A Parametric Interpolator with Minimal Contouring Position Errors for NC Machining

• Main Authors: Shao-En Sun, 孫紹恩
• Other Authors: Wei-Hua Chieng
• Format: Others
• Language: en_US
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/89978767152158908242

碩士 === 國立交通大學 === 機械工程系所 === 94 === In modern CAD/CAM systems profiles or curves for parts like dies, vanes, aircraft turbines, shoes, mobile phones, etc., are usually represented in parametric forms. As conventional CNC machines only provide linear and circular interpolators. The parametric curve is approximated by a lot of line segments and sent to CNC systems. It causes a lot of computer memories. Thus, it is necessary to embed the parametric interpolation inside CNC machine to achieve real-time parametric interpolation. There are a lot of researches about parametric curves, like position interpolation, constant speed interpolation, acceleration and deceleration control, reducing the chord error, and or concerning about the arc length of the curves. But these researches didn’t consider the issues of both achieving minimal chord error and maintaining the constant speed. This article proposes a method to decrease the chord errors while maintaining a constant speed under a radial error. The simulation and the experimental results show that the proposed method effectively improves the interpolation accuracy in terms of the contouring position error and maintains speed accuracy at the specified level.