2006.bib

@article{FERREIRA_II_2006,
  author = {Ferreira, J. and Almeida, L. and Fonseca, J. A. and Pedreiras, P. and Martins, E. and Rodriguez-Navas, G. and Rigo, J. and Proenza, J.},
  title = {Combining operational flexibility and dependability in FTT-CAN},
  journal = {IEEE Transactions on Industrial Informatics},
  year = {2006},
  volume = {2},
  number = {2},
  pages = {95--102},
  month = {May},
  doi = {10.1109/TII.2005.875508},
  issn = {1551-3203},
  isbn = {},
  keywords = {CAN, FTT-CAN, distributed safety-critical systems, dynamic online traffic scheduling, dynamic traffic management, fail-silence enforcement, fault tolerance, flexible time-triggered CAN, master replication, operational dependability, operational flexibility},
  note = {},
  key = {},
  abstract = {The traditional approaches to the design of distributed safety-critical systems, due to fault-tolerance reasons, have mostly considered static cyclic table-based traffic scheduling. However, there is a growing demand for operational flexibility and integration, mainly to improve efficiency in the use of system resources, with the network playing a central role to support such properties. This calls for dynamic online traffic scheduling techniques so that dynamic communication requirements are adequately supported. Nevertheless, using dynamic traffic management mechanisms raises additional problems, in terms of fault-tolerance, related with the weaker knowledge of the future system state caused by the higher level of operational flexibility. Such problems have been recently addressed in the scope of using flexible time-triggered CAN (FTT-CAN) in safety-critical applications in order to benefit from the high operational flexibility of this protocol. This paper gathers and reviews the main mechanisms that were developed to provide dependability to the protocol, namely, master replication and fail-silence enforcement}
}

@inproceedings{SANTOS_ETFA_2006,
  author = {Santos, F. and Trovao, J. and Marques, A. and Pedreiras, P. and Ferreira, J. and Almeida, L. and Santos, M.},
  title = {A Modular Control Architecture for a Small Electric Vehicle},
  booktitle = {11th IEEE International Conference on Emerging Technologies and Factory Automation (ETFA'2006) Proceedings},
  year = {2006},
  editor = {},
  volume = {},
  series = {},
  pages = {139-144},
  address = {Prague, Czech Republic},
  month = {September},
  organization = {},
  publisher = {},
  doi = {10.1109/ETFA.2006.355456},
  issn = {},
  isbn = {0-7803-9758-4},
  keywords = {CAN, FTT-CAN, accelerate-by-wire safety critical function, brake-by-wire safety critical functions, communication infrastructure, fault-tolerant modular control architecture, small electric vehicle, steer-by-wire safety critical function, x-by-wire subsystems},
  note = {},
  key = {},
  abstract = {This paper presents a fault-tolerant modular control architecture for an electrical vehicle (VEIL) equipped with x-by-wire sub-systems. The proposed architecture is based on COTS components and includes steer-by-wire, brake-by-wire and accelerate-by-wire safety critical functions. The communication infrastructure is based on the FTT-CAN protocol, which provides the joint scheduling of message and tasks, according to a holistic approach}
}

@inproceedings{ANTUNES_ANIPLA_2006,
  author = {Antunes, A. and Pedreiras, P. and Almeida, L. and Mota, A.},
  title = {Dynamic Rate Adaptation in Distributed Computer Control Systems},
  booktitle = {International Congress of the Italian National Association for Automation (ANIPLA'2006) Proceedings},
  year = {2006},
  editor = {},
  volume = {},
  series = {},
  pages = {},
  address = {Rome, Italy},
  month = {November},
  organization = {},
  publisher = {},
  doi = {},
  issn = {},
  isbn = {},
  keywords = {CAN, FTT-CAN, Real-Time, Embedded systems},
  note = {Best paper award; selected for journal publication},
  key = {},
  abstract = {There is currently a trend towards higher distribution in embedded control systems that leads to an increased information exchange among system nodes. Moreover, there are cases in which several subsystems exhibit varying communication requirements. Planning the whole distributed system according to worst-case requirements may lead to expensive and inefficient designs. On the other hand, considering lower requirements may lead to occasional run-time overloads. In this paper we propose a technique based on rate switching to adapt the communication requirements of distributed feedback control loops. This technique reduces the sampling rate of those loops to free network and processor bandwidth and oppose to the overload at the expense of a small degradation of the control quality. The dynamic rate adaptation is carried out using the built-in online scheduling and Quality-of-Service (QoS) management features of the FTT-CAN protocol. The paper includes the description of the approach together with a simulation using TrueTime that shows the effectiveness of the proposed technique}
}

