| 1. |
- Becker, Matthias, 1986-, et al.
(författare)
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A Many-Core based Execution Framework for IEC 61131-3
- 2015
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Ingår i: IECON 2015 - 41st Annual Conference of the IEEE Industrial Electronics Society. ; , s. 4525-4530
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Konferensbidrag (refereegranskat)abstract
- Programmable logic controllers are widely used for the control of automationsystems. The standard IEC 61131-3 defines the execution model as well as theprogramming languages for such systems. Nowadays, actuators and sensorsconnect to the programmable logic controller via automation buses. While suchbuses, as well as the sensors and actuators, become more and more powerful, ashift away from the current distributed operation of automation systems, closeto the field level, becomes possible. Instead, execution of complex controlfunctions can be relocated to more powerful hardware, and technologies. Thispaper presents an execution framework for IEC 61131-3, based on a many-coreprocessors. The presented execution model exploits the characteristics of theIEC 61131-3 applications as well as the characteristics of the many-core processor,yielding a predictable execution. We present the platform architectureand an algorithm to allocate a number of IEC 61131-3 conform applications.Experimental as well as simulation based evaluation is provided.
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| 2. |
- Becker, Matthias, et al.
(författare)
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Increased Reliability of Many-Core Platforms through Thermal Feedback Control
- 2014
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Ingår i: Performance, Power and Predictability of Many-Core Embedded Systems 3PMCES'14. - Dresden, Germany.
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Konferensbidrag (refereegranskat)abstract
- In this paper we present a low overhead thermal management approach to increase reliability of many-core embedded real-time systems. Each core is controlled by a feedback controller. We adapt the utilization of the core in order to decrease the dynamic power consumption and thus the corresponding heat development. Sophisticated control mechanisms allow us to migrate the load in advance, before reaching critical temperature values and thus we can migrate in a safe way with a guarantee to meet all deadlines.
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| 3. |
- Becker, Matthias, et al.
(författare)
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Limiting temperature gradients on many-cores by adaptive reallocation of real-time workloads
- 2014
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Ingår i: 19th IEEE International Conference on Emerging Technologies and Factory Automation, ETFA 2014. - 9781479948468 ; , s. Article number 7005241-
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Konferensbidrag (refereegranskat)abstract
- The advent of many-core processors came with the increase in computational power needed for future applications. However new challenges arrived at the same time, especially for the real-time community. Each core on such a processor is a heat source and uneven usage can lead to hot spots on the processor, affecting its lifetime and reliability. For real-time systems, it is therefore of paramount importance to keep the temperature differences between the individual cores below critical values, in order to prevent premature failure of the system. We argue that this problem can not be solved by traditional approaches, since the growing number of cores makes them intractable. We rather argue to split the problem in the spacial domain and control the temperature on core level. The cores control their temperature by rearranging the load in a predictable manner during runtime. To achieve this, a feedback controller is implemented on each core. We conclude our work with a simulation based evaluation of the proposed approach comparing its performance against a previously presented algorithm.
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| 4. |
- Becker, Matthias, et al.
(författare)
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Mapping Real-Time Tasks onto Many-Core Systems considering Message Flows
- 2014
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Ingår i: Proceedings of the Work-in-Progress Session of the 20th IEEE Real-Time and Embedded Technology and Applications Symposium. - Berlin, Germany. ; , s. 17-18
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Konferensbidrag (refereegranskat)abstract
- In this work we focus on the task mapping problem for many-core real-time systems. The growing number of cores connected by a Network-on-Chip (NoC) calls for sophisticated mapping techniques to meet the growing demands of real-time applications. Hardware should be used in an efficient way such that unnecessary resource usage is avoided. Because of the NP-hardness of the problem, heuristic and meta-heuristic techniques are used to find good solutions. We further consider periodic communication between tasks and we focus on a static mapping solution.
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| 5. |
- Faragardi, Hamid Reza, et al.
(författare)
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A communication-aware solution framework for mapping AUTOSAR runnables on multi-core systems
- 2014
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Ingår i: 19th IEEE International Conference on Emerging Technologies and Factory Automation, ETFA 2014. - 9781479948468 ; , s. Article number 7005244-
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Konferensbidrag (refereegranskat)abstract
- An AUTOSAR-based software application contains a set of software components, each of which encapsulates a set of runnable entities. In fact, the mission of the system is fulfilled as result of the collaboration between the runnables. Several trends have recently emerged to utilize multi-core technology to run AUTOSAR-based software. Not only the overhead of communication between the runnables is one of the major performance bottlenecks in multi-core processors but it is also the main source of unpredictability in the system. Appropriate mapping of the runnables onto a set of tasks (called mapping process) along with proper allocation of the tasks to processing cores (called task allocation process) can significantly reduce the communication overhead. In this paper, three solutions are suggested, each of which comprises both the mapping and the allocation processes. The goal is to maximize key performance aspects by reducing the overall inter-runnable communication time besides satisfying given timing and precedence constraints. A large number of randomly generated experiments are carried out to demonstrate the efficiency of the proposed solutions.
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| 6. |
- Faragardi, Hamid Reza, et al.
