Sensorless bldc motor controller six step trapezoidal control

[sambit_das]

I have implemented a sensorless, six-step trapezoidal control with feed-back as zero crossing detection using back emf with the help of ADC on the nucleo-G431 board.The BLDC motor is A2212/13T, 1000 kV.Without a propellor, the motor is spinning, and speed is also changing.But with the propellor, the motor is stuck at starting, and it is not rotating.Give some suggestions on what could be the reason and what modifications need to be done on the firmware and software sides.

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The propeller is most likely putting extra torque on the motor. is this direct drive? Do you have gearing?

Some sensorless implementations include a coarse start routine whereby the motor is bumped or forced along in order to ascertain signal from the Back EMF. You might want to look into sensorless startup routines.

[sambit_das]

It is a direct drive.The propellor is attached directly to the motor.I am initially running the motor in an open loop with a constant commutation interval.After detecting a zero crossing of the bemf in the open loop within a specified time range,closed loop commutation is initiated.

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Note AN1276 APPLICATION NOTE BLDC MOTOR START ROUTINE FOR THE ST72141 MICROCONTROLLER has a couple of start up routine descriptions that may help?