Keynote: Wireless Sensor Network in Industrial Automation

Although reports on actual implementations are rare, and potential applications in the projected areas are still under consideration, the wireless sensor networks are in the deployment stage by the manufacturing industry. The use of wireless links with field devices, such as sensors and actuators, allow for flexible installation and maintenance, mobile operation required in case of mobile robots, and alleviates problems with cabling. A wireless communication system to operate effectively in the industrial/factory floor environment has to guarantee high reliability, low and predictable delay of data transfer (typically, less than 10 ms for real time applications), support for high number of sensor/actuators (typically over 100 in a cell of a few meters radius, in a discrete manufacturing environment), and low power consumption, to mention some. This presentation will give a general overview of some of the most important requirements dictated by industrial automation applications most of wireless sensor networks have to comply with; to mention: availability and reliability, safety, survivability, security, and dependability. Then main characteristics of wireless sensor networks used in industrial automation applications are discussed including network topology and architectures, real-time restrictions, reliability, power consumption, and life-time issues. The presentation introduces four communication protocols used with wireless sensor networks: IEEE 802.15.4/ZigBee, and dedicated solutions to include wireless interface to sensors and actuators (WISA), and two most notable standardization initiatives aiming at wireless sensor networks for industrial applications: WirelessHART and ISA100. Some of the deployment issues and solutions are illustrated by an example of a wireless sensor/actuator network developed by ABB and deployed in a discrete manufacturing environment - in a robotic assembly cell.