学术论文

      无人机风梯度滑翔过程中能量变化

      Energy transformation in dynamic soaring of unmanned aerial vehicles

      摘要:
      风梯度滑翔是一种能够使飞行器从飞行环境中获取能量的飞行方式。在已建立的飞行器动力学模型的基础上,分析了无人机在已知的梯度风场中一个滑翔周期内的能量变化过程。采取分段解析的方法,将一个风梯度滑翔周期分为4个阶段进行分析,即逆风爬升、高空转弯、顺风下滑和低空转弯,其中高空转弯为整个滑翔周期内的关键阶段。采用三维空间路径结合二维平面投影的计算方法,详细分析了无人机在高空转弯过程中的运动方程和能量转化方程,同时分析了影响飞行器从梯度风场中获取能量以及梯度风场中由于空气阻力导致飞行器能量损失的相关参数,为无人机最大程度地从梯度风场中获取能量,同时减少自身能源损耗提供了理论指导,并且根据理论建模进行了仿真分析,得出了逆风爬升和高空转弯的初期是获取能量主要阶段的结论,对指导无动力滑翔有很大的意义。
      Abstract:
      Dynamic soaring is a special flying technique designed to allow air vehicles to extract energy from atmosphere.Based on the established dynamic model of the aircraft,the energy transformation of unmanned aerial vehicles (UAVs)in a gliding cycle of the known gradient wind field was analyzed.The method of subsection analysis was introduced and a dynamic soaring cycle was divided into four phases:climbing with headwind,turning in high altitude,gliding with tailwind,turning in low altitude.Turning in high altitude was the most critical phase in the dynamic soaring cycle.By using the calculation method which combines the three-dimensional space path with the two-dimensional plane projection,the motion equation and energy transformation equation of UAV in the phase of turning in high altitude were achieved.Based on the equations,the parameters which influenced the energy extract of UAVs from gradient wind field and which resulted in the energy loss because of the wind drag were analyzed.The conclusion provides theoretically guide for the UAV’s maximum extracted energy from gradient wind field and the decreasing of its energy loss.Besides,the dynamic soaring simulation was designed and results show that the phase of climbing with headwind and the early stage of turning in high altitude are the mainly periods to absorb energy from wind field.This conclusion is meaningful to direct the dynamic soaring without thrust.
      作者: 朱炳杰 侯中喜
      Author: ZHU Bingjie HOU Zhongxi
      作者单位: 国防科技大学 航天科学与工程学院,湖南 长沙,410073
      刊 名: 国防科技大学学报 ISTICEIPKU
      年,卷(期): 2015, (1)
      分类号: TK01+1
      机标分类号: V32 V27
      在线出版日期: 2015年4月7日
      基金项目: 国防科技大学科研计划资助项目