Research On Automatic Programming Technology Of Trajectory For Stone Five-axis CNC Tool

With the extensive use of stone,especially the use of special-shaped stone,it makes the traditional manual,semi-automatic processing methods have been unable to meet the needs of consumers on the stone precision and shape.Therefore,five-axis stone CNC machining center,especially the bridge structure processing center whose processing range is larger and processing tool is saw blade mainly,begin to be used in the stone industry for the processing of marble,granite and other complex surface.But the majority of existing general CAD/CAM software generated processing code for milling cutter,the structure of saw blade is so different from the milling cutter’s that the stone processing process must be considered,and thus the general CAD/CAM software is difficult to get a wide range of applications in the stone processing market.The CAD/CAM software is an important tool for the improvement of automation level of products and competitiveness of products,which also seriously hindered the development of China’s stone industry.In order to solve the above problems,this paper develops corresponding program to realize the automatic generation of the processing code through research on some issues in stone processing and theoretical knowledge related to the five-axis machining.Firstly,this paper creates corresponding data structure to achieve the storage and extraction of data from Auto CAD graphics exchange file through the object-oriented thinking.Based on the single document application program to create a graphical interface application software,build Open GL three-dimensional simulation environment,extract two-dimensional plane data and splice the plane graphics into a three-dimensional line model in Open GL environment display,realize translation function for observation of the line model in different positions to make the simulation process more intuitive.Then,build parameter settings dialog box for the corresponding processing module to achieve the interactive settings of blade and cutting parameters.Analyze the relative position of geometric elements commonly used in CNC machining that are line,arc and circle,and bias the generated model to produce a roughing/finishing cutting path.The generated roughing path is optimized to reduce the empty travel stroke by keeping the trajectory in the rough rectangular area and projecting the trajectory outside the area onto the rough rectangle.Finally,the trajectory needs to be optimized by the track point correction,and calculate the blade center coordinates and saw blade rotation angle for the output of NC processing program.In the above study,what we put forward include the method of creating a three-dimensional line model based on two-dimensional contours,the minimum distance intersection algorithm of the contour offset trajectory based on the unit normal vector,the trajectory intersections algorithm based on the relative position of the blank,the generating algorithm of cutting trajectory based on the bottom polygon shape and the generating algorithm of orthogonal cutting trajectory based on saw blade rotated angle.Through the above research and design of related algorithms,Visual Studio 2013 is used as the development tool to carry out the development of the five-axis stone tool path trajectory automatic programming program and simulate the generating trajectory.And verify the feasibility of program by the physical cutting with the generated processing code.