Analysis and optimization of assembly precision-cost model based on 3D tolerance expression

2018 ◽  
Vol 38 (4) ◽  
pp. 497-510 ◽  
Author(s):  
Wei Sun ◽  
Xiaokai Mu ◽  
Qingchao Sun ◽  
Zhiyong Sun ◽  
Xiaobang Wang
Keyword(s):  
Upper Bound ◽  
Cost Model ◽  
Low Cost ◽  
Great Influence ◽  
Small Displacement ◽  
Content Type ◽  
Model Based ◽  
Manufacturing Tolerances ◽  
Assembly Deviation ◽  
Assembly Precision

PurposeThis paper aims to comprehensively achieve the requirements of high assembly precision and low cost, a precision-cost model of assembly based on three-dimensional (3D) tolerance is established in this paper.Design/methodology/approachThe assembly precision is related to the tolerance of parts and the deformation of matching surfaces under load. In this paper, the small displacement torsor (SDT) theory is first utilized to analyze the manufacturing tolerances of parts and the assembly deformation deviation of matching surface. In the meanwhile, the extracting method of SDT parameters is proposed and the assembly precision calculation model based on the 3D tolerance is established. Second, an integrated optimization model based on the machining cost, assembly cost (mapping the deviation domain to the SDT domain) and quality loss cost is built. Finally, the practicability of the precision-cost model is verified by optimizing the horizontal machining center.FindingsThe assembly deviation has a great influence on cost fluctuation. By setting the optimization objective to maximize the assembly precision, the optimal total cost is CNY 72.77, decreasing by 16.83 per cent from the initial value, which meets economical requirements. Meanwhile, the upper bound of each processing tolerance is close to the maximum value of 0.01 mm, indicating that the load deformation can be offset by appropriately increasing the upper bound of the tolerance, but it is necessary to strictly restrict the manufacturing tolerances of lower parts in a reasonable range.Originality/valueIn this paper, a 3D deviation precision-cost model of assembly is established, which can describe the assembly precision more accurately and achieve a lower cost compared with the assembly precision model based on rigid parts.

ASEAN will gain new supply chain role

2016 ◽  
Keyword(s):  
Supply Chains ◽  
Global Economy ◽  
Cost Model ◽  
Low Cost ◽  
Value Added ◽  
Developed Countries ◽  
Content Type ◽  
Automation Technology ◽  
Changing Role

Subject Asia's changing role in global supply chains. Significance Asian supply chains and their role in the global economy are undergoing far-reaching change. They are shifting from a low-cost model based on a set of particular exports to Western developed countries to prioritising high value-added trade and putting stronger emphasis on Asian markets. Handling a wider variety of products and matching rapidly changing demand is becoming a top priority, making the role of technologically advanced suppliers of key inputs, including small and medium companies (SMEs), increasingly important. Impacts Demographic change will catalyse changes in consumption patterns and supply chains. Supply chains' development will drive demand for automation technology. South-east Asian supply chains will be constrained until infrastructure improves.

Combination modeling of auto body assembly dimension propagation considering multi-source information for variation reduction

2019 ◽  
Vol 39 (4) ◽  
pp. 514-522
Author(s):  
Yinhua Liu ◽  
Shiming Zhang ◽  
Guoping Chu
Keyword(s):  
Modeling Method ◽  
Propagation Model ◽  
Source Information ◽  
Content Type ◽  
Variation Reduction ◽  
Combination Model ◽  
Model Based ◽  
Variation Propagation ◽  
Variable Weight ◽  
Assembly Deviation

PurposeThis paper aims to present a combination modeling method using multi-source information in the process to improve the accuracy of the dimension propagation relationship for assembly variation reduction.Design/methodology/approachBased on a variable weight combination prediction method, the combination model that takes the mechanism model and data-driven model based on inspection data into consideration is established. Furthermore, the combination model is applied to qualification rate prediction for process alarming based on the Monte Carlo simulation and also used in engineering tolerance confirmation in mass production stage.FindingsThe combination model of variable weights considers both the static theoretical mechanic variation propagation model and the dynamic variation relationships from the regression model based on data collections, and provides more accurate assembly deviation predictions for process alarming.Originality/valueA combination modeling method could be used to provide more accurate variation predictions and new engineering tolerance design procedures for the assembly process.

On modeling mechanisms and applicable ranges of grey incidence analysis models

2018 ◽  
Vol 8 (4) ◽  
pp. 448-461 ◽  
Author(s):  
Wenjie Dong ◽  
Sifeng Liu ◽  
Zhigeng Fang
Keyword(s):  
Great Influence ◽  
Analytical Models ◽  
Analysis Model ◽  
Content Type ◽  
Model Based ◽  
Grey Incidence Analysis ◽  
Incidence Analysis ◽  
Different Characteristics ◽  
Analysis Models ◽  
Model Slope

