平流层飞艇定点保持模式的建模与稳定性分析

平流层飞艇作为一种新型的通信和观测等应用平台受到世界各国越来越多的重视,定点保持模式是平流层飞艇的飞行任务中很重要的一环。该模式下的控制系统与平飞模式下的传统舵面、螺旋桨控制系统相比具有较大的特殊性。文章建立了平流层飞艇定点保持模式的动力学模型,并分析了模型中假设的控制输入即矢量推力螺旋桨执行机构所产生的控制力和力矩在物理实现上的可行性。在此基础上,采用李雅普诺夫(Lyapunov)近似理论对无控制输入系统进行了稳定性分析,得出系统在无控制输入时是不稳定的,最后通过仿真验证了分析结果。

Modeling and Stability Analysis for a Stratospheric Airship in Position-Attitude Keeping Mode

As a new communication and observation platform,stratospheric airships draw more and more attention of the world.Position-attitude keeping mode is a very important part in stratospheric airships flight mission.The control system in this mode is quite different from that using typical rudders and airscrews in cruising mode.In this paper,a dynamic model for the airship in this mode is deduced,and the physical feasibility of the control system inputs by vector thrust airscrews in the model is analyzed.On the basis of the model and its analysis,the stability of the system with no control inputs is analyzed by using the approximate theory of Lyapunov.The analyses result shows that the system is not stable,which is validated by the simulation.Based on the results obtained in this paper,the control strategy can be discussed.