Sensorless control help

When I use the sensorless method, plus the speed loop and the current loop, after adding the load, the direction of rotation of the motor has changed. Why?

Did you let the motor stop? If the motor stops, then sensorless stops working.
Also can you show a video?

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Thanks for you replay, this problem trouble me a long time. I upload the video to the YouTube. In the video, when I use hand gently to catch the motor, the direction is changed.

Yes, we currently don’t have stall detection on the sensorless mode, and actually sensorless is not very supported yet. Sorry.

Is there any reason to explain why the motor will change direction when there is load?
I want to understand this intermediate process,so we can solve this problem。Thank you for your help!

I think actually your motor never spun up fast enough during the initial spin-up. If it goes too slow, then the rotor estimator doesn’t have enough back-emf over the current sensing noise to be detectable, so it just does something semi-random.