Study on wheel/rail adhesion force and its control of high-speed trains considering aerodynamic loads and track excitations

• A dynamic model of vehicle/track system considering aerodynamic loads and track excitations is established.
• The influence of aerodynamic loads on wheel/rail vertical contact force is discussed.
• The model of wheel/rail adhesion fuzzy control is built and preliminary analysis is conducted.
• The strategy of adhesion predictive control based on the vehicle system is introduced.

The wheel/rail vertical loads are strongly affected by the aerodynamic loads and track excitations, and will further influence the wheel/rail adhesion forces. With the increasing of train speed, the influence of aerodynamic loads becomes more and more significant. In order to probe into this problem, a simplified train dynamic model with three vehicles is established in which each vehicle system has 14 degrees of freedom. The track irregularity spectrum of a high speed line in China and steady aerodynamic loads are taken as the inputs to the vehicle system. Numerical simulation is carried out by using MATLAB. It is found that the aerodynamic loads obviously affect the wheel/rail contact forces for the high-speed train. Under the same train speed, with the increasing of crosswind velocity, the wheel/rail contact forces for cars at different positions in the train set are reduced gradually. Under the same crosswind velocity, the impact of aerodynamic loads on the different-position vehicle is different. The model of wheel/rail adhesion fuzzy control is built and preliminary analysis is conducted. The strategy of predictive control based on the vehicle system is introduced.