利用毫米波雷达测量系统的高铁车桥振动检测

Vibration Detection of High-speed Railway Bridge Using Millimeter Wave Radar Measurement System

针对高速铁路桥梁的实时高精度、非接触振动检测需求,以车桥竖向振动理论解析结果为参考提出了毫米波雷达精密测距改进算法,进而基于IWR1443芯片开发了毫米波雷达测量系统并实现了振动信号采集、解码及处理一体化。最后利用该系统开展了京沪线濉河特大桥徐州段32m简支梁桥振动检测试验和动态挠度计算及时频分析。结果显示,广义S变换和标准时频变换提取的三维谱阵揭示了高速列车动载下桥梁振动过程,竖向挠度、跨挠比和振动主频及类型均与理论分析一致且远高于《高速铁路设计规范》现行限值,表明所检测桥梁结构健康状况良好的同时验证了毫米波雷达车桥振动检测的准确性和有效性。

To meet the real-time,high-precision and noncontact vibration detection requirements of high-speed railway bridge,this paper investigates the theory of vertical vibration model of bridge and the precise ranging algorithm of millimeter wave radar.Based on the IWR1443 millimeter wave radar chip,a millimeter wave radar measurement system is developed to realize the integration of vibration signal measurement,acquisition,decoding and processing.Then the vibration detection experiment of 32m simply supported bridges in Xuzhou section of SUIHE super large bridge on Beijing-Shanghai line is carried out with this measurement system,and the data are analyzed by time-frequency analysis method.Analysis results show that the three-dimensional spectrum array,which is extracted by the generalized S-transform and the standard time-frequency transform,reveals the bridge vibration process under the dynamic load of the high-speed train.The dynamic vertical deflection,the deflection span ratio,the main frequencies and vibration type of bridge are determined,which are consistent with the theoretical analysis,and the performance of bridge structure is better than current design limit value of high speed railway.This indicates the SUIHE bridge structure is in good health and verifies the accuracy and effectiveness of millimeter wave radar measurement system.