ABSTRACT
ABSTRACT: The paper analyzes the maximum robust Controlled Invariant Sets of lateral vehicle dynamical actuators. In the analysis the nonlinear polynomial Sum-of-Squares (SOS) programming method is applied. It considers the nonlinear characteristics of the lateral tire force with a polynomial approximation. Since the tire force characteristics depend on several conditions (e.g. vertical loads, road frictions), their effects occur in the modeling as uncertainties. Parametric uncertainties of the tire model are considered in the robust stability of vehicle dynamics. The maximum robust Controlled Invariant Sets approximate the regions of the tire side-slip angles in which the vehicle can be robustly stabilized by constrained control inputs. As an example the maximum robust Controlled Invariant Sets of the steering and the brake control systems are estimated at various velocities and road conditions. The results of the analysis concerning the steering and the brake control will be illustrated through simulation examples.
