I have started to work on a little project of mines, which consists in implementing the stabilization a single axis gimbal using Arduino.

The gimbal is driven by a sensorless three phase brushless DC (BLDC) motor, while on it's shaft there is a generic payload provided with an IMU board (3 axes gyros + 3 axes accelometers), which can give feedback to the Arduino about the angular rates and accelerations.

enter image description here

I have googled a bit about this topic and there are so many solutions out there, the only thing I really do not understand is about the control of the BLDC motor.

  1. Can I use a sensorless control of the motor, by sensing the back EMF even if the motor is spinning very low?
  2. How can I energize properly the phases of the BLDC motor if it is sensorless?
  3. Can I use the IMU for finding out how to spin the BLDC motor properly without counter rotations?

Could you give me any help, please?


2 Answers 2


consider coupling the motor with an encoder that has enough resolution to tell you precisely when to ramp up current to a particular phase. this will give you precise feedback to develop a control loop that should give maximum torque for a given voltage.


Are you opposed to adding components to the power circuit? If you add in a portion that measures current being drawn by the motor, you can get some decent feedback about what the motor is doing and how much of a mechanical load is being applied to it.

  • $\begingroup$ It isn't that I'm opposed in adding components, the point is that I would like to achieve my goal by using what I currently have. Maybe in the future I would add current sensors. $\endgroup$
    – starScream
    Nov 21, 2016 at 18:08
  • $\begingroup$ That's reasonable. I'm just a big fan of the current sensing method to get a quick 'status' of a motor. $\endgroup$ Nov 21, 2016 at 18:11

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.