Method and apparatus for operating a steering system for a motor vehicle

Apparatus for operating a steering system for a motor vehicle with at least one steerable wheel, one steering actuator, and one auxiliary drive, with the auxiliary drive superimposing a steering motion initiated by a driver of the said vehicle and a motion initiated by the steering actuator to generate the steering motion of the steerable wheel, said apparatus comprising:

• means for detecting a yaw parameter representing yawing motion of the said vehicle;
• means for detecting a braking parameter representing the braking condition of the vehicle, wherein the detected braking parameter is detected as a function of an actuation of the vehicle braking system;
• means for determining the existence of a running condition as a function of the detected braking parameter;
• means for generating a control signal only when said predetermined running condition prevails and said braking parameter is present, wherein said control signal is generated as a function of said detected yaw parameter;
• and
• means for controlling the steering actuator to initiate a motion with said control signal.

Method for operating a steering system for a motor vehicle having a braking system, brake lights, at least one steerable wheel, one actuator, and one auxiliary drive, the auxiliary drive superimposing the steering motion initiated by a driver of the vehicle and the motion initiated by the actuator to generate the steering motion of the steerable wheel, said method comprising:

• detecting a yaw parameter representing the yawing motion of the vehicle;
• generating a control signal when a predetermined running condition prevails, wherein said control signal is generated as a function of the detected yaw parameter;
• controlling the actuator with the generated control signal to initiate an actuator motion;
• detecting a braking parameter representing the braking condition of the said vehicle;
• determining the existence of the running condition as a function of the detected braking parameter;
• and
• wherein, after determining the existence of the running condition, the control signal is decreased with time to a predetermined value, the decrease with time being accomplished on one of a linear slope and a first-order time delay curve, and wherein the decrease with time depends on the vehicle speed.