Research And Development Of Web-Based Virtual NC Milling System

In order to meet the requirement for the development of advanced manufacturing, the thesis deals with the virtual manufacturing technique by means of virtual reality technology, cyber-network technology, metal cutting theory and NC processing technology, etc. Emphases are placed on the key technology of web-based virtual NC milling system. The contributions may be summarized as follows.(1) Establishes a model of virtual NC milling machine and 3D milling scene by using 3DS MAX and VRML based on the practical NC milling system.(2) Constructs and implements the depth element (Dexel) based blank modeling method suitable for VRML language by considering the characteristics of VRML and using the dexel-based representation. To the general cubic blank, the combination method of IndexedFaceSet node and ElevationGrid node is adapted, and to the cylinder blank, the Extrusion node is utilized, which can farthest simplify the amount of calculation.(3) Realizes the interaction between Java Applet and VRML scene by applying the external authoring interface (EAI) of VRML. Java Applet is used to build control interface, complete the examination and compilation of NC codes, and transfer the processing data to VRML scene at the same time, while VRML is used to build machining scene, control the worktable movement and show the real-time changes of workpiece according to the received data, and also return the data of interest such as tool coordinates etc. to the control interface at the same time.(4) Develops a Web-based virtual NC milling system, and sets up the network environment based on Tomcat service platform, which makes users vividly operate the virtual NC machine tool through Web browser. In the meantime, under a certain machining condition, the data of interest to users such as milling force and milled surface topography can be acquired through the corresponding simulation models given, according to which the reasonability of the process parameters can be evaluated.The work in this thesis lays a solid foundation for improving the virtual manufacturing theory and developing more perfect and applicable web-based virtual NC milling system.