RESUMO

The paper concerns analysis and synthesis of optimal control systems for a certain class of nonlinear plants under uncertainty conditions with respect to both the plant parameters and uncontrolled bounded disturbances. Plants under consideration can be roughly classified as the catena of a nonlinear saturation-type subsystem and a linear one. It is assumed that the exact type of nonlinear function as well as the exact parameter values for the linear part describing the plants are unknown and the only their set-membership estimates are given. The performance of the introduced class of control systems over an infinite time interval is analyzed numerically by calculating the radius of a minimal invariant set.