Output Feedback Constrained Control for a Class of Nonlinear Cascade Systems with External Disturbance

A class of nonlinear systems with integral input to state stability, inverse dynamics, external disturbance, and asymmetric output constraints are investigated in this paper's study of the adaptive output feedback control problem. The external disturbance is resolved using the reduced-order extended state observer, and the error dynamic system is established. The asymmetric barrier Lyapunov function is used to deal with the output constraints. Supported by backstepping method and Young's inequality, it is proved that the involved control scheme not only satisfies the global asymptotic stability of the closed-loop system, but also makes the output not violate the asymmetric constraints. The simulation results demonstrate that the control scheme is effective.