Planning and Implementation of Motion Trajectory Based on C2 PH Spline

• Main Authors: I-HanLiu, 劉懿涵
• Other Authors: Ming-Ching Tsai
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/06307269126426222753

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 98 === Contour error reduction is an important issue in today’s industrial manufacturing systems. Thus, modern machine tools are required to provide high-precision and high-efficiency contour machining capabilities, particularly when machining complex contour shapes or sharp corner angles. Generally, poor machining performance may occur due to the abrupt change of acceleration at the portion of the curve with larger curvature. To cope with this problem, a modified trajectory planning scheme based on PH (Pythagorean Hodograph) curve is proposed for sharp corner angle contouring tasks. The scheme is developed according to simulated system dynamic response, estimated contour error, and a pattern search algorithm to construct a modified sharp corner contour by using C2 PH quintic spline curve. The main advantage of the proposes scheme is that it can force the actual cutting trajectory moving closer to the original command path by exploiting a modified command trajectory at sharp corner contour in advance. Therefore, the corner contouring accuracy can be further improved. Finally, to evaluate the effectiveness of the proposed approach, several different sharp corner contour following experiments were conducted. The experimental results indicate that the proposed approach can indeed reduce contour error in sharp corner angle contour following applications.