| 1. |
- Andersson, Kristin, 1976, et al.
(författare)
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Generation of restart states for manufacturing cell controllers
- 2011
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Ingår i: Control Engineering Practice. - : Elsevier BV. - 0967-0661. ; 19:9, s. 1014-1022
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Tidskriftsartikel (refereegranskat)abstract
- A method for restart of manufacturing systems has recently been introduced. After correction of a fault. the system resumes normal production by returning to a certain restart state in the control function. and from there reexecuting parts of the work schedule. The current paper concerns automatic generation of the restart states, using discrete event systems theory. The generation process finds all possible restart states that guarantee that the execution restrictions are fulfilled during a restart, and that the production goals can be maintained. The number of restart states is minimized to reduce the number of necessary extensions to the control program. (C) 2011 Elsevier Ltd. All rights reserved.
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| 2. |
- Bengtsson, Kristofer, 1979, et al.
(författare)
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Relations Identification and Visualization for Sequence Planning and Automation Design
- 2010
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Ingår i: In Proc. IEEE Conference on Automation Science and Engineering, Toronto. - 9781424454471 ; , s. 841 - 848
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Konferensbidrag (refereegranskat)abstract
- The sequential behavior of a manufacturing system results from a number of constraints introduced both in product, manufacturing and control logic development. Sequence planning is therefore an important activity throughout the complete development process. This paper proposes a sequence planning approach using self-contained manufacturing operations that model actions and relevant execution conditions. These operations can have temporal relations with each other, due to execution constraints expressed by operation pre- post- and reset conditions. The operation relations can for example be parallel, sequence, arbitrary order, alternative or hierarchy. Based on a formal operation model, the relations among operations are identified and visualized with a graphical language called Sequences of Operations, SOP.
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| 3. |
- Bengtsson, Kristofer, 1979, et al.
(författare)
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Sequence Planning Using Multiple and Coordinated Sequences of Operations
- 2012
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Ingår i: IEEE Transactions on Automation Science and Engineering. - 1558-3783 .- 1545-5955. ; 9:2, s. 308-319
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Tidskriftsartikel (refereegranskat)abstract
- The sequential behavior of a manufacturing system results from several constraints introduced during the product, manufacturing, and control logic development. This paper proposes methods and algorithms for automatically representing and visualizing this behavior from various perspectives throughout the development process. A new sequence planning approach is introduced that uses self-contained operations to model the activities and execution constraints. These operations can be represented and visualized from multiple perspectives using a graphical and formal language called Sequences of Operations (SOPs). The operations in a manufacturing system are related to each other in various ways, due to execution constraints expressed by operation pre- and post-conditions. These operation relations include parallel, sequence, arbitrary order, alternative, and hierarchy relations. Based on the SOP language, these relations are identified and visualized in various SOPs and sequences. A software tool, Sequence Planner, has been developed, for organizing the operations into SOPs that visualize only relevant operations and relations. Note to Practitioners-This paper proposes methods and algorithms for a new sequence planning approach in which sequences are automatically created based on the relations among operations instead of having to be manually constructed. Using various views, the sequences of operations related to, for example, part flow, robot operations, and operator tasks, can be visualized. The use of various views helps the user better understand the relations between cell control and mechanical design, and between product design and total system behavior.
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| 4. |
- Falkman, Petter, 1972, et al.
(författare)
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Automatic generation: A way of ensuring PLC and HMI standards
- 2011
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Ingår i: IEEE 16th Conference on Emerging Technologies and Factory Automation, ETFA 2011, Toulouse, 5-9 September 2011. - 9781457700187
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Konferensbidrag (refereegranskat)abstract
- Preparing an automatic production system takes a lot of time and to be able to decrease this time virtual simulation studies are used more and more frequently. However, even if more work is performed in a virtual environment a problem is still that the same work is done more than one time in different software tools due to the lack of integration between them. The present paper presents a case study that investigates how a newly developed tool called SIMATIC Automation Designer can be used in order to close the gap between the mechanical design and the electrical design. SIMATIC Automation Designer is a Siemens software that can generate PLC code and HMI screens. The result shows that by generating PLC code and HMI screens automatically, it is possible to get the same structure and naming standard in every PLC and HMI project. This will ensure a corporate standard and will be a quality assurance of the PLC code and HMI screens.
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| 5. |
- Falkman, Petter, 1972, et al.
(författare)
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Vendor independent control database for virtual preparation and formal verification
- 2011
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Ingår i: International Conference on Information and Automation, ICIA 2011; Shenzhen; 6 June 2011 through 8 June 2011. - 9781457702686 ; , s. 851-857
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Konferensbidrag (refereegranskat)abstract
- It is very advantageous to use virtual techniques for testing and developing new hardware and software systems within a manufacturing system. It is, however, of greatest importance that the virtual model can be trusted so that the results of the development and tests can be directly transferred to a real system without any manual last minute changes. In order to trust the result, formal verification techniques can be applied and by doing that guaranteeing a correct system behavior. Today, there is a gap between how systems are modeled in simulation softwares and formal verification softwares and it is therefore hard to perform formal verification. In order to limit the risk of introducing errors it is also important that the specifications created in the simulation softwares are not manually converted into formal languages. The present paper presents a method for sharing information between the different virtual development tools and formal verification tools. A database, storing necessary control information for verification and controller synthesis, is presented.
