As mentioned, closed-loop stepper control with feedback for step-loss compensation uses algorithms to detect lost steps. The many different compensation algorithms used in industry have advantages and disadvantages:
These types of algorithms can be used in many point-to-point motion applications but are less useful for maintaining a profiled trajectory under varying load.
This type of control suffers from the main weakness of traditional stepper motor control: Once pullout torque is exceeded, torque delivered to the load plummets to zero and a recovery algorithm must fix the problem.
This control also suffers from the traditional problem of stepperresonance excitation. Algorithms abound to reduce the effects of stepper resonance but none completely eliminate the issue.
Just like a traditional open-loop stepper, the motor can run hot because the control applies full current to the motor whenever it’s in motion.
Closed-loop stepper with load position control is similar to step-loss compensation as this drive scheme uses feedback and compensation algorithms to detect and address lost steps. This is a position-control scheme and dynamically controls and updates the output position when an error is present between commanded position and actual position. These compensation algorithms have advantages and disadvantages:
The algorithms are especially useful when a profiled trajectory must be maintained under varying load.
This type of control still suffers from the main weakness of traditional stepping motor control (that once pullout torque is exceeded the torque delivered to the load plummets).
This type of control also suffers from the stepperresonance problem.
Just like a traditional open-loop stepper, the motor can run hot because the control applies full current to the motor whenever it’s in motion.
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