2005.bib

@inproceedings{ANTUNES_ETFA_2005,
  author = {Antunes, A. and Pedreiras, P. and Mota, A.},
  title = {Adapting the sampling period of a real-time adaptive distributed controller to the bus load},
  booktitle = {10th IEEE Conference on Emerging Technologies and Factory Automation (ETFA'2005) Proceedings},
  year = {2005},
  editor = {},
  volume = {1},
  series = {},
  pages = {1084-1088},
  address = {Catania, Italy},
  month = {September},
  organization = {},
  publisher = {},
  doi = {10.1109/ETFA.2005.1612648},
  issn = {},
  isbn = {0-7803-9401-1},
  keywords = {CAN, FTT-CAN, communication infrastructure, distributed adaptive control system, field bus, message scheduling, network-induced jitter, pole-placement controller, real-time adaptive distributed controller},
  note = {},
  key = {},
  abstract = {This paper presents a new method to allow more flexibility on the scheduling of messages across a fieldbus in overload situations. The method proposes the on-line adaptation of the sampling period to the bus load, trying to keep it as low as possible during overloads. The sampling period is allowed to change inside an interval corresponding to 4 to 10 samples per rise time. To assess the solution herein presented, a distributed adaptive control system was implemented in TrueTime, using the FTT-CAN protocol, for the communication infrastructure, a pole-placement controller and a model for the identification of plant parameters that takes into account the network-induced jitter}
}

@inproceedings{FERREIRA_WTR_2005,
  author = {Ferreira, J. and Almeida, L. and Fonseca, J. A. and Pedreiras, P. and Santos, M.},
  title = {On the dependability and flexibility of CAN and CAN based protocols},
  booktitle = {VII Workshop de Tempo Real (WTR'2005) Proceedings},
  year = {2005},
  editor = {},
  volume = {},
  series = {},
  pages = {},
  address = {Fortaleza, Brazil},
  month = {May},
  organization = {},
  publisher = {},
  doi = {},
  issn = {},
  isbn = {},
  keywords = {CAN, FTT-CAN, FTT},
  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 on-line 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. The paper gathers and reviews the main mechanisms that were developed to provide dependability to the protocol, namely master replication and fail-silence enforcement}
}

@inproceedings{SILVA_ETFA_2005,
  author = {Silva, V. and Marau, R. and Almeida, L. and Ferreira, J. and Calha, M. and Pedreiras, P. and Fonseca, J. A.},
  title = {Implementing a distributed sensing and actuation system: The CAMBADA robots case study},
  booktitle = {10th IEEE Conference on Emerging Technologies and Factory Automation (ETFA'2005) Proceedings},
  year = {2005},
  editor = {},
  volume = {2},
  series = {},
  pages = {781--788},
  address = {Catania, Italy},
  month = {September},
  organization = {},
  publisher = {},
  doi = {10.1109/ETFA.2005.1612753},
  issn = {},
  isbn = {0-7803-9401-1},
  keywords = {CAN, FTT-CAN, CAMBADA, controller area network, distributed actuation system, distributed computing architecture, distributed embedded system, distributed sensing system, mobile autonomous robotics},
  note = {},
  key = {},
  abstract = {The use of distributed computing architectures has become commonplace in complex embedded systems with potential advantages, for example, in terms of scalability, dependability and maintainability. One particular area in which that trend can be witnessed is mobile autonomous robotics in which several sensors and actuators are interconnected by means of a control network. In this paper we address one case study concerning the CAMBADA robots that were developed at the University of Aveiro for the Robocup Middle Size League. These robots have a distributed architecture with two layers, a coordination layer responsible for the global behaviors and a distributed sensing and actuating layer that conveys internal state information and executes coordination commands. This paper focuses on the latter layer, which is based on the FTT-CAN protocol, following a network-centric approach that provides an efficient framework for the synchronization of all systems activities. We describe the computing and communication requirements, the robot architecture, the system design and implementation, and finally we provide experimental results that show advantages with respect to a non-synchronized distributed approach}
}

@article{PEDREIRAS_II_2005,
  author = {Pedreiras, P. and Gai, P. and Almeida, L. and Buttazzo, G.},
  title = {FTT-Ethernet: a flexible real-time communication protocol that supports dynamic QoS management on Ethernet-based systems},
  journal = {IEEE Transactions on Industrial Informatics},
  year = {2005},
  volume = {1},
  number = {3},
  pages = {162--172},
  month = {August},
  doi = {10.1109/TII.2005.852068},
  issn = {1551-3203},
  isbn = {},
  keywords = {Ethernet, FTT, FTT-Ethernet, distributed systems, dynamic QoS management, manufacturing automation, quality-of-service, real-time communication protocol, real-time industrial automation systems},
  note = {},
  key = {},
  abstract = {Ethernet was not originally developed to meet the requirements of real-time industrial automation systems and it was commonly considered unsuited for applications at the field level. Hence, several techniques were developed to make this protocol exhibit real-time behavior, some of them requiring specialized hardware, others providing soft-real-time guarantees only, or others achieving hard real-time guarantees with different levels of bandwidth efficiency. More recently, there has been an effort to support quality-of-service (QoS) negotiation and enforcement but there is not yet an Ethernet-based data link protocol capable of providing dynamic QoS management to further exploit the variable requirements of dynamic applications. This paper presents the FTT-Ethernet protocol, which efficiently supports hard-real-time operation in a flexible way, seamlessly over shared or switched Ethernet. The FTT-Ethernet protocol employs an efficient master/multislave transmission control technique and combines online scheduling with online admission control, to guarantee continued real-time operation under dynamic communication requirements, together with data structures and mechanisms that are tailored to support dynamic QoS management. The paper includes a sample application, aiming at the management of video streams, which highlights the protocol's ability to support dynamic QoS management with real-time guarantees}
}

@inproceedings{ALMEIDA_RTSS_2005,
  author = {Almeida, L. and Pedreiras, P.},
  title = {Hard Real-Time Communication over COTS Ethernet Switches},
  booktitle = {26th IEEE International Real-Time Systems Symposium (RTSS'2005) Work in Progress Session Proceedings},
  year = {2005},
  editor = {},
  volume = {},
  series = {},
  pages = {},
  address = {Miami Florida, USA},
  month = {December},
  organization = {},
  publisher = {},
  doi = {},
  issn = {},
  isbn = {},
  keywords = {Ethernet, FTT, FTT-SE},
  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 original shared Ethernet. However, the use of switches, just by itself, is not enough to provide the adequate support to hard real-time communication. For example, there can be overflows in ports queues 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 frames 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 an early formulation of the global periodic traffic scheduling problem that must be handled by the FTT master}
}