(författare)
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An efficient scheduling of AUTOSAR runnables to minimize communication cost in multi-core systems
- 2014
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Ingår i: 2014 7th International Symposium on Telecommunications, IST 2014. - 9781479953592 ; , s. 41-48
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Konferensbidrag (refereegranskat)abstract
- The AUTOSAR consortium has developed as the worldwide standard for automotive embedded software systems. From a processor perspective, AUTOSAR was originally developed for single-core processor platforms. Recent trends have raised the desire for using multi-core processors to run AUTOSAR software. However, there are several challenges in reaching a highly efficient and predictable design of AUTOSAR-based embedded software on multi-core processors. In this paper a solution framework comprising both the mapping of runnables onto a set of tasks and the scheduling of the generated task set on a multi-core processor is suggested. The goal of the work presented in this paper is to minimize the overall inter-runnable communication cost besides meeting all corresponding timing and precedence constraints. The proposed solution framework is evaluated and compared with an exhaustive method to demonstrate the convergence to an optimal solution. Since the exhaustive method is not applicable for large size instances of the problem, the proposed framework is also compared with a well-known meta-heuristic algorithm to substantiate the capability of the frameworks to scale up. The experimental results clearly demonstrate high efficiency of the solution in terms of both communication cost and average processor utilization.
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| 7. |
- Hallmans, Daniel, et al.
(författare)
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A method and industrial case : Replacement of an FPGA component in a legacy control system
- 2015
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Ingår i: Proceeding - 2015 IEEE International Conference on Industrial Informatics, INDIN 2015. - 9781479966493 ; , s. 208-214
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Konferensbidrag (refereegranskat)abstract
- A significant part of industrial systems have requirements on long life times. Such requirements on the complete system impose requirements on its corresponding embedded systems to be operational for an equally long time. As a consequence it is of paramount importance to be able to replace obsolete components of the embedded systems during the life time of the system, and to be able to update part of the design due to new requirements. In this paper we present a method to manage component replacement in such systems, and we present an industrial case study highlighting the work needed to replace an FPGA chip with another, including all corresponding legacy FPGA design challenges that comes with such a replacement. We have found one larger problem inherent in the ability to use the included components in a way that is not possible with the new circuits replacing the old ones. This problem significantly increased the work needed when performing the conversion and migration from the old design to the new, since parts of the design had to be redesigned from a functional perspective.
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| 8. |
- Hallmans, D., et al.
(författare)
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Challenges and opportunities when introducing cloud computing into embedded systems
- 2015
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Ingår i: Proceeding - 2015 IEEE International Conference on Industrial Informatics, INDIN 2015. - 9781479966493 ; , s. 454-459
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Konferensbidrag (refereegranskat)abstract
- The use of cloud computing in different application areas is growing fast. More and more functions are being moved into the cloud in order to take advantage of cloud computing strengths such as scalability, resources on demand, and usage based cost models. However, most types of embedded systems are still in an early phase of cloud adoption, with a few exceptions found in e.g., data storage and user interfaces. In this paper we present a number of challenges and opportunities when introducing cloud computing into embedded systems. In particular, we look at embedded systems with requirements on timing predictability, i.e., real-time systems. In the paper we conclude that it is possible to move a complete soft real-time system into the cloud. Moreover we see an upcoming development in cloud computing to potentially allow for hard real-time systems to be moved to the cloud.
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| 9. |
- Hallmans, Daniel, et al.
(författare)
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Challenges in providing sustainable analytic of system of systems with long life time
- 2021
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Ingår i: 2021 16th International Conference of System of Systems Engineering (SoSE). - 9781665444545 ; , s. 69-74
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Konferensbidrag (refereegranskat)abstract
- Embedded systems are today often self-sufficient systems with limited communication. However, this traditional view of an embedded system is changing rapidly. Embedded systems are nowadays evolving, e.g., an evolution pushed by the increased functional gain introduced with the concept of System of Systems (SoS) that is connecting multiple subsystems to achieve a combined functionality and/or information of a higher value. In such a SoS the subsystems will have to serve a dual purpose in a) the initial purpose that the subsystem was originally designed and deployed for, e.g., control and protection of the physical assets of a critical infrastructure system that could be up and running for 30-40 years, and b) at the same time provide information to a higher-level system for a potential future increase of system functionality as technology matures and/or new opportunities are provided by, e.g., greater analytics capabilities. In this paper, within the context of a “dual purpose use” of a) and b), we bring up three central challenges related to i) information gathering, ii) life-cycle management, and iii) data governance, and we propose directions for solutions to these challenges that need to be evaluated already at design time.
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| 10. |
- Hallmans, Daniel, et al.
(författare)
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Consistent sensor values on a real-time ethernet network
- 2016
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Ingår i: IEEE International Workshop on Factory Communication Systems - Proceedings, WFCS. - 9781509023394
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Konferensbidrag (refereegranskat)abstract
- Industrial control systems often exhibit a need for short latencies and/or consistent data gathering. In a system with limited resources it is a challenge to achieve the combination of short latencies and consistent data. In this paper we propose three different architectural solutions to this challenge, each having different trade-offs: one that gives a consistent set of data and also a short latency but with a higher resource usage, a second alternative that reduces resource needs but at the cost of an increased latency, and a third and final solution that reduces resource needs to a minimum but in doing so also increasing the latency. The results presented in this paper suggest that it is possible to get low latency and robustness at the cost of performance.
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