Study On Design And Optimization Of Spray-gun Trajectory For Spray-painting Robot

This thesis is undertaken on the design and optimization of spray-gun trajectory for spray-painting robot.The objective of the design and optimization is to determine a trajectory that results in minimal variation in accumulated film thickness on the surface of a workpiece.1.Firstly,the general situation and background about paining robot research and the developing about research are discussed. And then the frame of off-line programming system and the major problems of research are given. Finally some problems,which are studied in this thesis are illtroduced.2. According to the experimental data, founding the new model of paint desposition and simulating the peripheral curve of distribution off film base on theoretical analysis. The paint thickness at any point deviation from the average paint thickness required minimum, the variation in paint thickness can be as a standard of coating uniformity. Research on the problem of trajectory optimization along the designated path. Because it is more complex to use this equation when the trajectory optimization of in-plane spray painting is carried on, a method of fitting this equation to a simpleβ-distribution-equation is come up by the least square method.3. Trajectory design and optimization for painting robot of complex surface with small curvature is discussed. Because the current paint deposition rate function is too complicated, the paint deposition rate function on a plane according to the experiment data is provided. A complex surface with small curvature is divided into several patches under the principle of sharding and trajectory optimization for each patch is performed. In order to satisfy the material uniformity requirements, trajectory at the junction of patches need optimized. For the interferential problem of coating distribution appeared in the progress of the integrated spraying trajectory optimization on numerous patches, the method of changing the spray gun's height and optimizing the distance of trajectory is advanced.4. Trajectory design and optimization for painting robot of cylinder with large curvature is discussed. On the basis of current paint deposition rate function, the modeling principle of coating thickness on free surface is used, and the spray gun 3D model was deduced in cylndrical surface. The method of least squares approximation for cylindrical surface was proposed, cylindrical surface fractionize into the combination of cylndrical surface, the trajectory optimization problem in cylindrical surface can be approximated as cylndrical surface to deal with,and trajectory optimization objective function was established in each cylndrical surface, the calculation method of coating thickness and optimization algorithms are developed to integrate the trajectories on the intersecting area of two patch.In this thesis, simulations are made for major design schemes.The results of simulations have shown that the model and the tool planning algorithms are feasible.