Research On Numerical Control Simulation Technology For Subdivision Surface Based On Multi-resolution Mesh Segmentation

Numerical control machining simulation technology is the key technology in numerical control machining system.It can not only verify the correctness of tool path and the feasibility of machining program,but also analyze and calculate the geometric machining error of workpiece.In order to deal with the workpiece processing "overcut" and "undercut" problem.With the development of advanced manufacturing industry,machining parts become more and more complex,numerical control machining simulation technology also put forward higher requirements.Compared with the traditional NUBRS modeling method,subdivision surface modeling method can efficiently construct smooth surface with arbitrary topology structure without the operations of intersection and clipping.And the essence of the discrete grid is more convenient for the calculation of nc machining tool path and the implementation of nc machining simulation.In view of the advantages of subdivision surface model in complex surface design and manufacturing,subdivision surface has been widely used in animation,film and television production,CNC machining and other fields.However,there are few researches on numerical control machining simulation technology of subdivision surface.Therefore,this paper uses the multi-resolution characteristics of the subdivision surface and Catmull-Clark subdivision surface to study the related issues of numerical control machining simulation.The specific research content is as follows:(1)Study on the Catmull-Clark subdivision surface numerical control machining simulation blank model establishment method.According to the data of the machining model and the z-map method,the cuboid rough model is established to surround the machining model.Encrypting the mesh on the surface of the blank model,according to the different precision of the model in different processing stages.Proposing multi-resolution refinement method of blank model.(2)Study on the mathematical expressions of three kinds of cutters,such as annular milling cutters,ball end milling cutters and flat bottom milling cutters,the parameterized representation method of the three kinds of cutters(3)Study on three methods of cutting blank with cutting tool in real time.Constructing annular milling cutter,ball-end milling cutter and flat-bottom milling cutter according to the cutter geometry,and constructing three kinds of the cutter scanning bodies.(4)Study on the error analysis method of machining model.The main problem of error analysis is to calculate the nearest distance between the blank model and the machining model quickly.Based on subdivision surface multi-resolution mesh segmentation,combined with bounding box detection technology.Study on the method of searching the closest distance between the spatial point and the machining model.Finally,through algorithm verification and machining experiments,the practicability and feasibility of the numerical control machining simulation algorithm proposed in this paper are verified.