基于优化多核极限学习机的车轮多边形磨耗识别

多边形车轮是铁路机车车辆中普遍存在的一种磨损现象, 随着列车运营里程的增加, 车轮磨耗程度显著提升, 严重影响着列车乘坐舒适性和运营安全性, 借助于列车运营监测大数据开展多边形车轮动态检测方法研究具有重要意义. 本研究基于列车轴箱垂向加速度建立了多边形车轮定量识别模型, 首先通过阶次分析识别出轴箱加速度中包含的多边形车轮主要阶次, 同时获取各阶次对应的加速度幅值信息, 在此基础上引入加速度信号熵特征共同构建多边形车轮磨耗幅值识别特征矩阵, 然后建立遗传变异粒子群优化多核极限学习机 (GMPSO-MKELM) 识别模型, 通过特征矩阵与磨耗幅值的映射关系, 进一步实现了车轮多边形磨耗幅值识别. 通过仿真与现场实测数据研究结果表明, 所提出的识别模型能有效地从轴箱加速度中提取多边形车轮主要阶次, 磨耗幅值的识别精度均优于对比模型且具有较高的检测效率, 可实现均方根误差为0.0010 (仿真结果) 与0.0134 (试验结果) 的精确识别, 本文提出的多边形车轮磨耗识别模型可为列车车轮检测与智能维护提供理论基础. 

POLYGONAL WEAR IDENTIFICATION OF WHEELS BASED ON OPTIMIZED MULTIPLE KERNEL EXTREME LEARNING MACHINE

Polygonal wheel is a common wear phenomenon in railway vehicles. With the increase in operating mileage, the degree of wheel wear increases significantly, which seriously affects the ride comfort and operation safety of the trains. It is of great significance to develop the polygonal wheel dynamic detection method with the help of monitoring big data. In this study, a polygonal wheel quantitative identification model is established based on the vertical acceleration signals of the axle box. Firstly, the main orders of the polygonal wheels contained in the acceleration signals of the axle box are identified through order analysis, and the acceleration amplitude corresponding to the main order is obtained at the same time. On this basis, the characteristic matrix of polygonal wheel wear amplitude identification is constructed by the acceleration amplitude of the main order and the entropy characteristic of the acceleration signal. Then the genetic mutation particle swarm optimized multiple kernel extreme learning machine (GMPSO-MKELM) identification model is established. Through the mapping between the characteristic matrix and the wear amplitude of the polygonal wheel, the wear amplitude identification is realized. The results of the simulation and field test show that the proposed model can effectively extract the main order of polygonal wheels from axle box acceleration. The identification accuracy of the proposed model is better than that of the comparison models in wear amplitude, and it has high detection efficiency. The proposed model can achieve accurate identification with a root mean square error of 0.0010 (simulation) and 0.0134 (field test). The proposed polygonal wheel identification model can provide a theoretical basis for the detection and intelligent maintenance of railway vehicle wheels.