Modular Wireless Real-Time Sensor/Actuator Network for Factory Automation Applications

Modern factory facilities are characterized by highly flexible manufacturing cells and highly dynamic processes, where clusters of fixed or moving sensors and actuators have to be controlled in a limited space under stringent real-time and reliability constraints. In such demanding industrial environments, wireless systems can also be beneficial by improving flexibility, cutting cables, and enabling solutions, which are cumbersome or even not possible to realize with wireline systems, especially in controlling moving or rotating parts. In this paper, we present a conceptual study of a wireless real-time system dedicated for remote sensor/actuator control in production automation. System development is based on user requirements, which were extracted from customer interviews and a market research. Low level measurements of frequency- and space-selective wireless channels in a factory-like environment were carried out. System design aspects, i.e., network topology, multiple access schemes, and radio technologies, will be thoroughly reviewed. The performance of a first prototype implementation will be discussed with emphasis on timing behavior and power consumption, as sensors and actuators of the wireless system are intended to operate without power lines or batteries