We report the development of a network of wireless ultralow-power sensors to be deployed on freight railway cars, with the main purpose of detecting derailment events and alerting the engineer in the cab of the leading locomotive. Because no power bus is available on freight cars, we plan to rely on energy scavenging from vibrations; therefore, minimization of the power consumption has been one of our main priorities. We have, therefore, focused on ultralow-power hardware and strived to reduce the time intervals during which it is in active mode, achieving an average power consumption of    $\sim 0.5$    mW with an active cycle of    $\sim 20$    ms every 2 s. We discuss the overall concept that we propose, including the self-initialization protocol and the communication strategy that we have developed, and present the results of measurements on a prototype network that we have implemented.
['M. Macucci', 'Stefano Di Pascoli', 'Paolo Marconcini', 'Bernardo Tellini']
Derailment Detection and Data Collection in Freight Trains, Based on a Wireless Sensor Network