Outdoor navigation using two quadrotors and adaptive sliding mode control

In this work, a solution to outdoor trajectory tracking using quadrotors is presented. The unmanned aerial vehicles (UAVs) navigate under the leader-follower formation, where the pose of the leader is estimated using its onboard sensors, and the pose of the follower by position-based visual servoing. To handle the outdoor environment perturbations, unmodeled vehicle dynamics, and dynamic disturbances caused by wind and varying lightning conditions, a robust sliding mode controller is used. The proposal is experimentally validated using two Parrot Bebop 2 quadrotors in an outdoor scenario. The obtained results allow concluding that the proposed control system is able to accomplish trajectory tracking under parametric uncertainties and real-world disturbances.