Event-based slip–slide control system for railway vehicles

In railway transport, braking and traction forces mainly depend on the normal force and the adhesion coefficient between the wheel and the rail. Considering the restrictions on controlling the normal force, maximization of adhesion coefficient seems to be the only way of increasing braking and tractive efforts. Moreover, efficient utilization of adhesion can also reduce operating costs by avoiding early wheel and rail damages and minimizing trip time. However, the adhesion between the rail and the wheel is a highly dynamic function of many parameters, such as environmental conditions, speed, and slip ratio. Unfortunately, there is not yet any sufficiently accurate and reliable way of obtaining these parameters. In this paper, an event-based control scheme is presented to maximize adhesion utilization without necessitating any of the aforementioned parameters. The results obtained with the proposed method are compared with some of the experimentally proven and industrially applied successful methods for different driving scenarios and wheel–rail conditions.