Design of a low-latency, high-reliability wireless communication system for control applications

High-performance industrial control systems with tens to hundreds of sensors and actuators use wired connections between all of their components because they require low-latency, high-reliability links to maintain stability; however, the wires cause many mechanical problems that moving to wireless links would solve. No existing or proposed wireless system can achieve the latency and reliability required by the control algorithms because they are designed for either high-throughput or low-power communication between a pair or a small number of terminals. A preliminary wireless system architecture is proposed that focuses on low-latency operation through the use of reliable broadcasting, semi-fixed resource allocation, and low-rate coding. For an industrial printer application with 30 nodes in the control loop and a moderate information throughput of 4.8Mb/s, the system can achieve latencies under 2ms for SNRs above 7dB.