ESO-based output-feedback regulation control of nonlinear systems with SiISS inverse dynamics

This paper considers the output-feedback controller for a class of stochastic cascade nonlinear systems with stochastic integral input-to-state stable inverse dynamics, unknown control coefficients, and matching disturbances. By augmenting the existing disturbance as an extended state, a novel extended state observer (ESO) is constructed based on the Riccati differential equation. Based on the techniques of Nussbaum function and backstepping, an adaptive output feedback controller is proposed to guarantee that all system states of the resulting closed-loop system are globally asymptotically stable in probability. Meanwhile, the other signals are almost surely bounded. Additionally, the validity of the proposed control method is verified by simulation examples.