任意方位圆锥度误差的测量和评定

本文研究三坐标测量机对空间任意方位圆锥度误差的测量和评定．在机器坐标系中建立实测点到理想圆锥面的距离函数，运用文（１）中的方法，建立圆锥度误差最小条件评定的数学模型，这是个可微的无约束非线性优化模型．求解时，利用本文的距离函数直接从实测点数据中得到优化变量的初始值．结合ＤＰＦ算法，快速有效地求得理想锥面的描述变量和最小圆锥度误差，从而免除了为确定描述变量初始值所必须进行的种种辅助测量，提高测量效率．通过两个实测例子的计算结果表明，本文方法确定的描述变量初始值比较接近问题的最优值，从而确保了非线性优化计算的快速和稳定．

Measurement and Evaluation of Conicity Tolerance in Arbitrary Position and Orientation

The measurement and evaluation of the conicity tolerance in arbitrary position and orientation on three-dimensional coordinate machines are investigated in this paper.The distance functions of measuring points to the ideal profiles are expressed in the coordinate system of the machine.The mathematical model of the minimum zone evaluation of the conicity tolerance is presented by means of the method in ref.[1]. It is a differentiable and uncontrained nonlinear optimization. The original values of the optimal variables are directly obtained from the measuring points by the distance function.The describing parameters of the ideal conic surface and the minimum conicity tolerance are obtained by solving the nonlinear optimization with the algorithm DFP. The measurements for determining the origina lvalues of the describing parameters can be omitted, and the efficiency is significantly improyed. It is shown by the calculation results of two examples in the paper that the original values determined by the method are approaching to the optimum solution.The high speed and calculating stability of nonlinear optimization is ensured