Spraying Parameter Optimization And Trajectory Planning Of Electrostatic Spraying Painting Robots

In the field of automobile coating,the application of painting robots can not only increase production efficiency greatly,but also avoid the safety problem of workers exposed to toxic working environment for a long time.This paper centers on key technologies of off-line programming system of electrostatic rotary bell(ESRB)painting robot,such as the painting model of rotary bell,the extract and partition algorithm of surfaces to be sprayed,the building of brush table and the algorithm of trajectory planning and combining on surfaces.Aiming at laying the foundation for building the useful and advanced off-line programming system used in the spraying of automobiles.This article introduces the working principle of ESRB firstly.A dynamic spraying experiment under the influence of different factors was designed and finished to build the exact spraying model of ESRB.The influences of these factors on the dynamic model were studied based on experimental results,and a new dynamic spraying model,Composite Spline Model,was proposed,which can improve the accuracy of the fitting model.After that,the static spraying model was derived,and the program of automatically calculating the dynamic model of the ESRB with given spraying parameters was written,which lays a foundation for the creation of brush table and accurate simulation.Secondly,the method of picking up and handling the surfaces of workpieces was studied,and the transformation method of workpieces from 3D model to STL modelmainly on the redundancy removal method of STL model was researched,next,a partition method for complicated surfaces was presented,compared with predecessors,the innovation point lies in building the triangular patch adjacent table(TPAT),which contains the adjacent location relationship of the triangular patches.When it is partitioning the complex curved surfaces,the algorithm can call the TPAT directly,which can increase the searching efficiency greatly,and reduce the partition time of curved surfaces.Thirdly,the composite parameters of brush table were analysed,and based on the dynamic model and the spray thickness solver of round-trip,the automatic generation program of brush table was built using the genetic algorithm.Then the program was used to generate brush tables of a type of car and SUV to verify its correctness,providing the reference data for the set of painting parameters in the off-line programming system.Fourthly,this paper proposed a trajectory generation algorithm,Twice Section Method.This method can derive spraying trajectory which is closer to vertical and has smaller errors than once section method.In view of the shortcomings of predecessors’ trajectory combining methods such as particle swarm optimization algorithm and genetic algorithm,a high efficiency trajectory combining method,the progressive trajectory combination method based on twice ant colony algorithm,was proposed,which uses ant colony algorithm to derive preliminary coating order of the patches,and then plan the trajectory on every patch,then uses the ant colony algorithm to derive the final painting combination order of these trajectories.Finally,the features of spray-on stage were analysed.The conclusion was the spray-on stage cannot be used in real painting,and based on the conclusion,pre-spray points should be set before enter formal painting regions.The spraying trajectories of every region of a certain automobile were generated and the painting order of these trajectories were derived based on the above methods.The painting simulation module was built on the platform of MATLAB,which can show the painting result visually,so as to evaluate the painting result conveniently and intuitively.