Robust yaw damping of cars with front and rear wheel steering

For active car steering, a robust decoupling control law by feedback of the yaw rate to front wheel steering was derived earlier. In the present work, this control law is extended by feedback of the yaw rate to rear wheel steering. A controller structure with one free damping parameter, k_D, is derived with the following properties: (i) damping and natural frequency of the yaw mode become independent of speed; (ii) k_D can be adjusted to the desired damping level; and (iii) a variation of k_D has no influence on the natural frequency of the yaw mode and no influence on the steering transfer function by which the driver keeps the car-considered as a mass point-on its planned path