Effect of Mechanical Alignment System on Assembly Accuracy

2000 ◽  
Author(s):  
Neville K. S. Lee ◽  
Grace H. Yu ◽  
Y. Zou ◽  
J. Y. Chen ◽  
Ajay Joneja
Keyword(s):  
Alignment Accuracy ◽  
Mechanical Alignment ◽  
Mechanical Assembly ◽  
Surface Waviness ◽  
Form Errors ◽  
Multi Stage ◽  
Assembly Accuracy ◽  
Alignment System ◽  
Simulation Based ◽  
Selection Of

Abstract Mechanical means of positioning are frequently used in mechanical assembly processes. However, very little attention has been paid to the selection of mechanical alignment systems (MAS) for assembly processes. Our analysis shows that if the MAS are not properly selected, the form errors as well surface waviness and roughness of the workpieces to be assembled can badly limit the level of accuracy achievable. A simulation-based methodology is described to study the alignment accuracy for multi-stage processes. Such cases are common, where fabrication operations are done on parts before they are assembled. The study shows that if the workpieces are aligned in the same orientation, using similar or identical MAS for the fabrication processes and assembly processes, then the effect of the form errors as well as surface waviness and roughness of the workpieces can be greatly suppressed.

Effect of Mechanical Alignment System on Assembly Accuracy

2003 ◽  
Vol 125 (3) ◽  
pp. 595-608 ◽  
Author(s):  
Neville K. S. Lee ◽  
Grace H. Yu ◽  
J. Y. Chen ◽  
Ajay Joneja
Keyword(s):  
Simulation Models ◽  
Mechanical Alignment ◽  
Mechanical Assembly ◽  
Surface Errors ◽  
Error Surface ◽  
Assembly Accuracy ◽  
Alignment System ◽  
Order Of Magnitude ◽  
Proper Design ◽  
Selection Of

Mechanical means of positioning are frequently used in mechanical assembly processes. However, very little attention has been paid to the proper design and selection of mechanical alignment systems (MAS) for assembly processes. In this paper, we study the performance of different MAS in terms of assembly accuracy in the presence of the form error, surface waviness and surface roughness of the references surfaces. In particular, simulation models are used to investigate how the datum pin configuration, datum pin location and datum geometry of the MAS would affect the assembly accuracy in the presence of surface errors of the workpieces. Our investigation can provide insight into how to design MAS for optimum performance for assembly accuracy. Our analysis shows that over an order of magnitude of difference in assembly accuracy can exist between using properly designed MAS and poorly design MAS.

scholarly journals Multi-stage secure clusterhead selection using discrete rule-set against unknown attacks in wireless sensor network

2020 ◽  
Vol 10 (4) ◽  
pp. 4296
Author(s):  
Tejashwini N. ◽  
D. R. Shashi Kumar ◽  
K. Satyanarayana Reddy
Keyword(s):  
Wireless Sensor Network ◽  
Sensor Network ◽  
Cost Effective ◽  
Wireless Sensor ◽  
Cyber Physical System ◽  
Delivery Performance ◽  
Multi Stage ◽  
Simulation Based ◽  
Rule Set ◽  
Selection Of

Security is the rising concern of the wireless network as there are various forms of reonfigurable network that is arised from it. Wireless sensor network (WSN) is one such example that is found to be an integral part of cyber-physical system in upcoming times. After reviewing the existing system, it can be seen that there are less dominant and robust solutions towards mitigating the threats of upcoming applications of WSN. Therefore, this paper introduces a simple and cost-effective modelling of a security system that offers security by ensuring secure selection of clusterhead during the data aggregation process in WSN. The proposed system also makes construct a rule-set in order to learn the nature of the communication iin order to have a discrete knowledge about the intensity of adversaries. With an aid of simulation-based approach over MEMSIC nodes, the proposed system was proven to offer reduced energy consumption with good data delivery performance in contrast to existing approach.

scholarly journals Membrane Distillation for the Production of Pharmaceutical-Grade Water—Investigation into the Application of AGMD and VMD

2021 ◽  
Vol 18 (11) ◽  
pp. 6058
Author(s):  
Cornelius Nellessen ◽  
Thomas Klein ◽  
Hans-Jürgen Rapp ◽  
Frank Rögener
Keyword(s):  
Energy Demand ◽  
Tap Water ◽  
Membrane Distillation ◽  
Pharmaceutical Products ◽  
Optimum Process ◽  
The European Union ◽  
Pharmaceutical Ingredients ◽  
Multi Stage ◽  
One Step ◽  
Selection Of

The production of pharmaceutical ingredients, intermediates and final products strongly depends on the utilization of water. Water is also required for the purification and preparation of reagents. Each specific application determines the respective water quality. In the European Union, the European Pharmacopeia (Ph. Eur.) contains the official standards that assure quality control of pharmaceutical products during their life cycle. According to this, the production of water for pharmaceutical use is mainly based on multi-stage distillation and membrane processes, especially, reverse osmosis. Membrane distillation (MD) could be an alternative process to these classical methods. It offers advantages in terms of energy demand and a compact apparatus design. In the following study, the preparation of pharmaceutical-grade water from tap water in a one-step process using MD is presented. Special emphasis is placed on the performance of two different module designs and on the selection of optimum process parameters.

