Steering control system

摘要

In a steering control system for a motor vehicle, the magnitude of the steering assist torque is reduced from a normal value by a value depending on the ratio of the steering angle to a maximum permissible steering angle which is determined according to the frictional coefficient between the road surface and the road wheels so that excessive steering, which may otherwise occur on a slipper road surface, can be avoided. Additionally, the value by which the steering assist torque is reduced is increased with an increase in the steering speed so that a certain damping effect may be achieved in the system. This is particularly beneficial in preventing any ill effect which may arise when the steering wheel has a large mass of inertia, for instance by being equipped with an air bag system.