Nonsmooth 2DOF controller design for a class of third-order nonlinear systems with saturation

The design problem on high-order nonlinear control system with saturation is one of the most interesting design problems in the field of control theory. This paper proposes a nonsmooth two-degree-of-freedom (2DOF) controller for a class of third-order nonlinear systems with saturation such that the asymptotic constringency to the equilibrium point can be achieved. The nonsmooth feedback control insures the constringency to a constant ultimate value of the system states, and the 2DOF compensation design guarantees the ultimate value to be the equilibrium point of the system if the initial condition of the system is already known. The numerical simulation is carried out to verify the results.