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. Make sure that the voltage constant of the motor 0x8011:31 "Voltage constant" is set correctly.
2. Set the parameter 0x8010:60 "Sensorless max. acceleration" to a lower value, otherwise the velocity jump may become too large. E.g. 2000 °/s2.
3. Reduce the parameter 0x8010:5E "Sensorless offset voltage scaling" to approx. 50 ... 80 %.
4. Set parameter 0x8010:17 "Position loop proportional gain" to 0.
The position controller is disabled.
Interference of the position controller with the velocity controller is prevented.
5. Set parameter 0x8010:5B "Velocity loop proportional gain (voltage mode)" to 0.
6. Set parameter 0x8010:5C "Velocity loop voltage feed forward gain (voltage mode)" to 100 %.
7. Set the parameter 0x8010:5F "Sensorless observer bandwidth" to a lower value. E.g. 50 Hz.
8. Gradually increase parameter 0x8010:5F "Sensorless observer bandwidth" until oscillatory behavior. Then reduce by 50%.
9. Configure the integral component of the velocity controller in parameter 0x8010:5A "Velocity loop integral time (voltage mode)" to be rather sluggish.
10. Gradually increase the proportional component 0x8010:5B "Velocity loop proportional gain (voltage mode)" until the actual velocity in the scope starts to oscillate.
11. Reduce the proportional component by 20 %.
The 20 % serves as a control reserve for abrupt movements.
12. If velocity overshoots: slightly reduce 0x8010:5C "Velocity loop voltage feed forward gain (voltage mode)".
13. If necessary, increase parameter 0x8010:60 "Sensorless max. acceleration" again to the required dynamics.
The velocity controller is optimized.

Step 2: optimization of the position controller

Prerequisite: the velocity controller is optimized.
1. Gradually increase the proportional component 0x8010:17 "Position loop proportional gain" until oscillating behavior.
2. Reduce the proportional component by 20 %.
The 20 % serves as a control reserve for abrupt movements.
The position controller is optimized.