Paint Deposition Modeling Of Spraying Robot And Key Techniques Of Off-line Programming

Spraying robot is a kind of industrial robot used for spraying paint or other coatings.Because of its advantages of high quality,saving paint and liberating man from bad working environment,it has been more and more used in automobile spraying and other operations.In this paper,we mainly focus on the research on the spinning cup spraying model and off-line programming technology of car topcoat spraying,including spinning cup spraying model,car body surface treatment,car body surface paint film thickness calculation,discrete parameter selection,spraying trajectory planning and so on.The main work is as follows:1.The working principle and mathematical model of the rotary cup are studied.Based on the static cumulative rate model and uniform spraying thickness model,spraying experiments are designed and spraying models of the rotary cup are established.The spraying models of other process parameters in a given range are predicted by the experimental data,which lays a foundation for the calculation of film thickness and trajectory planning of free-form surfaces.2.The method of calculating the thickness of curved surface and setting related parameters is studied.The parametric surface and mesh model are studied.After analyzing the advantages and disadvantages of the two methods,combined with the two methods,the thickness calculation scheme of mesh model file is determined after using parametric surface to generate trajectory.Then,the formula for calculating the thickness of paint film on free-form surface is deduced,which provides a theoretical basis for the selection of the above parameters.It not only ensures the accuracy of the simulation of the thickness of paint film,but also saves the calculation resources.3.An off-line programming paint film thickness simulation system was built.The STL file is generated by CREO,the position and posture of trajectory points are derived,and the paint film thickness is calculated by simulation.The key is to redevelop CRIO,extract discrete point postures in batches,get the patch files and spraying trajectories,simulate the thickness of each patch with the algorithm of paint film thickness,and visually display the spraying effect in the form of clouds,and evaluate the spraying effect combined with the requirements of spraying thickness and uniformity.4.The trajectory planning of simple facets and composite surfaces is studied,and three brush tables of typical automobile surfaces are created.The evaluation index of trajectory is introduced.It is pointed out that the purpose of trajectory planning is to find the trajectory that satisfies the uniformity of spraying thickness for the target workpiece.The trajectory planning method of simple surface is studied.The trajectory planning method of simple plane and simple surface are studied first.Secondly,on the basis of simple facets,the block trajectory planning method of composite facets is studied.The spraying direction,block trajectory planning and trajectory integration of facets are determined by synthesizing the evaluation function of turning times and uniformity at the junction.Finally,a brush table was created to improve the uniformity of spraying by using different spraying parameters in different path sections of car body spraying.