用于圆柱体工件分段截面直径高精度测量方法

A High-precision Diameter Measuring Method for Multi-sections of Cylinder Workpiece

针对中/大尺寸圆柱体工件分段截面直径测量普遍存在的效率、精度低等问题,通过建立基于虚拟基准轴线和空间曲线误差数学模型,结合误差分离技术与分段补偿方法,校正被测截面相对于基准轴线的偏差,并规划出扫描探针的空间采样路径,进而解决被测截面相对位姿参数不准确以及测量数据空间坐标不统一的问题,实现截面直径高精度测量。为验证测量方法的精度和可靠性,基于Klingelberg齿轮测量中心,对某型号发动机两种曲轴标准棒(500±100) mm进行大样本误差检测实验,并与德国物理技术研究院的测量结果进行了比对,其结果表明,提出的圆柱体工件截面直径测量方法的精度为1. 5μm,重复检测精度优于0. 5μm,从而验证了该方法的可行性。

Diameter measurement error of multi-sectors of large-scale cylinder workpiece is necessary,thereby existing low efficiency,low accuracy presently. A high-precision diameter measuring model based on space curve and virtual datum axis was developed. Error separation technique and sub-segmented linear axis compensation were used to correct relative error between measured section and datum axis,thus the influences of pose error and coordinate transformation can be controlled effective. Then,sampling path was also generated according to measured area,and the diameter can be obtained by the use of space projection theory and least square method. Finally,by base of Klingelberg gear measuring center,a series of experiments on different standard bars( 500 ± 100) mm were carried out to determine the accuracy and reliability of measuring method. The experimental results showed that the diameter measurement error was less than 1. 5 μm compared with the results of Britain Metrology Institute,and repetition measurement error less than 0. 5 μm,therefore this method is correct in theory and feasible in practice.