A wireless low latency control system for harsh environments*

The use of wireless communication technologies in the industry offer several advantages. One advantage is the ability to deploy sensors where they previously could not easily be deployed, for instance on parts that rotate. To use wireless communication in industrial control loops, demands on reliability and latency requirements has to be met. This in an environment that may be harsh for radio communication. This work presents a reliable, low latency wireless communication system. The system is used in a wireless thyristor control loop in a hydro power plant generator. The wireless communication is based on Bluetooth radio modules. The work shows a latency analysis together with empirical hardware based latency and packet error rate measurements. The background noise of a hydro power plant station is also investigated. The average latency between the Bluetooth modules for the proposed system is 5.09 ms. The packet error rate is 0.00288 for the wireless low latency control system deployed in a hydro power plant.