You would need an encoder which generates already UVW signals or calculate from the absolute position(see ) or you take the sensorless approach using software in the motion controller.
thanx for you reply.
u said that the control of position will be by an encoder, but the problem is in the sensroless bldc that can't (according to the application notes) be rotates with a speed under 100 RPM = 1.6 RPS !!
so how can i control this bldc with a min speed = 1.6 RPS
so ....?
the sensorless a BLDC motor based on back EMF has a problem at low speed. The only way is to add an additional sensor outside or modify the motor and build a magnetic encoder pcb inside( like described here: **broken link removed** ).
Do you have access externally to the motor axis to add a position sensor in some way?
the sensorless driver software runs on the micro does not provide accurate position at low speed. To incorporate the actual position this driver software need to be changed to run position drive at low speed. Maybe you can drive the motor as a stepper and use the gyros or accelelerometer as a feedback. But this also requires a change in the sensorless driver software.
If the gimbal motor is of this type: **broken link removed** you might be able to glue a magnet onto the rotating axis in the back and then position a small PCB with the single chip encoder to output the position. But again the software need to be changed.