Glossary · Motion control and drives
Jerk limitation
Also known as: Jerk control, Jerk limit
German: Ruckbegrenzung
In motion control, jerk limitation is the restriction of the rate of change of acceleration in a motion profile, which smooths starts and stops and reduces vibration and mechanical stress.
- Motion control
In one sentence
Jerk limitation caps how fast acceleration changes in a motion profile, smoothing motion and reducing vibration and wear.
Example
A bottle transfer axis uses a jerk limit so bottles don't tip over when the axis starts moving.
How it applies
- Engineering: Jerk is the derivative of acceleration. Limiting it produces an S-curve profile instead of a Trapezoidal profile and excites fewer machine resonances.
- Commissioning: Jerk values are tuned together with acceleration: too low makes moves slow, too high brings back vibration.
- Operation: Some controllers apply different jerk limits for normal moves and for quick stops; a jerk-limited stop takes longer.
- Documentation: When jerk parameters appear in the parameter list, explain units (for example mm/s³) and effects. Note that changing ramp or jerk values can change Stopping time and thus safety distances, so such changes need to go through change control.
Jerk vs. acceleration limit
The acceleration limit caps how fast velocity changes. The jerk limit caps how fast acceleration itself changes. Both shape the motion profile.