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Assessment of Workload, Fatigue, and Musculoskeletal Discomfort Among computerized numerical control Lathe Operators in Mexico

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IISE TRANSACTIONS ON OCCUPATIONAL ERGONOMICS & HUMAN FACTORS 2017年第2期5卷 65-81页

作者： Hernandez Arellano, Juan Luis Serratos Perez, J. Nieves Garcia Alcaraz, Jorge Luis Maldonado Macias, Aide Aracely Autonomous Univ Ciudad Juarez Dept Design Ave Charro450 Norte Ciudad Juarez 32310 Mexico Univ Guanajuato Dept Appl Sci Work Leon Campus Leon De Los Aldama Mexico Autonomous Univ Ciudad Juarez Dept Ind Engn & Mfg Ciudad Juarez Mexico

OCCUPATIONAL APPLICATIONS Several manufacturing concerns in Mexico, as part of a broader effort to incorporate advanced manufacturing technology, have replaced traditional machines with those using computerized numerical control. As a result, workers have experienced new levels of workload and fatigue levels that have not been previously investigated in depth. Among a sample of over 400 computerized numerical control workers in Mexico, we found that workload has an important effect on the perception of fatigue. Our results also suggest that sleep hours per night, handled weight, and stature of the workers are variables that must be considered in the design of tasks wherein computerized numerical control lathes are present. These results can be useful for managers and industrial engineers to develop and improve production schedules when computerized numerical control machines are operated. TECHNICAL ABSTRACT Background: With the introduction of new and more sophisticated machinery-commonly classified as advanced manufacturing technology-industrial workers must increasingly perform both physical and mental efforts, often simultaneously. A typical case is the operation of computerized numerical control lathes. This type of work has not been thoroughly studied, particularly in developing countries. In these countries, high workload levels are frequently neglected and the extent of fatigue experienced by operators remains unknown and unaddressed. Purpose: We aimed to assess workload, fatigue, and work-related musculoskeletal consequences;to explore the relationship between workload and fatigue;and to identify differences in workload and fatigue levels related to demographic and work-related variables, among computerized numerical control lathe operators in Mexico. Methods: A cross-sectional, descriptive study was completed, using a survey. Workload was assessed using the NASA Task Load Index. Fatigue was assessed using the Swedish Occupational Fatigue Inventory and the O

关键词： Assessment mental workload physical workload fatigue advanced manufacturing technology computerized numerical control operators

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Concept of a computerized numerical control Kernel for Execution on Multi-core Processors 14

Concept of a Computerized Numerical Control Kernel for Execu...

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14th IEEE International Workshop on Advanced Motion control (AMC)

作者： Keinert, Matthias Lechler, Armin Verl, Alexander Univ Stuttgart Inst Control Engn Machine Tools & Mfg Units Stuttgart Germany

ISBN: (纸本)9781479984640

computerized numerical controls are more and more executed on off-the-shelf system platforms and can thus benefit from the developments in the area of processor technology. Multi-core processors provide sufficient processing power for these controls but require a specific system design that allows exploiting the parallel processing unit. This paper presents an approach on how computerized numerical controls may be partitioned on a task and a functional level using task and data parallelism for the efficient execution on multi-core system platforms.

关键词： computerized numerical control Multi-Core Concurrency Data parallelism Task parallelism

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Sustainability of self-healing polymers: A holistic perspective towards circularity in polymer networks

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PROGRESS IN POLYMER SCIENCE 2024年 152卷

作者： Cerdan, Kenneth Thys, Marlies Cornella, Aleix Costa Demir, Fatma Norvez, Sophie Vendamme, Richard Van den Brande, Niko Van Puyvelde, Peter Brancart, Joost Univ Calif Santa Barbara Dept Chem Engn Santa Barbara CA 93106 USA Univ Calif Santa Barbara Dept Mech Engn Santa Barbara CA 93106 USA Flemish Inst Technol Res VITO B-2400 Mol Belgium Vrije Univ Brussel VUB Phys Chem & Polymer Sci FYSC Sustainable Mat Engn SUME Res Grp Pl laan 2 B-1050 Brussels Belgium Vrije Univ Brussel VUB Brubot Pl laan 2 B-1050 Brussels Belgium Imec Pl laan 2 B-1050 Brussels Belgium PSL Univ Mol Macromol Chem & Mat ESPCI Paris CNRS UMR7167 F-75005 Paris France Katholieke Univ Leuven Dept Chem Engn Soft Matter Rheol & Technol SMaRT Celestijnenlaan 200J B-3001 Heverlee Belgium

