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Samii, Soheil
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Zhou, Y., Samii, S., Eles, P. & Peng, Z. (2019). Partitioned and overhead-aware scheduling of mixed-criticality real-time systems. In: 24th Asia and South Pacific Design Automation Conference: . Paper presented at Asia and South Pacific Design Automation Conference, Tokyo, Japan, January 21 - 24, 2019 (pp. 39-44). New York: Association for Computing Machinery (ACM)
Öppna denna publikation i ny flik eller fönster >>Partitioned and overhead-aware scheduling of mixed-criticality real-time systems
2019 (Engelska)Ingår i: 24th Asia and South Pacific Design Automation Conference, New York: Association for Computing Machinery (ACM), 2019, s. 39-44Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

Modern real-time embedded and cyber-physical systems comprise a large number of applications, often of different criticalities, executing on the same computing platform. Partitioned scheduling is used to provide temporal isolation among tasks with different criticalities. Isolation is often a requirement, for example, in order to avoid the case when a low criticality task overruns or fails in such a way that causes a failure in a high criticality task. When the number of partitions increases in mixed criticality systems, the size of the schedule table can become extremely large, which becomes a critical bottleneck due to design time and memory constraints of embedded systems. In addition, switching between partitions at runtime causes CPU overhead due to preemption. In this paper, we propose a design framework comprising a hyper-period optimization algorithm, which reduces the size of schedule table and preserves schedulability, and a re-scheduling algorithm to reduce the number of preemptions. Extensive experiments demonstrate the effectiveness of proposed algorithms and design framework.

Ort, förlag, år, upplaga, sidor
New York: Association for Computing Machinery (ACM), 2019
Nationell ämneskategori
Datavetenskap (datalogi)
Identifikatorer
urn:nbn:se:liu:diva-160489 (URN)10.1145/3287624.3287653 (DOI)000507459700016 ()2-s2.0-85061136107 (Scopus ID)978-1-4503-6007-4 (ISBN)
Konferens
Asia and South Pacific Design Automation Conference, Tokyo, Japan, January 21 - 24, 2019
Tillgänglig från: 2019-09-24 Skapad: 2019-09-24 Senast uppdaterad: 2020-02-17Bibliografiskt granskad
Zhou, Y., Samii, S., Eles, P. I. & Peng, Z. (2019). Scheduling optimization with partitioning for mixed-criticality systems. Journal of systems architecture, 98, 191-200
Öppna denna publikation i ny flik eller fönster >>Scheduling optimization with partitioning for mixed-criticality systems
2019 (Engelska)Ingår i: Journal of systems architecture, ISSN 1383-7621, E-ISSN 1873-6165, Vol. 98, s. 191-200Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Modern real-time embedded and cyber-physical systems comprise a large number of applications, often of different criticalities, executing on the same computing platform. Partitioned scheduling is used to provide temporal isolation among tasks with different criticalities. Isolation is often a requirement, for example, in order to avoid the case when a low criticality task overruns or fails in such a way that causes a failure in a high criticality task. When the number of partitions increases in mixed criticality systems, the size of the schedule table can become extremely large, which becomes a critical bottleneck due to design time and memory constraints of embedded systems. In addition, switching between partitions causes CPU overhead due to preemption. In this paper, we propose a design framework comprising the trade-off between schedule table size and system utilization, as well as a re-scheduling algorithm to reduce the effect of preemptions on utilization. Extensive experiments demonstrate the effectiveness of the proposed algorithms and design framework.

Ort, förlag, år, upplaga, sidor
Elsevier, 2019
Nyckelord
Real-time systems, Mixed-criticality systems, Scheduling
Nationell ämneskategori
Datavetenskap (datalogi)
Identifikatorer
urn:nbn:se:liu:diva-160490 (URN)10.1016/j.sysarc.2019.07.007 (DOI)000487166300015 ()2-s2.0-85069685876 (Scopus ID)
Tillgänglig från: 2019-09-24 Skapad: 2019-09-24 Senast uppdaterad: 2019-10-24Bibliografiskt granskad
Mahfouzi, R., Aminifar, A., Samii, S., Payer, M., Eles, P. & Peng, Z. (2019). Security-aware Routing and Scheduling for Control Applications on Ethernet TSN Networks. ACM Transactions on Design Automation of Electronic Systems, 25(1)
Öppna denna publikation i ny flik eller fönster >>Security-aware Routing and Scheduling for Control Applications on Ethernet TSN Networks
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2019 (Engelska)Ingår i: ACM Transactions on Design Automation of Electronic Systems, ISSN 1084-4309, E-ISSN 1557-7309, Vol. 25, nr 1Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Today, it is common knowledge in the cyber-physical systems domain that the tight interaction between the cyber and physical elements provides the possibility of substantially improving the performance of these systems that is otherwise impossible. On the downside, however, this tight interaction with cyber elements makes it easier for an adversary to compromise the safety of the system. This becomes particularly important, since such systems typically are composed of several critical physical components, e.g., adaptive cruise control or engine control that allow deep intervention in the driving of a vehicle. As a result, it is important to ensure not only the reliability of such systems, e.g., in terms of schedulability and stability of control plants, but also resilience to adversarial attacks.

