| 1. |
- Kaczynski, Giordano A., et al.
(författare)
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Deriving Exact Stochastic Response Times of Periodic Tasks in Hybrid Priority-driven Soft Real-time Systems
- 2007
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Ingår i: Proceedings of 12th IEEE International Conference on Emerging Technologies and Factory Automation (ETFA'07), Patras, Greece. - 9781424408269 ; , s. 101-110
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Konferensbidrag (refereegranskat)abstract
- The aim of this paper is to allow for hybrid task sets in the context of stochastic real-time analysis. The paper goes beyond previous work by allowing for the presence of aperiodic tasks in the system. Instead of representing a task with a fixed activation period and a Worst-Case Execution Time (WCET), here a task is characterized by an Arrival Profile (AP) and an Execution Time Profile (ETP), both given by random variables with known distributions. Any number of aperiodic tasks, with arbitrary arrival and execution time profiles, can be dealt with. To cope with the unbounded interference introduced by aperiodic tasks in the system, sporadic and aperiodic tasks are encapsulated within servers. The paper presents the calculus for obtaining the exact ETP of servers, which allows us to derive exact response time distributions of periodic tasks. Also, an example is used to show the potential and validity of the proposed approach.
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| 2. |
- Kaczynski, Giordano A., et al.
(författare)
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Towards stochastic response-time of hierarchically scheduled real-time tasks
- 2006
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Ingår i: IEEE Symposium on Emerging Technologies and Factory Automation, ETFA. - 1424406811 ; , s. 453-456
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Konferensbidrag (refereegranskat)abstract
- The growing need for providing real-time system designers with less pessimistic results than the ones given by traditional worst-case analysis motivates several recent works on stochastic analysis methods. This paper deals with the calculation of stochastic Response Time Profiles of tasks that are hierarchically scheduled using server-based techniques in a stochastic analysis framework. Depending on how tasks are scheduled within the server, differences in temporal performance are expected. In the paper, initial results on calculating the Response Time Profiles for these server-scheduled tasks are outlined.
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| 3. |
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| 4. |
- Lo Bello, Lucia, et al.
(författare)
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Towards a robust real-time wireless link in a land monitoring application
- 2006
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Ingår i: IEEE Symposium on Emerging Technologies and Factory Automation, ETFA. - 1424406811 ; , s. 449-452
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Konferensbidrag (refereegranskat)abstract
- This paper addresses on-going work on providing a model of a robust real-time wireless link intended to be used to connect a mobile platform to a ground station in a land monitoring system. This work is part of a project where the mobile platform is an Unmanned Aerial Vehicle (UAV), equipped with embedded devices which acquire and process sensor data to be sent to the ground station. Firstly, a temporal model of the communications link relying on radio modems is developed. Secondly, measurements have been made in order to determine packet loss probability. These two results are currently used to provide a robust real-time model of the wireless communications link.
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| 6. |
- Nolte, Thomas, et al.
(författare)
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Integration of networked subsystems in a resource constrained environment
- 2006
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Ingår i: Proceedings of 11th IEEE International Conference on Emerging Technologies and Factory Automation (ETFA'06), Prague, Czech Republic. - 9781424406814 ; , s. 905-912
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Konferensbidrag (refereegranskat)abstract
- When developing embedded systems, there is currently a trend to move from a traditional federated approach, where computer systems are developed for their own dedicated hardware architecture, to an integrated approach, where computer systems are encapsulated as subsystems and later integrated on a shared hardware architecture. The task of integrating subsystems is complex, and in resource constrained systems efficient techniques and methods are required. In this paper the issue of subsystem integration is thoroughly discussed, and it is shown how to use Server-CAN, a network scheduler for the Controller Area Network, in the context of subsystem integration. As the network is a resource shared by all subsystems in adistributed architecture, its role in the integration process is particularly important. Here, the usage of an efficient and flexible network scheduler is essential.
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