Simulation-Based Selection of Surgical Trainees: Considerations, Challenges, and Opportunities

2016 ◽  
Vol 223 (3) ◽  
pp. 530-536 ◽  
Author(s):  
Aimee K. Gardner ◽  
E. Matthew Ritter ◽  
John T. Paige ◽  
Rami A. Ahmed ◽  
Gladys Fernandez ◽  
...  
Keyword(s):  
Surgical Trainees ◽  
Simulation Based ◽  
Challenges And Opportunities ◽  
Selection Of

Sample selection of prognostics validation test based on multi-stage Wiener process

2018 ◽  
Vol 233 (4) ◽  
pp. 605-614
Author(s):  
Zhiao Zhao ◽  
Yong Zhang ◽  
Guanjun Liu ◽  
Jing Qiu
Keyword(s):  
Wiener Process ◽  
Process Model ◽  
Failure Modes ◽  
Early Stage ◽  
Sample Selection ◽  
Degradation Process ◽  
Time Interval ◽  
Degradation Data ◽  
Multi Stage ◽  
Selection Of

Sample allocation and selection technology is of great significance in the test plan design of prognostics validation. Considering the existing researches, the importance of prognostics samples of different moments is not considered in the degradation process of a single failure. Normally, prognostics samples are generated under the same time interval mechanism. However, a prognostics system may have low prognostics accuracy because of the small quantity of failure degradation and measurement randomness in the early stage of a failure degradation process. Historical degradation data onto equipment failure modes are collected, and the degradation process model based on the multi-stage Wiener process is established. Based on the multi-stage Wiener process model, we choose four parameters to describe different degradation stages in a degradation process. According to four parameters, the sample selection weight of each degradation stage is calculated and the weight of each degradation stage is used to select prognostics samples. Taking a bearing wear fault of a helicopter transmission device as an example, its degradation process is established and sample selection weights are calculated. According to the sample selection weight of each degradation process, we accomplish the prognostics sample selection of the bearing wear fault. The results show that the prognostics sample selection method proposed in this article has good applicability.

Multi-Stage Upscaling: Selection of Suitable Methods

2005 ◽  
pp. 191-216 ◽  
Author(s):  
G. E. Pickup ◽  
K. D. Stephen ◽  
J. Ma ◽  
P. Zhang ◽  
J. D. Clark
Keyword(s):  
Multi Stage ◽  
Selection Of

Exploring the policy selection of the P2P VoD system: A simulation-based research

2014 ◽  
Vol 8 (3) ◽  
pp. 459-473 ◽  
Author(s):  
Ke Xu ◽  
Xin Liu ◽  
Zhen Ma ◽  
Yifeng Zhong ◽  
Wenlong Chen
Keyword(s):  
System A ◽  
Policy Selection ◽  
Simulation Based ◽  
Selection Of

scholarly journals Selection of the Multiple-Criiater Decision-Making Method for Evaluation of Sustainable Energy Development: A Case Study of Poland

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6321
Author(s):  
Małgorzata Trojanowska ◽  
Krzysztof Nęcka
Keyword(s):  
Decision Making ◽  
Empirical Distribution ◽  
Sustainable Energy ◽  
Multiple Criteria Decision Making ◽  
Energy Development ◽  
Linear Ordering ◽  
Energy Sustainability ◽  
Multi Stage ◽  
Clustering Quality ◽  
Selection Of

One of the basic objectives of the European Union’s energy policy is to obtain and use energy in a sustainable way. Multiple-criteria decision making (MCDM) methods, in particular linear ordering based on the synthetic variable procedure, are used for comparative analyses of the level of energy sustainability. Despite many studies, the problem of choosing the optimal ordering method is still not fully resolved. This paper presents an original procedure that facilitates the selection of an effective method of the linear ordering of multi-feature objects for the evaluation of sustainable energy development of regions. What is understood as the effective ordering of regions is not only the effective ranking of objects but also their effective clustering. In order to obtain the best results of linear ordering, the authors put forward a multi-stage optimization of the selection of the method of ordering and normalization of diagnostic variables. Analysis of variance was used for the assessment of the object ranking quality, while for the assessment of the object clustering quality, an innovative approach was presented based on the analysis of the empirical distribution of the frequency of occurrence of the distance between objects. The linear ordering method, selected on the basis of the procedure proposed in the paper, was used to assess the energy sustainability of Polish regions. The calculations and analyses were carried out using the set of indicators developed by the authors. They characterize the sustainable energy development of regions in the social, economic, and environmental dimensions.

A new approach of surfaces registration considering form errors for precise assembly

2020 ◽  
Vol 40 (6) ◽  
pp. 789-800
Author(s):  
Qiushuang Zhang ◽  
Xin Jin ◽  
Zhihua Liu ◽  
Zhijing Zhang ◽  
Yan Fang ◽  
...  
Keyword(s):  
Manufacturing Industry ◽  
Optimal Solution ◽  
Registration Method ◽  
Content Type ◽  
Form Errors ◽  
Contact Points ◽  
Assembly Accuracy ◽  
Prediction And Control ◽  
Experimental Values ◽  
And Control

Purpose The modern manufacturing industry has put forward higher requirements for the assembly accuracy of components with the development of the industrial technology. For precision assembly, the traditional assembly process study based on tolerance has had difficulty in meeting these requirements. Hence, the distribution of the form errors must be considered. The registration between the two mating surfaces with form errors determines the parts’ assembly position, and is the basis for the prediction and control of the assembly accuracy. This study aims to provide a new surfaces registration method which takes form errors into consideration. Design/methodology/approach This study presents a new registration approach based on the minimum potential energy. A unique set of contact points on mating surfaces that meet the actual conditions can be obtained and the spatial position of the assembled part is calculated. Findings The experimental results show that the calculated values are in good agreement with the experimental values. Furthermore, the root mean square error is within 2%, which proves the validity and accuracy of the approach. Originality/value This paper provides an effective and new method for precision assembly which takes form errors into consideration. The method can give the optimal solution of the contact points, which is more consistent with the actual assembly situation and provides a basis for predicting assembly accuracy.

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