Purpose The purpose of this paper is to study the modelling mechanisms of several grey incidence analysis models with great influence, including Deng’s grey incidence model, absolute degree of grey incidence model, slope degree of incidence model, similitude degree of incidence model and closeness degree of incidence model; then analyse the problems to be solved in grey incidence analysis models; and clarify the applicable ranges of commonly used grey incidence models. Design/methodology/approach The paper comes to conclusions by means of comparable analysis. The authors compare several commonly used grey incidence analysis models, including Deng’s grey incidence model, absolute degree of grey incidence model, slope degree of incidence model, similitude degree of incidence model and closeness degree of incidence model and give several examples to clarify the reasons why quantitative analysis results of different models are not exactly the same. Findings As the intension of each kind of incidence model is clear and the extension is relatively obscure, grey incidence orders calculated by different incidence models are often different. When making actual decisions, incompatible results may appear. According to different characteristics of extraction, grey incidence analysis models can be divided into three types: incidence model based on closeness perspective, incidence model based on similarity perspective and incidence model based on comprehensive perspective. Practical implications The conclusions obtained in this paper can help people avoid some defects in the process of actual selection and choose the better incidence analysis model. Originality/value The conclusions can be used as a reference and basis for the selection of grey incidence analysis models, it can help to overcome the defects and shortcomings of models caused by themselves and screen out more excellent analytical models.

Monomer model: an integrated characterization method of geometrical deviations for assembly accuracy analysis

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Binbin Zhao ◽  
Yunlong Wang ◽  
Qingchao Sun ◽  
Yuanliang Zhang ◽  
Xiao Liang ◽  
...  
Keyword(s):  
Weak Links ◽  
Small Displacement ◽  
Accuracy Analysis ◽  
Content Type ◽  
Assembly Accuracy ◽  
Rotor Assembly ◽  
Relationship Of ◽  
Assembly Deviation ◽  
First Time

Purpose Assembly accuracy is the guarantee of mechanical product performance, and the characterization of the part with geometrical deviations is the basis of assembly accuracy analysis. Design/methodology/approach The existed small displacement torsors (SDT) model cannot fully describe the part with multiple mating surfaces, which increases the difficulty of accuracy analysis. This paper proposed an integrated characterization method for accuracy analysis. By analyzing the internal coupling relationship of the different geometrical deviations in a single part, the Monomer Model was established. Findings The effectiveness of the Monomer Model is verified through an analysis of a simulated rotor assembly analysis, and the corresponding accuracy analysis method based on the model reasonably predicts the assembly deviation of the rotor. Originality/value The Monomer Model realizes the reverse calculation of assembly deformation for the first time, which can be used to identify the weak links that affect the assembly accuracy, thus support the accuracy improvement in the re-assembly stage.

Ritz Model of a Lead-Acid Battery With Application to Electric Locomotives

2011 ◽  
Author(s):  
Zheng Shen ◽  
Jun Gou ◽  
Christopher D. Rahn ◽  
Chao-Yang Wang
Keyword(s):  
Discharge Rate ◽  
Cost Model ◽  
Low Cost ◽  
Storage System ◽  
Ritz Method ◽  
Open Circuit ◽  
Electric Locomotive ◽  
Governing Equations ◽  
Model Based ◽  
Charge Discharge

Pb-Acid batteries are excellent candidates for hybrid and electric locomotive, primarily due to their low cost. Model-based design, estimation, and control of a Pb-Acid energy storage system for a locomotive requires the development of efficient and accurate models. This paper presents a first principles model based on the fundamental governing equations of species and charge conservation for a Pb-Acid cell. The governing equations are discretized using a Ritz method to produce a low order and numerically efficient model that simulates over 20 times faster than CFD. The Ritz model outputs variables of interest such as voltage and internal potential, current, and concentration distributions in response to the current input. The Ritz model can be cast in state variable form, making it amenable to systems analysis using Matlab and model-based estimator and controller design. The accuracy of the Ritz model decreases with increasing charge/discharge rate, low or high State of Charge, and increasing charge/discharge time due to linearization of the Butler-Volmer equation, linearization of the open circuit voltage, and constant porosity assumptions, respectively. Finally, the time constant during charge is significantly different than that during discharge due to different specific areas, motivating the use of a time-varying model.

scholarly journals Urban Air Quality Modeling Using Low-Cost Sensor Network and Data Assimilation in the Aburrá Valley, Colombia

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 91
Author(s):  
Santiago Lopez-Restrepo ◽  
Andres Yarce ◽  
Nicolás Pinel ◽  
O.L. Quintero ◽  
Arjo Segers ◽  
...  
Keyword(s):  
Air Quality ◽  
Data Assimilation ◽  
Transport Model ◽  
Cost Model ◽  
Low Cost ◽  
Model Performance ◽  
Monitoring Network ◽  
Correlation Factor ◽  
Chemical Transport Model ◽  
High Quality

The use of low air quality networks has been increasing in recent years to study urban pollution dynamics. Here we show the evaluation of the operational Aburrá Valley’s low-cost network against the official monitoring network. The results show that the PM2.5 low-cost measurements are very close to those observed by the official network. Additionally, the low-cost allows a higher spatial representation of the concentrations across the valley. We integrate low-cost observations with the chemical transport model Long Term Ozone Simulation-European Operational Smog (LOTOS-EUROS) using data assimilation. Two different configurations of the low-cost network were assimilated: using the whole low-cost network (255 sensors), and a high-quality selection using just the sensors with a correlation factor greater than 0.8 with respect to the official network (115 sensors). The official stations were also assimilated to compare the more dense low-cost network’s impact on the model performance. Both simulations assimilating the low-cost model outperform the model without assimilation and assimilating the official network. The capability to issue warnings for pollution events is also improved by assimilating the low-cost network with respect to the other simulations. Finally, the simulation using the high-quality configuration has lower error values than using the complete low-cost network, showing that it is essential to consider the quality and location and not just the total number of sensors. Our results suggest that with the current advance in low-cost sensors, it is possible to improve model performance with low-cost network data assimilation.