Permanent polymer networks present an important sustainability challenge. Irreversible covalent crosslinks impart these materials excellent mechanical properties, thermal and chemical resistance, yet also render them difficult to repair and to recycle. Self-healing mechanisms can extend the lifetime of thermosets and elastomers, improving their durability and making their lifecycle more sustainable. In addition to the lifetime extension, this paper reviews the sustainability of self-healing polymers from a holistic point of view. The entire lifecycle of self-healing polymers is critically assessed with reference to the green chemistry principles and sustainable development. The relation between the self-healing chemistries and the sustainability aspects of each of the phases of the lifecycle are discussed, starting from the feedstocks, monomer functionalisation and polymer synthesis, to processing and manufacturing as well as end-of-life considerations, i.e. recycling or (bio)degradation. The review provides a toolbox for the development of more sustainable thermosets, elastomers and their composites. It is of utmost importance to consider the entire lifecycle of self-healing materials, derived products and - by extension - any material or product. The self-healing ability and often related recyclability should primarily reduce the amount of new materials that are necessary to fulfill societal needs, by extending the lifetime of products and maximizing reprocessing into new products. Increasing healing efficiency and the number of healing cycles improves the overall environmental impact relative to the extended service lifetime. Renewable resources derived from biomass, recycling processes or waste streams should be the first choice to create new self-healing polymers. Finally, biodegradability can be considered as a complementary end-of-life scenario upon accidental loss of self-healing polymer to the environment, provided that the biodegradation does not start und

关键词： ACAT Amino-capped aniline trimer CA citric acid CAD Computational aided design CNC computerized numerical control DCM dichloromethane DCPD Dicyclopentadiene DIW Direct ink writing DMI 1,2-dimethylimidazole ENR Epoxidized natural rubber FA Furfuryl amine FDC 2,5-furandicarboxaldehyde FDCA 2,5-furandicaboxylic acid FFF Fused filament fabrication FGF Fused granule fabrication HBE hyperbranched epoxy IPN Interpenetrated network KDV Catalytic pressure-less depolymerization LCA Life cycle analysis Mw Molecular weight NGP neighbouring group participation PDMS Polydimethylsiloxane PEDOT 3,4-ethylenedioxythiophene PET Polyethylene terephthalate PHAs Polyhydroxyalkanoates PLA Polylactic acid PVA Polyvinyl alcohol PVP Polyvinylpyrrolidone ROMP Ring opening metathesis polymerization SLA Stereolithography SLS Selective laser sintering SH Self-healing Tgel gel transition temperature THF Tetrahydrofuran TPS thermoplastic starch TsOH p-toluenesulfonic acid Tv Topology freezing transition temperature UPy 2-uredio-4-pyrimidone VOC Volatile organic compounds

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Research on a Rapid S-shaped Acceleration and Deceleration Method for computerized numerical control System

Research on a Rapid S-shaped Acceleration and Deceleration M...

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4th International Conference on Manufacturing Science and Engineering (ICMSE 2013)

作者： Wu, Ting Zhang, Libing Jiaxing Univ Coll Mech & Elect Engn Jiaxing 314001 Peoples R China

ISBN: (纸本)9783037856932

In order to get over the limitation of the velocity planning method of computerized numerical control (CNC) system, a rapid S-shaped acceleration and deceleration method is presented in this paper. In the method, the rapid solving model of S-shape velocity planning is proposed, and these displacement, velocity and acceleration formulae of a rapid S-shape acceleration and deceleration model are derived. Compared with the proposed approach and the traditional velocity planning method, the simulative and experimental results show that the proposed method is smoother, and the machining efficiency is greatly improved.

关键词： acceleration and deceleration velocity planning feedrate profile rapid S-shape model computerized numerical control

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Towards a Circular Economy of Industrial Software

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Procedia CIRP 2020年 90卷 37-42页

作者： Vladimir Kutscher Sebastian Ruland Patrick Müller Nathan Wasser Malte Lochau Reiner Anderl Andy Schürr Mira Mezini Reiner Hähnle Department of Computer Integrated Design TU Darmstadt Otto-Berndt-Str. 2 Darmstadt 64287 Germany Real-Time Systems Lab TU Darmstadt Magdalenenstr. 4 64289 Darmstadt Germany Software Technology Group TU Darmstadt Hochschulstr. 10 Darmstadt 64287 Germany Software Engineering Group TU Darmstadt Hochschulstr. 10 Darmstadt 64287 Germany

Software has become an indispensable part of industrial production and thus influences the life cycle of manufacturing systems, as many of these systems have to be replaced or evolved due to changing requirements. Software adaptation through continuous evolution extends the service time of these systems and thus saves valuable resources. In this paper we present an interdisciplinary methodology for reengineering legacy software to increase the productive lifetime. Our proposed approach systematically reuses implicit domain knowledge to evolve, validate and commission new software from legacy code. The approach is evaluated on a CNC machine as a special type of industrial system.

关键词： Software reengineering Industrial software Digital twin Industry 4.0 Legacy system computerized numerical control Circular economy

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Generative models for direct generation of CNC toolpaths 25

Generative models for direct generation of CNC toolpaths

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25th International Conference on Mechatronics and Machine Vision in Practice (M2VIP)

作者： Kaiser, Benjamin Csiszar, Akos Verl, Alexander Univ Stuttgart ISW Stuttgart Germany

ISBN: (纸本)9781538675441

Today, numerical controls (CNC) are the standard for the control of machine tools and industrial robots in production and enable highly flexible and efficient production, especially for frequently changing production tasks. A numerical control has discrete inputs and outputs. Within the NC channel, however, it is necessary to analytically describe curves for the calculation of the position setpoints and the jerk limitation. The resulting change between discrete and continuous description forms and the considerable restrictions in the parallelisation of the interpolation of continuous curves within the NC channel lead to a performance overhead that limits the performance of the NC channel with regard to the calculation of new position setpoints. This can lead to a drop in production speed and thus to longer production times. To solve this problem, we propose a new approach in this paper. This is based on the use of deep generative models and allows the direct generation of interpolated toolpaths without calculation of continuous curves and subsequent discretization. The generative models are being trained to create curves of certain types such as linear and parabolic curves or splines directly as discrete point sequences. This approach is very well feasible with regard to its parallelization and reduces the computing effort within the NC channel. First results with straight lines and parabolic curves show the feasibility of this new approach for the generation of CNC toolpaths.

