Adaptive control for a class of nonlinear systems with uncertain parameters and mismatched disturbances

This paper deals with the adaptive control problem for a class of nonlinear systems with mismatched disturbances. First, a nonlinear disturbance observer is constructed to estimate the mismatched external disturbances. Then, based on adding a power integrator technique, an adaptive control scheme is proposed for the nonlinear systems with uncertain parameters. It is proved that the designed adaptive controller ensures the global input-to-state stability of the closed-loop system. Finally, a simulation example is utilized to validate the applicability of the proposed control technique.