Glossary · Motion control and drives
Stall detection
Also known as: Sensorless stall detection, Stall monitoring
German: Blockiererkennung
In motion control, stall detection is a driver function that recognizes when a motor is blocked or overloaded to the point of losing steps, typically without sensors by evaluating the back EMF or current behavior, and signals this to the controller so that it can stop the axis or rehome it.
- Motion control
In one sentence
Stall detection recognizes a blocked or overloaded motor, often sensorless via back EMF, and signals it so the controller can react.
Example
A window-blind actuator uses sensorless stall detection to find the mechanical end stop as its reference position instead of a reference switch.
How it applies
- Engineering: Stall detection builds on Sensorless load measurement: the driver compares the load value with a threshold and sets a flag or output. It works only above a minimum speed. Vendors use trade names for it, for example ADI Trinamic StallGuard; keep in mind that product names change.
- Commissioning: The threshold must be tuned so that normal load peaks don't trigger it and a real block does. Sensorless homing against a hard stop needs low speed and reduced current to avoid mechanical damage.
- Operation: A stall flag means the position may be lost. The controller should stop the axis and require homing.
- Documentation: Stall detection protects the mechanism and the process; it is not a Safety function and doesn't protect people from being trapped. Describe what the machine does after a detected stall and what the operator must do.