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Embedded wireless networks have largely focused on open loop sensing and monitoring. To address actuation in closed loop wireless control systems there is a strong need to re-think the communication architectures and protocols for reliability, coordination and control. As the links, nodes and topology of wireless systems are inherently unreliable, such time-critical and safety-critical applications require programming abstractions where the tasks are assigned to the sensors, actuators and controllers as a single component rather than statically mapping a set of tasks to a specific physical node at design time. To this end, we introduce the Embedded Virtual Machine (EVM), a powerful and flexible programming abstraction where virtual components and their properties are maintained across node boundaries. In the context of process and discrete control, an EVM is the distributed runtime system that dynamically selects primary-backup sets of controllers to guarantee QoS given spatial and temporal constraints of the underlying wireless network. The EVM architecture defines explicit mechanisms for control, data and fault communication within the virtual component. EVM-based algorithms introduce new capabilities such as predictable outcomes and provably minimal graceful degradation during sensor/actuator failure, adaptation to mode changes and runtime optimization of resource consumption. Through the design of a natural gas process plant hardware-in-loop simulation we aim to demonstrate the preliminary capabilities of EVM-based wireless networks.
control engineering computing, control system synthesis, discrete systems, embedded systems, monitoring, object-oriented programming, optimising compilers, protocols, quality of service, robust control, system monitoring, systems analysis, telecommunication computing, telecommunication control, telecommunication network reliability, telecommunication network topology, virtual machines, wireless sensor networks, QoS, design time, discrete control, distributed runtime system, embedded virtual machine, open loop monitoring, open loop sensing, quality-of-service, reliability protocol, robust wireless control system, runtime optimization, software programming abstraction, virtual component, wireless sensor network, wireless system topology, Real-time systems, embedded systems, virtual machines, wireless sensor networks
Date Posted: 02 March 2010