| 1. |
- Bengtsson, Kristofer, 1979, et al.
(författare)
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Developing control logic using aspect-oriented programming and sequence planning
- 2013
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Ingår i: Control Engineering Practice. - : Elsevier BV. - 0967-0661. ; 21:1, s. 12-22
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Tidskriftsartikel (refereegranskat)abstract
- A fundamental functionality of a Programmable Logic Controller (PLC) is to control and execute a set of operations. But a large part of the program code is more involved in supporting the user with concerns like alarm, HMI, communication, safety and manual control. Code related to these supporting concerns is often tangled with operation execution code, the core concerns, which makes it hard to reuse.This paper describes a method to reuse code and functionality when developing PLC programs and code libraries. The method proposes that core concerns are planned with a software tool called Sequence Planner, and the supporting concerns are integrated into the core concerns with a tool based on aspect-oriented programming.
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| 2. |
- Bengtsson, Kristofer, 1979
(författare)
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Flexible design of operation behavior using modeling and visualization
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The behavior of a system can be described by a set of operations. The process of designing and developing these operations poses a real challenge in various situations, for example, when designing automation systems or keeping track of work in an emergency department. This thesis focuses on designing and developing the logical behavior of operations, for example, when they start, when they finish, and how they interact with the rest of the system. Being flexible during design and development entails coping with uncertainty. However, the practice of designing operation behavior is often fairly inflexible because every possible execution route is explicitly specified. This thesis suggests an operation design approach that does not explicitly specify operation routes. This is achieved in the proposed modeling method by only declaring current execution restriction using transition conditions in each operation, together with models representing entities, resources, and variables. A main benefit of the proposed modeling framework is the possibility it offers of creating multiple projections of operation relations to enable better understanding. This is accomplished by automatically generating a multiplicity of sequences showing various operation relations. The key discoveries that accomplish this are the state-based operation methods for relation identification and visualization. These methods make it possible to use the presented research not only when designing automation systems, but also in other applications, such as keeping track of all the patients in an emergency department. Some of the tools and methods presented here have been implemented in a prototype software called Sequence Planner.
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| 3. |
- Bengtsson, Kristofer, 1979, et al.
(författare)
-
Flexible Specification of Operation Behavior Using Multiple Projections
- 2014
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Ingår i: IEEE Transactions on Automation Science and Engineering. - 1558-3783 .- 1545-5955. ; 11:2, s. 504 - 515
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Tidskriftsartikel (refereegranskat)abstract
- The execution behavior of a system or a product can often be specified by a set of operations (sometimes called tasks, actions or activities). The process to specify these operations seems to be a real challenge in various situations, for example when designing automation systems or keeping track of the work at an emergency department. To be flexible during design and development, is about coping with uncertainty. However, in practice, specifying operation behavior is often quite inflexible because every possible execution route is explicitly defined. This approach is sometimes refereed to as point-based engineering, which is characterized by the early selection and approval of a single "best" specific solution. This approach can result in neither a robust nor a flexible design process with many rework iterations.
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| 4. |
- Bengtsson, Kristofer, 1979, et al.
(författare)
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Operation Behavior Modeling using Relation Identification and Visualization Algorithms
- 2013
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Ingår i: IEEE International Conference on Automation Science and Engineering. - 2161-8070 .- 2161-8089. ; , s. 368 - 373
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Konferensbidrag (refereegranskat)abstract
- The behavior of a system can be described by a set of operations - sometimes called activities or tasks. The process to specify these operation seems to be a real challenge in various situations, for example when designing automation systems or keeping track of the work at an emergency department. In practice, operation behavior specification is often quite inflexible because every possible execution route is explicitly defined. In this paper, a modeling method and a relation identification and visualization algorithm is introduced that does not explicitly specify operation routes, where instead the operation behavior is specified using the execution restrictions in transition conditions for each operation. This enables the possibility to create multiple projections of the operation relations to enable better understanding.
