Nonlinear hierarchical control allocation for vehicle yaw stabilization and rollover prevention

In ambition to minimize potential interferences between yaw stabilization and rollover prevention of an automotive vehicle, this work presents a new approach to integrate both objectives. It introduces rollover prevention in form of a nonlinear constraint on the control allocation of a yaw stabilizing controller, yielding a hierarchical allocation problem. A suitable algorithm in form of a dynamic update law addressing this problem is derived. Its implementation is computationally efficient and suitable for low cost automotive electronic control units. The proposed rollover constraint design does not require any sensory equipment in addition to the yaw stabilizing algorithm. Actuation is conducted by differential braking, while an extension to further actuators is possible. The method is validated using an industrial multi-body vehicle simulator.