Resonance is one of the most common — and potentially damaging — issues in servo system applications. If not addressed properly, it can lead to vibration, positioning errors, excessive noise, and even mechanical failure. In this article, we’ll explain what causes servo resonance and share practical methods to prevent it, helping you keep your motion control systems running smoothly and reliably.
What Is Resonance in a Servo System?
In a servo system, resonance occurs when the mechanical structure or load vibrates at its natural frequency due to internal or external excitation. This vibration can be amplified if the control loop or motor behavior matches that frequency, leading to instability. There are two common types:
Low-frequency resonance (0–50 Hz): Often caused by loose connections or high-inertia loads
Mid-to-high-frequency resonance (50 Hz–300+ Hz): Typically due to low structural stiffness or excessive control gain
Why Does Resonance Happen?
Several factors can trigger resonance in servo systems:
Insufficient mechanical rigidity
High load inertia causing overreaction and overshoot
Excessively high gain settings in the servo controller
Improper shaft or coupling alignment
Natural frequency of the structure overlapping with servo control frequency
How to Prevent Resonance in Servo Systems
Reduce Gain and Fine-Tune Servo Parameters
One of the most effective ways to suppress resonance is to reduce position loop gain and increase the velocity loop integration time. This softens the system’s response and helps prevent overshoot and vibration. X-TEAM servo drives feature auto-tuning functions that help optimize these parameters automatically.
Tip: Use frequency response analysis tools to detect critical resonance points and adjust your settings accordingly.
Use Notch Filters
A notch filter is designed to eliminate specific resonance frequencies. X-TEAM servo drives are equipped with multiple configurable notch filters that let users input the resonance frequency, bandwidth, and depth to effectively suppress harmful vibrations without affecting overall system response.
Improve Mechanical Design
Structural improvements can significantly reduce the risk of resonance:
Strengthen the mechanical frame or mounting structure
Use precision-aligned couplings
Add dampers or vibration-absorbing materials
Minimize mechanical play or backlash between components
For flexible systems, resonance frequency simulation during the design stage is highly recommended.
Use Advanced Anti-Resonance Algorithms
Modern servo systems, such as the X-TEAM series, offer advanced vibration suppression functions:
Adaptive filtering
Flexible load compensation
Dual-loop control with feedforward tuning
These features dynamically adjust the control signal in real time, suppressing vibrations caused by structural flexibility or load dynamics.
Tools for Detecting Resonance
Frequency response analyzers (FRF tools)
Accelerometers or vibration sensors
X-TEAM tuning software with gain scanning and auto-analysis
Oscilloscope monitoring of encoder signal for oscillation patterns
These tools help identify whether a vibration issue is due to resonance and what frequency range it affects.
Resonance isn’t just an issue of motor tuning — it involves the entire electromechanical system, including mechanical design, drive settings, load matching, and feedback control. Choosing a servo system with built-in anti-resonance features, such as the X-TEAM series, is a reliable way to ensure precision control and long-term stability.