A study on prediction model of dynamic matching characteristics of pantograph-catenary system based on the GBDT algorithm

High-speed railway acquires electric energy to drive a train through the sliding electric contact of a pantograph-catenary system. The dynamic matching characteristics of the pantograph-catenary system is the basis of ensuring good sliding electric contact. In this study, firstly, a finite element analysis model to simulate dynamic interaction of pantograph-catenary system was established, and its validity was verified by comparing with the results in literature. Then,the Latin hypercube sampling method was used to sample the main structural parameters of catenary as well as operating speed parameter, and the input parameters were obtained. Using the finite element model, a large number of calculation and analysis of the input parameter set were carried out and the results were extracted,and the output results of the key evaluation indexes of the dynamic matching characteristics were obtained. The input and output results were combined to form the sample data set. Finally, the gradient lifting decision tree (GBDT) algorithm was used to learn and train the dataset,based on which the prediction model of dynamic matching characteristics of the pantograph-catenary system was obtained. The model was compared with four other models, i. e. random forest, extreme random tree, and extreme gradient lifting tree algorithm. The results show that the prediction accuracy of the GBDT-based model is higher and the stability is better. The R2 on the test set reaches 0. 929,which can accurately and quickly evaluate the dynamic matching characteristics. The parameter importance analysis of the GBDT model shows that the operation speed has the greatest influence on the contact quality, which is 61%,followed by the tension in contact wire, the tension in messenger wire and the span length. This study explores the possibility of using machine learning methods to establish prediction models instead of finite element models, and the established models can be used for rapid prediction and evaluation of the dynamic matching characteristics of pantograph-catenary systems. © 2024 Chinese Vibration Engineering Society. All rights reserved.