Uniform rolling-wear-based robust adaptive control of high-speed trains in the presence of actuator differences

Small persistent differences of slip velocities due to different actuation effectiveness of driving motors/braking units may lead to severe nonuniform rolling wear or fatigue damage of a part of actuation wheelsets after long-term operation, which would shorten service life or even endanger operational safety of the high-speed train. How to eliminate the nonuniform rolling wear/fatigue damage of actuation wheelsets using the control method is a very interesting and challenging issue. In this paper, robust adaptive observers are developed to identify uncertain dynamics of the train body and actuation wheelsets, based on which a uniform rolling-wear-based traction/braking control scheme is established. It is shown that with this controller, not only the common objective of traction/braking operation is achieved, but also actuator differences are completely compensated such that the same slip velocity (implying uniform driving load and rolling wear) is ensured for all actuation wheelsets during long-term operation. Both theoretical analysis and numerical simulations validate the effectiveness of the proposed control method.