Study in Control of Thermal Errors and Compensation for Machine Tools

• Main Authors: Ming-Shiung Chang, 張銘雄
• Other Authors: Yuan Kang
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/q859q3

碩士 === 中原大學 === 機械工程研究所 === 91 === Because the high speed and high precision machining of the machine tools, the structural thermal expansion errors due to the spindle rotation and the variable environment temperature are the main factor that influence the machining accuracy of the machine tools. Hence, the computer compensation techniques for thermal expansion errors of CNC machine tools have received significant attention recently. In the research described in this paper, a real-time thermal errors compensation system on a vertical machining center was developed to reduce the thermal errors of machine tools. For this purpose, a precision measuring instrument be established to measure temperature variation and thermal errors on machine tools. A mathematical model is then derived, based on the sensed temperature variation and the thermal errors by Moving Average (MA) and Auto-Regression Moving Average (ARMA). A robust compensation modeling approach is also obtained by change the fixation and location of temperature sensors. A single chip and a PC based error compensation scheme has also been developed to connect a FANUC CNC controller for real-time compensation. And shift the zero point of the machine coordinate system to reduce the thermal errors for a vertical machining center. The experimental results show that the technology can successfully reduce the thermal errors from 60 μm to ±10μm for y axis in 16 hours, and from 30 μm to ±10μm for z axis.