Patent ID: 7786686

Claim:
A method for estimating an angular position in electrical degrees of a rotor of a brushless motor having position sensors spaced along a circumference of a stator, the position sensors generating digital signals that switch each time the rotor crosses certain angular positions, the method comprising: storing for each position sensor the angular position of the rotor in electrical degrees at a switching of the digital signal generated by the position sensor and determining for each revolution of the rotor a time interval elapsed between a current switching edge and a preceding switching edge of the digital signal generated by a same position sensor confirming revolution of the rotor again through a same mechanical angular position; and estimating the angular position in electrical degrees during a current revolution of the rotor by identifying which of the position sensors has generated a last switching edge, by identifying a corresponding angular position in electrical degrees, and by identifying a time interval elapsed between two consecutive revolutions of the rotor through a same mechanical angular position, the angular position in electrical degrees corresponding to a sum between the angular position in electrical degrees and a product between a fraction of the time interval elapsed from the corresponding preceding switching edge multiplied by 360 degrees and by a number of polar pairs of the brushless motor.