转向架轮对轮径与平行度测量

Measurement of Wheel Diameter and Parallelism of Train Bogie

为了实现准确、快速地测量列车转向架轮径与平行度,构建了列车转向架关键尺寸测量系统。对所述测量系统采用的GA-BP网络曲线拟合算法、约束整体最小二乘法、基准直线拟合算法、平行度测量算法等算法进行研究。首先,根据被测对象的特征介绍了基于GA-BP网络的车轮踏面曲线拟合算法,利用数控加工曲线训练出因传感器特性无法采集处的数据;然后,分析轮径特点,根据弦长定理求出列车转向架轮径,同时,利用全局标定技术将传感器采集数据转换至一个坐标系下,并提出了基于约束的整体最小二乘法,用于获取对应转向架轮对踏面截面上的空间圆圆心;接着,提出了基于蝙蝠算法的空间基准直线拟合方法,即通过踏面截面所处位置的列车转向架踏面截面空间圆的圆心坐标拟合列车转向架轮对轴线;最后,利用基准空间直线与测量点运算,求出列车转向架平行度,将测量数据与激光跟踪仪数据进行对比。实验结果表明:列车转向架轮径与平行度测量精度为0.1 mm。能够满足列车转向架轮径与平行度测量的高精度、高稳定性及测量重复性等要求。

In order to measure the wheel diameter and parallelism of train bogie accurately and quicklya key size measurement system of train bogie is constructed.The GA-BP network curve fitting algorithmconstrained global least square method, reference line fitting algorithm and parallelism measurement algorithm used in the measurement system are studied.Firstly, according to the characteristics of the measured objectthe fitting algorithm of wheel tread curve based on GA-BP network is introduced, and Using the NC machining curve the data is trained that cannot be collected due to the characteristics of the sensor.Secondlythe wheel diameter characteristics are analyzed, and the wheel diameter of train bogie is obtained according to the chord length theorem.At the same time, the global calibration technology is used to calculate the wheel diameter of the train bogie.The data collected by the sensor is transformed into a coordinate systemand a global least square method based on constraints is proposed to obtain the spatial circle center on the tread section of the corresponding bogie wheelset.Thirdly, a straight line fitting method based on bat algorithm is proposed, that is, the train bogie wheel alignment axis is fitted by the circular coordinate of the spatial circle of the tread section.Finally, the parallelism of train bogie is calculated by using the operation of reference space straight line and measuring pointand the measured data are compared with the data of laser tracker.The experimental results show that the measurement accuracy of wheel diameter and parallelism of train bogie is 0.1 mm.It can meet the requirements of high precision, high stability and repeatability of wheel diameter and parallelism measurement of train bogie.