Patent ID: 6705424
Filing Date: 2004-03-16
Classification: B62D

Abstract:
A vehicle steering system having a steering mechanism for steering steerable vehicle wheels in response to a rotating amount of a steering wheel and a biasing amount given by a sub steering mechanism for compensating for the rotating amount of the steering wheel by applying a drive torque thereto, said system comprising:a target reactive force generating means for generating a target value of a reactive torque to be applied to said steering wheel; a reactive torque detecting means for detecting the reactive torque being applied to said steering wheel; a reactive torque controlling means for controlling the drive torque to be applied to said sub steering mechanism so that a target torque generated by said target reactive force generating means and the reactive torque detected by said reactive torque detecting means become equal to each other; a steerable vehicle wheel controlling mechanism for controlling a steering direction of said steerable vehicle wheels; an actual steering angle detecting means for detecting an actual steering angle of said steerable vehicle wheels to be controlled by said steerable vehicle wheel controlling mechanism; a target steering angle generating means for generating a target value of the steering angle of said steerable vehicle wheels; an actual steering angle controlling means for driving and controlling said steerable vehicle wheel controlling mechanism so that the target steering angle generated by said target steering angle generating means and the actual steering angle detected by said actual steering angle detecting means become equal to each other; an abnormality detecting means for detecting abnormality of the vehicle steering system; a first interrupting means for interrupting a control signal sent from said actual steering angle controlling means to said sub steering mechanism on the basis of an abnormal signal from said abnormality detecting means; and a second interrupting means for interrupting a control signal sent from said reactive torque controlling means to said sub steering mechanism on the basis of an abnormal signal from said abnormality detecting means.