Research on the simulation system of nc milling

Based on the features of NC milling process, the 3D geometric model of virtual machine tool and the fixture are established by the virtual reality technology and OpenGL graphics library with the method of Construction of Solid Geometry(CSG) and Boundary Representation(B-Rep), and some realistic effects treatments(including material, light, texture mapping, etc.) are applied. The established virtual machine tool can be zoomed, rotated and translated in the view area. And a workpiece decomposition expression model based on the Z-MAP structure is put forward, and Boolean subtraction is performed by using this model and a tool solid model to simulate the real time process of cutting and test the simulation result. Simulation example proves that this system runs reliably and improves NC machining efficiency.