高速铁路车轮损伤实时识别的非线性盲源分离理论及关键技术研究

Wheel damages reduce the safety of train operation and may lead to serious railway derailment accidents. It is a hard work to diagnosis micro damages due to the vehicle/rail system nonlinear, non-stationary, multisource and multipath. This study aims at researching nonlinear blind source separation theory as well as experiments and simulation analysis to separate the wheel wear signals, track irregularity signals and vehicle-bridge vibration signals. By optimal stereo vision sensor measurement of wheel/rail contact geometry deformation and experimental modal analysis, this research also establishes a vehicle/rail multibody dynamic model to study the nonlinear mechanism, derailment processes and security criterion based on the explicit expression of the wheel wear, time varying performance conditions and nonlinear transmit characteristic. And then, this study makes a real-time wheel condition monitoring approach based on the information mining theory of multi-source heterogeneous data to diagnose wheel defect and calculate security surplus. The achievements can provide scientific theory and method in dealing with the nonlinear dynamics of vehicle/rail multibody system and nonlinear signal analysis, and enhance the ability of intelligently safety control for high speed railway.

车轮损伤引发的列车脱轨是长期危害高速铁路行车安全的一项关键难题，车辆/轨道系统的非线性、非平稳性、多源多径特性导致车轮损伤在途实时识别困难。本项目拟在理论分析、试验测试、数值建模研究基础上，提出能够稳健高效进行合成观测信号解构的非线性盲源分离新方法，开展车轮损伤、轨道不平顺、转向架激振分量辨识；研究多目立体视觉测量传感器优化布局理论，开展轮轨交互作用三维变形测试与试验模态分析；构建试验相符的车辆/轨道多体系统数值模型，深入揭示系统非线性行为机制与列车脱轨发生发展机理，提出车轮损伤作用下的高速列车脱轨安全裕度评价准则；建立车轮损伤、时变工况、系统非线性传递特性之间的显式关联，面向车轮服役状态实时识别与安全预警开展多源异构数据驱动信息挖掘关键技术理论研究进行在线试验验证。研究成果能为车辆/轨道多体系统动力学和非线性信号处理提供相关的理论基础，并为高速铁路主动安全智能保障技术发展提供有益探索。

车轮作为铁道车辆重要的走行部件，对于保障高速列车运行安全起着关键性的作用。针对车轮损伤激励下的高速列车轮轨振动信号的非线性与非平稳性特征，本项目开展了理论研究、试验研究、数值仿真研究。建立了变速工况与振动统计特征函数之间的显式表达，提出的变频抽样重构方法有效消除了车速变化导致的频谱畸变。提出了能够稳健高效进行车辆-轨道系统振动观测信号解耦的盲源分离理论算法，从剧烈的轮轨冲击振动背景噪声信号中提取出了车轮损伤信号分量，明晰了车轮损伤激励下车辆-轨道系统动力响应的激励源特征。建立了车轮损伤激励下的车轮-轨道多体系统有限元模型，系统表征了列车速度、车轮踏面损伤程度等关键参量对轮轨冲击力学响应的影响规律。开展了开展车轮损伤容限安全管理方法研究。研究成果可为车辆-轨道系统动力学与非平稳信号处理提供依据，为高速铁路运行安全保障控制提供指导。