电动无人机动力系统优化设计及航时评估

为提高电动无人机续航性能,针对动力系统进行了优化设计,并提出了相应的航时评估方法.首先采用涡流理论优化设计了小型螺旋桨,再通过实验测试优化选取了与螺旋桨高效率匹配的电动机.同时,考虑到锂离子电池放电倍率及电压降低对放电时间的影响,建立了恒功率条件下电池放电时间计算模型.最后,根据优化得到的动力系统和电池计算模型,推导出有弯度机翼的电动无人机航时公式.某电动飞翼布局无人机飞行试验结果显示,优化得到的动力系统具有较高的效率,测试得到的无人机续航时间与评估得到的理论值误差为12%,在允许误差范围内吻合较好.

Optimal design and endurance estimation of propulsion system for electric-powered unmanned aerial vehicle

For small electric-powered unmanned aerial vehicles (EPUAV), endurance performance largely depends on propulsion system. To improve EPUAV endurance, the electric-powered propulsion system was designed optimally. Meanwhile EPUAV endurance formula was presented. Based on vortex theory, a small screw propeller was designed optimally using genetic algorithm. A series of predicted motors were tested by dynamometer in order to match the optimized screw propeller effectively. The influences of discharged rating and voltage drop for lithium-ion battery were considered. Then a math model of battery discharge time was deduced while the battery output power was kept as constant. According to the optimal propulsion system and battery model, the EPUAV endurance formula was presented for cambered wing. Flight tests of a flying wing EPUAV indicate that optimized propulsion system operates more effectively after an optimal design. There exists approximately 12% error between flight tests and theoretical estimation. Within permissible error, good agreements have been obtained.