Adaptive Sliding Mode Controller for Overactuated Quadrotor UAV

Quadrotor unmanned aerial vehicles (UAV) are underactuated as although UAV has six degrees of freedom, only four control inputs are available. Under actuation limits the mobility of the UAV, as it cannot independently track a desired position and attitude trajectory in space. Thrust vectoring can be used to make the UAV into a fully actuated system. The most efficient method for thrust vectoring is by tilting the motors using actuators. The tilting mechanism will provide additional four control inputs, making the system overactuated. In this paper, a sliding mode controller is proposed for the simultaneous tracking of attitude and position of the overactuated quadrotor. Further a Takagi-Sugeno based fuzzy gain scheduling system is proposed for minimizing the chattering in the control signals. Finally, the performance of the designed control system is evaluated using simulation results.