Study On Three-axis CNC Milling Simulation Algorithm Based On Dispersion Modeling

NC machining simulation is a mapping of NC machining process in the virtual environment. As an important part of virtual manufacturing, NC machining simulation can be applied to verify the correctness of NC program and whether the work-piece has been over-cut or missed cut and so on. So, it has great practical significance in product development cycle shortening.Based on sufficient analyzing the existed three dimensional simulation theories and methods of domestics and abroad, the dispersion modeling technology is introduced into NC milling simulation modeling in this dissertation. The NC mill simulation method which contains the modeling of milling environment shapes based on triangle mesh dispersion modeling method, cutting tool and work-piece intersection algorithm based on cutting tool path bounding box, and simulation optimizing algorithm based on display list and vertex searching algorithm, and the key technologies of the above methods are researched deeply.(1) Based on the advantage and disadvantage of the common geometrical modeling method, and aimed to the characteristics of 3-axis NC milling, the 3-axis NC milling simulation modeling method which based on dispersion modeling is presented. And the principle of 3-axis NC milling simulation which considered both the effect and efficiency is presented, and the structure of 3-axis NC milling simulation system is built based on the above simulation principle.(2) By sufficient comparing all kinds of dispersion modeling methods, the dispersion modeling method which based on triangle mesh is introduced into NC milling modeling, and the models of work-piece and cutting tool is established by this method. The data structure of work-piece model and cutting tool model which can both satisfy the need of NC milling simulation and enhance the storing and visiting efficiency is built accordingly.(3) In processing the intersection of work-piece and cutting tool, the dispersing point searching field is shortened deeply by introducing the cutting tool path bounding box. The display list technology is applied to store the dispersing point of the work-piece, so the dispersing point of the work-piece un-cut zone can be visited directly, and in turn the efficiency of geometric modeling is improved. The vertex searching algorithm is presented to search the cut dispersing point of the work-piece, and the searching efficiency of the dispersing point in the cutting tool path bounding box is increased accordingly.