Flight control of tilt-rotor unmanned aerial vehicle based on two-level control allocation

As a special type of robot, tilt-rotor unmanned aerial vehicles have demonstrated great potential in performing tasks in complex environments. To improve its autonomy and adaptability to complex environments, robust flight control law and control allocation method was studied. A cascaded flight control framework based on two-level control allocation was proposed for the significant changes in control strategy and control effectiveness of tilt-rotor unmanned aerial vehicle in different flight modes. A top-level controller was developed for various control modes, and the actual control quantity was generated by a torque control allocation module in conjunction with attitude angle commands using a force control allocation module based on the weighted generalized inverse method. The attitude controller was designed based on a dual closed-loop control structure, and a disturbance observer was added to improve the robustness to external disturbances. Finally, the effectiveness and robustness of the flight control framework and controller were verified by full process simulation and transition simulation under interference conditions.