An application of computer vision for programming computer numerical control machines

Abstract

Generation of the part programs, or tool paths, for products to be manufactured by computer numerical control (CNC) machines is very important. Many methods have been used to produce part programs, ranging from manual calculations to computer aided design/ manufacturing (CAD/CAM) systems. This work introduces a new technique for generating the part programs of existing products using the latest technology of computer vision. The proposed vision system is applicable for two-dimensional vertical milling CNC machines and is calibrated to produce both metric and imperial dimensions. Two steps are used to generate the part program. In the first step, the vision system is used to capture an image for the product to be manufactured. In the second step, the image is processed and analysed by software specially written for this purpose. The software CNCVision is fully written (in lab) using Microsoft Visual C++ 6.0. It is ready to run on any Windows environment. The CNCVision software processes the captured images and applies computer vision techniques to extract the product dimensions, then generates a suitable part program. All required information for the part program is calculated automatically, such as G-codes, X and Y coordinates of start-points and end-points, radii of arcs and circles and direction of arcs (clockwise or counterclockwise). The generated part program can be displayed on screen, saved to a file or sent to MS Word or MS Excel. In addition, the engineering drawing of the product can be displayed on screen or sent to AutoCAD as a drawing file.