Indoor navigation for quadrotor UAVS using schematic environment maps

Quadrotor UAVs are a very promising type of small unmanned aerial vehicles for indoor applications because of the easy construction and propulsion principle that also allows very slow and hovering flight. However, the payload of the vehicle is very limited and the nonlinear dynamics requires advanced stabilizing control. In this paper, a flight control and navigation system for an autonomous quadrotor UAV is proposed which is especially suitable for indoor applications. The basic flight controller comprises a cascaded nonlinear control structure which finally stabilizes a commanded velocity vector. The navigation system is based on schematic maps of the environment and sensor information which is delivered by simple and small ultrasonic sensors. First simulation and experimental results underline the performance of the obtained solution.