The paper seeks to study the control system design of a novel unmanned aerial vehicle (UAV). The UAV is capable of vertical takeoff and landing (VTOL), transition flight and cruising via the technique of direct force control. The incremental nonlinear dynamic inversion (INDI) approach is adopted for the 6-DOF nonlinear and nonaffine control of the UAV. Based on the INDI control law, a method of two-layer cascaded optimal control allocation is proposed to handle the redundant and coupled control variables. For the weight selection in optimal control allocation, a dynamic weight strategy is proposed. This strategy can adjust the weight of the objective function according to the flight states and mission requirements, thus determining the optimizing direction and ensuring the rationality of the allocation results. Simulation results indicate that the UAV can track the target trajectory accurately and exhibit continuous maneuverability in transition flight.

the controller is designed for the vertical take-off and landing mode, the transient flight mode and the fixed wing flight mode, respectively; a control signal fusion method is introduced in the transition flight control mode, which realizes the smooth switching of aerial vehicle in different flight modes; aiming at the problem of the control plane redundancy, the method of advancing amplitude of redundant control quantity is adopted to simplify the control distribution process. It is verified that the control method of Vertical Take-Off and Landing UAV can track the flight path well via six degrees of freedom simulation of the aerial vehicle.