Nsk Corporation

Hideaki Okazaki

Sakae Nejo

Kenji Mori

Shuji Endo

Toru Sakaguchi

Yuho Aoki

Takeshi Hara

Yong Wei

Lilit Kovudhikulrungsri

An electric power steering apparatus including a steering angle detection part that detects a steering angle of a steering wheel and outputs a steering angle signal, a steering control unit that controls a motor to give an assist torque to the steering wheel, an abnormality detection part that determines an abnormality of the steering angle detection part, and a motor angle detection part that detects a rotational angle of the motor. The steering control unit calculates a steering angle information based on at least the steering angle signal, and includes a signal storage part that stores the steering angle information. The steering control unit runs the motor continuously when the abnormality detection part detects the abnormality of the steering angle detection part until a vehicle stops or until the abnormality detection part determines that the steering angle signal returns to a normal state from the occurrence of the abnormality.

Control apparatus for electric power steering

The present invention provides an excellent electric power steering apparatus in which torque ripple caused by a quantization error of a current control system generated in case of slow steering state and steering holding state, namely, vibration and noise on a steering wheel can be suppressed. A current controller in which a steady state gain of feedback control is a finite value is used so as to be capable of suppressing the vibration and noise. Further, according to the present invention, a smoothing filter is included in a current control system so that the quantization error is smoothed so that the torque ripple is suppressed.

Electric power steering apparatus

Growing community of inventors

Maebashi, Japan

Hideaki Okazaki