Research On Modeling Technology Of Ship Spraying Process For Wall Climbing Spraying Robot

In the process of ship building,ship coating,as one of the three major technologies of hull,outfitting and coating,occupies a crucial position and is an important index to measure the quality of shipbuilding.Ship coating can not only beautify and decorate the ship,but also make the ship surface have anti-corrosion,anti rust,fire prevention,stealth and other functions,extending the service life of the ship.When industrial robots are used to spray on ships,there are still some deficiencies in the planning and optimization of spray path for complex free-form surfaces(such as ship bow and stern area).In this thesis,a wall climbing spraying robot with four spray guns is taken as the research object.According to the characteristics of the ship’s outer panels and the difficulties of spraying,the problem of trajectory planning and optimization of wall climbing robot is studied.The main research contents are as follows:(1)The slice modeling based on the surface of the ship outer plate based on mesh.Through the software of 3ds max,the CAD model is triangulated;The deviation threshold is set according to the film thickness error specified by the ship painting process,and the adjacent triangular patches are connected into larger patches by the triangular mesh patch planning algorithm,and the curvature of the divided patches remains unchanged;The large curvature surface of outer plate is defined as the judging condition.The large curvature surface is quadratic processed,and the large curvature spraying area of outer plate is fitted to approximate quadratic surface by least square surface fitting algorithm.(2)The factors that affect the film thickness growth of robot are studied,and the film thickness growth models of planar and curved spraying areas are established.In order to simplify the uncontrollable parameters in the model,it is assumed that the parameters such as spraying equipment,coating properties and working environment are fixed in the actual spraying operation of robot;The ellipse double distribution model is used as the research basis of the plane film thickness of the wall climbing robot.Based on the plane spraying experiment,the film thickness data are analyzed and the unknown parameters in the spray gun model are calculated.The effectiveness of the model is verified by MATLAB numerical simulation;Based on the principle of equal spray flow and the differential magnifying projection method,the growth model of paint film thickness on the fixed curvature surface of ship outer panel is derived.(3)The multi-objective optimization of spraying trajectory for wall climbing robot is studied.The initial grating spray trajectory was generated based on bounding box method.Combined with the previous spray model,the spray trajectory optimization model of each spray area is established.According to the established objective function model of spraying trajectory,the multi-objective optimization function model of spraying trajectory on plane and surface is designed,and the optimal spraying process parameters of wall climbing robot are solved in Plat EMO platform.(4)Spray experiment verification.In order to verify the feasibility of the trajectory optimization method of the spraying robot,through the spraying experiment of the wall climbing robot,the film thickness data before and after trajectory optimization are compared,so as to illustrate the feasibility and rationality of the method.