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Finite-time tracking control of a quadrotor UAV without velocity measurement

In this paper, the problem of finite-time trajectory tracking control of a quadrotor Unmanned Aerial Vehicle (UAV) without velocity measurement is investigated. A hierarchical control strategy is employed based on the cascade property of the system. First, a virtual control signal is introduced for the translational subsystem, from which we extract the desired attitude and thrust. Second, considering the case that the velocity of the quadrotor UAV can not be available, a finite-time convergent observer is developed to reconstruct the information of the velocity, combining with the finite-time convergent observer, an output feedback-based position controller is derived. Finally, attitude controller is designed to force the actual attitude to the desired one. Finite-time stability of the overall closed-loop system is rigorously provided by means of Lyapunov theory. Simulations illustrate the effectiveness of the proposed control scheme.