Mechatronic Modeling and Analyzing for Feed Servo Control System Based on Torsion Dynamics of Lead-Screw

Dividing the rotor-screw system of machine tool into a multi-degree-of-freedom torsion system, this paper educes the transfer function model of the mechanism including torsion vibration modes of the first two orders. Consequently, a mechatronic model of servo control system of feed drive including lead-screw torsion vibration is built. Based on this model, the simulation comparisons of dynamic characteristics of the servo control system are analyzed considering the effects of the acceleration of the system input, the position loop gain and the nature frequencies of torsion vibration. The results demonstrate that the torsion vibration limits the acceleration of the system input and the position loop gain. After that, the influences of increasing nature frequencies of the torsion vibration modes on the fluctuations of angle velocities are analyzed. It is found that the first torsion vibration mode (mode 1) plays a major role in the velocity fluctuation and increasing the nature frequency of the mode 1 can improve the dynamic performance of the system.