关键词： CNC computerized numerical control interpolation generative adversarial networks machine learning

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Analysis and design of computerized numerical controls for execution on multi-core systems 48

Analysis and design of computerized numerical controls for e...

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48th CIRP International Conference on Manufacturing Systems (CIRP CMS)

作者： Vivanco, Jose Maria Keinert, Matthias Lechler, Armin Verl, Alexander Inst Control Engn Machine Tools & Mfg Units ISW Seidenstr 36 D-70174 Stuttgart Germany Fraunhofer Gesell Hansastr 27c D-80686 Munich Germany

Multi-core processors offer a performance increment compared to single-core platforms. This leap in performance is desired to be ported to computerized numerical controls. However, in order to profit of the benefits multi-core processors can bring, the software has to be tailored to real parallel execution. In this paper a concept is proposed for partitioning numerical control software functions for being concurrently executed on multi-core systems. Specifically, the interpreter and the cutter radius compensation modules have been analyzed for devising a feasible parallel architecture. The parser algorithm has been implemented following the proposed scheme in a thread-based approach. Experiments were conducted under a real time Linux kernel extension utilizing the PREEMPT_RT patch. The results were compared against its serial version in terms of execution times to validate the concept. (C) 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://***/licenses/by-nc-nd/4.0/).

关键词： computerized numerical control Multi-core Parallel computing

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Analysis and Design of computerized numerical controls for Execution on Multi-core Systems

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Procedia CIRP 2016年 41卷 864-869页

作者： José María Vivanco Matthias Keinert Armin Lechler Alexander Verl Institute for Control Engineering of Machine Tools and Manufacturing Units (ISW) Seidenstr. 36 Stuttgart 70174 Germany Fraunhofer-Gesellschaft Hansastr. 27c Munich 80686 Germany

关键词： computerized numerical control Multi-core Parallel computing

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A comprehensive reliability allocation method for series systems based on failure mode and effects analysis transformed functions

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PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART B-JOURNAL OF ENGINEERING MANUFACTURE 2016年第12期230卷 2239-2248页

作者： Yang, Zhou Liu, Panxue Zhu, Yunpeng Zhang, Yimin Northeastern Univ Sch Mech Engn & Automat Shenyang 110819 Peoples R China

In order to address the reliability allocation problem of the series system, a comprehensive reliability allocation method based on a transformed function of the failure mode and effects analysis is introduced. First, considering multiple factors that affect the reliability allocation, an allocation matrix is established by employing significance factors. Subsequently, to overcome the limitations of the conventional failure mode and effects analysis-based allocation method, non-linear transform laws of failure severity and occurrence, known as transformed functions, are established. The reliability allocation results could be adjusted appropriately by choosing transform coefficients according to the desired allocation results of the system. Then, the transformed failure mode and effects analysis and the comprehensive allocation matrix are combined to give an allocation vector. Finally, a computerized numerical controlled lathe and a spindle system are used as examples. The allocation results of the transformed method, the conventional failure mode and effects analysis method and those in the correlated references are compared to emphasize the significance of the proposed allocation method in engineering practice.

关键词： Series system reliability failure mode and effects analysis comprehensive allocation computerized numerical control

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Improvements of Educational Process of Automation and Optimization Using 2D Plotter

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IFAC-PapersOnLine 2016年第6期49卷 16-21页

作者： Oravec, Juraj Kalúz, Martin Bakára, Peter Bakoová, Monika Slovak University of Technology in Bratislava Faculty of Chemical and Food Technology Radlinského 9 SK-812 37 Bratislava Slovakia

The paper presents development and application of computerized numerical control (CNC) type laboratory-scale positioning tool 2D Plotter for both, education and research. Presented device was built in order to provide an effective tool for solving two types of automated tasks, the precise positioning control in planar space, e.g. plotting of vector graphics, and illustrative extremum seeking for two-dimensional functions using brightness map and moving light sensor. Since the device is intended mostly for educational purposes, its construction is easily reproducible and low-cost. 2D Plotter will directly take place in courses focused on automation, process control, and optimization. Its properties also determine its utilization in remote experimentation. The paper presents potential tasks that can be effectively solved in educational process using the device. © 2016

关键词： Process control Automation control theory Machinery Optimization Plotters (computer) Vector spaces CNC machinery computerized numerical control control education Development and applications Education and researches Educational process Precise positioning Remote experimentation

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