The applied case shows that this method has important guiding significance for engineering application.


2019 ◽  
Vol 2019.29 (0) ◽  
pp. 2313
Author(s):  
Haruo ISHIKAWA ◽  
Yasuhiro FUKUNAGA

Author(s):  
Y Cao ◽  
J Mao ◽  
H Ching ◽  
J Yang

Using the quality loss function developed by Taguchi, the manufacturing time and cost of a product can be reduced to improve the factory's competitiveness. However, the fuzziness in quality loss has not been considered in the Taguchi method. This article presents a fuzzy quality loss function model. First, fuzzy logic is used to describe the semantic of the quality, and the quality level is divided into several grades. Then the fuzzy quality loss function is developed utilizing the loss in monetary terms, which indicates the quality loss of each quality level and the normalized expected probability to each quality grade. Moreover, a new optimization model for tolerance design under fuzzy quality loss function is established. An example is used to illustrate the validity of the proposed model. The result shows that the proposed method is more flexible and can achieve the balance of quality and cost in tolerance design. It can be easily used in accordance with practical engineering applications.


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