Extended State Observer for Nonlinear Time-Varying Dynamic Systems

Abstract

In this paper, a new extended state observer (ESO) is proposed for a second-order general class of nonlinear dynamic systems. By tuning the parameters appropriately, it is shown that the proposed ESO can achieve the desired estimation performance under mild assumptions. Although these assumptions are not necessary, it is shown that if one of them is not satisfied, many ESO proposed in literature cannot work. Moreover, the implementation issues are discussed. Simulation results demonstrate the power of the proposed algorithm.