基于柔性传感技术的高速列车轮轨力在线监测方法

Application of flexible electronic technology in real-time monitoring for wheel-rail contact forces of high-speed trains

监测轮轨力信号对于保障高速列车的安全运行、提高轨道线路的质量管理具有重要意义.然而,现有的轮轨力测试方法不能保证车轮在任意旋转角度下的测试精度与灵敏度,难以实现列车在高速行驶过程中轮轨力的实时连续测量.本文基于柔性电子技术设计了一款新型轮轨力传感器,在柔性衬底上设计环形应变栅结构,利用金属的压阻效应,获取环形区域内的整体变形随轮轨力变化的情况.垂向加载实验结果表明,柔性轮轨力传感器不仅具有良好的线性度,且在循环加载测试中表现出优异的稳定性和可重复性.更重要的是,该柔性轮轨力传感器能保证车轮在旋转任意角度情况下的测试精度与灵敏度.有限元仿真结果表明,在车轮内外两侧相对轴心等距离处布置柔性环形传感器,通过两侧传感器的输出信号可实现对轮轨横向力和垂向力的有效解耦.配合无线传感技术,柔性轮轨力传感器可实现高速列车轮轨力实时连续监测,对我国发展下一代智能高铁具有重要意义.

Wheel-rail contact force monitoring enables the operational safety of high-speed trains and the quality management improvement of railway infrastructure.However,the available wheel-rail contact force measuring methods have difficulty in achieving precision and sensitivity for high-rotating wheels and real-time and continuous measurement of wheel-rail contact forces at high speed.In this work,a novel sensor for wheel-rail contact force monitoring is designed based on flexible electronic technology.A ring-shaped strain gage structure is designed on a flexible substrate,and the deformations of the annular region due to wheel-rail contact forces are detected according to the piezoresistive effect in the metal wire.The sensor is verified to have good linearity under vertical loading experiments and exhibits excellent stability and repeatability during cyclic loading.Furthermore,this sensor can guarantee measurement precision and sensitivity when the wheel is spinning.Additionally,the wheel-rail contact forces along the vertical and lateral directions are proved to be effectively decoupled by the output signals of the sensors conformal to relative positions on both sides of the wheel.Thus,combined with wireless sensing technology,the sensor developed here enables the real-time and continuous measurement of wheel-rail contact forces at high speed,which is of great importance for developing the next generation of high-speed railway intelligent transportation systems.