基于三坐标测量机的大口径球面拟合测量方法

在球面检测中,对大口径球面的测量和评价缺乏有效的手段。本文提出利用三坐标测量机获得被测球面面型的坐标数据,用最小二乘法对这些数据进行拟合,得到被测球面的几何参数。在最小二乘法的拟合过程中,提出通过改变目标函数将拟合计算转化为求解广义特征向量以获得较好的拟合效果并简化计算过程,客观地反映大口径球面的实际参数。借鉴圆度、圆柱度误差的评定建立球度误差以反映被测球面的形状误差。

Large Caliber Spherical Surface Fitting Method Based on MMC

There is not an effective method for measurement and assessment of large caliber spherical surface in the realm of spherical surface inspection. This paper proposes that MMC should be used to obtain coordinate data about the measured spherical surface and fitting calculation is carried out to obtain the geometrical parameter of the measured spherical surface by means of least square algorithm. In the process of least square fitting, the idea of changing the objective function to turn the fitting calculation into solving generalized eigenvector is presented which not only brings about good firing effect, but also objectively reflects the real parameter and simplifies the calculating process. Use circularity and cylindricity error for reference to set up sphericity error to reflect the geometrical error of measured spherical surface.