Vehicle stability enhancement by a robust cascade control of the brake system

In the paper the road holding of a heavy vehicle is improved by using unilateral braking. The goal of the control design is to reduce the effect of the lateral acceleration of the vehicle, when it exceeds a predefined critical limit. The safety critical requirements motivate the application of robust control theory. The design problem is solved by a three-level cascade control with H_∞ controllers on each level. The actuator dynamics of the brake system, the wheel dynamics and the nonlinear tire adhesion characteristics are taken into consideration. The effectiveness of the method is demonstrated through an overtaking maneuver.