Safety-concerned longitudinal control strategy for takeoff phase of UAV

In order to heighten the safety of unmanned aerial vehicle (UAV) taking off in atmospheric disturbance environment, a new safety-concerned longitudinal control strategy based on direct force control method was discussed as an improvement of the regular longitudinal control strategy for the takeoff phase of UAV. A combined filtering method was employed to resolve the acquisition of high-precision vertical speed signal of UAV, parameter selection and validation was carried out through frequency domain analysis method using the special testing equipment, the result verifies its feasibility and practicability, which satisfies the need of takeoff control. The nonlinear model of UAV was built in the Matlab/Simulink environment and then the flap control law was designed in accordance with the new control strategy. The simulation results show that the new control strategy is capable of enhancing the disturbance-resistance ability of UAV remarkably, thus ameliorating the safety performance of the takeoff phase.