The electric propulsion system (EPS) of a quadrotor fixed-wing hybrid unmanned aerial vehicle (QFHUAV) has important effects on its time of endurance and wind disturbance rejection capability in the quadrotor mode. Currently, the design methods of most QFHUAV EPSs are to design the quadrotor propulsion system and fixed-wing propulsion system independently. The wind disturbance rejection capability in the quadrotor mode is not considered in these methods. The multidisciplinary design optimization (MDO) method can reduce design time and cost by integrating all the disciplines involved in the design process. The MDO solutions are generally more optimal with respect to standard optimal sequential solutions. This paper proposes an MDO for a QFHUAV EPS considering the wind disturbance rejection capability in the quadrotor mode. The analysis modules of the propeller/rotor discipline, brushless direct current motor discipline, electronic speed control discipline, lithium polymer battery discipline, time of endurance discipline, mass discipline, and wind disturbance rejection capability in the quadrotor mode discipline are modeled. The MDO process of a QFHUAV EPS is constructed according to the transfer process and coupling relations among the discipline parameters. Based on the mission profile, the flight performance and mission requirements of the QFHUAV are created and a multi-objective optimization design model of the QFHUAV EPS is modeled. The Multidisciplinary feasible approach is implemented to decompose the mass coupling variables between the EPS component analysis modules and the mass analysis module effectively. A multi-objective evolutionary algorithm named NSGA-II is used to discover the full Pareto front for the multi-objective problem. The proposed MDO method is used to design the EPS of a self-developed QFHUAV. The optimal combination of QFHUAV EPS components is determined based on the optimization results. A comparison between the optimization results and the actual flight performance of the QFHUAV shows that the flight performance is in good agreement with the optimization results, which indicates that the MDO method proposed in this paper is feasible and reasonable.

四旋翼固定翼混合动力无人飞行器（QFHUAV）的电推进系统（EPS）对其续航时间和四旋翼模式下的抗风扰能力具有重要影响。目前，大多数QFHUAV EPS的设计方法是独立设计四旋翼推进系统和固定翼推进系统。在这些方法中未考虑四旋翼模式下的抗风扰能力。多学科设计优化（MDO）方法可以通过整合设计过程中涉及的所有学科来减少设计时间和成本。相对于标准最佳顺序解决方案，MDO解决方案通常是最佳选择。考虑到四旋翼模式下的抗风扰能力，本文提出了一种QFHUAV EPS的MDO。对螺旋桨/转子学科，无刷直流电动机学科，电子速度控制学科，锂聚合物电池学科，耐久时间学科，质量学科以及四旋翼模式学科中的风阻抑制能力的分析模块进行了建模。QFHUAV EPS的MDO过程是根据传递过程和学科参数之间的耦合关系构造的。基于任务概况，创建了QFHUAV的飞行性能和任务要求，并建立了QFHUAV EPS的多目标优化设计模型。实现了多学科可行方法，以有效地分解EPS成分分析模块和质量分析模块之间的质量耦合变量。一种名为NSGA-II的多目标进化算法用于发现多目标问题的完整Pareto前沿。提出的MDO方法用于设计自行开发的QFHUAV的EPS。根据优化结果确定QFHUAV EPS组件的最佳组合。将QFHUAV的优化结果与实际飞行性能进行比较，表明飞行性能与优化结果吻合良好，表明本文提出的MDO方法是可行，合理的。