鉄道車両の曲線通過時における輪軸回転角速度変化のメカニズムに関する考察

抄録

The moving block system provided by CBTC increases train operation frequency and improves facilities management efficiency compared to the fixed block system. Trains controlled by CBTC need to have onboard functions to estimate their locations. One method for location estimation involves integrating the measured translational velocity of the trains based on the angular velocity of the wheelset. However, this method may introduce errors in measuring the traveling distance because the angular velocity of the wheelset can be changed on curved tracks due to shifting contact points, longitudinal creepages, and other factors. To observe the phenomenon of angular velocity changes on curved tracks, experiments and simulations were conducted. The results of both experiments and simulations are similar, showing that the angular velocity of wheelsets changes on the curved track and the relative changes differ between the front and rear axles of the bogie. The mechanisms of the angular velocity changing is clarified, identifying three factors: arc length differences between high and low rails, changes in rolling radius on wheels, and longitudinal creepages. Additionally, the impacts of these factors are formulated, indicating that the relative change in angular velocity on curved tracks can be estimated by the sum of the formulated impact factors. Moreover, the visualization method for the mechanism determinating the wheelsets’ angular velocity is developed. This method helps to clarify the reasons for the different relative change observed between the front and rear axles in the bogie during experiments. Specifically, it suggests that the different directions of longitudinal creepages cause the different relative change in the wheelsets’ angular velocity.