Observer-based Control of an Unmanned Aerial Vehicle in a Non-inertial Reference Frame

Unmanned Aerial Vehicle (UAV) control in a non-inertial reference frame is of great importance. Its applications expand to several examples such as target tracking, landing on moving platforms, and flying inside moving vessels. The latter is specifically more challenging as it prevents the use of GPS. Therefore, the UAV cannot be controlled in the geostationary frame and needs to be controlled directly in the non-inertial frame of the vessel. In this paper, we present the model of the UAV in a non-inertial reference frame and propose an observer-based control strategy to track a desired trajectory in the non-inertial frame. Two sliding mode controllers are designed for relative position and attitude tracking, and a super-twisting sliding mode observer is used to estimate the relative linear velocities while accounting for the model uncertainties introduced by the non-inertial frame motion. The finite time convergence of the observer allows to satisfy the separation principle and ensures the overall convergence of the system. Numerical simulations are performed to evaluate the effectiveness of the proposed method.