Backstepping sliding-mode control of stratospheric airships using disturbance-observer

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 independence adjustment gains. Furthermore, designed process disturbance inputs BSMC performances. The closed-loop system plant proved be globally asymptotically stable Lyapunov theory. By comparing traditional SMC design, results obtained demonstrate capacity execute realistic mission, even in disturbances, aerodynamic coefficient uncertainties.