Patent attributes
The controller in an electric power steering apparatus stores the relationship between the steering torque and the basic assist torque in which the relationship is stored as assist characteristic, and stores the relationship between the steering angle correspondence value corresponding to the steering angle of the vehicle and the motor output correction value in which the relationship is stored as correction characteristic. The controller corrects the output of the motor, which is required in order to generate the basic assist torque, in accordance with the motor output correction value determined from the steering angle correspondence value and correction characteristic, in which the basic assist torque is determined from the steering torque and assist characteristic. The correction characteristic is set so that the denominator in the frequency transfer function (K1θp+K2θps+K3θps2)/(s2/ω0 2+2ζ0s/ω0+1) of the motor output correction value to the steering angle correspondence value has a term which includes the resonance angular frequency of the yaw motion of the vehicle, and a term which includes the damping ratio of the yaw motion of the vehicle.
