Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Seiji Sakanishi

Takayuki Kifuku

Masahiko Kurishige

Seiji Sawada

Akinobu Sugiyama

Masaharu Tanaka

Hanako Hamada

Noriyuki Inoue

Kenichi Kawakami

Sadaaki Kamei

Kouji Fukusumi

In an electric power steering control system, a phase compensator of the steering torque is made of an analog circuit and an anti-phase compensator is made by the software of a microcomputer, thereby to eliminate the changes in the gain and the phase by the phase compensator of the analog circuit near the oscillation frequency, so that the steering torque signal equivalent to that of no phase compensation necessary for the computation at the observer is computed from the phase-compensated steering torque signal.

Electric power steering control system

An identification is made of an abnormal condition in a motor due to an influence of a disturbance voltage, without addition of hardware, by estimating the disturbance voltage based on a target voltage and actual current flowing in the motor. An apparatus for detecting the abnormal condition of a motor in an electric power steering apparatus includes a motor current detecting unit for detecting an actual current flowing through the motor; a feedback controlling unit for feedback-controlling a target voltage value that gives the motor a driving command in accordance with the deviation of the actual current from an input target current; an abnormal voltage estimating unit for, based on the target voltage and the actual current, estimating an abnormal voltage estimation value corresponding to a voltage indicating an abnormal condition of the motor; and a motor abnormality judging unit for judging abnormality of the motor based on a comparison of the abnormal voltage estimation value with an abnormal voltage value previously stored.

Motor abnormality detecting apparatus

In the conventional electric power steering control system, a gain by which an approximate differentiation value of a torque signal is multiplied comes to be large at high speed driving. Therefore, a problem exits in that unstable feel of steering increases, thereby steering convergence getting worse. An electric power steering control system includes a variable type torque differential operation device A that makes variable a differential time constant at the time of outputting a second motor current, and a time constant determining device X that commands the time constant to the variable type torque differential operation device A. The time constant determining device X determines the time constant in response to any change in not less than one signal selected and used in an arbitrary manner out of a speed signal , a torque signal , a yaw rate signal and a steering rate signal

Growing community of inventors

Tokyo, Japan

Seiji Sakanishi