A servo system that hums, vibrates, or emits a high-pitched whine during deceleration is telling you something about the mechanical coupling between the motor and the load. The noise isn't just annoying—it's a sign that the drive and the load are fighting each other at a resonant frequency. The EMSD5 servo drive has built-in tools to suppress this resonance without adding mechanical dampers or changing the coupling.
Resonance shows up in different ways depending on its root cause, and the EMSD5 parameters to adjust vary accordingly:
| Symptom | Likely Cause | EMSD5 Parameter |
|---|---|---|
| High-pitched whine during deceleration | Gain too high / resonance peak | Pn103 (auto notch filter) |
| Low-frequency vibration at standstill | Integral gain saturation | Pn101 (speed loop gain) |
| Overshoot after positioning | Position loop gain too high | Pn102 (position loop gain) |
| Chattering at low speed | Friction compensation mismatch | Pn401 (friction compensation) |
A systematic tuning sequence resolves most resonance issues in a single pass. Start by enabling auto-tuning—set Pn100 to 1 and run the motor through a full cycle. The drive measures the load inertia and detects resonant frequencies automatically. Next, apply the notch filter by writing the detected resonant frequency to Pn103; the EMSD5 can suppress up to three notch frequencies simultaneously. Then adjust the speed loop gain (Pn101) upward until you hear the beginning of audible ringing, and back it off by 20 percent. Set the position loop gain (Pn102) to roughly 30–50 percent of Pn101 and increase until positioning time meets specification. Finally, repeat these adjustments under full load to capture the real operating conditions.
For extreme cases—long timing belts or high-compliance couplings—the manual notch filters (Pn104 through Pn106) provide three additional suppression bands beyond what auto-tuning detects.
The EMSD5 series makes resonance suppression accessible even for teams without deep servo tuning experience. In most applications, the auto-notch and inertia estimation algorithms produce acceptable performance within a single tuning cycle.
Download the complete EMSD5 tuning guide with parameter tables and oscilloscope waveforms. Contact our application engineers for remote tuning assistance on complex multi-axis systems.
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