Patent ID: 6364050
Filing Date: 2002-04-02
Classification: B62D

Abstract:
An electric power assisted system comprising a steering assembly, an electric motor which includes a rotor, and a gearbox, said electric motor being operatively connected to said steering assembly through said gearbox to apply an assistance torque to said steering assembly, and further comprising a motor position sensor adapted to produce an output indicative of angular position of said motor rotor, said output undergoing a plurality of transitions as said rotor rotates, a counter adapted to generate a count signal indicative of said transitions in said output of said motor position sensor whereby said count signal is indicative of angular position of said rotor relative to an arbitrary zero position, a steering position sensor having an output which comprises at least one position index signal indicative of a known angular position of a portion of said steering assembly, and a reset means adapted to reset the output of said counter whenever said portion of said steering assembly is at said known angular position by monitoring said index signal.