大型军用运输机的飞行航迹优化

Vertical flight trajectory optimization of heavy military airlift aircraft

军用运输机通常在紧急情况下执行空运任务,应以时间成本作为此类飞机垂直剖面飞行航迹的优化指标.将飞行时间按上升、巡航和下滑3个阶段进行分解,采用能量状态法简化飞机质点运动方程,将优化指标转化为等效能量形式.优化巡航段参数,采用最小值原理分别完成纵向最优剖面上升和下滑飞行航迹的优化.仿真结果表明:军用运输机在上升段采用各高度的最大可用速度上升,在低于升限的某高度以最大飞行速度巡航,在下滑段采用各高度的最大可用速度下降时,全剖面飞行时间最短.研究结果对提高大型军用运输机在可能存在威胁的前线环境下的运输效率和飞行安全性等均具有一定的实用参考价值.

Vertical profile flight trajectory of heavy military airlift aircraft,which is often time-critical was optimized.Flight time was chosen as the cost function and divided into climb,cruise and descent parts.Flight point-mass motion equation was transferred into equivalent-energy form using energy-state method.Climb and descent segment flight trajectory optimization was carried out by applying Pontryagin＇s minimum principle after optimizing cruise altitude and speed.Numerical result was obtained that trajectory of such aircraft was made up of three parts： a climb segment along a maximum feasible speed path,a maximum level speed cruise segment at lower altitude and a descent and approach segment along a maximum feasible speed path.This result will be significant for improving airlift efficiency and safety of military transport aircraft which is operated in hazardous frontline environment.