Study of Error Measurement and Compensation Systems for CNC Machine Tools and Micro Machine Tools

• Main Authors: Shih-His Liu, 劉世喜
• Other Authors: Shih-Ming Wang
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/92866931650314102446

碩士 === 中原大學 === 機械工程研究所 === 99 === For general CNC machine tools, the volumetric error measurement and compensation can further enhance its machining accuracy without increasing manufacturing cost. According to the manufacturing demand of miniature parts, the non-MENS micro machining technology with characteristics of ultra-high accuracy and small workspace, also needs error measurement and compensation technology to improve its machining performance. However, due to the limitation of workspace of micro machine tools, the current measurement method currently used in industry cannot be applied. In this study, the volumetric error measurement and compensation method for general CNC machine tools and the machining error measurement and compensation method for micro machine tools were developed. For general CNC machine tools, with use of Single Socket Method and Element free method a complete system with friendly human-machine interface that can perform error measurement, prediction, and compensation was developed. For micro machine tools, with use of image filtering, edge identification, coordinates transformation, and image comparison method, an error measurement system which can on-machine inspect the machining error directly from the workpiece was developed, and an automatic NC-code identification/rewriting system was also developed for generating the error-compensated NC codes for production. The proposed method resolves the drawback of the previous method developed by our lab which cannot measure the errors of contours with different heights. Besides, a new image comparison method which provides better computation efficiency was also proposed. The experimental results have shown that the proposed method can further improve machining accuracy 62.7% for a CNC machine tool, and 52.3% for a micro machining tool.