Exploration of high-altitude dynamic soaring based on six-degree-of-freedom model

基于六自由度模型的高空动态滑翔探究

School of Aeronautics, Northwestern Polytechnical University, Xi’an 710072, China

Received: 9 November 2020

Abstract

Dynamic soaring is an emerging flight range-extension technology that effectively reduces UAV's energy consumption by deriving wind energy from lateral gradient wind fields. Comparing with the small UAV's near the surface, the application of dynamic soaring technology in the high-altitude long-endurance flight requires the additional consideration of the influence of sustained side wind, the influence of the sideslip angle cannot be ignored. This puts higher requirements on the flight dynamics model. In this paper, the dynamic model for the high-altitude dynamic soaring based on the six-degree-of-freedom equation is modeled to replace the traditional mass point model; the energy change principle of the high-altitude dynamic gliding is derived; the effect of the high-altitude wind field on the dynamic soaring UAV is analyzed; and the way to get optimal wind field energy acquisition and energy saving efficiency are analyzed. The results show that the dynamics model based on the six-degree-of-freedom equation can more realistically reflect at high altitude; the application of dynamic soaring can effectively improve the range of the high-altitude UAV; the wind direction at high-altitude wind field has a significant effect on the dynamic soaring efficiency.

摘要

动态滑翔技术是一种新兴的飞行器增程技术，通过从横向梯度风场中获取能量，有效减少了飞行器能量消耗。相对于近地表小型无人机，动态滑翔技术在高空长航时飞行器的应用中需要额外考虑存在的持续侧风影响，侧滑角的影响不能直接忽略，对飞行动力学模型提出了更高的要求。基于六自由度方程的高空动态滑翔动力学模型进行了动力学建模，以代替传统的质点模型；针对高空动态滑翔的能量变化原理进行了推导；分析了高空风场对动态滑翔无人机的影响及最优风场能量获取方法及能量节约效率，并通过飞行仿真验证了高空风向对动态滑翔的效果影响。研究结果表明：基于六自由度方程的高空动态滑翔动力学模型能够更真实地反映高空动态滑翔动力学特点；动态滑翔能够有效提高高空飞行器续航能力；高空风向对动态滑翔效率有明显影响。