Eric D. Rotvold

Measuring WirelessHART against wired fieldbus for control

Wireless applications in process automation started in areas where wireless sensors provide rich process information to the automation systems. Shortly after WirelessHART became the international standard, both ISA100.11a and WirelessHART claimed that their respective wireless technology could be applied to control as well. Although both standards provide provisions for supporting control over wireless, actual installations of wireless control systems have been slow to be adopted. Due to peoples wariness of using wireless in combination with the serious nature of control, what is needed is a demonstration of performance and reliability of control when being executed across wireless media. A good starting point is a comparison between a wireless control system and its wired counterpart. In this paper we first study if we can establish a WirelessHART control loop the same way as a wired one; then we study if our WirelessHART control loop could achieve the same execution rates and reliability as a wired Foundation Fieldbus control loop. The experiment affirms that, in most likely cases, control over a WirelessHART network could be as good as control over a wired fieldbus.

Building wireless embedded internet for industrial automation

The Internet of Things (IoT) is considered to be the biggest challenge and opportunity for the Internet today. The Internet of Things makes it possible to connect embedded devices in physical environments to the Internet and interact with those devices through both IP and web interfaces. As a subset of the Internet of Things, the wireless embedded Internet targets at enabling resource-limited wireless devices with IP functions and connecting them to the Internet through low-power and low-bandwidth wireless networks. In this paper, we describe our design of the network infrastructure of wireless embedded Internet for industrial automation, and present the implementation and demonstration of a prototype system which integrates WirelessHART mesh networks into the Internet and supports web-based monitoring and control services.

An empirical study of industrial real-time wireless mesh network in field deployments

Real-time wireless sensor and actuator networks (WSANs) have experienced widespread adoption across many industries due to their great advantages of enhanced mobility, easier deployment as well as reduced configuration and maintenance costs. To compensate for the dynamic and unpredictable nature of wireless networks, extensive research efforts have been devoted on algorithm design for efficient network resource management to both meet robustness requirements and optimize the overall network for latency, power, and throughput. Very limited results, however have been reported for the network performance in real field deployments. This paper presents an in-depth exploration of a WirelessHART mesh network deployed in a separations research facility. To understand how the network performs under different scenarios it is restarted and data traces are collected at three points in time with different experiment settings. We examine the impact of initial neighbor selection and observe the network manager adapting the network. The mesh network performance is reported in terms of its primary functions, which are to report process measurements and maintain the network operations.