轨道局部缺陷动态检测冲击特征定位比较法

利用前后车轮相继冲击轨道局部缺陷特点,提出轨道局部缺陷车载动态检测新方法。即对车速积分确定车轮旋转一圈对应的起止时刻,用该起止时刻去截取对应时间历程前后轴箱垂向加速度,对截取信号作频率切片小波变换提取信号的时频特征,将时频特征时间轴变换为车轮弧长位移轴,实现冲击特征车轮圈内定位,在车轮连续旋转三圈内定位特征中,比较前后轴箱加速能量峰位置,建立轨道局部缺陷动态检测模型。经动力学仿真数据对该方法及模型的有效性验证结果表明,该方法精准性好、可靠性高,具有一定工程适应性。

Dynamic detection of short track defects comparing position ofImpact characteristics

A new method of detecting short track defects from in-service vehicles is developed using successive impact of the leading and rear wheels on short track defects. The initial moment and the end moment as a rotation of wheel, which are determined through integration of the operational velocity of train, are used to truncate and divide the time history of leading and rear axle vertical accelerations. The truncated acceleration signals between initial moment and the end moment were transformed by frequency sliced wavelet transform (FSWT) to get the time-frequency characteristic of wheel-rail impact. The time axis was replaced by displacement axis signifying wheel circumference in the time-frequency figures to achieve time-frequency feature locations as a rotation of wheel. The model of detecting short track defects was constructed by comparing the location of wavelet energy peak in continuous three circles. The effectiveness of way has been proved through much dynamics simulation data, with high real-time, high accuracy and a good engineering applicability.