Research On Key Technologies Of Large-Scale 3D Printing Control System Based On Digital Light Processing

The principle of 3D printing technology based on Digital Light Processing(DLP)technology is that ultraviolet light can solidify liquid photosensitive resin.This technique sequentially stacks resin layers to construct model entities.It is mainly used to manufacture small and delicate parts.Small forming size is the key point restricting its development and application.This thesis proposes a design scheme of DLP large-scale 3D printing control system based on mobile stitching forming method.In-depth exploration and research are made in terms of large-format expansion methods,adapted three-dimensional model slicing methods,seam elimination methods,and equipment remote maintenance.The main contents of this thesis are as follows:(1)Aiming at the problem of small forming size of 3D printers based on DLP,a mobile splicing forming scheme is proposed,which moves the DLP projection device horizontally to expand the forming size.Compared with the method of using multiple DLP devices to combine projections,the solution has lower hardware cost and less installation and maintenance work.The 3D printing control system designed and implemented based on this scheme has laid the foundation for the software and hardware platform for the subsequent research.(2)In view of the requirement of slicing in splicing forming and the problem of filling STL model's slicing contour,a STL model slicing method for splicing for splicing forming is proposed.The contours are filled according to the voxel quantization information of STL model,which improves the accuracy of slice results.According to the needs of mosaic printing,each slice bitmap is divided into several small-sized unit bitmaps,which can be directly projected.It provides good support for large format splicing 3D printing control system.(3)In order to solve the problem that the model printed by splicing method is easy to have seams,this thesis proposes a method of eliminating seams by staggering and spreading equally.The method of eliminating seams by staggering and spreading optimizes the 3D printing process of model slice processing and moving splicing printing,so that the seams of adjacent layers are staggered with each other,which can effectively improve the quality of large-scale model products.(4)According to the requirement of remote maintenance of 3D printing equipment,a remote update scheme based on NB-IoT is designed,which overcomes the high cost made by traditional maintenance schemes such as on-site debugging and loading program.The scheme adopts response mechanism,breakpoint continuation mechanism and frame loss retransmission mechanism to improve the stability and reliability of remote update.It can provide reference for the remote update and maintenance of automation equipment.The large-scale 3D printing control system based on DLP technology developed in this thesis has entered the stage of small test,and the system is operating normally.