NeTS: Small: Towards Efficient and Reliable Communication Infrastructure for Network Controlled Cyber Physical Systems with Application in Smart Grids

典型的网络物理系统（CPS），如智能电网，无人机（UAV）和机器人网络，包括物理动力学，传感器，通信网络和控制器。通信网络将系统测量从传感器传递到控制器，在CPS中起着关键作用，类似于人类的神经系统。传统的数据通信网络（例如，蜂窝网络或WiFi）仅关注数据分组的传递，而CPS的最终目标是控制物理动态（例如，稳定电网中的电压和频率）。因此，由于设计目标的不匹配，传统的通信网络设计在CPS的上下文中可能不是最优的。这就迫切需要研究CPS中通信网络的设计，以提高CPS的灵活性、鲁棒性和效率。 本项目研究如何有效地为CPS设计系统动态感知通信网络，它集成了通信、网络、控制和动态系统等领域，并应用于关键基础设施中重要且不断发展的CPS领域。本项目具体涉及以下研究任务：（a）混合系统的联合设计：采用混杂系统理论对CPS进行建模，将通信网络的运行模式建模为混杂系统的离散状态，而物理动力学模型采用连续状态。通信和控制子系统通过优化混合系统动力学来联合设计;（B）经由信息接口的单独设计：通信和控制子系统被单独设计，并且经由指定的接口（诸如通信服务质量（QoS）或虚拟队列映射）桥接;（c）与弹性数据流的共存：实时数据业务可以与诸如互联网数据的弹性数据业务共享相同的通信资源。弹性数据流量的排队动态和CPS的物理动态集成在同一个框架中，两种类型的流量（弹性和实时）的调度进行了研究;（四）在智能电网中的应用和实现：在前两个任务中获得的原则，算法和协议的应用和实现在智能电网中作为CPS的案例研究。重点研究了微网电压控制的集中式和分散式两种形式。分别在通信子系统和控制子系统联合仿真的软件仿真试验平台和利用USRP板和微电网试验平台的硬件试验平台上进行了实现。

Typical cyber physical systems (CPSs), such as smart grid, unmanned aerial vehicles (UAVs) and robotic networks, consist of physical dynamics, sensors, communication network and controllers. The Communication network, which conveys system measurements from sensors to controllers, plays a key role in CPSs, similarly to the nerve system in human beings. Traditional data communication networks (e.g., cellular networks or WiFi) focus only the delivery of data packets, while the ultimate goal of a CPS is to control the physical dynamics (e.g., stabilizing the voltages and frequencies in power networks). Hence, the traditional design of communication network may not be optimal in the context of CPSs, due to the mismatched goals of designs. This results in a pressing need to study the design of communication networks in CPSs, which helps to enhance the agility, robustness and efficiency of CPSs. This project studies how to efficiently design system-dynamics-aware communication networks for CPS, which integrates the areas of communications, networking, control, and dynamical systems, and has applications to the important and growing field of CPS in critical infrastructures.The project specifically addresses the following research tasks: (a) Joint Design as Hybrid Systems: The theory of hybrid systems is used to model CPS, in which the operation mode of communication network is modeled as the discrete state of a hybrid system, while the physical dynamics are modeled using the continuous state. The communication and control sub-systems are designed jointly by optimizing the hybrid system dynamics; (b) Separate Design via Information Interface: The communication and control sub-systems are designed separately and are bridged via designated interfaces, such as communication quality of service (QoS) or virtual queue mapping; (c) Coexistence with Elastic Data Traffics: The realtime data traffic may share the same communication resource with elastic data traffics such as Internet data. The queuing dynamics of elastic data traffic and the physical dynamics of CPS are integrated in the same framework, and the scheduling for the two types of traffics (elastic and realtime) is studied; (d) Application and Implementation in Smart Grid: The principles, algorithms, and protocols obtained in the previous two tasks are applied and substantiated in smart grids as a case study for CPS. The voltage control in microgrid, both centralized and decentralized, is particularly studied. They are implemented in both software simulation testbed, in which the communication and control sub-systems are co-simulated, and hardware testbed using USRP boards and the microgrid testbed.