Reduced-order Washout Controllers Stabilizing Uncertain Equilibrium Points

We consider a local stabilization problem of an uncertain equilibrium point existed in a nonlinear continuous-time system by a finite-dimensional dynamical state feedback controller. In previous research, it is investigated that steady-state blocking zeros of the stabilizing controller play an important role. Such a controller is called a washout controller. In this paper, we develop a design method for reduced-order washout controllers whose order is less than the plant's order. Additionally, we also consider a local stabilization problem of an uncertain fixed point of a given discrete-time system.