A Real-Time Polygonal Wheel-Rail Force Identification Method Based on Convolutional Neural Networks (CNN)

Abstract Wheel-rail force identification is one of the most challenging issues in the railway industry, which can provide real-time safety evaluation and fault diagnosis for railway vehciles in operation. A new real-time polygonal wheel-rail force identification method is proposed. Firstly, aiming at the characteristic of high-order polygon feature frequency of wheelset, multi-rigid dynamics model and flexibility-rigid dynamics model are established in SIMPACK to obtain data. Then, the data of rail force and vibration acceleration of vehicle components are normalized, graphically and discretized processed. Finally, the data are input into the designed real-time polygonal wheel-rail force identification network for learning. Simulation data are used for network learning and comparison. The experimental results demonstrate that the vibration acceleration of vehicle components along with the vertical displacement data of primary springs, exhibit optimal performance in the identification of wheel-rail forces when employed as inputs for the network. Interval usage polygonal data of different orders to fine-tuning the network yield the most accurate identification of polygonal wheel-rail forces. For the multi-rigid model, the average absolute error and determination coefficient of vertical force identification are 1039 N and 0.895, and the lateral force is 362 N and 0.833. For the flexibility-rigid model are 1529.2 N and 0.929 in vertical force identification, and 1734.5 N and 0.948 in lateral force identification. Furthermore, the wheel-rail identification can be real-time because the average calculation time is far less than the sampling time. Consequently, the proposed method can provide strong support for the safety evaluation of running railway vehicles based on monitoring data.