Fixed-time Backstepping Control of QUAV Based on Prescribed Performance

This article proposes a fixed-time control method with prescribed performance constraints for a quadcopter unmanned aerial vehicle (QUAV) with unknown disturbances. Firstly, the fixed-time extended state observer (ESO) is designed to estimate unknown disturbances. Secondly, the new barrier Lyapunov function (BLF) is proposed, which can handle constrained and unconstrained, symmetric and asymmetric situations. Thirdly, the tracking error is proved to converge to the origin within fixed-time by Lyapunov function. Ultimately, the effectiveness of algorithm is verified by numerical simulation.