Wireless Networks for Industrial Applications

该计划的目标是消除使用无线网络连接工业设施中使用的传感器和控制器的障碍。这项工作属于网络物理系统领域，涉及到在数据网络上找到控制物理系统的最佳方法。虽然这项研究适用于任何工业环境，但由于能源工业对阿尔伯塔省和加拿大的重要性，重点将放在炼油厂的网络上。***尽管无线传感器网络是一个流行多年的研究课题，但尚未实现广泛的商业部署。相比之下，有线传感器和控制网络已经在全球工业设施中使用了30多年。将这些有线网络转变为无线网络有很强的经济动机。由于炼油厂可能存在爆炸性气体，安全法规要求所有的网络电缆都用钢屏蔽罩包裹起来。这意味着安装电线连接新传感器的成本从200美元/英尺到2000美元/英尺不等。使用无线连接可以省去大部分费用。***无线工业网络的经济案例是明确的，但在无线技术可以充满信心地使用之前，仍然有必须克服的技术挑战。这项研究计划的目的是解决这些挑战中最关键的问题。首先，关于无线信号在炼油厂环境中的表现的信息很少。与其他工业场所相比，炼油厂环境中管道和容器等金属物体的浓度要高得多。该项目将首次在运营中的炼油厂进行无线现场测量活动。下一个挑战是使用无线测量数据来开发更准确的模型，以预测工业环境中接收到的无线信号功率。无线反射引起接收功率的随机变化，从而导致在规划维持可靠链路所需的发射功率时的不确定性。这使得很难预测节点的功耗和寿命。该计划将利用基于不同密度散射体随机分布的理论来开发更精确的无线传播模型，以减少网络规划中的不确定性。***最后的挑战是确定是否有可能保证在高可靠性无线网络上运行的工业过程控制算法的稳定性。当传感器和控制器命令在网络上传输延迟或丢失时，控制算法就会变得不稳定。这可能会使设施和生命都处于危险之中。该程序将利用数学分析来确定无线网络中预期的随机延迟分布。然后，该分布将用于分析使用该网络的工业控制算法的稳定性

The goal of this program is to remove the barriers for using wireless networks to connect the sensors and controllers used at industrial facilities. This work falls into the area of cyber-physical systems and involves finding the best ways to control physical systems over data networks. While this research is applicable to any industrial setting, the focus will be on networks for petroleum refineries due to the importance of the energy industry to Alberta and Canada.*** Wireless sensor networks have yet to achieve wide commercial deployment in spite of being a popular research topic for many years. In contrast, wired sensor and control networks have been used in industrial facilities worldwide for over 30 years. There is strong economic incentive to transition these wired networks to wireless. Since explosive vapors may be present at a refinery, safety regulations require all network cables to be encased in steel shielding. This means that the cost of installing wires to connect new sensors can range from $200/foot to $2,000/foot. Using a wireless link would eliminate most of this cost.*** The economic case for wireless industrial networks is clear but there are still technical challenges that must be overcome before wireless can be used with confidence. The purpose of this research program is to address the most critical of these challenges.*** First, there is little information on how the wireless signal behaves in a refinery environment. Compared to other industrial sites, refinery environments have a much higher concentration of metal objects such as pipes and vessels. This program will be the first to conduct a wireless field measurement campaign at an operating petroleum refinery.*** The next challenge is to use the wireless measurement data to develop more accurate models for predicting received wireless signal power in an industrial environment. Wireless reflections cause random variations in received power which lead to uncertainty when planning how much transmit power is required to maintain reliable links. This makes it difficult to predict node power consumption and lifetime. This program will utilize theory based on random distributions of scatterers with different densities to develop more accurate wireless propagation models that will reduce uncertainty during network planning.*** The final challenge is to determine if it is possible to guarantee the stability of industrial process control algorithms that are running over high reliability wireless networks. A control algorithm can become unstable when sensor and controller commands traveling over a network are delayed or lost. This can place both the facility and lives at risk. This program will utilize mathematical analysis to determine the distribution of random delays that can be expected over a wireless network. That distribution will then be used in an analysis of the stability of the industrial control algorithm that is using the network.**