Research Of Trajectory Planning Of Spray Painting System Based On CAD Model Of Surface

Paint spray robot, an advanced painting equipment, has been widely used in painting both inside and outside surface of products. Because the morden product's appearance is very complex, how to painting it uniformly has become extremely important. Thus, the painting trajectory planning has become the key point to achieve the painting coating uniformity.Automatic trajectory planning has overcome many shortcomings of teaching trajectory planning, the three-dimensional(3D) information is input into the interactive painting system with a CAD model in the industrial painting process, the painting path can be automatically generated based on 3D information. It determines whether the technology of painting robot's off-line programming can be widely used, and it has become an active area of research, many experts are researching spraying modeling, robot trajectory and optimization of trajectory and so on. Through studying domestic and international research in this field, the work mainly focuses on the 3D CAD model information, the coating deposition rate model, trajectory planning and trajectory simulation.(1)Based on the 3D CAD model of product, with the polyhedron construction method, the product surface is fragmented in triangle style. A Z-map model can be constructed by scaning projection plane. Then the spraying node coordinates and normal vectors of every triangles can be extracted. Finally, the significance information of CAD painting suface can be easily stored and read.(2)After the paint atomizing, there will be a lot of particles on the surface of workpiece. These particles will form a depositional model which has a variety of shapes. By studying the function of theβdepositional model, the deposition thickness equation of plane, surface and the transition surface can be derived.(3)The variable parameters, such as the spray rate, the gun's distance, the distance between the spray paths, the way of spraying trajectory, and the spraying time, which influence the effect of painting, are optimized. A mathematical equation of the path's optimization of surface coating could be constracted. Then, the most uniform coating of the two intersecting planes is obtained.(4)A specific car's roof surface is taken as a spraying object, First, model parameters of the spray deposition rate is selected, its best overlap is calculated by MATLAB, the coordinates and normal vectors of the triangle surface'points is extracted by Pro/E'analysis. Finally, the spraying trajectory of car's roof can be generated accurately.(5)Based on OpenGL, 3D spray simulation system was developed with Visual C Language. The model of high-speed spinning cup, particle painting, 3D spray environment is established, and the work perspective changes of the system scene is realized.