Nsk Corporation

Fumitoshi Nakamura

Tomonori Hisanaga

Yuzuru Hoshi

An electric power steering apparatus that performs an assist control of a steering system, including: at least two respectively independent torque sensors and angle sensors, wherein having a function that respectively calculates steering angles from the torque sensors and the angle sensors to utilize, wherein comparison diagnoses of independent signals are performed and also concurrently individual diagnoses of each individual signal are performed, in a case that it is judged that there is an abnormality in the comparison diagnoses, the angle sensor signals are not used, in a case that it is judged that at least one of the individual diagnoses is abnormal, the angle sensor signal is treated as downgrading, and in a case that it is judged that two or more of the individual diagnoses are abnormal, the angle sensor signals are not used.

Electric power steering apparatus

An electric power steering apparatus having a function for detecting a steering speed, includes a time stamp attaching section that attaches a time stamp (ATi) to a detection signal (Ai) and attaches a time stamp (BTj) to a detection signal (Bj); a storing section that stores the detection signal (Bj) to which the time stamp (BTj) is attached; a synchronous signal searching section that searches the detection signal (Bj) most synchronized with the detection signal (Ai) based on the time stamps (ATi and BTj); a vernier calculating section that performs a calculation of an angle difference between synchronous signals searched by the synchronous signal searching section and a vernier calculation and outputs an absolute steering angle of a sensor reference; an initial steering angle calculating section that calculates an initial steering angle value from the absolute steering angle; and a steering angle output section that obtains a steering angle.

[Problem] An object of the present invention is to provide a control apparatus for an electric power steering apparatus that improves ripple accuracy of a torque, a velocity and so on, does not generate abnormal noises and does not generate an uncomfortable feeling with respect to a steering by compensating each-phase characteristics of a motor and the control apparatus and converting into a desired characteristic, and at the same time conforming each-phase characteristics. [Means for Solving the Problem] The present invention is a control apparatus for an electric power steering apparatus that calculates a steering assist torque command value based on a steering torque generated in a steering shaft and a velocity, calculates each-phase current command values from the steering assist torque command value, and controls a motor that provides a steering mechanism with a steering assist torque based on current control values calculated from the each-phase current command values and each-phase current values of the motor, comprising: arranging filters having a characteristic that compensates each-phase characteristics of the motor and the control apparatus at each pathway, and conforming the each-phase characteristics of the motor and the control apparatus, and at the same time, making the each-phase characteristics of the motor and the control apparatus becoming a desired characteristic.

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Maebashi, Japan

Fumitoshi Nakamura