Process of 1 foreword CNC Machining is implicit in numerical control program, the mistake in numerical control program discovers not easily, often use contrail of cutting tool of computer graph simulation to show law and machine tool try the logarithm that cut a way to accuse a program to have desired result at present, but both is faulty. Contrail of cutting tool of computer graph simulation shows the law lacks sense of reality, the interference of cutting tool and workpiece and cut too discover hard; Try the cost that cut a way tall, cycle is long. Fictitious processing technique is to point to numerical control machine tool the map in fictitious environment, theory of numerical control of its collect production technology, machine tool, CAD (CAD) , CAM (CAM) and build model and emulation technology at an organic whole. The person can feel the fictitious environment of the three-dimensional emulation model that the computer produces by intuition, when devise new plan or changing plan, can be in true the fictitious design that makes the machine tool of ongoing travel numerical control that move, the CNC Machining of the spare parts undertakes in fictitious environment, try to examine to numerical control program, the appears possibly collision in examining CNC Machining process, interference is dangerous, analyse the rationality of the machinability of the spare parts and working procedure. The adoption of fictitious processing technique can shorten the development cycle of the product, reduce manufacturing cost, improve product quality and manufacturing efficiency. Graph 1 construction of system pursues on the foundation that 2 construction of system study in technology of domestic fictitious machine tool, the author is right of CNC Machining process visible undertook study, summary gives the initial executive plan of a fictitious processing technique. This system is development platform with Windows98, use Visual C++ software and OpenGL of interface of standard of three-dimensional graph software to be a tool, preliminary the process that designed whole and fictitious treatment. The system that we design uses diagnostic modelling means, construct namely with spare parts, cutting tool and model of clamping apparatus product treatment process, treatment the process regards a 4 dimension as spatio-temporal, namely space dimension of time of three peace keeping. The system basically comprises by the following module (1) seeing a picture: Fictitious treatment environment: Fictitious treatment environment is formed by machine tool, workpiece, cutting tool and clamping apparatus, use OpenGL and AutoCAD to have diagnostic model to machine tool, clamping apparatus, cutting tool and workpiece. Fictitious treatment process: This module includes coding of numerical control program, three-dimensional animation to emulate, statistic of man-hour of analysis of precision of collision interference examination, treatment, treatment analyses 5 module. CNC Machining process is emulated include geometry to emulate emulate two parts with physics. Geometry is emulated regard cutting tool and part as rigid body, take no account of force of cutting parameter, cutting and other element to be affected to what cutting machines, just undertake an interpreter to numerical control program, generate data of cutting tool position, use component of machine tool motion and tool carrier campaign with this data drive, cutting tool undertakes fictitious cutting to workpiece, whether does the examination have collision, interference at the same time. Physics is emulated include to machine precision analysis, the heat of cutting process is out of shape, the systematic flexibility below cutting strength effect is out of shape, clamp is out of shape, and analysis of the trends of the machine tool, static state. Process of CNC Machining of 3 systems implementation is emulated include to machine concealed of disappear of environmental data description, graph and animation to show wait for each parts. Will be opposite below the implementation of a few bodies undertakes discussion. The data that processes an environment describes lathe of numerical control of double tool carrier to realize much knife to undertake machining at the same time, treatment environment is complex, the graphical tool with can strong, tall efficiency checks this requirement have rendered great service its have a description. OpenGL makes medium excellent performance in graph of three-dimensional sense of reality, make it already became the interface of software of three-dimensional computer graph of standard of new generation industry. Use it to be able to have a description to machining an environment conveniently. The graphical library of OpenGL besides offer main geometrical essential factor (dot, line, polygonal, image, bitmap) outside scale function, also offerred the three-dimensional object with complex scale (like ball, awl, polyhedron) and complex curve curved surface (like Bezier, nurbs) scale function, on this foundation the architect can build complex three-dimensional model, can install qualitative attribute of illumination model and material in order to create clearer image. To machining the more complex three-dimensional graph part in the environment, use AutoCAD, software changes his the data pattern that is OpenGL related repass. The indication list of OpenGL is a very useful tool, it is cache of a series of jussive high speed that can carry out repeatedly. These OpenGL commands carry out a memory to all jussive its are final result, because this can avoid,a large number of time are wasted in plot process. The partial definition that OpenGL replaces suspension points with following statements shows list for: GlNewList (listIndex, mode): . .
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GlEndList(); is opposite for example all directions tool carrier of numerical control machine tool (2) seeing a picture, if a few identical cutting tool are drawn in the computer, as a result of every scale a cutting tool needs much consideration and waste time. If use indication list, openGL needs scale only a cutting tool, with respect to meeting scale the cutting tool of likeness of structure of other principal part, saved time consequently. The purpose of concealed of disappear of graph of graphical disappear concealed is the sightless part in find out and eliminating the object that should show, in order to enhance graphical authenticity. OpenGL itself provided this one function, examine through deepness namely. Every resembles element deepness on screen, namely point of observation and the distance that resemble element protect existence deepness buffer (in Z-Buffer) , but the distance of basis resembling element and point of observation, with closer enclothe like element further like element, achieve the goal of concealed of curved surface disappear. User of a lot of personal computer is added now installed OpenGL graph to quicken card, huge increased the capacity of disappear concealed. Of the implementation computer animation of animation generate normally two kinds make way, one kind is the animation that chase frame, another kind is real time animation. The animation that chase frame is when the computer every make an appearance, it with respect to seasonable ground the record comes down, insert all pictures continuously again finally put, its advantage is to show rate is rapidder, but cannot change interactively according to the requirement of the user, applied scope is less. Real time animation is to be calculated at the same time produce animation directly on computer terminal at the same time, the advantage is alternant ability strong, can change a picture in real time according to the requirement of the user, but to the graph of the computer processing capability raised taller requirement. According to the analysis of above, what union makes a task the requirement of alternant sex, we use means of real time animation. Animation of the implementation in OpenGL comes true with double cache area, show buffer and tiring-room show buffer downstage namely. When tiring-room buffer carries out current scale to command, undertake in downstage indication buffer the graph shows, enhanced lathe of numerical control of double tool carrier to machine a process so what three-dimensional animation shows is successional feel with motion. Graph emulation graph of process of 2 fictitious CNC Machining is shown 2 times is process of CNC Machining of a double tool carrier is emulated, can be clear about by the graph see slick surface is machining the metal the Gao Guang that forms in the process is taken, the administrative levels that the brightness that the shadow that illuminant place forms each objects in setting and object surface resemble element every is worth alone computation place to form feels, make emulation degree more distinct. The sex of characteristic easy transplanting of 4 systems: Although this system is developed on Windows98 platform, but use OpenGL to make a figure, it is mixed at window system independently control system, accordingly very convenient be inning moves between all sorts of platform value. Define a gender oneself: Because this system uses seesaw pattern design, allow an user to specific requirement chooses or modify treatment environment structure by oneself, because of the demand of this contented user of great limit. Authenticity: Because introduce hypostatic model, combine a series of special processing such as illumination, grain, color, make emulation treatment environment more adjacent and real. Easy development sex: The use of OpenGL, make the process designing quantity of systematic graph decreases, developer need not master many graphics knowledge, and the algorithmic issue that can focus energy control difficulty. Lathe of numerical control of 5 summary double tool carrier, because use much knife treatment, treatment process is complex, this development of emulation system has economic value, can improve manufacturing efficiency not only, the move since the application that also is technology of machine tool of virtual numerical control and development urges action. CNC Milling
CNC Machining