55,022 research outputs found
Real-time and fault tolerance in distributed control software
Closed loop control systems typically contain multitude of spatially distributed sensors and actuators operated simultaneously. So those systems are parallel and distributed in their essence. But mapping this parallelism onto the given distributed hardware architecture, brings in some additional requirements: safe multithreading, optimal process allocation, real-time scheduling of bus and network resources. Nowadays, fault tolerance methods and fast even online reconfiguration are becoming increasingly important. All those often conflicting requirements, make design and implementation of real-time distributed control systems an extremely difficult task, that requires substantial knowledge in several areas of control and computer science. Although many design methods have been proposed so far, none of them had succeeded to cover all important aspects of the problem at hand. [1] Continuous increase of production in embedded market, makes a simple and natural design methodology for real-time systems needed more then ever
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Programming MPSoC platforms: Road works ahead
This paper summarizes a special session on multicore/multi-processor system-on-chip (MPSoC) programming challenges. The current trend towards MPSoC platforms in most computing domains does not only mean a radical change in computer architecture. Even more important from a SW developer´s viewpoint, at the same time the classical sequential von Neumann programming model needs to be overcome. Efficient utilization of the MPSoC HW resources demands for radically new models and corresponding SW development tools, capable of exploiting the available parallelism and guaranteeing bug-free parallel SW. While several standards are established in the high-performance computing domain (e.g. OpenMP), it is clear that more innovations are required for successful\ud
deployment of heterogeneous embedded MPSoC. On the other hand, at least for coming years, the freedom for disruptive programming technologies is limited by the huge amount of certified sequential code that demands for a more pragmatic, gradual tool and code replacement strategy
Multi-task Implementation for Image Reconstruction of an AER Communication
Address-Event-Representation (AER) is a communication protocol
for transferring spikes between bio-inspired chips. Such systems may consist of
a hierarchical structure with several chips that transmit spikes among them in
real time, while performing some processing. There exist several AER tools to
help in developing and testing AER based systems. These tools require the use
of a computer to allow the processing of the event information, reaching very
high bandwidth at the AER communication level. We propose to use an
embedded platform based on multi-task operating system to allow both, the
AER communication and the AER processing without a laptop or a computer.
We have connected and programmed a Gumstix computer to process Address-
Event information and measured the performance referred to the previous AER
tools solutions. In this paper, we present and study the performance of a new
philosophy of a frame-grabber AER tool based on a multi-task environment,
composed by the Intel XScale processor governed by an embedded GNU/Linux
system.Ministerio de Ciencia e Innovación TEC2006-11730-C03-0
Communicating Processes with Data for Supervisory Coordination
We employ supervisory controllers to safely coordinate high-level
discrete(-event) behavior of distributed components of complex systems.
Supervisory controllers observe discrete-event system behavior, make a decision
on allowed activities, and communicate the control signals to the involved
parties. Models of the supervisory controllers can be automatically synthesized
based on formal models of the system components and a formalization of the safe
coordination (control) requirements. Based on the obtained models, code
generation can be used to implement the supervisory controllers in software, on
a PLC, or an embedded (micro)processor. In this article, we develop a process
theory with data that supports a model-based systems engineering framework for
supervisory coordination. We employ communication to distinguish between the
different flows of information, i.e., observation and supervision, whereas we
employ data to specify the coordination requirements more compactly, and to
increase the expressivity of the framework. To illustrate the framework, we
remodel an industrial case study involving coordination of maintenance
procedures of a printing process of a high-tech Oce printer.Comment: In Proceedings FOCLASA 2012, arXiv:1208.432
Communicating Java Threads
The incorporation of multithreading in Java may be considered a significant part of the Java language, because it provides udimentary facilities for concurrent programming. However, we belief that the use of channels is a fundamental concept for concurrent programming. The channel approach as described in this paper is a realization of a systematic design method for concurrent programming in Java based on the CSP paradigm. CSP requires the availability of a Channel class and the addition of composition constructs for sequential, parallel and alternative processes. The Channel class and the constructs have been implemented in Java in compliance with the definitions in CSP. As a result, implementing communication between processes is facilitated, enabling the programmer to avoid deadlock more easily, and freeing the programmer from synchronization and scheduling constructs. The use of the Channel class and the additional constructs is illustrated in a simple application
Embedding Multi-Task Address-Event- Representation Computation
Address-Event-Representation, AER, is a communication protocol that is
intended to transfer neuronal spikes between bioinspired chips. There are
several AER tools to help to develop and test AER based systems, which may
consist of a hierarchical structure with several chips that transmit spikes
among them in real-time, while performing some processing. Although these
tools reach very high bandwidth at the AER communication level, they require
the use of a personal computer to allow the higher level processing of the
event information. We propose the use of an embedded platform based on a
multi-task operating system to allow both, the AER communication and
processing without the requirement of either a laptop or a computer. In this
paper, we present and study the performance of an embedded multi-task AER
tool, connecting and programming it for processing Address-Event
information from a spiking generator.Ministerio de Ciencia e Innovación TEC2006-11730-C03-0
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