@article{MARAU_SAE_2006,
  author = {Marau, R. and Almeida, L. and Fonseca, J. A. and Ferreira, J. and Silva, V.},
  title = {Assessment of FTT-CAN master replication mechanisms for safety-critical applications},
  journal = {SAE 2006 Transactions Journal of Passenger Cars: Electronic and Electrical Systems},
  year = {2006},
  volume = {},
  number = {},
  pages = {},
  month = {April},
  doi = {10.4271/2006-01-1024},
  issn = {},
  isbn = {},
  keywords = {CAN, FTT, FTT-CAN, Real-Time communications, Embedded systems, protocols},
  note = {E	XTRA-INFO-OPTIONAL},
  key = {KEY-OPTIONAL},
  abstract = {The operational flexibility of distributed embedded systems is receiving growing attention because it is required to support on-line adaptation to varying operational conditions, either due to changes in the environment or to faults in the system. However, flexibility makes dependability more difficult to achieve, because there is less a priori knowledge. One protocol that favors flexibility and is widely used in embedded systems, particularly in automotive and robotic systems, is CAN, but some claim that it is not adequate to support safety-critical applications. We argue that CAN, deployed with an adequate overlay protocol, can provide the required support for dependability and flexibility. One such overlying protocol is Flexible Time-Triggered CAN (FTTCAN), that enforces a global notion of time and a global periodic schedule by means of specific messages issued by a master node. In this paper we assess the FTT-CAN master replication mechanisms implemented in a distributed robot control system. Above all, we provide experimental results that show the robustness of such mechanisms}
}

@inproceedings{MARAU_WFCS_2006,
  author = {Marau, R. and Almeida, L. and Pedreiras, P.},
  title = {Enhancing real-time communication over COTS ethernet switches},
  booktitle = {6th IEEE International Workshop on Factory Communication Systems (WFCS'2006) Proceedings},
  year = {2006},
  editor = {},
  volume = {},
  series = {},
  pages = {295--302 },
  address = {Torino, Italy},
  month = {June},
  organization = {},
  publisher = {},
  doi = {10.1109/WFCS.2006.1704170},
  issn = {},
  isbn = {1-4244-0379-0},
  keywords = {Ethernet, Real-Time, Communication switching, Delay, Ethernet networks, Job shop scheduling, Multi-access communication, Multicast protocols, Switches, Telecommunication traffic, Throughput, Traffic control},
  note = {},
  key = {},
  abstract = {Switched Ethernet arose in the last decade as a means to increase global throughput with parallel switching paths, segment the network and create isolated collision domains, thus reducing the non determinism of the original shared Ethernet. However, COTS Ethernet switches still suffer from a few drawbacks that affect negatively their real-time communication capabilities. For example, there can be overflows in ports queues with consequences across ports, priority levels and virtual LANs, and the number of priorities is too short for any kind of priority-based scheduling. Moreover, switches present extra latencies and jitter due to the need to interpret frame addresses and also due to different internal architectural solutions. In this paper we propose using the Flexible Time-Triggered communication paradigm to enhance the temporal behavior of Ethernet switches with respect to periodic streams. We explain the system architecture and we present a formulation of the global periodic traffic scheduling problem handled by the FTT master. Simulation and experimental results show the advantages of using such synchronized framework}
}

@article{ALMEIDA_MDRMDES_2006,
  author = {Almeida, L. and Pedreiras, P. and Marau, R.},
  title = {Traffic scheduling anomalies in temporal partitions},
  journal = {From Model-driven Design To Resource Management For Distributed Embedded Systems},
  year = {2006},
  volume = {225},
  number = {},
  pages = {95--104},
  month = {October},
  doi = {},
  issn = {},
  isbn = {978-0-387-39361-2},
  keywords = {Real-Time, TDMA},
  note = {},
  key = {},
  abstract = {Many network protocols rely on temporal partitions to provide isolation between different nodes (TDMA slots) or different traffic classes (multi-phase cyclic frameworks). Typically, the duration of the slots or phases is not correlated with the duration of packet transmissions, which is variable and non-preemptive. Thus, it is possible that the limit of the slot or phase be overrun by an on-going packet transmission or, if this cannot be tolerated, idle-time must be inserted at the end of the slot or phase whenever a packet does not fit in. Nevertheless, both situations lead to scheduling anomalies in which the worst-case network delay does not occur necessarily with the synchronous release of all other packets, or just the higher priority ones. This paper highlights two such anomalies showing their origin and indicating that, in such circumstances, it is not possible to determine the worst-case network delay with exactitude in the general case. However, it is still possible to upper bound the network delay and the paper shows non-optimal solutions for those cases}
}

@inproceedings{MARAU_RTN_2006,
  author = {Marau, R. and Almeida, L. and Pedreiras, P.},
  title = {Enhanced Ethernet Switching for Flexible Hard Real-Time Communication},
  booktitle = {5th International Workshop on Real Time Networks (RTN'2006) Proceedings},
  year = {2006},
  editor = {},
  volume = {},
  series = {},
  pages = {},
  address = {Dresden, Germany},
  month = {July},
  organization = {},
  publisher = {},
  doi = {},
  issn = {},
  isbn = {},
  keywords = {FTT, FTT-SE, Ethernet, Real-Time Communication},
  note = {},
  key = {},
  abstract = {Switched Ethernet arose in the last decade as a means to increase global throughput with parallel switching paths, segment the network and create isolated collision domains, thus reducing the non determinism of the original shared Ethernet. However the services provided by COTS Ethernet switches are not enough to guarantee real-time communication, which lead to the development of several switch Ethernet-based protocols, among which the recently proposed FTT-SE. This paper proposes moving the FTT traffic management into the Ethernet switch and discusses how this architectural change enhances the performance of the transmission control and service differentiation mechanisms as well as how error confinement mechanisms can be efficiently deployed. Preliminary experimental results from a prototype implementation validate the services provided by the enhanced Ethernet switch framework}
}