基于遗传算法的插值Coons曲面孔位修正方法

在机器人自动制孔过程中，制孔点位信息通常从待制孔工件工艺数模上获取，而待制孔工件安装过程中会出现位置偏移和变形，由工艺数模得到的点位信息无法直接满足孔位精度要求。为了保证自动制孔的孔位精度，提出了一种基于遗传算法的插值Coons曲面孔位修正方法。利用制孔区域边角基准孔建立双线性Coons误差曲面模型，通过模型计算出待制孔的误差补偿向量，并补偿至理论制孔位置。针对误差曲面切矢模长无法确定的情况，利用制孔区域内的基准孔构建遗传算法模型，计算出切矢模长最优值，使拟合的误差曲面更符合实际制孔区域曲面。通过试验对算法的有效性和精度进行验证，结果表明:采用基于遗传算法的插值Coons曲面孔位修正方法，可以使孔位误差得到有效的补偿。补偿后的平均孔位误差仅为0.195 6 mm，与传统的插值曲面方法相比，孔位误差降低了5%~10%。 

A hole position correction method of interpolation Coons surface based on genetic algorithm

In the automatic drilling process of the robot, the position of drilling is usually obtained from the process digital model of the workpiece to be drilled, and the position deviation and deformation will occur during the installation process of the workpiece to be drilled. Hence, the hole position accuracy requirement cannot be met if drilling according to the point position obtained from the process digital model directly. This paper proposes an interpolation Coons surface hole position correction method based on genetic algorithm to ensure the hole position accuracy of automatic drilling. The bilinear Coons error surface model is established using the corner reference holes in the drilling area, the error compensation vector of the hole to be drilled is calculated by the model, and the theoretical drilling position is compensated using the error compensation vector. At the same time, the reference holes in the drilling area are used to construct a genetic algorithm model to calculate the optimal value of the tangent vector modulus length to solve the problem that the tangent vector modulus length of the bilinear Coons error surface cannot be determined. The effectiveness and accuracy of the algorithm are verified through experiments. The results show that the use of interpolation Coons surface hole position correction method based on genetic algorithm can effectively compensate the hole position error, and the average hole position error is only 0.195 6 mm after compensation. Compared with the traditional interpolation surface methods, the hole position error is reduced by 5%-10% using interpolation Coons surface hole position correction method based on genetic algorithm.