基于本征模函数的轨道质量评价方法

rack Quality Assessment Method Based on Intrinsic Mode Function

摘要:

为了更合理有效的评价轨道质量，将轨道不平顺波长因素纳入轨道质量评价中，提出基于本征模函数（Intrinsic Mode Function, IMF）的轨道质量评价方法-轨道质量能量指标（track quality energy index, TQEI）。通过对轨道不平顺数据进行经验模态分解法（empirical mode decomposition，EMD）得到对应波长频段的不平顺IMF，利用频谱分析的方法求得各个IMF的能量；将各个IMF的能量与总能量的比值作为特征向量，并进行其归一化处理，从而得到轨道不平顺IMF的能量系数；最后利用能量系数计算求得TQGI。通过理论推导证明了TQI是在不考虑波长因素作用下轨道质量能量指标的特殊形式。以京广提速干线轨道不平顺数据为例，对比分析了实际数据TQEI与TQI的关系，结果表明：轨道质量能量指标是对TQI的细化和延续，其可以起到TQI的均值管理作用，又可以弥补TQI在波长及幅值管理方面的缺陷，可以准确有效地对轨道质量进行评价。

Abstract:

In order to more effectively assess track quality, a new assessment method of track quality energy index (TQEI) is presented in this paper, which based on Intrinsic Mode Function (IMF) and included the factor of track irregularity wavelength. The data of track irregularity is decomposed into finite IMFs by empirical mode decomposition (EMD). The frequency spectrum and the power of each IMF are calculated by using FFT. The energy coefficient of track irregularity IMF is chosen as the ratio of IMF signal energy to the original signal energy, and then track quality energy index is obtained with the corresponding calculation. Track quality index (TQI) is proved to be a special form of TQEI on certain basis. Finally, the track irregularity signal is studied by the new index, which collected by track recording vehicles from Beijing-Guangzhou Railway. The statistic and analysis result indicates that track quality energy index is the development and deepen of track quality index and to assess the track quality accurately and effectively.