Ride Comfort Control of an Innovative Two-Axle Vehicle Considering Wheel Wear Evolution

In the Shift2Rail project Pivot2 an innovative two-axle single suspension step metro vehicle is proposed. The single suspension step requires active suspensions to improve passenger ride comfort both in vertical and lateral direction. Two control approaches are developed, modal and blended control. Despite the good achievements with regard to comfort improvement, the robustness and performance of the developed controllers in relation to wheel degradation due to wear is unknown. Two different track types and three rail inclinations are used to generate worn wheel profiles with the KTH wear method creating a 75 wheel-rail combination set. For each combination, the comfort is evaluated with the vehicle travelling at constant speed from 50 km/h to 120 km/h with 5 km/h interval, producing a set of 1125 ride comfort evaluation points. Results show that both controllers are robust and that good ride comfort of the innovative vehicle can be maintained according to the EN12299 standard also in case of wheel degradation due to wear. Blended control produces enhanced performance with respect to its modal counterpart in vertical direction.