Dynamic Inversion-Based Sliding Mode Control of a Tilt Tri-Rotor UAV

The modeling and controller design for a tilt tri-rotor unmanned aerial vehicle (UAV) is studied in this paper. Taking the advantages of high cruise efficiency and vertical takeoff and landing (VTOL) capability, the tilt tri-rotor UAV attracts many researchers' attentions. However, due to the existing nonlinearities and time-varying structure, research on the modeling and control scheme of the tilt tri-rotor UAV is still a challenging work. To achieve stable flight control in helicopter mode, a robust and efficient controller is developed. First, the aircraft is described in detail, and the mathematical model of the aircraft is obtained. Then, a control allocation algorithm is developed to improve modeling precision. Finally, a hierarchical flight controller is designed by combining the theory of dynamic inversion and sliding mode control. The results show that the proposed control scheme can achieve strong robustness.