Glossary · Motion control and drives
Closed-loop stepper
Also known as: Closed-loop stepper motor, Hybrid servo, Stepper motor with encoder feedback
German: Closed-Loop-Schrittmotor
In motion control, a closed-loop stepper is a stepper motor operated with position feedback, usually from an encoder, so that the driver detects and corrects deviations such as lost steps and can adapt the current to the load, combining stepper construction with servo-like monitoring.
- Motion control
In one sentence
A closed-loop stepper uses encoder feedback to detect and correct position deviations, adding servo-like monitoring to a stepper motor.
Example
A label applicator switched to closed-loop steppers, so that a jam triggers a following error message instead of silently misplacing labels.
How it applies
- Engineering: Feedback enables position monitoring, Following error detection and current control by load, so the motor runs cooler than in open loop. Some systems commutate on the measured rotor angle like a servo.
- Commissioning: Encoder direction, resolution and the alignment between encoder and motor phases must be set up before closing the loop.
- Operation: The system corrects small deviations; large ones end in a following error fault instead of unnoticed Step loss.
- Documentation: Explain which faults the closed loop detects and how the machine reacts. Don't call the product a servo motor, and state which open-loop behaviors (homing after power loss with an incremental encoder) still apply.