ISAE-SUPAERO, Université de Toulouse, 31400 Toulouse, France.
Bioinspir Biomim. 2018 Nov 20;14(1):016006. doi: 10.1088/1748-3190/aaec61.
Fixed-wing small, unmanned aerial vehicles usually fly in atmospheric boundary layers that are often under the influence of turbulent environments. Inspired by nature's flyers, an application of an energy-harvesting flight strategy for increasing the energy state of the aircraft is presented. This paper provides basic longitudinal flight dynamic model exposing the physics behind the process. It shows significant power savings in flight with a sinusoidal and stochastic wind profile with active control of energy-harvesting. The active control based on optimized proportional gains was implemented for energy extraction from realistic atmospheric conditions, leading to significant energy savings for a 'bird-sized' vehicle. The paper reveals the equipment and necessary preparations for the flight test campaign. Moreover, it describes the design of a custom controller and its calibration in the wind tunnel against roll movements during pitching maneuvers. Finally, it investigates the benefits and potential of the automated process of energy-harvesting with simple proportional control through flight tests in a turbulent environment, validating the concept through the increased energy state of the aircraft.
固定翼小型无人机通常在大气边界层中飞行，而大气边界层经常受到紊流环境的影响。受自然界飞行器的启发，提出了一种利用能量收集飞行策略来增加飞机能量状态的应用。本文提供了基本的纵向飞行动力学模型，揭示了这一过程背后的物理原理。研究结果表明，在具有正弦和随机风廓线的飞行中，通过主动控制能量收集，可以显著节省飞行中的能量。针对实际大气条件，基于优化比例增益的主动控制实现了从环境中提取能量，从而为“鸟类大小”的飞行器节省了大量能量。本文揭示了飞行测试活动所需的设备和必要准备。此外，它还描述了定制控制器的设计及其在风洞中针对俯仰机动期间的滚转运动进行校准的过程。最后，通过在紊流环境中的飞行测试，研究了通过简单的比例控制自动进行能量收集的益处和潜力，通过飞机的能量状态增加验证了该概念。
