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dc.contributor.advisor Amer, Hassanein Halawa, Hassan Hesham 2015-01-26T06:46:15Z 2017-01-25T22:00:09Z 2014 Fall en_US 2015-01-26
dc.description.abstract Networked Control Systems (NCSs) consist of sensors, controllers and actuators which are all interconnected via a network fabric. Such an architecture has proven advantageous for industrial communication networks compared to traditional approaches. Lately, Wireless NCSs (WNCSs) have also been rising in popularity due to their ease of installation and maintenance compared to equivalent wired NCSs. However, a significant drawback of WNCSs is the experienced wireless interference which arises from the shared nature of the wireless medium. In any NCS, the failure of a single component can cause complete control system failure in the absence of fault-tolerance. As a result of the ensuing system downtime due to such failures, large production losses could potentially occur. Thus, fault-tolerance is now becoming a crucial aspect of the design and evaluation of NCSs. Fault-tolerance can be implemented at various levels of an NCS in order to improve system reliability: either at the node level and/or at the network fabric level. Nevertheless, the incorporation of fault-tolerance in NCSs involves additional overhead traffic which can have a noticeable impact on the overall system performance. This overhead traffic may cause the real-time NCS to miss crucial control deadlines. Therefore, minimizing the amount of traffic overhead necessary for the implementation of fault-tolerance is desired. This research is focused on the design and performance optimization of reliable fault-tolerant NCSs and WNCSs. First, a fault-tolerant WNCS is proposed based on unmodified IEEE 802.11b implementing 1-out-of-3 controller level fault-tolerance utilizing a wired backbone. The interference tolerance of the system was quantified and certain performance optimizations were investigated in order to improve the overall system’s interference resilience. Moreover, an additional fault-tolerant WNCS with a reliable wireless backbone is proposed. The proposed WNCS is based on unmodified IEEE 802.11g and implements 1-out-of-2 controller level fault-tolerance in addition to network fabric level fault-tolerance on the critical wireless backbone link using the Parallel Redundant Protocol (PRP). Second, a network fabric fault-tolerance methodology is investigated for wired Ethernet NCSs utilizing the Rapid Spanning Tree Protocol (RSTP). A performance optimization is proposed which halves the amount of traffic necessary for the implementation of fault-tolerance while guaranteeing system resilience to any individual network fabric failure. Furthermore, a reliability modeling methodology is developed for the proposed model. A case study is subsequently presented to compare reliability of different system architectures using typical industrial parameters. Finally, an expanded two cell model is developed which not only provides the same degree of network fabric level fault-tolerance but also controller level fault-tolerance. en_US
dc.format.extent 92 p. en_US
dc.format.medium theses en_US
dc.language.iso en en_US
dc.rights Author retains all rights with regard to copyright. en
dc.subject factory automation en_US
dc.subject networked control systems en_US
dc.subject NCSs en_US
dc.subject Ethernet en_US
dc.subject wireless networked control systems en_US
dc.subject WNCSs en_US
dc.subject Wi-Fi en_US
dc.subject WLAN en_US
dc.subject IEEE 802.11 en_US
dc.subject Parallel Redundancy en_US
dc.subject PRP en_US
dc.subject PRP-WLAN en_US
dc.subject backbone en_US
dc.subject network fabric en_US
dc.subject fault-tolerance en_US
dc.subject RSTP en_US
dc.subject PRP-Ethernet en_US
dc.subject optimization en_US
dc.subject redundancy en_US
dc.subject reliability modeling en_US
dc.subject OPNET en_US
dc.subject.lcsh Thesis (M.S.)--American University in Cairo en_US
dc.subject.lcsh Intelligent control systems.
dc.subject.lcsh Network computers.
dc.subject.lcsh Ethernet (Local area network system)
dc.subject.lcsh Electrical engineering.
dc.subject.lcsh Computer engineering.
dc.title On the performance optimization of reliable networked control systems en_US
dc.type Text en_US
dc.subject.discipline Electronics Engineering en_US
dc.rights.access This item is restricted for 2 years from the date issued en_US
dc.contributor.department American University in Cairo. Dept. of Electronics Engineering en_US
dc.description.irb American University in Cairo Institutional Review Board approval has been obtained for this item. en_US
dc.contributor.committeeMember El-Soudani, Magdy
dc.contributor.committeeMember Abdel Azeem, Sherif

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  • Theses and Dissertations [1733]
    This collection includes theses and dissertations authored by American University in Cairo graduate students.

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