Output Feedback Stabilization of a Class of Uncertain Nonaffine Nonlinear Systems

In this paper, output feedback control is presented for a general class of uncertain nonaffine nonlinear systems, that does not rely on state estimation. Under the condition that only the system output is available for feedback, a dynamic linear filter is built to estimate unknown nonlinearities, and an output feedback controller is developed to stabilize the systems by utilizing the estimation to compensate for the unknown nonlinearities. One important feature of the proposed control is that the controller is developed under mild conditions with simple control algorithms, which is of great significance in engineering practice. Simulation results show the effectiveness of the control approach.