Adhesion control method based on optimal slip velocity searching and tracking

Abstract

The adhesion coefficient between the wheel and rail is complex and variable, and it can be affected by factors such as axle weight, rail surface and line condition. The adhesion characteristic curve has a peak point, and in this point, the maximum adhesion force can be achieved. In this paper, we propose an adhesion control method based on optimal slip velocity searching and tracking, and the system can realize the train operating stably near the peak adhesion point to ensure that the train can exert high traction performance. The method firstly generates a reference slip velocity threshold based on the slip velocity and the adhesion coefficient. The reference slip velocity threshold can search for the optimal slip velocity under the current rail surface, and then based on the reference slip velocity threshold, the torque controller is used to generate the motor torque signal. The change rate of torque can be adjusted according to the adhesion state of the wheel-rail, and the slip velocity is controlled to run stably around the optimal slip velocity value to achieve the maximum utilization of the adhesion.