飞机蒙皮铆钉孔的位置与法矢检测技术研究

Research on inspection technology for positions and normal vectors of rivet holes on aircraft surface

在飞机蒙皮的自动铆接装配中,为将铆钉准确插入到相应的铆钉孔中,该文开展铆钉孔的位置与法矢检测技术研究。将单目视觉与十字线结构光投影相结合,研制一套十字线结构光视觉检测系统,并提出一种基于投影光条的位置与变化规律而获取铆钉孔空间方位的方法。由十字线激光器将十字线结构光投射于被测蒙皮表面并在其上形成投影光条,再通过摄像机采集其视野范围内的、同时包含有投影光条和铆钉孔的二维图像,而后经由系统标定和光条中心线提取来计算和表征出蒙皮曲面的成形轮廓和结构特征,并通过等效与叠加运算等获取到铆钉孔的孔心三维坐标与孔心法线方向。实验结果表明,该系统对于铆钉孔的坐标单次测量极限误差在±0.06 mm内,法矢方向的单次测量极限误差在±0.4°内,具有良好的重复性精度,可以满足蒙皮自动铆接过程中的插钉要求,从而为实现视觉伺服插钉功能提供检测技术支撑。

For inserting the rivets into the corresponding holes in an accurate manner in the automatic riveting procedure,the inspection technology for positions and normal vectors of rivet holes is researched in the paper.Combining monocular vision with cross structured light projection,a cross structured light vision inspecting system established,as well as an acquisition method of the spatial positions and orientations of rivet holes based on the location and changing rule of the projection strips.In the system,the cross structured light emitted by the laser device was projected onto the aircraft surface and formed projection strips on it.And then,the image containing the projection strips and rivet holes was captured by the CCD,which could be used to calculate and characterize the contour and structure features of the target surface after system calibration and center line extraction of projection strips.Finally,the 3D coordinates and normal vectors of the rivet holes could be derived through equivalence and superposition etc.As the experiment results showed,the limit errors of single measurement of the 3D coordinates were smaller than±0.06 mm,while those of normal vectors smaller than±0.44°.Therefore,the system possessed good repeatability accuracy that it could meet the sprigging requirements in the automatic riveting,which could serve as an inspection support for the vision servo sprigging.