Robust control design using ultra-local model-based approach for vehicle-oriented control problems

Model Free Control (MFC) with ultra-local model is novel design method to provide high performance control for systems with nonlinear dynamics. The basic concept of this approach is to compute an ultra-local model, which is valid for a short period of time. Although the concept has already been successfully applied for various vehicle control problems, there are some open issues regarding the robustness and the stability of the closed-loop controlled system. This paper presents a method for designing a robust control based on
$\mathcal{H}_{\infty}$
synthesis, with which a solution on these issues can be found. In the proposed MFC strategy the ultra-local model-based control is in the inner loop of the control structure. Moreover, a robust
$\mathcal{H}_{\infty}$
control for the outer loop is designed, in whose control-oriented model the control of the inner loop is incorporated. The control strategy is implemented in high-fidelity vehicle dynamic environment and its efficiency and operation are demonstrated through a complex simulation example.