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| 2. |
- Duffie, N., et al.
(författare)
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Development of a Menu-Driven Programmable System of Machinery Drives
- 1983
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Ingår i: CIRP annals. - 0007-8506 .- 1726-0604. ; 32:1, s. 281-285
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Tidskriftsartikel (refereegranskat)abstract
- In many industrial applications of machinery drives, there is need for controlling two or more drive elements with various speed and or position relationships maintained between drives. Drive motors may incorporate a wide variety of feedback transducers and have command signals derived from programmable sources or other drives in the system. This paper describes the development of a generalized system which incorporates a variety of sensors and allows a machinery designer to establish master/slave relationships to suit requirements for particular applications. The software system supporting the configurable drive allows a particular system configuration to be determined through presentation of a menu to an operator who selects the number of drives, appropriate sensors and inter-drive relationships dictated by the machine specifications. Individual drives are configured by selecting either a speed or a position feedback sensor and the source of commands for that drive. Commands for a given drive can be determined as a ratio of either the command input or the measured output of another drive as well as an operator programmable drive profile. The paper presents a summary of the control philosophy, detailed algorithms for establishing a variety of drive configurations, and techniques used to achieve the various features of the configurable drive including velocity ratioing, position phase control, and program indexing of one drive relative to another. The software package developed includes a diagnostic system for identifying and observing dynamic performances
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| 3. |
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| 4. |
- Kang, J. G., et al.
(författare)
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Parallel disassembly sequencing with sequence-dependent operation times
- 2001
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Ingår i: Cirp Annals-Manufacturing Technology. - 0007-8506. ; 50:1, s. 343-346
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Tidskriftsartikel (refereegranskat)abstract
- This paper focuses on the disassembly sequencing, which is the problem of determining the disassembly level and the corresponding disassembly sequence for a product at its end-of-life with the objective of maximizing the overall profit. Parallel disassembly and sequence-dependent operation times are considered by developing an extended process graph obtained from a transformation of a conventional AND/OR graph. Then, an integer programming formulation is developed with precedence constraints that allows its resolution with standard techniques. Finally, an optimal solution is obtained, with a reasonable amount of computation time, for an industrial application of a subassembly of a copy machine.
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| 5. |
- Kinnander, Anders, et al.
(författare)
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Competence requirements and their impact on manufacturing system performance
- 1998
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Ingår i: CIRP annals. - 0007-8506 .- 1726-0604. ; 47:1, s. 385-388
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Tidskriftsartikel (refereegranskat)abstract
- Research into `Next generation manufacturing systems' stresses the use of semi-automated systems to handle short product life cycles and customer oriented production. Despite increasing dependency on technology, the importance of humans is expected to increase and to provide a realistic basis for decision support, both technical and organizational processes must be included in simulation models. In a rapidly changing environment, skill development is also important and should be considered when developing simulation models. This paper describes two case studies where competence and skill development were modelled using learning curves to obtain a more representative simulation of system performance.
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| 6. |
- Novak, A, et al.
(författare)
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On-Line prediction of the tool lLife
- 1996
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Ingår i: CIRP Annals - manufacturing technology. - 0007-8506 .- 1726-0604. ; 45:1, s. 93-97
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Tidskriftsartikel (refereegranskat)abstract
- The paper presents a new approach improving the reliability of on-line prediction of tool-life without the need of pre-process data. The ambition has been to develop a robust monitoring strategy feasible fGr practical implementation on a CNC lathe. The tool-life is related to a selected critical point on the tool wear curve. Applied multisensing is based on the cutting force ratio correlated with in-process measurement of the flank wear by a vision system. The acquired process data are evaluated and handled by means of the modified and combined statistical methods. Initial cut is used to monitor the process and to evaluate the model parameters when critical conditions are simultaneously supervised by an additional monitoring method, The process model development, reference value setting and tool-life prediction have been automated as machine tool control features. Traditional tool condition monitoring can be improved by the reduced need of pre-process reference or machinability data, no need of calibrating procedures and, by early prediction of the tool-life with uncertainty of about 15% after 1.5-2.0 minutes of cutting. The efficiency and flexibility of the developed method has been verified by several machinability tests performed under various machining conditions but for the same work material.
