Modeling and Control of Outdoor Quadrotor UAVs

In this paper an improved approach is presented for modeling and control of outdoor quadrotor UAVs. A precise and an approximated dynamic model was elaborated for quadrotors. A hierarchical integrating backstepping control algorithm was constructed that has the capability of handling every effect in the dynamic model and in the meantime successfully ignore the realistic measurement noises. The hierarchical control structure consists of position, attitude and rotor control, extended with path design and state estimation. Control parameters can be easily tuned. The tracking algorithm is able to follow the prescribed path with small error. The sensory system and the state estimation are prepared for outdoor applications. The embedded control system contains a HIL extension to test control algorithms before the first flight under real time conditions. Path tracking results show the effectiveness of the embedded control system.