Patent ID: 7837004
Filing Date: 2010-11-23
Classification: B62D

Abstract:
1. A steering assisting system for a vehicle having a steering wheel and steered wheels steered by the steering wheel, the steering assisting system comprising: an electric power steering apparatus including a first electric motor for generating a torque to assist steering operation of the steering wheel; and a variable transfer ratio steering apparatus including a second electric motor for rotating an output steering shaft operatively coupled with the steered wheels relative to an input steering shaft operatively coupled with the steering wheel, the variable transfer ratio steering apparatus driving the second motor to vary a transfer ratio between a steering angle of the steering wheel and a steered angle of the steered wheel, wherein the electric power steering apparatus and the variable transfer ratio steering apparatus further include electronic control units, which are provided separately to control the motors of the electric power steering apparatus and the variable ratio steering apparatus, respectively, wherein the electronic control unit of the electric power steering apparatus is configured to output a failure signal to the electronic control unit of the variable transfer ratio steering apparatus upon detection of a predetermined failure in the electric power steering apparatus, the electronic control unit of the variable transfer ratio steering apparatus is configured to determine, based on the failure signal, that the electric power steering apparatus is in the predetermined failure, wherein the electronic control unit of the variable transfer ratio steering apparatus is configured to control the second motor of the variable transfer ratio steering apparatus to generate torque to power-assist the steering operation of the steering wheel only upon the predetermined failure of the electric power steering apparatus.