Research On NC Machining Simulation System Based On Three-Dimensional Entity

Simulation technique of NC machining is adopted not only in real production but also in training. In this dissertation, NC machine tool is the main research object. The theoretical methods and key techniques of NC machining simulation system are studied. On the basis of simulation and modeling theories of machining system, the NC machining simulation system based on three-dimensional entity is developed, associated with the principles of computer graphics technology and simulation technology. The main content of this dissertation is as follows: 1. The general structure of NC machining simulation system based on three-dimensional entity is proposed according to the function requirements of the NC machining simulation. Moreover the models in the system are designed on the whole. 2. The analyzing method of NC code that coincides with the international ISO standards is studied. In terms of programming criterion of FANUC system, the dissertation proposes and realizes the theory of compiling and explaining NC code, verification methods of NC code, and interpolation algorithms of NC instruction in machining simulation process. And the NC cutter location information file is produced to drive NC machining simulation system. 3. Based on the analysis of the characteristics of structure and movement, hierarchy modeling methods are applied to geometric modeling and the movement modeling of NC machine tool so as to represent, display and process movement of NC machine tool more accurately. 4. The significance of some databases is discussed in NC machining simulation system. The methods of building and managing these databases are suggested. 5. The flow structure of NC machining simulation is analyzed. The 3-D solid representation models and their data structures of machined parts are presented based on the characteristics of turning and milling processes. Upon both structures, the algorithms for detecting the collision and intervention between machined part and cutter in simulation are studied. 6. Based on the results of the study, 3-D simulation of NC machining is implemented. The machining process is realized dynamically on screen to carry out automatic NC program verification.