Barrier Lyapunov Functions-based Output Feedback Control for a Class of Nonlinear Cascade Systems With Time-varying Output Constraints

In this study, a class of nonlinear systems with integral input to state stability (iISS) inverse dynamics and unknown control direction are examined for the issue of time-varying asymmetric output constraints of adaptive output feedback controller. To deal with unmeasured state variables and unknown directions, the state observer is constructed using a Rickati matrix differential equation with time variation. A backstepping-based method is recommended for establishing the dynamic output feedback control law. By ensuring boundedness for the time-dependent barrier Lyapunov function (BLF) in the closed loop, we may not only maintain the boundedness and stability of other signals, but also avoid breaking the time-varying asymmetric constraint of the output. Finally, simulation analyses are used to confirm the scheme’s efficacy.