Key Techniques Research On Automatic Detection Of Riveting Gap Based On Line Structured Light

Chinese aviation industry is constantly developing,which imporves the technical requirements of aircraft manufacturing and assembly.Currently,the riveting gap of aircraft skin is detected manually,which is inefficient and inaccurate.In this paper,a method is proposed to detect the riveting gap of aircraft skin automatically based on line structured light.The method can detect the gap between the rivet head and the surface of the skin efficiently and accurately without contacting skin.The contents of this issue are as follows.(1)An automatic detection system of riveting gap was built.In this system,the line structured light sensor is composed of an oblique irradiated laser and a vertical received camera,then fixes it on the end effector of the robot.An automatic detection scheme was designed to detect the riveting gap of aircraft skin.(2)The automatic detection method of riveting gap based on line structure light was studied.The measurement model of riveting gap was established,which is based on the measurement principle of line structured light;According to the technical requirements for riveting gap,the Zhang calibration method was used for camera calibration,the singular value decomposition was used for light plane calibration,and the Tsai two-step method was used for hand-eye calibration.These methods are unified the coordinates of the detection system.The automatic detection path for complex curved surface was planning to realize continuous automatic detection of riveting gap.(3)The feature extraction method of riveting gap based on line structure light was studied.The rivet strip image was preprocessed according to the imaging characteristics of image;the center line with sub-pixel accuracy level was obtained by combining the Zhang-suen skeleton extraction method and geometric center method;The features of riveting gap was extracted accurately by the Harris corner detection method.(4)The software development and experiment study of the detection of riveting gap were carried out.The software for the detection of riveting gap was developed based on theory and method;the detection experiment of riveting gap was carried out by taking the riveting gap automatic detection platform as the object.The results show that the method in this paper has high accuracy and feasibility of engineering application.