Research On Spray Painting Trajectory Planning Method Based On Surface Segmentation

The trajectory planning of spray painting robot is an important research content of robot automatic spraying.Taking the automobile bumper spraying as an example,the trajectory planning methods currently used is overall planning for bumper point cloud models.The normal direction of the track points are not regular which are obtained by using the slicing method directly,because the surface model of the bumper is not a regular curved surface.The normal direction of track points should be fitted,and sometimes manual adjustment is needed.Later processing is more troublesome and time-consuming.Aimed at this case,this paper proposes a spray painting trajectory planning method based on surface segmentation.Main research contents of this article are as follows:1.For complex surfaces,Split into several more smooth surface patchs.Combined these surface patchs into larger patchs according to shape,and fitting the patchs to aregular patchs;Analysis the spray thickness of plane,cylinder,sphere and cone surface based on elliptic double-? distribution model and get the spray thickness accumulation models on these surfaces.2.According to the spraying cumulative model on regular surfaces,get the feasible path of spray painting on each regular surface.When the spray gun is spraying at constant height and constant speed,minimize the error between the actual spray thickness and the desired spray thickness,and take it as the goal of optimization.According to the relationship between velocity and cumulative thickness,velocity can be expressed as a function of track spacing.So,the two variables are simplified to one variable and make the optimization problem more convenient to solve.Finally,get the adjacent track spacing and spraying speed on each regular surface.3.For the continuous connection between the surfaces,the relationship between the surface tracks of the junctions is divided into three categories by the location relationship between the track direction and the boundary line and discuss the trajectory of the intersection of these three conditions;For the case where there is a gap between the patches,by taking a certain space on the two sides of the boundary line and fitting the gap at the intersection into a plane.The projection of the boundary points on the plane are taken as trajectory points,get the spray trajectory at the junction gap.4.For the actual spraying of automobile bumpers,using region growth algorithm divide the bumper model into four patches and fit them into regular surfaces.After that,the trajectory planning of the fitted patches was performed and solve the junctions' trajectory.Finally,the spray trajectory of the bumper model and the spraying speed were obtained.Complete the trajectory planning of the automobile bumper,and validate the effectiveness of the proposed method.