Glossary · Motion control and drives
Servo pneumatics
Also known as: Servo-pneumatic positioning
German: Servopneumatik
In fluid power, servo pneumatics is closed-loop control of pneumatic actuators using proportional valves, position or pressure sensors and a controller, so that a cylinder can stop at any position or apply a controlled force instead of only moving between end positions.
- Motion control
In one sentence
Servo pneumatics controls pneumatic cylinders in closed loop with proportional valves and sensors, for any position or controlled force.
Example
A soft-stop pneumatic axis uses servo pneumatics to position a gripper at three intermediate positions without mechanical stops.
How it applies
- Engineering: Servo pneumatics combines a Proportional valve, a displacement encoder on the cylinder and a controller. It is lighter and cheaper than electric axes for some tasks but less stiff because air is compressible.
- Commissioning: Controllers identify the system (cylinder, load, supply pressure); stable supply pressure matters for repeatability.
- Operation: Pressure loss or air quality problems affect positioning accuracy.
- Documentation: Explain behavior on loss of air or power: the cylinder may drift, move or lose force, depending on valve design. Include venting procedures, since compressed air in the cylinder is Stored energy.
Servo pneumatics vs. servo electric axis
An electric servo axis is stiffer and more precise. Servo pneumatics is compact and robust and offers inherent compliance, but positioning is limited by air compressibility and friction.