In this article, we propose a security-aware methodology for routing and scheduling for control applications in Ethernet networks. The goal is to maximize the resilience of control applications within these networked control systems to malicious interference while guaranteeing the stability of all control plants, despite the stringent resource constraints in such cyber-physical systems. Our experimental evaluations demonstrate that careful optimization of available resources can significantly improve the resilience of these networked control systems to attacks.

Ort, förlag, år, upplaga, sidor
ACM Publications, 2019
Nationell ämneskategori
Datavetenskap (datalogi)
Identifikatorer
urn:nbn:se:liu:diva-162609 (URN)10.1145/3358604 (DOI)
Tillgänglig från: 2019-12-11 Skapad: 2019-12-11 Senast uppdaterad: 2019-12-18Bibliografiskt granskad
Samii, S. (2018). Level 5 by Layer 2: Time-Sensitive Networking for Autonomous Vehicles. IEEE Communications Standards Magazine, 2(2), 62-68
Öppna denna publikation i ny flik eller fönster >>Level 5 by Layer 2: Time-Sensitive Networking for Autonomous Vehicles
2018 (Engelska)Ingår i: IEEE Communications Standards Magazine, ISSN 2471-2825, Vol. 2, nr 2, s. 62-68Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Time-Sensitive Networking standards for Ethernet provide real-time and dependability mechanisms such as traffic shaping and scheduling, time synchronization, and redundancy. This article provides a review of these standards in light of possible future use cases in automotive systems using in-vehicle Ethernet networks.

Ort, förlag, år, upplaga, sidor
IEEE, 2018
Nationell ämneskategori
Datavetenskap (datalogi)
Identifikatorer
urn:nbn:se:liu:diva-150524 (URN)10.1109/MCOMSTD.2018.1700079 (DOI)
Tillgänglig från: 2018-08-24 Skapad: 2018-08-24 Senast uppdaterad: 2018-09-06Bibliografiskt granskad
Bordoloi, U. & Samii, S. (2014). The Frame Packing Problem for CAN-FD. In: Real-Time Systems Symposium (RTSS 2014), Rome, Italy, Dec. 2-5, 2014.: . Paper presented at RTSS 14 (pp. 284-293). IEEE Press
Öppna denna publikation i ny flik eller fönster >>The Frame Packing Problem for CAN-FD
2014 (Engelska)Ingår i: Real-Time Systems Symposium (RTSS 2014), Rome, Italy, Dec. 2-5, 2014., IEEE Press, 2014, s. 284-293Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

CAN with flexible data rate (CAN-FD) allows transmission of larger payloads compared to standard CAN. However, efficient utilization of CAN-FD bandwidth space calls for a systematic strategy. The challenge arises from the nature of the frame sizes stipulated by CAN-FD as well as the heterogeneity of the periods of the messages and the signals. In this paper, we formulate a frame packing problem for CAN-FD with the optimization objective of bandwidth utilization while meeting temporal constraints. As part of the solution, first, we propose a formula to compute the best-case and the worst-case transmission times of the CAN-FD frames. Thereafter, we propose a framework that solves the optimization problem in pseudo-polynomial time. Experiments show the gains achieved by our framework. The results also show that, when applied to standard CAN, our heuristic provides improved results over existing techniques.

Ort, förlag, år, upplaga, sidor
IEEE Press, 2014
Serie
Real-Time Systems Symposium, ISSN 1052-8725
Nationell ämneskategori
Data- och informationsvetenskap
Identifikatorer
urn:nbn:se:liu:diva-114468 (URN)10.1109/RTSS.2014.8 (DOI)
Konferens
RTSS 14
Tillgänglig från: 2015-02-20 Skapad: 2015-02-20 Senast uppdaterad: 2018-01-11
Samii, S., Bordoloi, U. D., Eles, P., Peng, Z. & Cervin, A. (2012). Control-Quality Optimization for Distributed Embedded Systems with Adaptive Fault Tolerance. In: ECRTS 2012: . Paper presented at 24th Euromicro Conference on Real-Time Systems (ECRTS 2012), Pisa, Italy, July 10-13, 2012. IEEE
Öppna denna publikation i ny flik eller fönster >>Control-Quality Optimization for Distributed Embedded Systems with Adaptive Fault Tolerance
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2012 (Engelska)Ingår i: ECRTS 2012, IEEE, 2012Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

