Study On Automatic Inspection Method Of Ship-hull Curved Plate Forming

Line Heating, a very special technology in steel plate forming process, has a broad application in the shipyard to create ship-hull curved plate. Line Heating is a technology of shell plate forming, which has strong skill technicality and high processing difficuty, mainly uesd in the forming of double ship-hull curved plate. Up to now ,ship-hull curved plate forming still depends on workers' skill,and the judgment of the forming still depends on the template. For the plate which has not been shaped, the heating location and heating quantity are determined entirely by workers' experience, so the efficiency and the quality are very low. so the judgment of hull shell plate forming is a important research theme. At the same time, but also it's a key part of the automated Line Heating processing.The object of this paper is based on the "Large Complex Hull Shell Plate Line Heating Molding Products Robot", which obtaines 3D point cloud data from the hull plate surface with laser. Because of the precision of measuring instruments, the operator's experience and objects surface quality and other reasons, inevitably error data has been introduced, this paper uses curve test and the second value to filtrate and smooth measurement data , thereby the noise data is effectively suppressed. In addition, point cloud data is so intensive that influences the efficiency of the surface reconstruction after matching Re-sampling technology have been presented, which greatly reduces the volume of data and obtains topology point cloud data for Surface Reconstruction. This paper uses NURBS-spline surfaces methods to reconstruct the hull shell plate, Meanwhile, the paper utilizes programming language Visual C++ and OpenGL graphics tools to show 3D surface model of ship-hull curved plate.According to reconstruction plate surface and the actual design surface model, the paper uses profile error evaluation. Improving Iterative the closet Point algorithm (ICP) is presented. Two steps: initial matching and precise matching. Based on the surface character and the coordinate swtich, the paper uses initial matching, then the result of initial matching is as a begin value of precise matching, the measure plate surface and the object plate surface achieve the best matching. The feasibility is proved at last.