The design of an optical wireless sensor network based train vibration monitoring system

In this paper, we investigate the design of an optical wireless sensor network using laser beam reflection and optical wireless technology deployed on train to monitor and analyze the vibration patterns caused by the train motion on the rails it is using. Our architecture is based on measuring efficiently the train structure intrinsic vibration as well as the vibration due to the interaction between the train and railway tracks. To this purpose, we propose a light based sensor node architecture capable of sending and receiving light signals at controllable frequencies to cope with the intensity of the vibration, analysing the local structure health, and helping decision making to react to high vibrations in a distributive manner. The measurements of our sensor network include a tight estimation of the railway track displacement due to the train vibration during motion, geographic localization of the measurements, and real time communication between the sensors nodes and the embedded controlling centre. Finally, a numerical experimentation is conducted to evaluate the efficiency of the proposed optical wireless sensor network.