No More Worries About Machine Tool “Shaking”! Complete Guide to Solving Low-Frequency & High-Frequency Oscillations on FANUC 0i System in Semi-Closed Loop Mode
Is your machine tool suddenly “shaking” during operation? This not only severely affects machining accuracy but also accelerates equipment wear—something that frustrates many engineers! Don’t panic! Whether it’s low-frequency or high-frequency oscillations, identifying the root cause and applying targeted adjustments can make your machine run rock-solid again. Today, we’re sharing a practical parameter tuning guide based on the FANUC 0i system. Save it for future reference!
I. Low-Frequency Oscillation (Intermittent, Rhythmic)
Symptoms:
Low-frequency vibration with a noticeable regular pattern, typically occurring during acceleration/deceleration or sudden load changes.
Solutions:
1. Lower the Position Loop Gain
Parameter 1825 controls the position loop gain. The default value is 3000. Reducing this parameter can effectively minimize overshoot in the position response, helping the machine run more smoothly.
2. Control the Load Inertia Ratio
Parameter 2021 sets the load inertia ratio. Keep it ≤ 70% to avoid resonance caused by excessive inertia.
3. Enable PI Control
Set parameter 2003#3 to 1 to activate both proportional and integral control, providing stronger suppression of low-frequency fluctuations and improving overall stability.
4. Fine-Tune the Speed Integral Gain
Slightly increasing parameter 2043 can enhance the stability of the speed loop, further improving low-frequency oscillation issues.
II. High-Frequency Oscillation (100–400Hz Continuous Noise)
Symptoms:
Sharp, high-pitched noise accompanied by continuous vibration—usually caused by mechanical elasticity or inertia mismatch.
Solutions:
1. Enable 250µs Acceleration Feedback
Parameter 2066 is used to compensate for elastic deformation in the drive system. Set it between -10 to -20. However, be cautious—if the value is too large, it can actually worsen the vibration. Adjust carefully! |
