Study on detection of the early signs of derailment for railway vehicles

This paper proposes a technique for detecting the early signs of derailment of a railway vehicle. The proposed system detects abnormal vehicle signs before derailment using micro-electromechanical system acceleration sensors for automobiles. A derailment detection algorithm has been investigated using derailment simulations and experiments. A numerical analysis with a scaled vehicle model simulating wheelclimb derailment at low speeds has been examined. A scale model of a railway vehicle, including one carbody with two bogies, as well as an original device that can simulate various wheelclimb derailments for the selected wheel was designed and made. Based on a numerical analysis and scaled derailment experiments, an algorithm for detecting the signs of derailment beforehand has been proposed and verified. It is found that, using the peak threshold of the pitch angular rate and the integral threshold of the roll angular rate of the truck frame, it is possible to detect the signs of the derailment.