In this paper, we propose a design framework for distributed embedded control systems that ensures reliable execution and high quality of control even if some computation nodes fail. When a node fails, the configuration of the underlying distributed system changes and the system must adapt to this new situation by activating tasks at operational nodes. The task mapping as well as schedules and control laws that are customized for the new configuration influence the control quality and must, therefore, be optimized. The number of possible configurations due to faults is exponential in the number of nodes in the system. This design-space complexity leads to unaffordable design time and large memory requirements to store information related to mappings, schedules, and controllers. We demonstrate that it is sufficient to synthesize solutions for a small number of base and minimal configurations to achieve fault tolerance with an inherent minimum level of control quality. We also propose an algorithm to further improve control quality with a priority-based search of the set of configurations and trade-offs between task migration and replication.

Ort, förlag, år, upplaga, sidor
IEEE, 2012
Serie
EUROMICRO Conference on Real-Time Systems, ISSN 1068-3070
Nationell ämneskategori
Data- och informationsvetenskap
Identifikatorer
urn:nbn:se:liu:diva-77286 (URN)10.1109/ECRTS.2012.40 (DOI)978-1-4673-2032-0 (ISBN)
Konferens
24th Euromicro Conference on Real-Time Systems (ECRTS 2012), Pisa, Italy, July 10-13, 2012
Tillgänglig från: 2012-05-10 Skapad: 2012-05-10 Senast uppdaterad: 2018-01-12
Aminifar, A., Samii, S., Eles, P., Peng, Z. & Cervin, A. (2012). Designing High-Quality Embedded Control Systems with Guaranteed Stability. In: 33rd IEEE Real-Time Systems Symposium (RTSS 2012: . Paper presented at 33rd IEEE Real-Time Systems Symposium (RTSS 2012), San Juan, Puerto Rico, December 5-7, 2012.
Öppna denna publikation i ny flik eller fönster >>Designing High-Quality Embedded Control Systems with Guaranteed Stability
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2012 (Engelska)Ingår i: 33rd IEEE Real-Time Systems Symposium (RTSS 2012, 2012Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

Many embedded systems comprise several controllers sharing available resources. It is well known that such resource sharing leads to complex timing behavior that degrades the quality of control, and more importantly, can jeopardize stability in the worst-case, if not properly taken into account during design. Although stability of the control applications is absolutely essential, a design flow driven by the worst-case scenario often leads to poor control quality due to the significant amount of pessimism involved and the fact that the worst-case scenario occurs very rarely. On the other hand, designing the system merely based on control quality, determined by the expected (average-case) behavior, does not guarantee the stability of control applications in the worst-case. Therefore, both control quality and worst-case stability have to be considered during the design process, i.e., period assignment, task scheduling, and control-synthesis. In this paper, we present an integrated approach for designing high-quality embedded control systems, while guaranteeing their stability.

Serie
Real-Time Systems Symposium (RTSS), ISSN 1052-8725
Nationell ämneskategori
Data- och informationsvetenskap
Identifikatorer
urn:nbn:se:liu:diva-80768 (URN)10.1109/RTSS.2012.79 (DOI)000317284200026 ()978-1-4673-3098-5 (ISBN)
Konferens
33rd IEEE Real-Time Systems Symposium (RTSS 2012), San Juan, Puerto Rico, December 5-7, 2012
Tillgänglig från: 2012-08-29 Skapad: 2012-08-29 Senast uppdaterad: 2018-01-12
Aminifar, A., Samii, S., Eles, P. & Peng, Z. (2011). Control-Quality Driven Task Mapping for Distributed Embedded Control Systems. In: Embedded and Real-Time Computing Systems and Applications (RTCSA), 2011 IEEE 17th International Conference on: . Paper presented at 17th IEEE Intl. Conf. on Embedded and Real-Time Computing Systems and Applications (RTCSA11), Toyama, Japan, August 29-31, 2011. (pp. 133-142). IEEE
Öppna denna publikation i ny flik eller fönster >>Control-Quality Driven Task Mapping for Distributed Embedded Control Systems
2011 (Engelska)Ingår i: Embedded and Real-Time Computing Systems and Applications (RTCSA), 2011 IEEE 17th International Conference on, IEEE, 2011, s. 133-142Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

Many embedded control systems are implemented on execution platforms with several computation nodes and communication components. Distributed embedded control systems typically comprise multiple control loops that share the available computation and communication resources of the platform. It is well known that such resource sharing leads to complex delay characteristics that degrade the control quality if not properly taken into account at design time. Scheduling in computation nodes and communication infrastructure, as well as execution periods of the controllers impact the delay characteristics and, consequently, the control quality. In addition, mapping of tasks on computation nodes affect both scheduling of tasks and messages, and the assignment of periods of the control applications. Therefore, control synthesis must be considered during mapping, scheduling, and period assignment in order to achieve high control quality. This paper presents a control-quality optimization approach for integrated mapping, scheduling, period selection, and control synthesis for distributed embedded control systems.

