NeTS: Small: Real-Time Wireless Sensor-Actuator Networks

近年来，无线传感器-执行器网络(WSAN)在流程工业中得到了迅速采用。WirelessHART等工业标准的实际部署证明了在工业环境中实现可靠无线通信的可行性。然而，现有的无线技术在支持对网络通信提出严格的实时要求的过程控制应用方面仍然面临着巨大的挑战。此外，由于控制性能和通信延迟之间的耦合以及网络协议栈的多层之间的相互依赖，在无线网络上优化控制性能是具有挑战性的。为了应对流程工业面临的这些关键挑战，该项目正在为WSAN开发一种控制感知网络设计方法。这种整体方法将无线网络、实时调度和非线性优化集成在一个统一的框架中，并采用了三项新技术：(1)高效的局部搜索方法，利用实时调度分析来优化无线网络的控制性能；(2)灵活的多层优化方法，根据网络变化以分层的方式调整传输调度、路由和采样率选择；(3)分层网络结构，使大规模实时无线控制网络成为可能。该项目通过与无线HART标准的行业领导者艾默生合作，在物理无线试验台上使用现实的工业过程控制应用来实施和评估网络架构和协议。这项研究的成功完成将使具有高社会和工业影响的广泛过程控制应用得以实现，如炼油、石化和水处理。与行业合作伙伴的合作将导致通过行业标准向流程行业进行实际部署和技术转让。这项研究将产生实时无线协议栈的开源实现，这将进一步扩大对研究、教育和工业的影响。

Recent years have witnessed rapid adoption of wireless sensor-actuator networks (WSANs) in process industries. Real-world deployments of industrial standards such as WirelessHART have demonstrated the feasibility to achieve reliable wireless communication in industrial environments. However, existing wireless technologies still face significant challenges in supporting process control applications that impose stringent real-time requirements on network communication. Moreover, optimizing control performance over wireless networks is challenging due to the coupling between control performance and communication delays, as well as inter-dependencies among multiple layers of the network protocol stack. To meet these critical challenges faced by process industries, this project is developing a control-aware network design approach for WSANs. This holistic approach integrates wireless networking, real-time scheduling and non-linear optimization in a unified framework with three novel technologies: (1) an efficient local search approach that leverages real-time scheduling analysis to optimize control performance over wireless networks; (2) an agile multilayer optimization approach that adapts transmission scheduling, routing and sampling rate selection in a hierarchical fashion in response to network changes; (3) a hierarchical network architecture that enables large-scale real-time wireless control networks. The project implements and evaluates the network architecture and protocols using realistic industrial process control applications on physical wireless testbeds through collaboration with Emerson, an industrial leader of the WirelessHART standard.Successful completion of this research will enable a broad range of process control applications with high societal and industrial impacts such as oil refining, petrochemicals and water treatment. Collaboration with industrial partners will lead to real-world deployments and technology transfer to process industries through industrial standards. This research will produce an open-source implementation of the real-time wireless protocol stack, which will further broaden the impacts on research, education and industry.