Adaptive fixed-time trajectory tracking control of a stratospheric airship

• Published in: ISA transactions Vol. 76; pp. 134 - 144
• Main Authors: Zheng, Zewei, Feroskhan, Mir, Sun, Liang
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01-05-2018
• Subjects: Adaptive control; Fixed-time control; Stratospheric airship; Trajectory tracking; Stratospheric airship; Fixed-time control; Trajectory tracking; Adaptive control
• ISSN: 0019-0578; 1879-2022
• DOI: 10.1016/j.isatra.2018.03.016

This paper addresses the fixed-time trajectory tracking control problem of a stratospheric airship. By extending the method of adding a power integrator to a novel adaptive fixed-time control method, the convergence of a stratospheric airship to its reference trajectory is guaranteed to be achieved within a fixed time. The control algorithm is firstly formulated without the consideration of external disturbances to establish the stability of the closed-loop system in fixed-time and demonstrate that the convergence time of the airship is essentially independent of its initial conditions. Subsequently, a smooth adaptive law is incorporated into the proposed fixed-time control framework to provide the system with robustness to external disturbances. Theoretical analyses demonstrate that under the adaptive fixed-time controller, the tracking errors will converge towards a residual set in fixed-time. The results of a comparative simulation study with other recent methods illustrate the remarkable performance and superiority of the proposed control method.
•We present a fixed-time trajectory tracking method for a stratospheric airship with disturbances.•A novel fixed-time method is proposed to guarantee the convergence of tracking errors.•Smooth adaptive law is incorporated into the controller to provide the robustness.•Tracking errors will converge towards a residual set in fixed-time.•Comparative simulations show that the method has an excellent performance.