In the presence of unknown disturbances and model parameter uncertainties, this paper develop a nonlinear backstepping sliding-mode controller (BSMC) for trajectory tracking control stratospheric airship using disturbance-observer (DO). Compared with conventional sliding mode surface (SMS) constructed by linear combination errors, new SMS manifold is selected as last back-step error to improve ...

A state observer is a system that models a real system in order to provide an estimate of the internal state of the system. The design techniques and comparison of four different types of state observers are presented in this paper. The considered observers include Luenberger observer, Kalman observer, unknown input observer and sliding mode observer. The application of these observers to a Mul...