Design And Nc Machining Simula Tion Of Freeform Surface In Ug

From the given points on the freeform surface, the paper presents a method to generate a NURBS surface by calculating the control points. The surface is analyzed based on its engineering applications and the new points that should be on the surface are obtained. The new control points are calculated by comparing the new points on the surface with the given ones. Then the modified surface is generated. The menu and the dialog boxes were developed and functions mentioned above were added into UG system, so that the machining simulation, the generating of the cutter location file and the NC code could the carried out by using the functions of UG system.The outlines of the paper are following: 1. The coordinates of given points are read and processed first, and then the control points are calculated based on the given points by using the method called bi-curve inverse calculation. 2. The original surface is analyzed from the viewpoint of its applications and the new points on the surface are obtained. 3. The new points are compared with the original given points and the new control points are determined. The new surface is generated. The steps maybe carried out repeatedly until the surface can meet the requirement of application. 4. The machining parameters are determined based on the data of the surface and the machining precision. The machining simulation, the generation of cutter location file* machine tool data file and the NC code are carried out by using the modules in UG such as UG/CAM, MDFG and UG/POST. The software system is developed with VisualC++6.0 and is added into UG. The interface betweens UG and the software are developed so that the functions mentioned above can be carried out interactively.This paper presents a method of the control points inverse calculation of NURBS surface -, surface design and modify which is feasible, and melt it into the UG system. Those modules can remarkably advance the function of surface design in reverse engineering and efficiency of surface modify.