Finite-time trajectory tracking control for a stratospheric airship with full-state constraint and disturbances

This paper investigates the finite-time trajectory tracking problem of a stratospheric airship subject to full-state constraint, input saturation, and disturbance. First, a disturbance observer is designed such that the estimation of disturbances can be accomplished within fixed time. Second, a Lyapunov barrier function-based finite-time controller is constructed to address the time-varying constraints of tracking errors, while a smooth filter is used to restrict the virtual signals and to generate their derivatives. Furthermore, novel auxiliary systems are proposed to compensate the possible saturation effect and to maintain the finite-time property. Comparative simulations are carried out to evaluate the effectiveness of the proposed controller.