Application of error compensation technology for positioning precision of hydrostatic rotary table based on UMAC

Compensation of the positioning error caused by external uncontrollable factors is an important issue for studying the hydrostatic rotary table in the closed loop control of 5-axis ultra-precision machine tool. In order to solve the problem, improve the surface roughness and the dimensional accuracy of the parts, the paper proposes a hardware platform based on the UMAC (Universal Motion and Automation Controller), drive and IPC (Industrial Personal Computer). High-precision detection method with laser interferometer is used to measure and assess the positioning error of the turntable under closed loop control so as to establish error compensation table. The algorithm of UMAC inserted is used to compensate the positioning error in real time. The experimental results show that the UMAC error compensation function improves the hydrostatic rotary table positioning accuracy (up to ±2").