柔性太阳能无人机飞行动力学与控制仿真研究

Simulation of Flight Dynamics and Control of HALE Solar UAV

高空长航时太阳能无人机采用大展弦比柔性机翼,在飞行中存在大幅度静态和动态变形,变形体现出几何非线性特征。为了对其进行分析,采用基于Hamilton原理的Hodges本征梁动力学方程,对高空太阳能无人机的柔性机翼建立了分布式非线性的动力学模型。采用空间离散、时域积分的方法,对高空太阳能无人机的飞行动态和非线性变形情况进行了仿真分析。结果显示,加入俯仰控制后,可能出现无人机姿态与机翼扭转变形的不利耦合,影响了无人机的控制特性,该效应与传感器分布位置有关。通过合理的设计控制律和布置传感器,可以减弱机翼扭转带来的不利影响,保证无人机的航迹姿态及气动弹性特性稳定。

The large-aspect-ratio flexible wing of the HALE Solar UAV has geometrically nonlinear static and dynamic deformation during flight, which has a great influence on the flight dynamic characteristic of the UAV. Considering the coupling of flight dynamics and geometrically nonlinear structure deformation, Hodges geometrically exact beam equations based on Hamilton principle were applied to found the dynamic model of the UAV. Numerical simulation and analysis were taken by discretizing the model in space and integrating it in time domain. Adding a basic pitch control law with single attitude sensor, results show an oscillation coupled with pitch motion and wing twist deformation. This effect has been reduced on another simulation with four elaborately arranged sensors, and illustrates that basic control law using reasonable arranged multi-sensors can effectively ensure flight trajectory, attitude and aeroelastic stability of the UAV.