Research On Algorithm Of3D Anti-collision Detection Based On Multi-axis CNC Milling Machine

The NC machining simulation indicates a mapping of NC machine tool in the virtual environment, and it integrates the technique of manufacture, the control theories of NC machine tool, CAD, CAM and the technique of modeling and simulating. Prior to actual NC machining, NC simulation system can simulate the process of NC machining, to verify NC programs and machining parameters. Thereby the intention, abridging the time of developing products, depressing the cost of manufacture, advancing the quality of products and the efficiency of production, can be finally achieved.This paper mainly studies the process of multi-axis CNC milling and analyzes the overall structure of CNC simulation system. The interface of CNC simulation system is designed with MFC, and arbitrary projection of CNC machining process is achieved through OpenGL to improve the quality of the graphics display and human-computer interaction performance. STL files are used to import three-dimensional geometric model data, and the geometric models of CNC simulation system are displayed with triangular facets. Light, material properties and hidden lines are employed to enhance realistic effect of graphical display. To speed up graphical display of CNC simulation system, key technologies of OpenGL, such as display list and double buffer mechanism, are introduced to simulate CNC machining process.In the paper, the Dexel structure, adopted to build simulation models, can simplify boolean operation between entities into one-dimensional subtraction, in order to improve the efficiency of removing material. In the process of converting geometric model to Dexel model, fast intersection algorithm is proposed to boost generation of Dexel model of entities.At the end of this paper, NC program module is designed, through which NC program can be directly edited and saved. NC program is compiled into tool motion information which drives the tool in CNC machining process.