一种非接触式R-test测量仪球心坐标计算方法

R-test测量仪是用于五轴数控机床转动轴结构误差测量的专用设备,其通过测量球相对测量坐标系的位置变化进行误差辨识。在测量坐标系中,测量球球心坐标计算的准确性和稳定性是保证测量精度的重要前提。为进行测量球球心坐标的精确计算,构建了非接触式R-test测量仪的结构模型并建立了球心坐标计算方程组。以球心坐标计算方程组为基础,简化得到用于球心坐标求解的非线性方程组并构建其目标函数,然后采用差分进化算法提高球心坐标求解的精度。最后,在GF Mikron UCP800五轴机床上进行对比实验,将测量球球心坐标的计算结果与机床实际坐标进行对比,验证所提出球心坐标计算方法的精度和可靠性。

One Kind of Sphere Center Coordinate Calculation Method for Non-Contact R-test Measuring Instrument

R-test measuring instrument is a special device for measuring the structure error of the rotating shaft of five-axis CNC machine tools.It performs error identification by the position change of the measuring sphere relative to measurement coordinate system.In the measurement coordinate system,the accuracy and stability of the measuring spherical center coordinate calculation is an important prerequisite for ensuring the measurement accuracy.In order to accurately calculate the spherical coordinates of the measuring sphere,the structural model of the non-contact R-test measuring instrument was constructed and the system of spherical coordinate calculation equations was established.Based on the spherical coordinates calculation equations,the nonlinear equations for solving the spherical coordinates were simplified and it’s objective function was constructed.Then the differential evolution algorithm was used to improve the accuracy of the spherical coordinates solution.Finally,a comparative experiment was carried out on the GF Mikron UCP800 five-axis machine tool.The calculation results of the spherical center coordinates were compared with the actual machine coordinates to verify the accuracy and reliability of the proposed spherical coordinate calculation method.