Study of Relationship between Car-body Rolling Angular Velocity and Track Cross Level Irregularity

Recently, several train derailment accidents occurred caused by vehicle rolling movement. When rolling occurs, the vertical force (wheel load) acting between the wheels and rails fluctuates and decreases. This causes the wheels to climb onto the rails, leading to derailment. One of the causes of vehicle rolling movement is known to be track cross level irregularity. However, there are not many examples which investigated the relationships between vehicle rolling and track cross level irregularity by actual vehicle and track. Therefore, the authors measured the rolling angular velocity of vehicles using a vibration gyro sensor in a mobile terminal device along a local railway line and investigated the relationship between vehicle rolling angular velocity and track cross level irregularity.