We delivered a robust, CAN-controlled, sensorless BLDC controller design for our client.
Brushless motors are desirable from the standpoint of efficiency and durability in many applications. However, because they do not have a built-in commutation mechanism (no brushes / commutator) they require position feedback and electronic control. For this application we did a sensorless commutation design that uses back-EMF from the motor windings to determine the commutation points. The advantage is a simpler motor design. The sensorless motor has three winding leads. A motor with Hall-effect position sensors adds 5 more leads: power, ground, 3 halls. Sensorless isn't right for every application, particularly for slow running or motion control, but for this application, it was perfect.