Adaptive safe control for tethered aircrafts with input and output constraints

In this article, an adaptive safe control scheme is presented for tethered aircrafts subject to unknown disturbances, input saturations, and deferred asymmetric time-varying output constraints. By integrating a shifting function into an asymmetric barrier Lyapunov function, the deferred asymmetric time-varying output constraints are first solved. Then, to eliminate the conflict between input saturations and output constraints, an auxiliary system is designed to enlarge output constraint boundaries when input saturation occurs and the system has no tolerance for output constraints, which ensures system safety. Furthermore, disturbance observers are employed to estimate unknown disturbances. Finally, both theoretical proof and simulation results demonstrate the validity of the proposed control scheme.