Abstract: An electric power steering device includes an electric motor configured to selectively perform steering assistance based on a detection result of a torque sensor and automatic steering based on information outside a vehicle, a breakdown determination unit configured to determine the breakdown of the torque sensor, and an intervention determination unit configured to determine a steering intervention operation by the driver when the torque sensor breaks down during the automatic steering. The automatic steering is released when the intervention determination unit determines that the steering intervention operation has been performed.

Abstract: A electric power steering device includes: a torque sensor and an automatic steering control unit that controls an electric motor during automatic steering. The automatic steering control unit includes: an angular velocity target value computation unit that computes an angular velocity target value for controlling the electric motor and a vibration compensation unit that computes a twist angle of a torsion bar, and computes a vibration compensation signal for controlling the electric motor. The automatic steering control unit controls the electric motor on the basis of the angular velocity target value and the vibration compensation signal.

Abstract: A electric power steering device includes a basic return command value calculation unit configured to calculate a basic return command value in a direction to return a steering wheel to a neutral position on the basis of a steering angle of the steering wheel, a return command value calculation unit configured to calculate a return command value by correcting the basic return command value by the first correction gain, and an opposite return command value calculation unit configured to calculate an opposite return command value in a direction not to return the steering wheel to the neutral position on the basis of an angular acceleration of an electric motor. A correction return command value is calculated on the basis of the return command value and the opposite return command value and the electric motor is driven by adding the correction return command value to the assist command value.

Abstract: A electric power steering device includes a basic return command value calculation unit configured to calculate a basic return command value in a direction to return a steering wheel to a neutral position on the basis of a steering angle of the steering wheel, a return command value calculation unit configured to calculate a return command value by correcting the basic return command value by the first correction gain, and an opposite return command value calculation unit configured to calculate an opposite return command value in a direction not to return the steering wheel to the neutral position on the basis of an angular acceleration of an electric motor. A correction return command value is calculated on the basis of the return command value and the opposite return command value and the electric motor is driven by adding the correction return command value to the assist command value.

Abstract: An apparatus for diagnosing an abnormality in a torque sensor that is connected to a controller of an electric power steering apparatus by two systems includes a steering speed determination unit that determines whether a variation speed of a steering angle equals or exceeds a predetermined speed on the basis of a detection result from a steering angle sensor, an integrated value calculation unit that calculates an integrated value of an input torque detected by the torque sensor within a sampling period extending from a point at which a steering wheel is steered at or above the predetermined speed to a point at which the steering wheel returns to a neutral position, and an abnormality determination unit that determines that an abnormality has occurred in the torque sensor when the integrated value of the input torque is equal to or smaller than a predetermined reference integrated torque.

Abstract: An apparatus for diagnosing an abnormality in a torque sensor that is connected to a controller of an electric power steering apparatus by two systems includes a steering speed determination unit that determines whether a variation speed of a steering angle equals or exceeds a predetermined speed on the basis of a detection result from a steering angle sensor, an integrated value calculation unit that calculates an integrated value of an input torque detected by the torque sensor within a sampling period extending from a point at which a steering wheel is steered at or above the predetermined speed to a point at which the steering wheel returns to a neutral position, and an abnormality determination unit that determines that an abnormality has occurred in the torque sensor when the integrated value of the input torque is equal to or smaller than a predetermined reference integrated torque.

Abstract: An electric power steering system remaining stable when subjected to forces from the road surface, the engine or motor, or from other sources. The electric power steering system has a torque sensor for outputting a signal corresponding to the value of the steering torque, a derivative component for outputting a signal obtained by differentiating the output signal of the torque sensor, a driver for electrically driving an assist apparatus which assists a steering force, an assist current determining component for determining current flowing to the driver in accordance with the output signal of the torque sensor and the output signal of the derivative, and a gain control for setting a gain of the derivative component to zero or reducing the gain when the output signal of the torque sensor is smaller than a predetermined value. Methods to provide a stable steering system are also part of the subject matter.

Abstract: A challenge of the present invention is to provide a system for controlling electric power steering which does not allow a pulsing motion to occur when a steering wheel W is positioned around the middle position. To answer the challenge, the system has signal level decision means 16 for selecting a reference level or an amplification level in response to a steering-torque detection signal or a motor current command-value signal; first adjustment device 17 for carrying out the selection of the reference level or the amplification level for the signal level of the motor current command-value signal; second adjustment device 18 for carrying out the selection of the reference level or the amplification level for the signal level of the motor current detection signal; Ad conversion device 15 for converting the signal sent from the second adjustment signal into a digital signal; and third adjustment device 19 for adjusting the motor current control signal to be at the reference level.

Abstract: An electric power steering system that is stable when subjected to forces from the road surface, the engine or motor, or from other sources. The electric power steering system has a torque sensor for outputting a signal corresponding to the value of the steering torque, a derivative means for outputting a signal obtained by differentiating the output signal of the torque sensor, a driving means for electrically driving an assist apparatus which assists a steering force, an assist current determining means for determining current flowing to the drive means in accordance with the output signal of the torque sensor and the output signal of the derivative means, and a gain control means for setting a gain of the derivative means to zero or reducing the gain when the output signal of the torque sensor is smaller than a predetermined value. Methods to provide a stable steering system are also part of the subject matter.

Abstract: A challenge of the present invention is to provide a system for controlling electric power steering which does not allow a pulsing motion to occur when a steering wheel W is positioned around the middle position. To answer the challenge, the system has signal level decision means 16 for selecting a reference level or an amplification level in response to a steering-torque detection signal or a motor current command-value signal; first adjustment means 17 for carrying out the selection of the reference level or the amplification level for the signal level of the motor current command-value signal; second adjustment means 18 for carrying out the selection of the reference level or the amplification level for the signal level of the motor current detection signal; Ad conversion means 15 for converting the signal sent from the second adjustment signal into a digital signal; and third adjustment means 19 for adjusting the motor current control signal to be at the reference level.