Research On The Position Recognition Of Assembly Robot Of Nuclear Fuel Bundle Based On Visual Servo

The assembling of nuclear fuel bundle is a kind of high-risk operation, we can not assemble them by human hands, and because of the fitting of the fuel rods and the grid framework is precision and particular, the traditional means such as remote operation are not well qualified. Due to the robot based on visual servo has high positioning accuracy and assembly speed, it is a hotspot of research on the industry and application research direction of the assembling of nuclear in this paper.The key of the high-precision extraction of the fuel rods posture is the selection of servo system structure, the camera calibration, edge detection and feature extraction work in the vision system. Based on the project requirements, this paper selectes the type of monocular, Eye-to-Hand and visual servo based on the location, and the requirements of image processing precision and fuel rods position were studied.In order to locate the fuel rods, established linear and nonlinear model of the camera, analyzes the calculating process of the parameters of the coplanar calibration method. High precision parameters inside and outside of the camera are obtained by MATLAB, in order to achieve accurate detection of the edge of the bottom plug of the fuel rods, this paper analyzes the detection results of various derivative operators, presents a method of Canny operator combined with boundary tracking.In order to achieve the high-precision extraction of the bottom plug of the fuel rods, the common extraction algorithm for line, circle, ellipse are analyzed. Based on the project requirements, an improved detection algorithm of polar Hough Transform, an improved detection algorithm of circle detection Hough Transform based on the optimal edge and the improved algorithm of least squares e llipse for fitting ellipse are presented, implements the high-precision extraction of features.Based on the using of the mixed programming of Lab VIEW and MATLAB, a software testing platform is prepared, And in order to test all the functions in it. A precision fine-tuning test platform with two degrees is set up, then the development of the simulation environment for the visual servo system is completed. Finally, through the line detection and the other tests by adjusting the position and pose of the fuel rods, the functions of each module of the simulation system are verified.