Design and validation of observer-based control for railway vehicles with driven independently rotating wheels: an experimental validation on a 1:5 scale test rig with coupled front and rear axis

This paper presents a comprehensive study on the modelling, con- trol, and observation of railway running gears with driven inde- pendently rotating wheels (DIRWs), focusing on both analytical derivations and experimental validation. A detailed system model is developed, capturing the coupling between front and rear axes, their different stability properties. A combined control and observer framework is proposed, with analytical formulations and closed- loop derivations provided. The control gains are tuned based on a decoupled axis assumption. Validation on the coupled system demonstrates that the dynamic behaviour remains consistent across configurations. This consistency is reflected in the eigenvalue com- parisons, regardless of whether coupling or observation is included. Experimental tests conducted on a 1:5 scaled test rig confirm the effectiveness of the proposed approach. The system achieves satis- factory reference tracking within a few seconds, with steady-state deviations below 0.5 mm. Observations highlight small oscillations at wheel rotation frequencies, with the front axis exhibiting slightly higher deviations due to its inherent instability without control.