Finite time positioning control for a stratospheric airship

The stratospheric airship provides a unique and promising aerostatic platform for broad applications, which requires fast and robust positioning control to support these tasks. A finite time control scheme is proposed to address the problem of positioning control for stratospheric airships subject to dynamics uncertainty. A nonsingular terminal sliding mode controller is designed for positioning control, which overcomes the problem of asymptotical convergence of sliding mode control and the singularity problem of terminal sliding mode control. Under the framework of nonsingular terminal sliding mode control, a fuzzy logic system is employed to approximate the uncertain dynamics of the stratospheric airship, and the fuzzy logic system approximation-based finite time sliding mode controller is designed. The finite-time convergence of positioning errors and the stability of the closed loop system are guaranteed by Lyapunov theory. Finally, the effectiveness and performances of the proposed controller are demonstrated through experimental simulations. Contrasting simulation results illustrate that the proposed controller decreases chattering effectively and ensures faster convergence compared to sliding mode controller. (C) 2019 COSPAR. Published by Elsevier Ltd. All rights reserved.