How do you improve slow speed control?

[runger]

@Backflip

In order to remove offset from the amplifiers, you need to measure all four inputs with the motor standing completely still. This is then the zero value to be subtracted, when you use the signals from the AD converter. I hope this makes sense.

It makes sense as long as the sensor motor is wound in a way that it’s BEMF voltage doesn’t exceed this reference voltage in the expected speed range to be measured.

Calibrating the ADC offset in this way is what SimpleFOC does also.

@Backflip

You cannot reduce measurement bandwidth at slow speeds, because then you cannot have the fast response in the control loop as you need.

I wasn’t suggesting that. I was simply saying these sensors aren’t subject to the problems of the motor sensor, and work well at slow speeds. Their internal processing has bandwidth limitations which come into play at higher speeds, but at low speeds you can get their full resolution. The opposite of the motor sensor, which loses resolution as speed decreases.