Electric power steering apparatus

An electric power steering apparatus comprising:

• an electric motor applying an assist torque to a steering system;
• a vehicle speed detecting section detecting a vehicle speed of the vehicle;
• a shifting state detecting section detecting a shifting state of the vehicle;
• an engine rotational speed detecting section detecting an engine rotational speed;
• and
• a motor control section for controlling drive of the electric motor based on an output from the vehicle speed detecting section, wherein the motor control section includes a failure determination section for determining failure of the vehicle speed detecting section on the basis of the vehicle speed detected by the vehicle speed detecting section, the shifting state detected by the shifting state detecting section, and the engine rotational speed detected by the engine rotational speed detecting section, and wherein the failure determination section determines that the vehicle speed detecting section malfunctions if the engine rotational speed is equal to or greater than a predetermined rotational speed for a second determinative integrated time while the vehicle speed is zero and the shifting state is not a vehicle driving state.

An electric power steering apparatus comprising:

• an electric motor applying an assist torque to a steering system;
• a vehicle speed detecting section detecting a vehicle speed of the vehicle;
• an engine rotational speed detecting section detecting an engine rotational speed;
• and
• a motor control section for controlling drive of the electric motor based on an output from the vehicle speed detecting section, wherein the motor control section includes a failure determination section for determining failure of the vehicle speed detecting section on the basis of the vehicle speed detected by the vehicle speed detecting section and the engine rotational speed detected by the engine rotational speed detecting section;
• and
• a racing detecting section detecting a racing state of the vehicle,
• wherein the failure determination section determines that the vehicle speed detecting section malfunctions if the racing detecting section detects a non-racing state while the vehicle speed is zero and the engine rotational speed is equal to or greater than a predetermined rotational speed.