Research On Automatic Spray Control Technology For Complex Free Surface

Robot automatic spraying control technology is a hot topic in recent years at home and abroad.Robot automatic spraying control technology refers to the computer using reliable trajectory planning algorithm to process the trajectory of the sprayed parts to obtain a smooth spray gun trajectory,and control spraying in a virtual environment The robot completes the simulation of the machining process and the analysis of the spraying effect.The application of robot automatic spraying control technology can avoid the waste of time and environmental pollution caused by manual teaching,thereby significantly improving the efficiency of processing and production.With more and more complex freeform surfaces being used in product design,traditional planning methods can not obtain satisfactory spraying results for the planning of complex freeform surfaces.Therefore,the research of automatic spraying technology based on complex freeform surfaces has practical significance..This paper studies the automatic spraying control technology of complex free-form surfaces.The main research contents are as follows:First,the kinematics of a six-degree-of-freedom spraying robot was studied and analyzed.The D-H method was used to establish the robot linkage coordinate system and solve the positive kinematics.For the problem that there is no closed solution to the inverse kinematics of the oblique cross-end mechanism of the spraying robot,this paper proposes to use the Jacobian method to calculate the inverse kinematics of the 6-degree-of-freedom spraying robot.Verification through simulation provides a theoretical basis for subsequent trajectory planning and robot control.Secondly,the research on spraying technology is carried out,and the main factors that affect the spraying effect are modeled with reasonable assumptions.Then,based on the plane spraying,the distribution rule of the paint film on the surface of the workpiece is comprehensively analyzed,and an accurate paint film thickness distribution model is established.Finally,it extends from the plane model to the complex surface.The film thickness distribution model on the complex surface is deduced from the projection theorem.The formation rule of the dynamic sprayed paint film and the mathematical model of coating accumulation are studied and deduced.The correctness and reliability of the model established by the Matlab platform are verified.Then,for the problem that it is difficult to plan complex surfaces,this paper proposes an optimized STL slicing algorithm.Compared with the basic slicing algorithm,it proposes a quick sorting method of triangular patches to improve the efficiency of solving the intersection point of the tangent plane and the patch,and proposes a fast method of generating contour lines.Finally,the approximate replacement of normal vectors is introduced to improve the efficiency of the entire algorithm.Then the trajectory optimization algorithm is studied,the target optimization function is established based on the expected paint film thickness and the maximum allowable error,and the golden spray method is used to obtain the best spraying speed and stroke distance.Finally,the trajectory planning in Cartesian space is studied,and the position and attitude of the generated spray trajectory are planned,so as to obtain a smoother and dense spray trajectory.Finally,this paper develops an automatic spraying software system based on WPF,OpenTK,C#and Matlab mixed programming technology in Visual Studio2017 platform,which can generate spraying trajectories based on planes and complex curved surfaces,simulate the spraying process in the simulation interface and generate robot control codes.The simulation experiment proves that the spraying trajectory generated by the software is smooth and continuous,based on the complete coverage of the free-form surface spraying paint film,thus verifying the feasibility and practicability of the designed automatic spraying software system.