公开(公告)号：US09796411B2

公开(公告)日：2017-10-24

申请号：US15038770

申请日：2015-04-07

Applicant: NSK LTD.

Inventor： Masahiro Ieyasu ,  Masahiro Maeda

IPC: B62D5/04 ,  B62D6/00

CPC classification number: B62D5/0463 ,  B62D5/0466 ,  B62D6/008 ,  B62D5/0469 ,  B62D5/0409

Abstract: [Problem]An object of the present invention is to provide a high-performance electric power steering apparatus that reduces uncomfortable feeling of a driver by improving judgment of turning or returning and performing fine control of a steering state to improve a function of convergence control.[Means for solving the problem]An electric power steering apparatus comprises: a turning or returning state index calculating section that calculates a turning or returning state index based on a steering torque and a motor angle velocity; a turning or returning state ratio calculating section that calculates a turning or returning state ratio with a nominal value as a reference based on the turning or returning state index; and a convergence control section that comprises a sensitive gain section that calculates a turning gain and a returning gain based on the steering torque, a vehicle speed and the motor angle velocity, a gain correcting section that performs gain correction for the turning gain and the returning gain by the turning or returning state ratio, and an output processing section that outputs a convergence control value by performing output processing of a gain signal from the gain correcting section based on an absolute value and a sign inversion signal of a yaw rate estimation value.