Mitsubishi Denki Kabushiki Kaisha

Hirohisa Awa

Kazuhisa Nishino

Shunichi Wada

A DC motor driven power steering system for a motor vehicle includes a motor current detection circuit for detecting a motor current flowing through the DC motor, a power supply voltage detection circuit for detecting a power supply voltage applied to the bridge commutation circuit, a motor voltage estimating unit for estimating a voltage applied across the DC motor on the basis of the power supply voltage applied to the bridge commutation circuit and the pulse-width modulated control signals used for controlling the bridge commutation circuit, and a motor rotation detecting means for detecting the rotation state of the DC motor on the basis of the motor current and the estimated motor voltage applied to the DC motor. High reliability can be ensured for detection of the rotation state of the DC motor.

DC motor driven power steering system for a motor vehicle

A vehicle control apparatus includes a steering torque sensor (1) for sensing a steering torque, a motor (3) for generating a steering assisting force, a CPU (22) for determining a motor drive direction based on at least the steering force and a motor drive direction restricting circuit (25) for restricting the drive direction of the motor (3) determined by the CPU (22) based on a steering force determination level as a motor drive direction determination criterion and the steering force, and the steering force determination level is changeable. With this arrangement, there is provided the vehicle control apparatus with safety and reliability by which the motor can be controlled with redundancy, the steering force determination level does not require such accuracy as to use pinpoint accuracy and further even if an abnormal state is caused in a motor output when a steering wheel is released from a hand and a steering torque exceeding the steering force determination level is generated, the steering force determination level is instantly changed to thereby restrict a motor drive direction so that the self-turn of the steering wheel is prevented.

Vehicle control apparatus

vehicle control apparatus

A control system for an electrically operated power steering apparatus which is capable of eliminating an incongruous steering sensation and improving the converging performance of a steering wheel. The control system comprises a steering torque detecting unit 20 for detecting a steering torque applied to a steering system, a motor 10 coupled to the steering system, and a control unit for controlling the motor 10 using an output of the steering torque detecting unit 20 phase-compensated on the basis of a speed of the motor 10. The control unit includes a target current determining section 25 for determining a target current to the motor 10 on the basis of the output of the steering torque detecting unit 20 and a phase compensating section 21 for obtaining a phase compensation value on the basis of the output of the steering torque detecting unit 20 and the speed of the motor 10. The target current is corrected by the phase compensation value.

Control system for electrically operated power steering apparatus

[Object] To improve system reliability and safety. [Constitution] The rotation speed of the motor 6 is detected by the motor rotation speed detection circuit 17 and the amount of rotation of the motor 6 is calculated from the detected rotation speed by the motor rotation amount calculating means 10a. Then, a fault is determined when the amount of rotation exceeds a predetermined value and the drive of the motor 6 is stopped by the motor stopping means 123.

Motor controller

A control apparatus for an electric motor-driven power steering system includes a main CPU for arithmetically determining the steering assist torque to be generated by the electric motor and a driving direction thereof on the basis of outputs of a torque sensor and the vehicle speed sensor, a subsidiary CPU for arithmetically determining the driving direction of the motor on the basis of outputs of the torque sensor and the vehicle speed sensor and compare the driving direction signal supplied from the main CPU with a signal of the driving direction determined by the subsidiary CPU to generate a second driving direction signal. A coincidence/discrepancy signal representing coincidence or discrepancy between the motor driving direction signal and the steering torque signal is also supplied to the subsidiary CPU from the main CPU. The subsidiary CPU decides whether the motor driving direction signal coincides with a steering direction signal generated by the subsidiary CPU on the basis of the coincidence/discrepancy signal and the torque sensor signal. In dependence on the decision result, an enable/inhibit signal for enabling or inhibiting supply of the assist torque signal is issued. Each of the main and subsidiary CPUs includes a signal transfer circuit for allowing a signal indicative of the result of the decision to be transferred between the CPUs, and a circuit for interrupting supply of the driving control information to the motor controller when the diagnostic result indication signal indicates occurrence of abnormality in the main or subsidiary CPU.

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Kobe, Japan

Hirohisa Awa