为了实现磁流变抛光的确定性加工, 对磁流变抛光去除函数的原点位置进行了标定。分析了磁流变抛光去除函数的产生过程及其去除率分布。利用标准圆柱, 建立了抛光轮最低点与数控加工中心测头的相对位置坐标变换关系, 实现了光学元件在机床坐标系中的精确对准。通过在光学元件的特征点上进行去除函数实验测试, 实现了抛光轮最低点对应的去除函数原点位置标定, 对标定误差进行了分析。选择圆形平面光学元件, 应用以金刚石颗粒为抛光粉的水基磁流液, 对抛光轮直径为360 mm的磁流变抛光系统进行去除函数原点标定, 单次标定精度达到0.030 mm。实验结果表明: 本文提出的去除函数原点标定方法简单可靠, 能够满足磁流变抛光技术的修形需求, 可为磁流变抛光在光学制造中的应用提供有力支持。

In order to realize determined fabrication by the Magnetorheological Finishing(MRF), the coordinate origin of removal function was calibrated according to the lowest point of polishing wheel. The generation of removal function and the distribution of removing rate were analyzed. Then the coordinate relationship between the lowest point of polishing wheel and the testing probe was deduced by using a standard cylinder, realizing the precise alignment of optical elements. The removal function was tested on special points of the optics, and the coordinate origin of the removal function derived from the lowest point of the polishing pad was calibrated. Furthermore the calibrating error was analyzed clearly. The calibration experiment was performed on the polishing wheel with a diameter of 360 mm, where a circle plane mirror was fabricated with aqueous magnetorheological fluid made of diamond polishing powder. The precision of calibration is up to 0.030 mm. The result indicates that the proposed calibration method is simple and reliable, therefore can meet the demands of the MRF and establish a strong foundation for MRF in optical fabrications.