Wireless Sensors for Instrumented Machines: Propagation Study for Stationary Industrial Environments

Wireless sensor networks (WSN) are now being used in a growing number and variety of systems and applications. The present paper addresses the issue of wireless sensors operating in specific, possibly harsh propagation conditions in industrial environments employing instrumented machines. These environments are characterized by almost stationary propagation conditions and no mobility, as well as specific, often conductive, materials used. We use simulations to model a real scenario and separately analyse reflection, diffraction and absorption at different frequency bands. Our simulation results are confirmed by classical propagation theory. The results are then validated by measurements in a machine compartment. We draw a conclusion on potential frequencies to be used for wireless sensors applied to the control of instrumented machines.