Patent ID: 8466646

Claim:
A method for determining a position of a rotor of a motor, the motor including the rotor and a stator, the stator including a plurality of coils, the rotor further including at least one rotating magnetic field device, the method comprising: when the rotor moving below a threshold speed: measuring the current in each of the plurality of coils of the stator; accessing a pre-programmed data structure, the pre-programmed data structure storing a plurality of stator currents associated with a plurality of predetermined rotor positions; determining a first absolute position of the rotor from the data structure according to the measured current from each of the plurality of coils; when the rotor is moving above the threshold speed: sensing one or more rising or falling edges of magnetic field strength associated with the at least one rotating magnetic field device of the rotor; comparing at least one timing aspect of the rising and falling edges of magnetic field strength to determine a second absolute position of the rotor.