基于曲率自适应的航空零件法矢量测量研究

Research on Normal Vector Measurement of Aero-parts Based on Adaptive Curvature

现有的法矢量测量技术无法满足测量准确度和实时性的双重要求,法矢量计算方法不能适用于不同曲率的曲面。利用双目立体视觉,本文提出了一种基于曲率自适应的法矢量测量方法。首先,在双目立体视觉的基础上,基于变曲率曲面特征建立制孔区域曲面模型,提出投影点的布局方法;然后,基于三维重建的投影点数据,提出了基于曲面曲率自适应识别的法矢量计算方法;最后,针对小曲率曲面样件的测量结果,与三坐标测量仪测得的法矢量进行对比,用以验证本双目视觉测量方法的精度。实验结果表明:该方法测量法矢量误差为1.6°。该方法可有效提高法矢量测量的准确度,满足大型航空零件现场测量的工程要求。

The existing technology of the measurement of normal vector cannot meet the requirements of accuracy and timeliness. The meth-ods of calculating normal vector cannot be applied to surfaces with different curvatures. In this paper, a method of normal vector measurement based on adaptive curvature is proposed by using binocular stereo vision. Firstly, based on the binocular stereo vision, the surface model of the hole point is established in accordance with the features of the variable curvature surface, and the layout method of the projected point is proposed. Then, according to the 3D coordinates of the projected points, the method of calculating normal vector based on the adaptive recogni-tion of curvature is proposed. Finally, the measurement results of the small curvature surface part are compared with the normal vectors measured by CMM, to verify the accuracy of the method in this paper. The experimental results show that the error of the method is 1.6 °. The method can effectively improve the measurement accuracy of normal vector and satisfy the requirements of the in - site measurement of large aerial parts.