基于多步误差分离法的主轴回转误差检测方法

Research on Spindle Rotation Error Detection Method Based on Multi-Step Error Separation Method

为高效快速获得高精密数控铣床主轴工作时的回转误差,笔者提出了基于数理统计法与位移信号的多步误差分离方法。设计了一套包含x向和y向的2个电涡流传感器以及1个光电编码器的测量装置,并使用数据采集卡对传感器和光电编码器进行同步数据采集;设置不同的采样率,使主轴在不同的转速下,每圈的采样点数保持一致;在不借助标准球或者标准棒的情况下对数控铣床的主轴外轮廓进行直接测量,避免标准球或标准棒在安装过程中引入的安装误差和主轴运行时的轴向窜动对测量造成影响;根据误差特性将传感器采集到的混合误差(主轴原始数据)进行逐步分离(消除白噪声和主轴形状误差),最终得到准确的数控铣床主轴回转误差。通过使用美国LionPrecision主轴回转误差分析仪验证了所求主轴回转误差的准确性。该主轴回转误差分离方法能够在不借助标准球或标准棒的情况下,完成对工况下主轴回转误差数据的采集与处理,进而方便、高效地获得比较精确的主轴回转误差。

In order to obtain the rotation error of high precision CNC milling machine spindle efficiently and quickly,a multi-step error separation method based on mathematical statistics and displacement signal was proposed.A set of measuring device including two eddy current sensors in x and y direction and a photoelectric encoder was designed;the data acquisition card was used for simultaneous data acquisition of sensor and photoelectric encoder;different sampling rates were set to maintain the consistent number of sampling points in each turn of the spindle at different speeds;the extemal contour of the spindle of the CNC milling machine was directly measured without the help of the standard ball or standard bar to avoid the influence of the installation error introduced in the installation process of the standard ball or standard bar and the axial movement of the spindle during operation on the measurement;according to the eror characteristics,the mixed error(the original data of the spindle)collcted by the sensor was gradually separated(eliminating white noise and the shape error of the spindle),and finally the accurate spindle rotation error of the CNC milling machine was obtained.The accumcy of the spindle rotation error was verified by using the American Lion Precision spindle rotation error analyzer.The spindle rotation error separation method can complete the collection and processing of spindle rotation error data under working conditions without the help of standard ball or standard bar,thus obtaining relatively accurate spindle rotation error conveniently and fficiently.