Output feedback controller design for a class of uncertain feedforward nonlinear systems

This paper investigates output feedback stabilization for a class of feedforward nonlinear systems with unknown control coefficient. For design convenience, a state transformation is first introduced such that the control coefficient of the new system is known while the states are unmeasured. Then, an appropriate observer is constructed and the output feedback controller is proposed in a step-by-step manner. By appropriate choice of the design parameters, the original system is globally asymptotically stabilized.