Disturbance attenuation by output feedback for a class of uncertain nonlinear systems

This paper focuses on the disturbance attenuation by output feedback for a class of nonlinear systems with uncertain control coefficient and unmeasured states dependent growth. In order to realize disturbance attenuation, a high-gain observer is first introduced. Then, a linear output feedback controller is designed based on the backstepping technique. By choosing appropriate design parameters, disturbance attenuation is achieved in the sense of L₂ gain.