No feedback system: Sensorless operation
Without a feedback system, the following error (following error = actual position - target position) is much harder to optimize than when operating with Hall sensors and/or incremental encoders.
Step 1: Optimization of the velocity controller
- 1. Ensure that the voltage constant of the motor 8011:31 "Voltage constant" is set correctly.
- 2. Set the parameter 8010:60 "Sensorless max. acceleration" to a lower value, otherwise the velocity jump can become too big. e.g. 2000 °/s2.
- 3. Reduce the parameter 8010:5E "Sensorless offset voltage scaling" to approx. 50 ... 80%.
- 4. Set the parameter 8010:17 "Position loop proportional gain" to 0.
- The position controller is disabled.
- Interference of the position controller with the velocity controller is prevented.
- 5. Set the parameter 8010:5B "Velocity loop proportional gain (voltage mode)" to 0.
- 6. Set the parameter 8010:5C "Velocity loop voltage feed forward gain (voltage mode)" to 100%.
- 7. Set the parameter 8010:5F "Sensorless observer bandwidth" to a lower value. e.g. 50 Hz.
- 8. Gradually increase the parameter 8010:5F "Sensorless observer bandwidth" until oscillation occurs. Then reduce by 50%.
- 9. Configure the integral component of the velocity controller in parameter 8010:5A "Velocity loop integral time (voltage mode)" to be rather sluggish.
- 10. Gradually increase the proportional component 8010:5B "Velocity loop proportional gain (voltage mode)" until the actual velocity in the scope begins to oscillate.
- 11. Reduce the proportional component by 20%.
The 20% serves as a control reserve for abrupt movements. - 12. If the velocity overshoots: slightly reduce the parameter 8010:5C "Velocity loop voltage feed forward gain (voltage mode)".
- 13. If necessary, increase the parameter 8010:60 "Sensorless max. acceleration" back to the required dynamics.
- The velocity controller is optimized.
Step 2: Optimization of the position controller
- Requirement: the velocity controller is optimized.
- 1. Gradually increase the proportional component 8010:17 "Position loop proportional gain" until oscillation occurs.
- 2. Reduce the proportional component by 20%.
The 20% serves as a control reserve for abrupt movements.
- The position controller is optimized.