High precision and full digital servo system.

This paper reports new servo control technology to realize high precision and high speed machining of machine tool. The conventional analogue servo control technology, due to its generic errors such as non-linearity, offset (drift) and insufficient resolution, has its limitation in high precision and high speed machining. A full digital servo control method, a high resolution absolute position encoder and brushless servo motors have been developed and the high resolution of 0.1 μm and high speed machining of 56 m/min have been achieved.