非正交模拟接触式测头的标定算法研究

模拟测头是实现扫描测量的核心部件,进行非正交模拟接触式测头标定方法及算法研究,对于开发标定及测量软件具有重要意义。本文在分析非正交模拟接触式测头测量原理的基础上,采用以幂函数为基函数的转换公式,将公共球面作为约束条件建立了测头的超定非线性标定模型,从而确定了标定矩阵的组成。基于非线性最小二乘迭代方法计算标定矩阵并进行了算例验证,结果表明该方法及算法具有足够精度,可以实现非正交模拟接触式测头的标定。

Research on calibration algorithm of analogue touch probe with non-orthogonal coordinate system

Analogue probe is a key component for scanning measurement. Research on calibrating method and algorithm of analogue touch probe with non-orthogonal coordinate system is of great meaning for the development of calibration and measurement software. Based on analyzing the measurement principle of analogue touch probe with nonorthogonal coordinate system, an over-determined nonlinear calibration model of the probe is established, which adopts power function as the transform formula of base function and uses common spherical surface as the constraint; and then the composition of calibration matrix is determined. The calibration matrix is calculated using nonlinear least square iteration method and an example is given to verify the presented approach. The results show that the proposed method and algorithm have sufficient precision and can fulfill the calibration requirement of analogue touch probe with non-orthogonal coordinate system.