Patent ID: 7447578
Filing Date: 2008-11-04
Classification: B62D

Abstract:
1. A steering control apparatus for an automotive vehicle, comprising: a camera photographing a travel path in a traveling direction of a vehicle; a lateral displacement calculating circuit that calculates a lateral displacement of the vehicle with respect to the travel path according to an image of the travel path photographed by the camera; a differentiator that calculates a differential value of the lateral displacement; a vehicle speed sensor that detects a vehicle speed; a relative yaw rate calculating section that calculates a relative yaw rate with respect to the travel path of the vehicle on the basis of the lateral displacement, the differential value of the lateral displacement, and the vehicle speed; an actuator that provides an assistance force for the steering mechanism; and an actuator controlling section that drivingly controls the actuator in a direction toward which the relative yaw rate is cancelled on the basis of the relative yaw rate, wherein the actuator controlling section outputs a steering torque command value to the actuator, the steering torque command value being a sum of a steering assistance quantity calculated on the basis of a steering torque and the vehicle speed and a stability direction steering quantity calculated on the basis of the calculated relative yaw rate, and wherein the actuator controlling section comprises a relative yaw rate controlling section comprising: a differentiator that differentiates the lateral displacement; a pseudo differentiation filter constituted by a predetermined forward distance (L) and the vehicle speed; and a control gain section that provides a control gain in the direction toward which the relative yaw rate extracted from the pseudo differentiation filter is cancelled and outputs the stability direction steering quantity.