Investigation on performance improvement of a fully-actuated quadrotor

Quadrotors provide exclusive performances like vertical landing and taking off, load carrying capacity, and possibility of remote control. A pertinent deficiency of them however concerns their underactuated configuration, which is one of the inherent characteristics of these robots. A dependency between different movements of quadrotor is unavoidable due to this characteristic. To eliminate the dependencies between linear and rotational motions and so increase the number of controllable degrees of freedom, a novel configuration has been presented for the fully-actuated quadrotor. The rotors have the ability to rotate around two perpendicular directions and two degrees of freedom have been added to the system. The motion dependencies between linear and angular degrees are omitted. To investigate the capability of the fully-actuated quadrotor, the novel configuration is introduced and the capabilities of this configuration in eliminating movement dependencies are discussed. To this end, after extracting the motion equations governing the fully-actuated quadrotor using Newton-Euler method and applying a proportional-derivative controller to the model, the performance of this configuration in eliminating the motion dependencies is compared against a conventional underactuated type. It is shown that this configuration is capable of eliminating motion dependencies to a great extent within various simulation results. Finally, by designing a back-stepping controller and applying different trajectories to the proposed fully-actuated quadrotor, its motion capabilities and limitations are thoroughly investigated.