Robotic spray painting path planning for complex surface: boundary fitting approach

摘要

Currently, most of the robot path planning methods for spray painting are based on slicing the Computer-Aided Design model of the target surface to generate a series of path points. They usually neglect the geometricboundary of the model and the smoothness of the generated path, leading to a non-uniform coating thickness. Toameliorate it, an improved “boundary fitting approach” is proposed. In this method, the upper and lower boundariesof the target surface are firstly detected based on the topology of the stereolithography model. For each pass, severalsample points are extracted with a uniform length interval from the intersection points generated by the basic slicingmethod. The path pass is then described by a fourth-order polynomial curve. It fits the boundary points and samplepoints for the z-t and y-t relationships, respectively. Based on the spray gun’s motion direction and spray direction,the orientation of each path point is also defined. The parameters of the path pass are optimized by particle swarmoptimization to get the optimal uniformity of the resulting coating thickness. Both of the global uniformity and thelocal uniformity between two adjacent passes are considered. The strength of the proposed approach is validatedby comparing the simulation with the basic and other typical algorithms. The results denote that boundary fittingapproach could improve the uniformity of coating thickness. It brings about a better performance for the paintedworkpiece.