R-Test Analysis Software for Error Calibration of Five-Axis Machine Tools – Application to a Five-Axis Machine Tool with Two Rotary Axes on the Tool Side –
Soichi Ibaraki*,†, Yu Nagai*, Hisashi Otsubo**, Yasutaka Sakai***, Shigeki Morimoto***, and Yosuke Miyazaki***
*Department of Micro Engineering, Kyoto University
Katsura, Nishigyo-ku, Kyoto 616-8540, Japan
**Otsubo Engineering Research Center, Fukuyama, Japan
***Fukuda Corporation, Tokyo, Japan
The R-test measures the three-dimensional displacement of a precision sphere, attached to a machine spindle, by using three displacement sensors fixed to the machine’s table. Its application to error calibration for five-axis machine tools has long been studied. This paper presents software for analyzing the measured R-test trajectories for error diagnosis and numerical compensation for rotary axis location errors and error motions. The developed software first graphically presents the measured R-test trajectories to help a user intuitively understand error motions of the rotary axes. It also numerically parameterizes the rotary axis geometric error parameters, and then generates a compensation table that can be implemented in some latest-generation commercial CNC systems. An actual demonstration of its application to a five-axis machine tool with a universal head (two rotary axes on the spindle side) is presented.
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