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| 6. |
- Kanthabhabhajeya, Sathyamyla, 1985, et al.
(författare)
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Interface between SysML and Sequence Planner Language for Formal Verification
- 2013
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Ingår i: 23rd Annual International Symposium of the International Council on Systems Engineering, INCOSE 2013. ; 1, s. 222-236
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Konferensbidrag (refereegranskat)abstract
- This paper presents a method and software for interfacing Systems Modeling Language (SysML) and Sequence Planner Language (SPL). Exchange of information between different software tools is of major interest for modern manufacturing industries from early design to final implementation. SysML, with its structure as a common platform, can then be interfaced with other domain-specific modeling tools to achieve information exchange. This paper presents a method to interface SysML with a recently introduced language for operation sequences called Sequence Planner Language (SPL). By this method, necessary information from behavioral constructs of SysML model are extracted and structured in SPL. This language, being a formal, graphical language,can be used to formally verify the system for any blocking states. An academic and an industrial model developed in SysML are tested using the interface implementation and the results show that information from SysML can be visualized in SPL and formally verified to have no blocking states.
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| 7. |
- Kanthabhabhajeya, Sathyamyla, 1985, et al.
(författare)
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System Modeling Specification in SysML and Sequence Planner Language - Comparison Study
- 2012
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - 2405-8963. - 9783902661982 ; 14:PART 1, s. 1543-1550
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Konferensbidrag (refereegranskat)abstract
- This paper compares two languages, Systems Modeling Language(SysML) based on Unified Modeling Language and Sequence Planner Language, where both are used for systems engineering applications. As the modern manufacturing industries pass through a challenging period in storing and exchanging huge amounts of information/data, a common platform that is helpful in putting different parts together is of major interest. This paper presents an analysis of these two languages focusing on their behavioral constructs and details their advantages and disadvantages. This paper concludes by mentioning the points that are lacking in SysML, which could be solved by combining it with Sequence Planner Language and using the combined approach for system engineering applications.
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| 8. |
- Lennartson, Bengt, 1956, et al.
(författare)
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Sequence Planning for Integrated Product, Process and Automation Design
- 2010
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Ingår i: IEEE Transactions on Automation Science and Engineering. - 1558-3783 .- 1545-5955. ; 7:4, s. 791-802
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Tidskriftsartikel (refereegranskat)abstract
- In order to obtain a unified information flow from early product design to final production, an integrated framework for product, process and automation design is presented. The framework is based on sequences of operations and includes a formal relation between product properties and process operations. This relation includes liaisons (interfaces) and precedence relations, where the precedence relations generate preconditions for the related process operations. From this information a set of sequences of operations (SOPs) is generated. A formal graphical language for hierarchical operations and SOPs is then introduced and defined based on automata extended with variables. Since the operations are self-contained they can be grouped and viewed from different angles, e. g., from a product or a resource perspective. These multiple views increase the interoperability between different engineering disciplines. A case study is performed on a car manufacturing cell, where the suggested modeling framework is shown to give comprehensible SOPs. Note to Practitioners-When designing an automation system, an important challenge is to specify in what sequence the different tasks, or operations, should be executed. This has become a problematic bottleneck in the automotive industry, especially for body-in-white manufacturing. The rising needs on manufacturing flexibility increases the complexity of the entire manufacturing system, as well as its control function, the sequence of operations. This paper proposes a new sequence planning approach, where sequences are viewed based on the relations among operations instead of manually constructing the sequence. By the use of different views the sequence of operations related to, e. g., the part flow, robot operations or operator tasks can be visualized. Different views help the user to easier understand the relation between different parts and components, as well as the total system behavior.
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| 9. |
- Magnusson, Patrik, 1984, et al.
(författare)
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Planning transport sequences for flexible manufacturing systems
- 2011
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - 2405-8963. - 9783902661937 ; 18:PART 1, s. 9494-9499
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Konferensbidrag (refereegranskat)abstract
- When designing a manufacturing system it is important to plan what the systemshould do. One important activity in most manufacturing systems is to transport products orresources between different positions. In a flexible manufacturing system it can be challengingto design and plan these transport operations due to their complex logical behavior. This paperpresents a method that identifies, creates and visualizes these transport operations based oninputs from a standard virtual manufacturing tool and a high level product operation recipe.The planning of the created transport operations is transformed into a problem of finding anon-blocking solution for a discrete model of the product refinement.
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| 10. |
- Sundström, Nina, 1980, et al.
(författare)
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Optimization of operation sequences using constraint programming
- 2012
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - 2405-8963. - 9783902661982 ; 14:1, s. 1580-1585
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Konferensbidrag (refereegranskat)abstract
- In this paper, we connect the dots: design and optimization of production systems. A possible link between these two areas, is a previously presented modeling language, Sequence Planner Language (SPL). It has been demonstrated how relevant information can be extracted from production systems modeling applications, and converted into SPL. We show how the SPL model can be converted into a constraint programming model for optimization. Also, a useful abstraction concept, work-equivalence, is introduced to enable alternative model formulations. A case study consisting of an aero engine structure assembly plant is presented, in which the efficiency of the resulting constraint programs is investigated. The formulations enabled by abstraction are shown to perform better than the standard formulation.
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