Robust stabilization of cascaded nonlinear systems with gain bounded uncertainty

In this paper, we solve a robust stabilization problem for cascaded nonlinear systems with uncertainty using an integral forwarding method. It is assumed that the uncertainty is expressed by a gain bounded unknown nonlinear function. First, under suitable assumptions, a storage function which renders the cascaded nonlinear system robust passive is constructed. Next, it is shown that the storage function plays the role of a Lyapunov function with which the nonlinear system can be made globally robust stabilized by output feedback control. (C) 2000 Scripta Technica, Electr Eng Jpn, 134(2): 29-35, 2001.