Apparatus and method for determining angular position

摘要

The position of a rotor of a motor is determined. The motor includes a stator having a plurality of coils. The rotor includes at least one rotating magnetic field device. When the rotor is moving below a threshold speed, the current in the coils is measured. A pre-programmed data structure is accessed. The data structure stores stator currents associated with predetermined rotor positions. A first absolute position of the rotor is determined from the data structure according to the measured current from each of the coils. When the rotor is moving above the threshold speed, one or more rising or falling edges of magnetic field strength associated with the at least one rotating magnetic field device are sensed. At least one timing aspect of the rising and falling edges of magnetic field strength are compared to determine a second absolute position of the rotor.