Off-line Programming And Simulation System Of Spray Robot For The Facade Of The Large Ship

It is an inevitable trend for the development of shipbuilding industry to introduce robots into the spraying operation of large ships.The existing robot application is mainly conducted in the way of manual teaching.However,the artificial teaching method has some disadvantages,such as difficult operation and poor spraying effect,which limits the application of robots in the spraying task of large ships.An effective solution is to use off-line programming for the trajectory planning of spraying robot.However,most of the existing off-line programming systems are only applicable to small and medium-sized simple spraying scenes,and the trajectory planning ability for large and complex scenes is weak,so it is impossible to solve the difficult problem of ship facade spraying with huge area and variable curvature.Based on this background,this paper studies the off-line programming method of spraying operation on the facade of large ships,constructs a set of off-line programming and simulation system of spraying robot for the facade of large ships,and realizes the spraying trajectory planning on the surface of complex ships.Specific research contents are as follows:Aiming at the introduction and processing of the painting scene of large ships,a half-edge structure is introduced to represent the topological information of the ship grid model.Firstly,a fast topology reconstruction algorithm is proposed on the basis of the half-edge structure.In the process of STL file reading,the redundant vertices are removed by hash table,and the half-edge table is built for each vertex to complete the half-edge merging,so as to realize the rapid topology reconstruction of triangular mesh under the condition of large amount of data.Then some important geometric features of the ship’s facade are extracted based on the half-edge structure.Through the fast and efficient neighborhood query ability of the half-edge structure,the difficult problem of large scene processing can be solved,and the foundation for subsequent trajectory planning can be laid.For the planning of spray trajectory of large and complex ship exterior facades,a segmented spray solution for large and complex ship exterior facades is presented based on detailed requirements analysis.First,the area is divided based on the spray process characteristics of the ship’s exterior facade;then,according to its geometric characteristics,a half-edge extended growth algorithm based on dihedral angle is proposed to divide the complex ship’s exterior facade into several sub-areas with small area,consistent spray process and simple geometry through two area divisions;finally,different trajectory generation algorithms are used for sub-regions with different characteristics: slice trajectory generation algorithm is used for areas close to the plane,and datum curve trajectory generation method is used for areas with slightly larger curvature.For the intersection problem between the truncated plane and the surface to be sprayed in the trajectory generation,an intersection point solution algorithm based on the half-edge topology structure is proposed to speed up the generation of intersection lines.Finally,on the basis of the existing research results of our group,the design and implementation of offline programming and simulation system for the spray robot facing the exterior facade of large ships are completed.In addition to the spray trajectory planning subsystem,it also includes a kinematics calculation subsystem for forward and inverse kinematics modeling of the spray robot,an intermediate language subsystem based on the national standard of the robot programming language,and a program conversion subsystem for the conversion between the intermediate language and the target robot language.Using this system as the experimental platform,the segmented spraying solution and the related algorithm of trajectory planning proposed in this paper are simulated and experimented to verify the validity and practicability of this method.