车轮不圆顺动态检测的时频特征圈内定位比较法

Dynamic detection of out-of-round wheels using a comparison of time-frequency feature locatings

利用车轮旋转中车轮不圆顺循环冲击轨道的特点,提出一种车轮不圆顺车载动态检测的新方法。该方法的核心是: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的轴箱垂向振动加速度,对截取信号作频率切片小波变换提取信号的时频特征,将时频特征图的时间轴变换为车轮弧长的位移轴,在车轮旋转一周内实现时频特征定位,通过比较连续不同起止时刻的时频圈内定位特征来检测车轮的不圆顺。应用带有车轮不圆顺的动力学仿真数据对该方法的有效性进行了验证,结果表明:该方法实时性好,准确性高,具有良好工程适应性。

A new method of detecting out-of-round wheels on in-service vehicles was developed using the feature of cyclic impacts between out-of-round wheel and track. The initial instant and the end instant for a revolution of wheel were determined through integration of the operational velocity of train, they were used to truncate and divide the time history of vertical axle accelerations. The truncated acceleration signal between initial instant and the end one was transformed with the frequency sliced wavelet transformation (FSWT) to get the time-frequency characteristic figures of wheel-rail impact. The time axis was replaced by a displacement axis signifying wheel circumference in the time-frequency figures to achieve time-frequency feature locations within a revolution of wheel. The adjacent time-frequency feature locatings during one revolution by one of wheel were compared to detect out-of-round wheels. The dynamic simulation data verified the effectiveness of the proposed method. The results showed that the proposed method has higher accuracy, and is applicable for engineering usage with better real-time performance.