Glossary · Motion control and drives
S-curve profile
Also known as: S-curve velocity profile, Jerk-limited profile
German: S-Kurven-Profil
In motion control, an S-curve profile is a jerk-limited motion profile in which acceleration rises and falls gradually, so the velocity curve over time has an S shape at the start and end of each ramp.
- Motion control
In one sentence
An S-curve profile ramps acceleration up and down gradually, giving an S-shaped velocity curve and smoother, gentler moves.
Example
A wafer transfer axis uses an S-curve profile so the wafer doesn't slide on the end effector during acceleration.
How it applies
- Engineering: S-curves reduce excitation of resonances and mechanical stress, at the price of slightly longer move times for the same peak acceleration.
- Commissioning: The jerk parameter controls how rounded the corners are; it is tuned with acceleration and velocity.
- Operation: Smoother moves reduce noise, wear and product slipping.
- Documentation: Use velocity-over-time diagrams to explain the difference to a trapezoidal profile in training material. When stop ramps are jerk-limited, note that stopping takes longer.
S-curve vs. trapezoidal profile
A Trapezoidal profile has constant acceleration and jumps in acceleration at the corners (infinite jerk in theory). An S-curve limits jerk and removes those jumps.
For translators, keep "S-curve" as a technical term; the German "S-Kurven-Profil" and the English term should be paired in the terminology database.