Providing wireless communications in a factory, plant or other industrial environment these days means more than just helping employees talk with each other while they work. By eliminating physical connections such as wires and cables from a facility’s communication network, wireless technology offers many manufacturing, chemical processing and municipal (such as water treatment) organizations a means to run their entire operation more efficiently, more productively and at less cost. However, a perceived lack of reliability, integrity and security has hampered the adoption and use of industrial wireless, especially when wireless communication can often be corrupted or disrupted in harsh industrial settings.
The National Institute of Standards and Technology (NIST) - through its Wireless Systems for Industrial Environments project - is working with private-sector collaborators to overcome these obstacles and make industrial wireless communication a more viable choice. The latest milestone in this effort is a newly published study in which rigorous scientific experiments evaluated how well radio frequency (RF) signals propagated in three different factory environments: an automobile transmission assembly facility, a steam generation plant and a machine shop.
In their study of the three factory settings, NIST’s Rick Candell, the lead researcher on the study and his colleagues looked at three RF propagation characteristics. They made precise measurements of how the signals lost power over distance, dispersed over the factory floor and varied in strength due to absorption or reflection by the specific environment. They realised that wireless transmission of data in industrial facilities is completely different from signal propagation in a home or office setting. It’s a harsh environment where reflective or absorbent surfaces, interference from competing RF signal traffic and other obstacles must be overcome if they want to deploy secure, integrated wireless platforms that perform dependably.
The researchers performed mathematical and statistical analyses of the data from the three factory experiments and are incorporating them into a NIST test bed designed to replicate a manufacturing environment. This “factory in a box” re-creates the conditions found in a variety of industrial settings, allowing researchers to study the impacts on signal propagation in controlled laboratory conditions.
The Wireless Systems for Industrial Environments project will deliver comprehensive guidelines in the selection, deployment, and optimization of wireless technologies in manufacturing environments. Reliable and secure real-time performance of wireless platforms are challenging problems faced by manufacturers who choose wireless platforms to replace wired platforms due to their ease of installation, maintenance, and reconfigurability. Wireless technology creates enormous potential for manufacturers by increasing the monitoring and control surface of their physical processes. This potentiation for fine resolution monitoring and control also brings with it technical challenges. These challenges include the impact of the unreliable wireless environment on the ability to monitor the processes and adapt quickly. Where wireless is used for control, security, safety, and reliability become chief concerns. Current wireless technologies employed include IEEE 802.11, IEEE 802.15.4, and some proprietary protocols. The key objective for this project is to develop best-practice guidelines for evaluating and integrating wireless technologies into modern factories. The guidelines will include methodology and protocols that will enable, assess, and assure real-time performance of secure wireless platforms in "smart manufacturing" systems. These guidelines will enable manufacturers, technology providers, and solution providers to design, deploy, and assess robust, secure integrated wireless platforms.
The research will be conducted in multiple overlapping phases. Phase 1 is the radio frequency (RF) measurement phase in which the RF environment in factories is assessed through active and passive measurements. Phase 2 entails the quantification of the factory RF environment as a parameterized statistical channel model representation. Phase 3 is the study of the cyber-physical impacts of the wireless network on the physical systems through simulation. Phase 4 is entails the use of testbed methodologies to study realized wireless networks on physical process performance. Phase 5 is the development of a set of guidelines for selecting and deploying wireless technologies in manufacturing environments.
The NIST team also wants to hear from people involved with factories and plants about their specific industrial environments, including details about layout, structural makeup, operations and communications networking, as well as future needs and plans for wireless. They hope that more managers will consider letting us conduct field trials of wireless in their facilities, especially ones with outdoor operations such as oil refineries or with possible signal-absorbing materials such as paper mills.
