Patent ID: 7423397

Claim:
An electric power steering device, comprising: a torque sensor to detect at least steering torque generated in a steering shaft; a target current computing unit to compute a target current value for regulating motor current based on the detected steering torque; motor drive circuits to drive a motor that supplies auxiliary steering force; motor current detectors to detect motor current value in said motor; a motor rotation number detector to detect the rotation number of said motor; a motor terminal voltage controller to control the voltage between the terminals of said motor based on the difference between said computed target current value and said detected motor current value; and an offset correction device to correct a detected motor current value, wherein said offset correction device adds or subtracts a minimum correction amount to or from said detected motor current value and said calculations are repeated until a computed average value of sampled target motor terminal voltage values falls within a prescribed range including zero therein, when said motor terminal voltage controller judges the state wherein said motor terminal voltage value is deemed to be zero.