基于中点弦测法的车载式车轮不圆度测量

Measurement of Vehicle Wheel Out-of-Roundness Based on Midpoint Chord Method

列车车轮不圆度是影响列车运行平稳性的重要因素,目前静态检测设备均需抬轮的准备工作,极大降低了检测效率,接触式传感器测量易发生损耗,导致测量发生误差,为提高检测效率以及避免检测误差,采用中点弦测法结合逆滤波器实现对车轮不圆度的车载式测量。检测时列车以低速运行,通过激光位移传感器实现非接触式测量,并同时利用3个激光位移传感器的具体位置关系和测量值得到弦测值作为逆滤波器的输入,构造逆滤波器的频率响应函数使一定波长范围内的不圆度数据得到还原,最后再构造低通滤波器以及进行离散傅里叶变换该车轮各个阶次多边形磨耗的粗糙度等级。通过实验测量数据验证,采用中点弦测法测得的车轮不圆度数据与真实不圆度数值的误差较小,可以实现车轮不圆度数据的车载式测量,各个阶次的粗糙度等级也可反映被测车轮目前的磨损状态。

The wheel out-of-roundness is an important factor influencing the train running stability.The lifting of wheels required by the static test equipment in preparation greatly reduces the detection efficiency and results in loss of contact sensor measurement and measurement error.In order to improve the detection efficiency and avoid detection error,midpoint chord measurement method is employed combining with the inverse filter to conduct on-board wheel out-of-roundness test.Testing at a lower speed of the train,non-contact measurement is realized by laser displacement sensor,and relevant locations of the three laser displacement sensors and chord measurements obtained are used as the input of the inverse filter.The out-of-roundness of data within a certain wavelength range of the frequency is restored by creating response function of the inverse filter.Finally,a low-pass filter is constructed and a discrete Fourier transform is carried out to obtain the roughness level of each order polygon wear of the wheel.It is verified by experimental measurement data that the errors of wheel out-of-roundness data measured by midpoint string measurement method are basically consistent with the real out-of-roundness value,which can realize on-board measurement of wheel out-of-roundness data,and the roughness level of each order can also reflect the current wear state of the measured wheel.