A WSN system powered by vibrations to improve safety of machinery with trailer

In this paper we present an energetically autonomous wireless sensor system designed to enhance safety in industrial machinery comprising a main vehicle with an attached trailer. The proposed system establishes a wireless link between the vehicle ECU and our sensors to provide motion dynamic data of trailer to the vehicle stability control algorithm. The wireless sensor devices we implemented comprise a 3-axial accelerometer and a 3-axial magnetometer to detect the trailer operating conditions. Such motion data are elaborated using an ultra-low power MCU, which communicates to vehicle' ECU using an IEEE 802.15.4 channel at 2.4GHz. To enable perpetual operation of the system, we developed a vibrational energy harvesting system, VIBester, capable to gather kinetic energy from trailer natural vibrations and convert such energy in electrical energy for the system power supply. The vibrational energy harvester adopts a piezoelectric (PZT) transducer to convert the kinetic energy and a custom AC/DC converter to supply the wireless sensor device.