复合翼无人机加速段纵向飞行特性分析与控制设计

针对高成本的大型复合翼(VTOL)无人机(UAV)从悬停到巡航的纵向加速飞行转换阶段开展气动/控制综合研究。基于叶素动量(BEMT)理论建立斜向入流下旋翼气动载荷计算模型，并与CFD算例对比验证其准确性。分析出旋翼系统引起整机焦点前移产生静不定效应，其中心应置于全机重心之后。仿真对比不同加速策略下的加速特性、控制效能余量等指标，给出-5°俯仰角，定推进油门的加速策略。考虑控制输入冗余，作动器动态响应不同，引入虚拟控制量的概念，采用频域分解的效能分配准则实现静态分配。考虑建模误差，设计L1自适应姿态控制框架实现动态控制增稳，拉偏仿真验证其鲁棒性。飞行试验验证了所述建模方法、加速策略及控制律框架的有效性。 

Longitudinal flight characteristics analysis and control design for hybrid VTOL UAV in accelerative transition

A comprehensive aerodynamic/flight-control problem was studied on a high-cost hybrid vertical take-off and landing (VTOL) unmanned aerial vehicle (UAV) in the accelerative stage from hovering to cruising. A computational model of the rotor under oblique inflow was established based on the blade-element momentum theory (BEMT), and its accuracy was verified by comparison with the CFD calculation model. It was analyzed that the rotor system caused the aerodynamic focus of the aircraft to move forward, resulting in static instability effect, and its center should be placed after the center of gravity of the aircraft. By analyzing acceleration features and the control input margin under different acceleration strategies, the fixed -5 degree pitch angle and fixed throttle acceleration strategy were determined. Considering the control input redundancy and the different response of the actuator, the allocation criterion of frequency domain was adopted to realize static allocation. Considering the modeling error, the L1 adaptive attitude control framework was designed to achieve dynamic control stabilization, and the deflection simulation was used to verify its robustness. Flight test verified the effectiveness of the modeling method, acceleration strategy, and control law framework.