Vehicle steering control system

摘要

In a vehicle steering control system, an actuating torque is applied to steerable wheels according to a steering torque applied to a steering wheel in a conventional manner, and an additional actuating torque is applied to the steering wheel by an electric motor according to lateral dynamic conditions of the vehicle so as to control the lateral stability of the vehicle even in the presence of external interferences such as crosswind. Such external interferences are detected as a lateral dynamic condition of the vehicle such as the yaw rate of the vehicle, and the steering control system produces a steering reaction which counteracts such a lateral dynamic condition by applying the additional actuating torque to the steerable wheels so that the vehicle may maintain a straight course in spite of such external interferences without requiring any intentional efforts by the vehicle operator. A torque steer arising from the drive force applied to power driven steerable wheels can be also controlled as one form of external disturbances. In particular, by amplifying the steering reaction torque when the drive force is great, it is possible to favorably control the influences of a torque steer under any operation conditions.