A dual observer design for global output feedback stabilization of nonlinear systems with low-order and high-order nonlinearities

This paper employs a dual-observer design to solve the problem of global output feedback stabilization of a class of nonlinear systems whose nonlinearities are bounded by both low-order and high-order terms. We show that the dual-observer comprised of two individual homogeneous observers, can be implemented together to estimate low-order and high-order states in parallel. The proposed dual-observer, together with a feedback controller which has both low-order and high-order modes, will lead to a new result combining and generalizing two recent results [9] and [13].