Stepper motor stall detection
AssigneeAnalog Devices International Unlimited Company
InventorBernhard Karl-Heinz Dwersteg
Life of this patent
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Abstract
A new method and circuit arrangement for operating a stepper motor in a control loop. Load values associated with a mechanical load of a stepper motor in operation are filtered to generate stall detection values. A step value is determined based on the difference between two stall detection values. The step value is compared to a threshold, and the stepper motor is determined to be in a stall condition based on the comparison between the step value to the threshold. This arrangement enables improved detection of stepper motor stall conditions when the stepper motor is operated at low velocities.
Claims20
A method of operating a stepper motor, the method comprising:
- operating the stepper motor in a control loop;
- receiving load values associated with a mechanical load of the stepper motor;
- filtering the load values to generate stall detection values;
- determining a step value based on a difference between two stall detection values sampled at respective different times;
- determining a comparison between the step value and a predetermined threshold;
- and
- determining the stepper motor is in a stall condition based on the comparison between the step value and the predetermined threshold.
A circuit arrangement for operating a stepper motor in a control loop, the circuit arrangement comprising:
- a controller, configured to:
- operate the stepper motor at a velocity:
- receive load values associated with a mechanical load of the stepper motor;
- filter the load values to generate stall detection values;
- determine a step value based on a difference between two stall detection values at respective different times;
- determine a comparison between the step value and a predetermined threshold;
- and
- determine the stepper motor is in a stall condition based on the comparison between the step value and the predetermined threshold.
Dependencies are inferred from the claim text.