Optimization of Transition Trajectory for High-Lift Hybrid Mode UAV

The hybrid mode UAV has the characteristics of a fixed-wing UAV for high-speed cruising, but also has the functions of a rotary-wing UAV for vertical take-off and landing, fixed-point hovering and low-speed maneuver, which can be an effective solution for the future of the small and medium-sized UAV field. The most prominent feature of the hybrid mode UAV is the existence of a transition flight phase, which can be divided into forward transition and backward transition. In this study, the trajectory optimization problem for transition flight is transformed into a nonlinear programming problem and solved by the direct collocation method. According to the given state and constraints, the optimal transition strategy is obtained by solving the forward and backward transition flight phases respectively while maintaining a constant height, with the minimum energy consumption as the objective.