IJCAS

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 timedependent 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.

Keywords: Barrier Lyapunov function, integral input to state stability, inverse dynamics, unknown control directions.