Patent ID: 8718873

Claim:
An electric power steering device comprising: a steering input unit to be operated by a driver; a steering unit that is provided between said steering input unit and steered wheels and steers said steered wheels in response to a steering operation conducted by a driver with said steering input unit; an electric steering assist force generator to impart a steering assist force to said steering unit; a steering force sensor to obtain a steering force of the steering operation imparted to said steering input unit; a steering operation amount sensor to obtain a steering operation amount of the steering operation imparted to said steering input unit; and a control unit to calculate a target steering assist force in accordance with at least said steering force and to control said steering assist force generated by said steering assist force generator on the basis of said target steering assist force, and to calculate a velocity of the steering operation imparted to said steering input unit as a steering velocity, wherein said control unit is configured to: calculate a coefficient by filtering said steering velocity with a filter of second-order lag and first-order advance; calculate a correction amount on the basis of a product of said coefficient and said steering operation amount; correct said target steering assist force with said correction amount; and control the steering assist force generated by said steering assist force generator on the basis of the corrected target steering assist force.