System Modeling And Experiment Of Gum Line Autom-Atic Extraction And Nurbs Interpolation Programming

Teeth are not neat,which not only affects beautiful,there are many health problems.Stealth orthotics,in recent years the rise of people’s favor,has become the hottest industry in the field of oral health care.Required for the production of stealth orthotics along the gum line(lines of teeth and gums)cutting teeth hot-pressing model,its core technology is the gum line data extraction and processing code generation.Now the technology still relies on manual tracing point extraction individually,but low efficiency,poor accuracy,and the problem of low efficiency.Therefore,how to automatically from teeth in the 3d model to extract the gum line processing file and generate dao road has become a research focus in the field.In order to improve production efficiency,ensure the quality of processing,and address the pain points above problems,the author of this paper,from the perspective of medical application,this thesis proposes a gum line automatic extraction and orthotics integrated processing system,the main research content is as follows:(1)Contact orthotics automation processing technology is proposed.First,noise in point cloud type and k neighborhood search method determines the removal point cloud discrete points and search method of optimal path distance.It was then based on the NURBS curve fitting theory,using the technique of different parameters to the same set of values point was calculated and the fitting,choose the optimal method of fitting parameters.Then combined with the characteristics of five-axis linkage and high-end CNC machine tool system,analyze and identify the automation processing technology of this invisible orthotics and gum line NC code automatically generated.(2)In view of the gum line extraction accuracy of low degree of automation and problems,this thesis proposes using a triangular mesh mixed with point cloud processing gum line automatic extraction technology.Through the calculation of the curvature of teeth triangular mesh model data type,get the curvature of tooth model features.Based on the curvature threshold selection,and computer graphics processing,the extract contains the gum line feature of the data area and removes the isolated location;preliminary messy transparent boundary data are obtained.Further,in order to more accurately extract the gum line,converting triangular mesh suitable data point cloud types,removing the discrete points,strengthening the boundary extraction and custom path search,finally got a closed circle and orderly gum line data points,which can be generated gum line nc code for subsequent data provide firm support.(3)In view of the gum line processing code generation of complicated issues,it is based on the characteristics of the five-axis machining and programming environment to develop a numerical control code automatic generation module.First of all,through the analysis of the processing characteristics,using NURBS interpolation,the gum line of discrete data points,to close the infinite small line segments in the theory of the gum line.Then through carries on the error analysis,extracted from the gum line to ensure reliability and accuracy,and to generate the data point vector as the knife axis,the I,J,K vector is studied,and the cutter axis vector conversion relationship between machine tool rotary table generated the identifiable five-axis linkage machine tool nc machining code and designed the program compiled automatically processing software modules.(4)They completed the gum line automatic extraction and integration of the orthotics processing experiment.To automatically extract the gum line as the research object,first of all,based on the post-processing of nc code file,using VERICUT numerical control simulation software to verify the feasibility of processing code.Then use five-axis linkage droplet spray experiment platform is completed,and the opponents move the trajectory of the gum line extraction and automatic extraction of inkjet printing,verifying the accuracy of the gum line automatically extracting the data.Analysis based on the gum line character of the optimal process parameters,using five-axis machine tools to complete the gum line automatic extraction and integration of teeth orthotics processing experiment.The experimental results show that the automatic generation of tool path processing speed occupies less computer memory,feeding step length distribution uniformity,and high processing efficiency,which proves the feasibility and validity of this study.