Vibrationless alignment algorithm for incremental encoder based BLDC drives

Incremental encoder based BLDC drives are widely employed in industry whenever smooth and efficient operation is needed in the whole speed range. Their weak spot lies in the need for a phase of initial alignment. Such task is traditionally performed by forcing the motor through a series of fixed phase supply configurations, causing strong vibrations which can be intolerable for certain applications. In this paper a novel algorithm that allows determining the initial rotor position (sector) and aligning the encoder while minimizing vibrations and oscillations is presented.