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| 5. |
- Bengtsson, Kristofer, 1979
(författare)
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Operation Specification for Sequence Planning and Automation Design
- 2010
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- When designing an automation system, an important challenge is to specify the different tasks, or operations, of the system. This has become a problematic bottle-neck in industry, since the rising needs on manufacturing flexibility increases the complexity of the entire manufacturing system, as well as its control function. This thesis studies how to specify the manufacturing operations when developing an automation system, especially how to plan the operations and the relations among them, called sequence planning, and how to implement them in a programmable logic controller (PLC).To manage the complete automation development process, a formal language called sequences of operations, SOP, is introduced. This language, together with a set of methods, are used to represent, identify and visualize complex operation relations, so that the behavior of the system can be understood. By the use of different views or perspectives, the sequence of operations related to e.g the part flow, robot operations or operator tasks can be visualized. These different perspectives help the user to easier understand the relation between the control of a cell and the mechanical design, as well as the product design and the total system behavior. The proposed language is based on a formal model, thus formal verification, optimization and synthesis are available. This is necessary since it is hard to find errors in complex system specifications.When implementing the control of manufacturing operations, much of the code is related to supporting concerns like alarm handling, logging, user interface, etc. These parts tend to be hard to fully reuse and implement, since they are tangled with other functionalities, and are located at many places in the program. An aspect-oriented programming (AOP) approach is proposed, to reuse and implement these concerns. AOP is an emerging programming methodology in computer science, which helps the programmer by separating crosscutting and tangled concerns in a program. The approach is focused on how to adapt the AOP methodology for PLC program development, and how it can benefit the control design process.
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| 6. |
- Bengtsson, Kristofer, 1979, et al.
(författare)
-
Patient coordination in emergency departments using an event-based information architecture
- 2014
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Ingår i: The 19th IEEE International Conference on Emerging Technologies and Factory Automation. - 9781479948451 ; , s. 1-6
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Konferensbidrag (refereegranskat)abstract
- It is challenging to get an overview and understanding of the activities and their relations at an emergency department (ED). This is due to the complicated relations among activities - called operations in this paper - and the always changing system behavior. Two key enablers to get this overview are the transformation of real-time events into understandable information and an operation-based behavior description. This paper presents an event-based information architecture for healthcare (EVAH) for gathering state changing events in real-time at an ED and how these are transformed into an operation-based representation. EVAH together with the tool Sequence Planner, will be used for visualization, online prognosis and optimization.
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| 7. |
- Bengtsson, Kristofer, 1979, et al.
(författare)
-
Patient coordination in emergency departments using visualization of operation behavior
- 2013
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Ingår i: Proceedings of the 2013 IEEE Symposium on Computational Intelligence in Healthcare and e-Health, CICARE 2013 - 2013 IEEE Symposium Series on Computational Intelligence, SSCI 2013. - 9781467358835 ; , s. 58-63
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Konferensbidrag (refereegranskat)abstract
- It is challenging to get an overview and understanding of the activities and their relations at an emergency department (ED). This is due to the complicated relations among activities called operations in this paper and the always changing system behavior. This paper presents a method to represent and visualize operations during the actual work at the ED that enables flexibility during modeling and actual care. By specifying operation behavior using only execution restrictions in transition conditions for each operation instead of fixed sequences, the method and related visualization tool can describe the ever changing and complex ED flows. Using the proposed approach, the ED staff will therefore have the possibility to in a better way coordinate the operations due to the increased overview.
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| 8. |
- 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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| 9. |
- 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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| 10. |
- Bengtsson, Kristofer, 1979, et al.
(författare)
-
Towards Sequence Planning Based on Configurable Product and Manufacturing System Platforms
- 2010
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Ingår i: Proceedings of the 8th International Conference NordDesign 2010. - 9789163370649 ; Vol. 2, s. 467-476
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Konferensbidrag (refereegranskat)abstract
- Operation sequences are central in the interaction between product and manufacturing development. This is because the sequences create an understanding of how a product is manufactured. The high degree of complexity in managing and planning manufacturing operations during the development of a configurable product and manufacturing platform requires a new and more flexible sequence planning approach. By integrating configurable product and manufacturing system platform descriptions, product variance, manufacturing system flexibility, and product and manufacturing system complexity can all be efficiently adapted to each other by considering interrelated constraints. Such an integrated platform system also provides the information required to describe the operations needed to manufacture an instantiated product variant. This paper proposes an approach in which sequences are viewed based on the relations among self-contained operations, thus saving engineers from manually constructing sequences for each product variant. The sequences of operations related to, for example, the part flow for a specific platform configuration, robot operations or operator tasks can be automatically visualized through the use of different perspectives.
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