Electrically operated power steering apparatus

An electrically operated power steering apparatus for use with a steering system of a motor vehicle, comprising:

• said steering system for steering the motor vehicle;
• steering torque detecting means for detecting a manual steering torque applied to said steering system;
• target assistive torque generating means for generating a target assistive torque signal depending on the manual steering torque detected by said steering torque detecting means;
• an electric motor for generating an assistive torque to be transmitted as a steering assistive force to said steering system;
• actual assistive torque detecting means for detecting an actual assistive steering torque which is actually transmitted from said electric motor to said steering system based on at least a motor current of said electric motor;
• and
• motor driving means for energizing said electric motor based on respective output signals from said target assistive torque generating means and said actual assistive torque detecting means.

An electrically operated power steering apparatus in a motor vehicle, comprising:

• a steering system for steering the motor vehicle, said steering system comprising a steering wheel, a pinion coupled to said steering wheel, a rack shaft having rack teeth meshing with said pinion, and a steerable wheel operatively coupled to said rack shaft;
• steering torque detecting means for detecting a manual steering torque applied to said steering wheel;
• an electric motor for generating an assistive torque to be transmitted as a steering assistive force to said rack shaft;
• an actual assistive torque detecting means for detecting an actual assistive steering torque which is actually transmitted from said electric motor to said rack shaft;
• control means having at least target assistive torque generating means for generating a target value for an assistive torque to be generated by said electric motor depending on the manual steering torque detected by said steering torque detecting means, for generating a control signal based on the difference between the actual assistive steering torque detected by said actual assistive torque detecting means and the target value generated by said target assistive torque generating means;
• and
• motor driving means for energizing said electric motor based on said control signal from said control means.