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Performance Analysis in IP-Based Industrial Communication Networks
Beran, Jan ; Švéda, Miroslav (oponent) ; Hanzálek, Zdeněk (oponent) ; Zezulka, František (vedoucí práce)
With the growing scale of control systems and their distributed nature, communication networks have been gaining importance and new research challenges have been appearing. The major problem, contrary to previously used control systems with dedicated communication circuits, is time-varying delay of control and measurement signals introduced by packet-switched networks, such as Ethernet. The real-time issues in these networks have been tackled by proper adaptations. Nevertheless, market trend analyses foresee also future adoptions of IP-based communication networks in industrial automation for time-critical run-time data exchange. IP-based communication has only a limited support from the existing instrumentation in industrial automation. This challenge has recently been technically tackled within the Virtual Automation Networks (VAN) project by adopting the quality of service (QoS) architecture delivering soft-real-time communication behaviour. This dissertation focuses on the real-time performance aspects from the analytical point of view and provides means for applicability assessment of IP-based communication for future industrial applications. The main objective of this dissertation is establishment of a relevant modelling framework based on network calculus which will assist worst-case performance analysis of temporal behaviour of IP-based communication networks and networking devices intended for future use in industrial automation. Empirical analysis was used to identify dominant factors influencing the temporal performance of networking devices and for model parameter identification. The empirical analysis makes use of the TestQoS tool developed for this purpose. Minor extensions to the network calculus framework were proposed enabling to model the required temporal behaviour of networking devices. Several exemplary models were inferred as a result of classification of different networking device architectures and empirically identified dominant factors. A novel method for parameter identification was used with the modelled devices. Finally, two temporal models of networking devices (a switch and a router) were validated against empirical observations.
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Integrating Planning and Scheduling
Dvořák, Filip ; Barták, Roman (vedoucí práce) ; Smith, David E. (oponent) ; Hanzálek, Zdeněk (oponent)
Hlavním tématem práce je navržení a vývoj plánovacího systému FAPE, který integruje explicitní reprezentaci času, rozhodování s diskrétními zdroji a rezervoáry, a hierarchické dekompozice. FAPE je první plánovací systém, který akceptuje jazyk ANML a podporuje většinu jeho hlavních vlastností. V~práci se zabýváme různými aspekty integrace zmíněných konceptů, také navrhneme novou techniku pro reformulaci plánovacích problémů do reprezentace pomocí stavových proměnných a identifikujeme přechod výkonosti mezi používaním řídkých a minimálních časových sítí. FAPE dále rozšíříme o schopnosti konání a experimentálně vyhodnotíme výkonnost a výhody jeho vysoké expresivity. Na závěr předvedeme FAPE jako systém, který umí plánovat i konat v experimentech v realném světě, kdy FAPE ovládá robota PR2. Powered by TCPDF (www.tcpdf.org)
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Performance Analysis in IP-Based Industrial Communication Networks
Beran, Jan ; Švéda, Miroslav (oponent) ; Hanzálek, Zdeněk (oponent) ; Zezulka, František (vedoucí práce)
With the growing scale of control systems and their distributed nature, communication networks have been gaining importance and new research challenges have been appearing. The major problem, contrary to previously used control systems with dedicated communication circuits, is time-varying delay of control and measurement signals introduced by packet-switched networks, such as Ethernet. The real-time issues in these networks have been tackled by proper adaptations. Nevertheless, market trend analyses foresee also future adoptions of IP-based communication networks in industrial automation for time-critical run-time data exchange. IP-based communication has only a limited support from the existing instrumentation in industrial automation. This challenge has recently been technically tackled within the Virtual Automation Networks (VAN) project by adopting the quality of service (QoS) architecture delivering soft-real-time communication behaviour. This dissertation focuses on the real-time performance aspects from the analytical point of view and provides means for applicability assessment of IP-based communication for future industrial applications. The main objective of this dissertation is establishment of a relevant modelling framework based on network calculus which will assist worst-case performance analysis of temporal behaviour of IP-based communication networks and networking devices intended for future use in industrial automation. Empirical analysis was used to identify dominant factors influencing the temporal performance of networking devices and for model parameter identification. The empirical analysis makes use of the TestQoS tool developed for this purpose. Minor extensions to the network calculus framework were proposed enabling to model the required temporal behaviour of networking devices. Several exemplary models were inferred as a result of classification of different networking device architectures and empirically identified dominant factors. A novel method for parameter identification was used with the modelled devices. Finally, two temporal models of networking devices (a switch and a router) were validated against empirical observations.
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