Image Processing Technology For Curvature Parameter Measurement Of Special Type Tube

High precision special type tube is widely used in many fields such as weapon, spaceflight and nuclear energy etc. Measurement of the static parameters is a prerequisite and important technique process in designing.Based on thorough study of the measuring principle of the special type tube and composition and working principle of measuring system, image processing technologies of the measuring system are analyzed and researched in depth in this paper with curvature parameter measurement as an example. Firstly, for noise characteristics of the spot and target image, the way of median filter is designed to filter the mixed noise of image. Secondly, piecewise linear gray-scale transformation method is used to realize image enhancement. Thirdly, according to the differences of target images and spot images in gray-scale features, Otsu adaptive segmentation method is adopt to realize the image segmentation. Fourthly, zone division method and laser spot positioning method based on least-squares method are respectively used to realize concentric circle detection and accurate position of spot. Lastly, the method of concentric calibration is designed to realize image distortion correction.The curvature measurement experiment of special type tube is done and experimental data is obtained. The measurement accuracy of system is better than 0.1mm . This experiment verifies the effectiveness of image processing algorithms. And three-dimensional space curve of curvature is fitted based on experimental data. Error analysis is given in this paper in the end.