The high-frequency and high-precision machine tool motion axis location information can be used to fit the machining trajectory of the machine tool accurately

which is the foundation of dynamic error monitoring and dynamic machining accuracy evaluation. Aiming at the problem of acquiring high-frequency and high-precision machine tool motion axis location information

a method of high-frequency high-precision real-time acquisition for the motion axis of five-axis machine tool was put forward. This method based on gathering and analyzing the signal of the CNC servo system position loop for getting the high-frequency original position information. And then

compensate the linear errors and using homogeneous coordinates transformation which considers the rotary errors after the high-frequency original position information was transformed to coordinate values. The acquisition method was verified on a DMU 80P five-axis machine tool with Sinumerik 840Dsl system. The test indicates a conclusion that five-axis synchronous acquisition frequency reaches 1kHz

compared with the precision of the static location

linear axis acquisition precision reaches ±2μm and rotary axis acquisition precision reaches ±0.0025°.