Research On Virtual NC Turning System Based On Parametric Feature Modeling

The virtual NC technology, which was put forward in 1990's, is a new research field with the development of Virtual Manufacturing (VM), and it's one of the key technologies of VM. NC turning is one of the most widely used machining methods. The research on the virtual NC turning technology is gradually becoming a focus in the world because of its wide application prospect and practical application value.By deep studying and analyzing the present situation and related techniques of virtual NC machining technology, the practical virtual NC turning system based on Visual C++ and OpenGL is established. The general structure of system is built in modular thinking, and the functional modules in the system are designed. The key technologies in the system, such as parametric feature modeling, the main algorithm, processing simulation and so on, are made a detailed analysis.Aim to the disadvantage of the current geometric modeling, such as the large data volume, complex Boolean operations, the poor real-time etc, the parametric feature modeling method is introduced to establish the 3D geometrical model of turning environment and turning feature firstly. Moreover the geometric features of the machining parts are described in detail by the method. After establishing the feature library, the processing geometrical model is built by the geometric elements in the feature library. This method accelerates the speed of solid modeling.Then according to the system function, the NC code is read by using LEX language to get the cutting tool path data. The dates of the processing information file are generated after intersection operation between the cutting tool path and the processing feature model. The frame animation technology is applied to the realization of the simulation process finally. The animation display problem of the moving cutting and the real-time changing work piece in the processing simulation can be better solved through controlling the key parameters of the work piece diameter and the length.The virtual NC turning system has showed that it has good real-time, effective interaction and visualization of 3D graphics, and it avoids the complicated Boolean arithmetic. So the speed and quality of the simulation can be guaranteed...