Research On Location Of Shoe Sole Glue Spraying Trajectory Based On Double-Line Structured Light

In recent years,with the rapid development of the shoemaking industry,many enterprises have disorderly competition.And the low degree of automation of shoemaking technology,result in the unstable quality of shoes.The traditional shoemaking process has high requirements for workers' technical proficiency.It will also cause different degree of pollution to the environment.Nowadays,the difficulty of recruiting workers and rising labor costs have become a major bottleneck for the development of shoe enterprises.Therefore,intelligent,automation and green production have begun to be put on the agenda.In this paper,the sole-spraying process in the shoemaking process is taken as the research background.The double-line structured light 3D system is combined with industrial robot technology.The reconstruct method of the 3D model of the sole and the generation method of the sole spray trajectory are deeply studied.The traditional single-line structured light measuring system often encounters the problem that some of the soles have a occlusive visible area during the sole scanning process,resulting in the lack of scanning data,thereby causing defects in the reconstructed sole model.Based on the consideration of the above problems,this paper has made in-depth research and analysis,and proposed a 3D method using double-line structured light.This method focuses on the pre-data scanning process,obtains two point clouds from different angles on both sides of the sole,and then splices the two point clouds to make up for the defect of single point cloud.It solves the defect of reconstruction model effectively.So it has certain theoretical significance and practical value.The main work of this paper can be listed as follows:(1)Calibration of camera internal and external parameters,distortion coefficients and light plane in line structured light system.After analyzing the camera imaging model and the calibration principle of line structured light,the camera is calibrated and the camera's internal parameters,external parameters and distortion coefficients are obtained.According to the internal and external parameters of the camera and the principle of line structured light system,the optical plane is calibrated and the position relationship between the camera and the line laser is obtained.(2)The process of 3D reconstruction and stitching of point-cloud.The double-line structured light system is used to scan from both sides of the sole,and the laser stripes on the sole are captured by the camera.Then the image of the stripes is processed.The purpose of image processing is to find the center line of the stripe.The processing is divided into three steps:A.stripe image preprocessing;B.stripe image segmentation;C.calculation the center of the stripe.After image processing,two sets of point cloud data on the left and right sides are reconstructed,and then two sets of point clouds are joined by ICP algorithm to get a complete sole model.(3)The generation of the glue trajectory of the sole.The breaking point and the bending.point formed by projecting the laser strip on the sole are extracted as a point set.And interpolation algorithm is used for calculation to obtain a inner contour curve of the sole.By obtaining the chord length offset curve of the inner contour,the sole trajectory curve under the vision system is finally obtained.(4)Hand-eye calibration of line structured light system and robot system.A robot hand-eye calibration algorithm for line structured light systems is proposed,and the Eye-in-Hand and Eye-to-Hand calibration methods are analyzed.This article selects the Eye-to-Hand form in combination with the actual application scenario of the project.Through the principle derivation of the Eye-to-Hand form,the specific coordinate values of the input data are changed into coordinate difference values,so iterative optimization is performed.The optimized hand-eye calibration algorithm is used to transform the coordinates of the sole spray trajectory in the visual system into the spatial coordinates recognized by the robot.