Real-Time Maximum Tangential Torque Seeking for Locomotives using Pseudo-Derivative Control

Abstract

In railway traction systems, optimizing the tangential force acting between the wheels and the rails is crucial for improving transport capacity. The tangential force coefficient fluctuates because of factors such as moisture on the rail surface, resulting in slip phenomena. Various methods for anti-slip control have been proposed in the literature. This study introduces a peak-seeking method to regulate the tangential force in wheel-speed feedback control. With recent advancements in microcontroller performance, the accuracy of tangential force estimation is expected to improve. Therefore, this study proposes a method that employs a disturbance observer to identify the maximum tangential force in locomotive anti-slip control. The design of the observer and peak-seeking gain are analyzed via Bode plots, considering the effects of the calculation cycle. Simulations demonstrate improved tangential force estimation, thereby validating the proposed method.