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Samii, Soheil
Publications (10 of 17) Show all publications
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)
Open this publication in new window or tab >>Partitioned and overhead-aware scheduling of mixed-criticality real-time systems
2019 (English)In: 24th Asia and South Pacific Design Automation Conference, New York: Association for Computing Machinery (ACM), 2019, p. 39-44Conference paper, Published paper (Refereed)
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.

Place, publisher, year, edition, pages
New York: Association for Computing Machinery (ACM), 2019
National Category
Computer Sciences
Identifiers
urn:nbn:se:liu:diva-160489 (URN)10.1145/3287624.3287653 (DOI)2-s2.0-85061136107 (Scopus ID)978-1-4503-6007-4 (ISBN)
Conference
Asia and South Pacific Design Automation Conference, Tokyo, Japan, January 21 - 24, 2019
Available from: 2019-09-24 Created: 2019-09-24 Last updated: 2019-10-02Bibliographically approved
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
Open this publication in new window or tab >>Scheduling optimization with partitioning for mixed-criticality systems
2019 (English)In: Journal of systems architecture, ISSN 1383-7621, E-ISSN 1873-6165, Vol. 98, p. 191-200Article in journal (Refereed) 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.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Real-time systems, Mixed-criticality systems, Scheduling
National Category
Computer Sciences
Identifiers
urn:nbn:se:liu:diva-160490 (URN)10.1016/j.sysarc.2019.07.007 (DOI)000487166300015 ()2-s2.0-85069685876 (Scopus ID)
Available from: 2019-09-24 Created: 2019-09-24 Last updated: 2019-10-24Bibliographically approved
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)
Open this publication in new window or tab >>Security-aware Routing and Scheduling for Control Applications on Ethernet TSN Networks
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2019 (English)In: ACM Transactions on Design Automation of Electronic Systems, ISSN 1084-4309, E-ISSN 1557-7309, Vol. 25, no 1Article in journal (Refereed) 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.

Place, publisher, year, edition, pages
ACM Publications, 2019
National Category
Computer Sciences
Identifiers
urn:nbn:se:liu:diva-162609 (URN)10.1145/3358604 (DOI)
Available from: 2019-12-11 Created: 2019-12-11 Last updated: 2019-12-18Bibliographically approved
Samii, S. (2018). Level 5 by Layer 2: Time-Sensitive Networking for Autonomous Vehicles. IEEE Communications Standards Magazine, 2(2), 62-68
Open this publication in new window or tab >>Level 5 by Layer 2: Time-Sensitive Networking for Autonomous Vehicles
2018 (English)In: IEEE Communications Standards Magazine, ISSN 2471-2825, Vol. 2, no 2, p. 62-68Article in journal (Refereed) 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.

Place, publisher, year, edition, pages
IEEE, 2018
National Category
Computer Sciences
Identifiers
urn:nbn:se:liu:diva-150524 (URN)10.1109/MCOMSTD.2018.1700079 (DOI)
Available from: 2018-08-24 Created: 2018-08-24 Last updated: 2018-09-06Bibliographically approved
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
Open this publication in new window or tab >>The Frame Packing Problem for CAN-FD
2014 (English)In: Real-Time Systems Symposium (RTSS 2014), Rome, Italy, Dec. 2-5, 2014., IEEE Press, 2014, p. 284-293Conference paper, Published paper (Refereed)
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.

Place, publisher, year, edition, pages
IEEE Press, 2014
Series
Real-Time Systems Symposium, ISSN 1052-8725
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:liu:diva-114468 (URN)10.1109/RTSS.2014.8 (DOI)
Conference
RTSS 14
Available from: 2015-02-20 Created: 2015-02-20 Last updated: 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
Open this publication in new window or tab >>Control-Quality Optimization for Distributed Embedded Systems with Adaptive Fault Tolerance
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2012 (English)In: ECRTS 2012, IEEE, 2012Conference paper, Published paper (Refereed)
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.

Place, publisher, year, edition, pages
IEEE, 2012
Series
EUROMICRO Conference on Real-Time Systems, ISSN 1068-3070
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:liu:diva-77286 (URN)10.1109/ECRTS.2012.40 (DOI)978-1-4673-2032-0 (ISBN)
Conference
24th Euromicro Conference on Real-Time Systems (ECRTS 2012), Pisa, Italy, July 10-13, 2012
Available from: 2012-05-10 Created: 2012-05-10 Last updated: 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.
Open this publication in new window or tab >>Designing High-Quality Embedded Control Systems with Guaranteed Stability
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2012 (English)In: 33rd IEEE Real-Time Systems Symposium (RTSS 2012, 2012Conference paper, Published paper (Refereed)
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.

Series
Real-Time Systems Symposium (RTSS), ISSN 1052-8725
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:liu:diva-80768 (URN)10.1109/RTSS.2012.79 (DOI)000317284200026 ()978-1-4673-3098-5 (ISBN)
Conference
33rd IEEE Real-Time Systems Symposium (RTSS 2012), San Juan, Puerto Rico, December 5-7, 2012
Available from: 2012-08-29 Created: 2012-08-29 Last updated: 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
Open this publication in new window or tab >>Control-Quality Driven Task Mapping for Distributed Embedded Control Systems
2011 (English)In: Embedded and Real-Time Computing Systems and Applications (RTCSA), 2011 IEEE 17th International Conference on, IEEE, 2011, p. 133-142Conference paper, Published paper (Refereed)
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.

Place, publisher, year, edition, pages
IEEE, 2011
Series
Embedded and Real-Time Computing Systems and Applications (RTCSA), ISSN 2325-1271, E-ISSN 2325-1301
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-69733 (URN)10.1109/RTCSA.2011.41 (DOI)978-1-4577-1118-3 (ISBN)
Conference
17th IEEE Intl. Conf. on Embedded and Real-Time Computing Systems and Applications (RTCSA11), Toyama, Japan, August 29-31, 2011.
Available from: 2011-08-01 Created: 2011-08-01 Last updated: 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
Open this publication in new window or tab >>Design Optimization and Synthesis of FlexRay Parameters for Embedded Control Applications
2011 (English)In: 6th International Symposium on Electronic Design, Test and Applications (DELTA 2011), Queenstown, New Zealand, January 17-19, 2011., IEEE, 2011Conference paper, Published paper (Refereed)
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.

Place, publisher, year, edition, pages
IEEE, 2011
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-63321 (URN)10.1109/DELTA.2011.22 (DOI)978-1-4244-9357-9 (ISBN)
Conference
DELTA 2011
Available from: 2010-12-15 Created: 2010-12-15 Last updated: 2017-01-23Bibliographically approved
Samii, S. (2011). Quality-Driven Synthesis and Optimization of Embedded Control Systems. (Doctoral dissertation). Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Quality-Driven Synthesis and Optimization of Embedded Control Systems
2011 (English)Doctoral thesis, monograph (Other academic)
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.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2011. p. 173
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1386
Keywords
Embedded control, distributed embedded systems, distributed control, control quality, control performance, scheduling, optimization, adaptive system, multi-mode system, fault tolerance, self-triggered control
National Category
Computer Sciences
Identifiers
urn:nbn:se:liu:diva-68641 (URN)978-91-7393-102-1 (ISBN)
Public defence
2011-09-23, Visionen, hus B, Campus Valla, Linköpings universitet, Linköping, 13:15 (English)
Opponent
Supervisors
Available from: 2011-08-22 Created: 2011-05-25 Last updated: 2019-12-19Bibliographically approved
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