14,295 research outputs found

    An environment for object-oriented real-time system design

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    A concise object-oriented method for the development of real-time systems has been composed. Hardware components are modelled by (software) base objects; base objects are controlled by a hierarchy of coordinator objects, expressed in an organizational diagram. The behaviour of objects is specified by state transition diagrams. This approach considerably promotes requirements analysis and communication with the customer. A CASE tool has been constructed with diagram editors for graphical specifications of real-time systems. The tool can generate executable code for PLCs from these graphical specifications; reuse of previous results is supported by the repository function of the tool. Experiences attained in practice with method and tool show that time spent in system testing and installation is reduced considerabl

    Domain-oriented architecture design for production control software

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    this paper, we present domain-oriented architectural design heuristics for production control software. Our approach is based upon the following premisses. First, software design, like all other forms of design, consists of the reduction of uncertainty about a final product by making design decisions. These decisions should as much as possible be based upon information that is certain, either because they represent laws of nature or because they represent previously made design decisions. An import class of information concerns the domain of the software. The domain of control software is the part of the world monitored and controlled by the software; it is the larger system into which the software is embedded. The software engineer should exploit system-level domain knowledge in order to make software design decisions. Second, in the case of production control software, using system-level knowledge is not only justified, it is also imposed on the software engineer by the necessity to cooperate with hardware engineers. These represent their designs by means of Process and Instrumentation Diagrams (PIDs) and Input-Output (IO) lists. They do not want to spend time, nor do they see the need, to duplicate the information represented by these diagrams by means of diagrams from software engineering methods. Such a duplication would be an occasion to introduce errors of omission (information lost during the translation process) or commission (misinterpretation, misguided but invisible design decisions made during the translation) anyway. We think it is up to the software engineer to adapt his or her notations to those of the system engineers he or she must work with. Third, work in patterns and software architectures started from the programminglanguage level and is now moving..

    The KELT-South Telescope

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    The Kilodegree Extremely Little Telescope (KELT) project is a survey for new transiting planets around bright stars. KELT-South is a small-aperture, wide-field automated telescope located at Sutherland, South Africa. The telescope surveys a set of 26 degree by 26 degree fields around the southern sky, and targets stars in the range of 8 < V < 10 mag, searching for transits by Hot Jupiters. This paper describes the KELT-South system hardware and software and discusses the quality of the observations. We show that KELT-South is able to achieve the necessary photometric precision to detect transits of Hot Jupiters around solar-type main-sequence stars.Comment: 26 pages, 13 figure

    The Joint COntrols Project Framework

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    The Framework is one of the subprojects of the Joint COntrols Project (JCOP), which is collaboration between the four LHC experiments and CERN. By sharing development, this will reduce the overall effort required to build and maintain the experiment control systems. As such, the main aim of the Framework is to deliver a common set of software components, tools and guidelines that can be used by the four LHC experiments to build their control systems. Although commercial components are used wherever possible, further added value is obtained by customisation for HEP-specific applications. The supervisory layer of the Framework is based on the SCADA tool PVSS, which was selected after a detailed evaluation. This is integrated with the front-end layer via both OPC (OLE for Process Control), an industrial standard, and the CERN-developed DIM (Distributed Information Management System) protocol. Several components are already in production and being used by running fixed-target experiments at CERN as well as for the LHC experiment test beams. The paper will give an overview of the key concepts behind the project as well as the state of the current development and future plans.Comment: Paper from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 4 pages, PDF. PSN THGT00

    UML design and AWL programming for reconfigurable control software development of a robotic manipulator

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    The goal of the presented research is to face the topic of reconfigurable control software development in a concrete fashion, i.e., by presenting a control software system development approach which has been used for a specific, although easy to be generalized, robotized manufacturing cell component. In particular, a methodology for the control software development of a planar robot (2-degrees of freedom) is presented, from the conceptual design to the actual implementation. The methodology suggests UAL and object-oriented modeling and programming techniques for the design phase, while AWL programming language run by a PLC for the implementation phase. The analysis has been conducted considering the internal and external requirements of the manufacturing system which comprises the. robot, mostly driven by the contemporary industrial need of reconfigurable control systems, critical key to succeed in the new era of mass customization
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