Decentralized direct MRAC for attitude control of a quadrotor UAV

In this paper, a decentralized direct model reference adaptive control (MRAC) scheme is proposed in order to achieve the attitude control task for a quadrotor unmanned aerial vehicle (UAV). On the one hand, the nonlinear model for the quadrotor UAV is decomposed in the rotational and translational systems. Thus, a second order subsystem for each attitude angle is extracted from the rotational system dynamics. Then, under the assumption that a linear-in-the-parameters model for each subsystem can be defined, each subsystem is represented by a parameterized model from which a direct MRAC is designed. On the other hand, a PID controller is implemented for altitude control. The performance of our decentralized adaptive control scheme is validated via simulation results taking into account parametric variations, noise in the measurements and external perturbations.