Ort, förlag, år, upplaga, sidor
IEEE, 2011
Serie
Embedded and Real-Time Computing Systems and Applications (RTCSA), ISSN 2325-1271, E-ISSN 2325-1301
Nationell ämneskategori
Teknik och teknologier
Identifikatorer
urn:nbn:se:liu:diva-69733 (URN)10.1109/RTCSA.2011.41 (DOI)978-1-4577-1118-3 (ISBN)
Konferens
17th IEEE Intl. Conf. on Embedded and Real-Time Computing Systems and Applications (RTCSA11), Toyama, Japan, August 29-31, 2011.
Tillgänglig från: 2011-08-01 Skapad: 2011-08-01 Senast uppdaterad: 2017-01-23
Samii, S., Eles, P. I., Peng, Z. & Cervin, A. (2011). Design Optimization and Synthesis of FlexRay Parameters for Embedded Control Applications. In: 6th International Symposium on Electronic Design, Test and Applications (DELTA 2011), Queenstown, New Zealand, January 17-19, 2011.: . Paper presented at DELTA 2011. IEEE
Öppna denna publikation i ny flik eller fönster >>Design Optimization and Synthesis of FlexRay Parameters for Embedded Control Applications
2011 (Engelska)Ingår i: 6th International Symposium on Electronic Design, Test and Applications (DELTA 2011), Queenstown, New Zealand, January 17-19, 2011., IEEE, 2011Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

FlexRay is a popular communication protocol in modern automotive systems with several computation nodes and communication units. The complex temporal behavior of such systems depends highly on the FlexRay configuration and influences the performance of running control applications. In our previous work, we presented a design framework for integrated scheduling and design of embedded control applications, where control quality is the optimization objective. This paper presents our extension to the design framework to handle FlexRay-based embedded control systems. Our contribution is a method for the decision of FlexRay parameters and optimization of control quality.

Ort, förlag, år, upplaga, sidor
IEEE, 2011
Nationell ämneskategori
Teknik och teknologier
Identifikatorer
urn:nbn:se:liu:diva-63321 (URN)10.1109/DELTA.2011.22 (DOI)978-1-4244-9357-9 (ISBN)
Konferens
DELTA 2011
Tillgänglig från: 2010-12-15 Skapad: 2010-12-15 Senast uppdaterad: 2017-01-23Bibliografiskt granskad
Samii, S. (2011). Quality-Driven Synthesis and Optimization of Embedded Control Systems. (Doctoral dissertation). Linköping: Linköping University Electronic Press
Öppna denna publikation i ny flik eller fönster >>Quality-Driven Synthesis and Optimization of Embedded Control Systems
2011 (Engelska)Doktorsavhandling, monografi (Övrigt vetenskapligt)
Abstract [en]

This thesis addresses several synthesis and optimization issues for embedded control systems. Examples of such systems are automotive and avionics systems in which physical processes are controlled by embedded computers through sensor and actuator interfaces. The execution of multiple control applications, spanning several computation and communication components, leads to a complex temporal behavior that affects control quality. The relationship between system timing and control quality is a key issue to consider across the control design and computer implementation phases in an integrated manner. We present such an integrated framework for scheduling, controller synthesis, and quality optimization for distributed embedded control systems.

At runtime, an embedded control system may need to adapt to environmental changes that affect its workload and computational capacity. Examples of such changes, which inherently increase the design complexity, are mode changes, component failures, and resource usages of the running control applications. For these three cases, we present trade-offs among control quality, resource usage, and the time complexity of design and runtime algorithms for embedded control systems.

The solutions proposed in this thesis have been validated by extensive experiments. The experimental results demonstrate the efficiency and importance of the presented techniques.

Ort, förlag, år, upplaga, sidor
Linköping: Linköping University Electronic Press, 2011. s. 173
Serie
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1386
Nyckelord
Embedded control, distributed embedded systems, distributed control, control quality, control performance, scheduling, optimization, adaptive system, multi-mode system, fault tolerance, self-triggered control
Nationell ämneskategori
Datavetenskap (datalogi)
Identifikatorer
urn:nbn:se:liu:diva-68641 (URN)978-91-7393-102-1 (ISBN)
Disputation
2011-09-23, Visionen, hus B, Campus Valla, Linköpings universitet, Linköping, 13:15 (Engelska)
Opponent
Handledare
Tillgänglig från: 2011-08-22 Skapad: 2011-05-25 Senast uppdaterad: 2019-12-19Bibliografiskt granskad
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