Decentralized Control of the Quadrotor's 6-DOF

In this paper, a decentralized control scheme is proposed in order to achieve the control goal of 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 second-order subsystem for each translational coordinate is extracted from the translational system dynamics. Then, a PID controller is implemented for each translational coordinate subsystem. The performance of our decentralized control scheme is validated via simulation results taking into account parametric variations, noise in the measurements and external perturbations.