Vibratory weld conditioning during gas tungsten arc welding of al 5052 alloy on the mechanical and micro-structural behavior

2020 ◽  
Vol 17 (6) ◽  
pp. 831-836
Author(s):  
M. Vykunta Rao ◽  
Srinivasa Rao P. ◽  
B. Surendra Babu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Welded Joints ◽  
Great Influence ◽  
Welding Process ◽  
Microstructural Characterization ◽  
Content Type ◽  
Average Grain Size

Purpose Vibratory weld conditioning parameters have a great influence on the improvement of mechanical properties of weld connections. The purpose of this paper is to understand the influence of vibratory weld conditioning on the mechanical and microstructural characterization of aluminum 5052 alloy weldments. An attempt is made to understand the effect of the vibratory tungsten inert gas (TIG) welding process parameters on the hardness, ultimate tensile strength and microstructure of Al 5052-H32 alloy weldments. Design/methodology/approach Aluminum 5052 H32 specimens are welded at different combinations of vibromotor voltage inputs and time of vibrations. Voltage input is varied from 50 to 230 V at an interval of 10 V. At each voltage input to the vibromotor, there are three levels of time of vibration, i.e. 80, 90 and 100 s. The vibratory TIG-welded specimens are tested for their mechanical and microstructural properties. Findings The results indicate that the mechanical properties of aluminum alloy weld connections improved by increasing voltage input up to 160 V. Also, it has been observed that by increasing vibromotor voltage input beyond 160 V, mechanical properties were reduced significantly. It is also found that vibration time has less influence on the mechanical properties of weld connections. Improvement in hardness and ultimate tensile strength of vibratory welded joints is 16 and 14%, respectively, when compared without vibration, i.e. normal weld conditions. Average grain size is measured as per ASTM E 112–96. Average grain size is in the case of 0, 120, 160 and 230 is 20.709, 17.99, 16.57 and 20.8086 µm, respectively. Originality/value Novel vibratory TIG welded joints are prepared. Mechanical and micro-structural properties are tested.

A model of mobile technologies acceptance for knowledge transfer by employees

2017 ◽  
Vol 21 (5) ◽  
pp. 1053-1076 ◽  
Author(s):  
Michal Kuciapski
Keyword(s):  
Knowledge Management ◽  
Knowledge Transfer ◽  
Conceptual Model ◽  
Mobile Devices ◽  
Mobile Technologies ◽  
Intention To Use ◽  
Content Type ◽  
Model Based ◽  
New Variables ◽  
Practical Implications

Purpose Although mobile devices are ubiquitous among employees, their awareness and readiness to use mobile technologies for competence development is still not widespread and therefore requires further exploration. The purpose of this study is to propose a conceptual model based on the unified theory of acceptance and use of technology (UTAUT) to explain the determinants that affect employees’ intention to use mobile devices and software for knowledge transfer during the process of knowledge management. Design/methodology/approach A conceptual model based on the UTAUT with new variables concerning relative usability (RU) and user autonomy (UA) and new connections between the determinants was developed as a result of a subject matter literature review. A structural equation modelling approach was used to validate the model on the basis of data collected via a survey collected from 371 employees from 21 sectors, both public and private. Findings The UTAUT model extended by new variables like RU and UA explains employee acceptance of mobile technologies for knowledge transfer reasonably well. New proposed variables highlighted that the usability of technology compared to other solutions and user autonomy in the selection and the use of applications have the strongest impact on the employees’ intention to use mobile devices and software for knowledge transfer. Research limitations/implications This model explains the 55 per cent behavioral intention of employees to use mobile technologies for knowledge transfer. Even though it is quite high in terms of acceptance theories, some new variables should be explored. Furthermore, study does not verify whether m-learning acceptance for knowledge transfer is sector-specific. Practical implications Mobile technologies used for knowledge transfer by employees should allow for high UA through their ability to select solutions that they find convenient, use of preferred platforms, personalize applications and utilize devices and software in various environments. They should not be simplified and should have the same functionality and efficiency of use as alternative solutions like web and desktop applications, even if additional effort to learn them would be required. Mobile technologies that take into account UA and RU support the process of employees capturing, distributing and effectively using knowledge. Originality/value The elaborated model provides a valuable solution with practical implications for increasing mobile technologies acceptance for knowledge transfer. The study results contribute both to knowledge management and technology acceptance research fields by introducing two new determinants for the acceptance of technologies in knowledge transfer, such as UA and RU with several additional connections between existing UTAUT variables.

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