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| 7. |
- Tseng, M. M., et al.
(författare)
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Design in the new e-commerce era
- 2003
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Ingår i: Cirp Annals-Manufacturing Technology. - 0007-8506. ; 52:2, s. 509-519
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Tidskriftsartikel (refereegranskat)abstract
- The computing and communication have become indispensable in every aspect of design and manufacturing. Its impacts on production engineering community have been significant and long lasting. In this paper, we reviewed new e-Commerce models that directly link among production capabilities and with end consumers. We then identified three major forces that will affect the design community, namely, speed of decision, expansion of scope and degree of concurrency. Understanding the implication of these forces would be conducive to leading structural changes in design. The transformations include expanding the scope of design, linking customers and suppliers proactively throughout the entire value chain, and collaborating across boundaries.
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| 8. |
- Abele, Eberhard, et al.
(författare)
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Learning factories for future oriented research and education in manufacturing
- 2017
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Ingår i: CIRP annals. - : ELSEVIER SCIENCE BV. - 0007-8506 .- 1726-0604. ; 66:2, s. 803-826
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Tidskriftsartikel (refereegranskat)abstract
- Learning factories present a promising environment for education, training and research, especially in manufacturing related areas which are a main driver for wealth creation in any nation. While numerous learning factories have been built in industry and academia in the last decades, a comprehensive scientific overview of the topic is still missing. This paper intends to close this gap by establishing the state of the art of learning factories. The motivations, historic background, and the didactic foundations of learning factories are outlined. Definitions of the term learning factory and the corresponding morphological model are provided. An overview of existing learning factory approaches in industry and academia is provided, showing the broad range of different applications and varying contents. The state of the art of learning factories curricula design and their use to enhance learning and research as well as potentials and limitations are presented. Conclusions and an outlook on further research priorities are offered. (C) 2017 Published by Elsevier Ltd on behalf of CIRP.
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| 9. |
- Akay, Haluk, et al.
(författare)
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Push-pull digital thread for digital transformation of manufacturing systems
- 2023
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Ingår i: CIRP annals. - : Elsevier BV. - 0007-8506 .- 1726-0604. ; 72:1, s. 401-404
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Tidskriftsartikel (refereegranskat)abstract
- Current digitalized manufacturing systems do not yet achieve the goal of smart manufacturing: precise con-trol and agility under unexpected disruptions. Push-Pull Digital Thread is a solution concept to enable contex-tual data and knowledge exchange across operational and functional units in a manufacturing enterprise. The extraction of decision reasoning and functional information can be facilitated by Large Language Models proc-essing information obtained from a decision maker at the point of decision. This concept shows a potential to address critical limitations in previous endeavours for smart manufacturing systems by building a semanti-cally searchable and sharable knowledge base in manufacturing systems and beyond.
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| 10. |
- Altintas, Yusuf, et al.
(författare)
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Identification of dynamic cutting force coefficients and chatter stability with process damping
- 2008
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Ingår i: CIRP annals. - : Elsevier. - 0007-8506 .- 1726-0604. ; 57:1, s. 371-374
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a cutting force model which has three dynamic cutting force coefficients related to regenerative chip thickness, velocity and acceleration terms, respectively. The dynamic cutting force coefficients are identified from controlled orthogonal cutting tests with a fast tool servo oscillated at the desired frequency to vary the phase between inner and outer modulations. It is shown that the process damping coefficient increases as the tool is worn, which increases the chatter stability limit in cutting. The chatter stability of the dynamic cutting process is solved using Nyquist law, and compared favourably against experimental results at low cutting speeds.
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