Scaled Roller Rig Simulation Method for Axle Load Fluctuation in Railway Vehicles and Experimental Evaluation of Adhesion Characteristics

Precise vehicle control is required for improving the performance of automated operation in rail vehicles. Axle load fluctuations arising from bogie vibrations induced by traction motor torque can trigger wheel slip, highlighting the need to clarify adhesion characteristics under fluctuating axle loads. This study proposes a method to simulate axle load fluctuations using a scaled roller rig hardware-in-the-loop system (HILS). The fundamental relationships among axle load fluctuation amplitude and frequency, and slip velocity, and traction behavior were experimentally evaluated, together with the effects of the main motor torque gradient on slip velocity and adhesive force. The results identify experimental conditions that promote increased slip velocity and demonstrate that the scaled roller rig system successfully reproduces rolling stock adhesion phenomena as well as variations in re-adhesion control behavior under the influence of axle load fluctuations.