Abstract: A power source for a hybrid vehicle is provided which can protect its electric motor driving circuit from being damaged by a back electromotive force generated in a motor. The back electromotive force generated in an electric motor is detected by a high voltage detector circuit and converted by a step-down circuit into a low voltage which is then stored in a low-voltage second battery. Accordingly, as the back electromotive force does not become excessively high, it will be prevented from damaging a switching circuit. Also, the back electromotive force generated in the motor is charged in the low-voltage battery and can thus be supplied to a control circuit or any other component, contributing to the reduction of the fuel consumption of the hybrid vehicle. The back electromotive force can alternatively be diverted for charging a medium-voltage third battery.

Abstract: A transformer section transforms a primary voltage and outputs secondary voltage. A control section inputs a first signal indicating a state of electricity supply of a primary power source through an in-vehicle network. The transformer section outputs a second signal indicating a state of electricity supply of the transformer section. When the input of the first signal is disrupted, the control section limits the driving electricity supplied to the steering motor based on at least one of a value of the secondary voltage and the electricity supply state of the transformer section indicated by the second signal. Accordingly, driving electricity is stably supplied with the steering motor with a simple configuration even if the input of the first signal is disrupted due to a failure in the in-vehicle network.

Abstract: A power source for a hybrid vehicle is provided which can protect its electric motor driving circuit from being damaged by a back electromotive force generated in a motor. The back electromotive force generated in an electric motor 44 is detected by a high voltage detector circuit 48 and converted by a step-down circuit 46into a low voltage which is then stored in a low-voltage secondary battery 28. Accordingly, as the back electromotive force does not become excessively high, it will be prevented from damaging a switching circuit 42. Also, the back electromotive force generated in the motor 44 is charged in the low-voltage secondary battery 28 and can thus be supplied to a control circuit 40 or any other component, contributing to the reduction of the fuel consumption of the hybrid vehicle.

Abstract: A transformer section transforms a primary voltage and outputs secondary voltage. A control section inputs a first signal indicating a state of electricity supply of a primary power source through an in-vehicle network. The transformer section outputs a second signal indicating a state of electricity supply of the transformer section. When the input of the first signal is disrupted, the control section limits the driving electricity supplied to the steering motor based on at least one of a value of the secondary voltage and the electricity supply state of the transformer section indicated by the second signal. Accordingly, driving electricity is stably supplied with the steering motor with a simple configuration even if the input of the first signal is disrupted due to a failure in the in-vehicle network.

Abstract: A controller controls an electric motor to provide assist power corresponding to steering operation for an electric power steering apparatus. The controller comprises a detecting device, a filtering device, a judging device and a determining device. The detecting device detects present voltage of a power source for the electric motor. The filtering device filters the present voltage based on a small time-constant when the voltage of the power source increases and based on a large time-constant when the voltage of the power source decreases. The judging device judges whether the filtered voltage is lower than a predetermined threshold. And, the determining device determines being abnormality of the power source when it is judged that the filtered voltage is lower than the threshold.

Abstract: A steering apparatus controller for an electric power steering apparatus, which includes an electric motor for generating assist torque for assisting steering of a steering wheel and the steering apparatus controller is designed to execute a feedback control of the applied drive voltage to the electric motor based on the detection result of the actual current that flows through the motor. A sensor detects the actual current to produce the detection result. When detecting an abnormal decrease of the drive voltage of the sensor, a voltage controller maintains the applied voltage to the electric motor at the voltage at a predetermined time before the drive voltage abnormally decreased.

Abstract: A control apparatus of an electric power steering system has first to fourth calculators and an abnormality detector. The first calculator calculates an assist current command value, which corresponds to assist force for reducing steering force of the steering wheel, based on the steering torque of the steering wheel. The second to fourth calculators calculate a compensation current command value, which corresponds to compensation force for compensating for movement of the steering wheel, based on the angular velocity of the steering wheel that has been estimated based on the terminal-to-terminal voltage of the motor. The abnormality detector detects an abnormality of the terminal voltages of the motor. When the abnormality detector detects an abnormality, the second to fourth calculators substitute zero for the steering wheel angular velocity and then calculates the compensation current command value.

Abstract: A control apparatus of an electric power steering system has calculating means, controlling means, determining means suppressing means, canceling means. Calculating means calculates an assist current value that corresponds to the assist force based on steering torque of a steering wheel. Controlling means executes assist control of the motor based on the assist current value. Determining means determines an abnormality in the circuit. Suppressing means suppresses the assist control when an abnormality in the circuit is determined. If the determination of an abnormality has continued longer than a predetermined time since the suppression of the assist control, the suppressing means opens relay means that permits electric power to be supplied to the motor. When it is determined that the circuit returns to normal with the assist control suppressed, the canceling means cancels the suppression of the assist control.

Abstract: A controller controls an electric motor to provide assist power corresponding to steering operation for an electric power steering apparatus. The controller comprises a detecting device, a filtering device, a judging device and a determining device. The detecting device detects present voltage of a power source for the electric motor. The filtering device filters the present voltage based on a small time-constant when the voltage of the power source increases and based on a large time-constant when the voltage of the power source decreases. The judging device judges whether the filtered voltage is lower than a predetermined threshold. And, the determining device determines being abnormality of the power source when it is judged that the filtered voltage is lower than the threshold.

Abstract: A control apparatus of an electric power steering system has first to fourth calculators and an abnormality detector. The first calculator calculates an assist current command value, which corresponds to assist force for reducing steering force of the steering wheel, based on the steering torque of the steering wheel. The second to fourth calculators calculate a compensation current command value, which corresponds to compensation force for compensating for movement of the steering wheel, based on the angular velocity of the steering wheel that has been estimated based on the terminal-to-terminal voltage of the motor. The abnormality detector detects an abnormality of the terminal voltages of the motor. When the abnormality detector detects an abnormality, the second to fourth calculators substitute zero for the steering wheel angular velocity and then calculates the compensation current command value.

Abstract: A steering apparatus controller for an electric power steering apparatus, which includes an electric motor for generating assist torque for assisting steering of a steering wheel and the steering apparatus controller is designed to execute a feedback control of the applied drive voltage to the electric motor based on the detection result of the actual current that flows through the motor. A sensor detects the actual current to produce the detection result. When detecting an abnormal decrease of the drive voltage of the sensor, a voltage controller maintains the applied voltage to the electric motor at the voltage at a predetermined time before the drive voltage abnormally decreased.

Abstract: A control apparatus of an electric power steering system has calculating means, controlling means, determining means suppressing means, canceling means. Calculating means calculates an assist current value that corresponds to the assist force based on steering torque of a steering wheel. Controlling means executes assist control of the motor based on the assist current value. Determining means determines an abnormality in the circuit. Suppressing means suppresses the assist control when an abnormality in the circuit is determined. If the determination of an abnormality has continued longer than a predetermined time since the suppression of the assist control, the suppressing means opens relay means that permits electric power to be supplied to the motor. When it is determined that the circuit returns to normal with the assist control suppressed, the canceling means cancels the suppression of the assist control.