Patent ID: 8437915

Claim:
A steering control device, comprising: a torque detecting section for detecting a steering torque applied by a driver; a motor for generating an assist torque for assisting the steering torque; an electric power assist control section for computing a target current for electric power assist of the motor, which is required for generating the assist torque, based on the detected steering torque; an angle detecting section for detecting a rotation angle of the motor; a current control section for controlling a current of the motor so that the current of the motor becomes equal to the target current for electric power assist; and a pulsating component extractor for extracting a pulsating component of the steering torque, comprising: a variable time-constant band pass filter having a variable time constant; a time-constant computing section for computing a time constant of the band pass filter, by using the rotation angle of the motor, so that the center frequency of the band pass filter can vary according to a frequency of a cogging torque or a torque ripple generated by the motor, wherein a torque-ripple generation harmonic order is an integer; wherein the pulsating component of the steering torque is extracted by performing filter processing on the steering torque by the variable time-constant band pass filter, wherein a compensation current, which is calculated according to the extracted pulsating component of the steering torque, is added to the target current for electric power assist to correct the target current for electric power assist.