How to Eliminate Vibration of CNC Lathe?

There are many reasons for the oscillation of CNC machine tools. In addition to the mechanical factors such as transmission clearance, elastic deformation, friction resistance, etc. that cannot be eliminated, the influence of the relevant parameters of the servo system is also the focus.

1. Reduce the position loop gain

The proportional integrator is a multifunctional controller. It can not only effectively perform proportional gain on the current and voltage signals, but also adjust the output signal lag to advance. Oscillation failure is sometimes caused by the lag of the output current and voltage. At this time, the output current and voltage phase can be adjusted by PID.

2. Oscillation caused by closed-loop servo system

Some CNC servo systems use semi-closed-loop devices, and the full closed-loop servo system must adjust the parameters under the premise that the local semi-closed-loop system does not oscillate, so the two are similar.

3. Use high-frequency suppression function

The above discussion is about the parameter optimization method for low-frequency oscillation. Sometimes the CNC system will produce high-frequency harmonics in the feedback signal due to some mechanical oscillation reasons, which makes the output torque unstable and produces vibration. For this high-frequency oscillation, a first-order low-pass filter link can be added to the speed loop, which is a torque filter.