The Quality Inspection And Repairing Of 3D Printed Objects By Combining 3D Model And Computer Vision

With the rapid development of 3D printing technology,3D printed products have been applied to various fields.As a result,high printing quality is required to 3D printed products.The surface of 3D printed products is usually affected by the manufacturing mechanism and materials.The surface is rough and uneven.The precision of the 3D printed products is lower than that of products from the traditional cutting technology.In order to improve the precision of 3D printed products,it is necessary to carry out the quality inspection and repairing it by the results of quality inspection.The thesis mainly studies the 3D printed product quality inspection scheme to combining 3D model and machine vision.Furthermore,a quality repairing scheme based on the quality inspection results is proposed.It includes a quality inspection scheme,a set of evaluation metrics,product repairing scheme,the repairing path for curve and plane model surfaces.The details are as follows.1.A vision based quality inspection scheme to personal 3D printed products is proposed.Firstly,the 3D printed products are scanned from multi views by using the 3D scanner.And the point cloud data could be obtained automatically.Secondly,the 3D model and the point cloud data are aligned and the errors are computed.Furthermore,referring to the evaluation standard of roughness of product surface,and considering the characteristics of 3D printed products,a set of measurement metrics are proposed.Based the proposed metrics,two kinds of products printed from photosensitive resin 3D printer and fused deposition modeling(FDM)are evaluated.The evaluation results are consistent with subjective perception.2.Design the repairing scheme for 3D printed products.By the error distribution and the polishing tools,the repairing scheme could be designed automatically to different 3D printed products.Considering the printed products and the errors,the repairing regions could be recognized.And then different repairing algorithms are designed based on different surfaces of 3D printed products.Furthermore,the repaired products are inspected and evaluated,until the products are qualified.If the surface of the model is curve,the straight path polishing is designed for the volumes with the bigger errors.Then the curve path polishing is designed for the volumes with small errors.Both kinds of polishing are implemented at point level,it can preserve the effectiveness of polishing.3.A quality inspection and repairing system for 3D printed products is designed and implemented.The entire system includes three-dimensional scanning,model alignment,data processing,planar polishing and repairing,surface polishing and repairing,emergency stop and other function buttons,as well as the important parameter display module of controller,display of the grinding area and synchronization display of the polishing area and so on.