Robust active steering control of autonomous vehicles: A state space disturbance observer approach

Unknown and uncertain disturbance significantly affects the performance of a active steering control such as lane keeping and lane changing control. Such performance degradation is here considered to be due to input equivalent disturbance that is to be compensated by the state space disturbance observer we are to design. In contrast to some existing methods that employ explicit models for disturbance or adjust the sensitivity curve at steady state, the proposed method effectively compensates for such input equivalent disturbance even in transient state such as lane changing. This is a significant advantage over conventional approaches such as an integrator or a frequency domain disturbance observer.