平流层飞艇滑模姿态控制系统设计

Design of sliding mode attitude control system for stratospheric airship

针对平流层飞艇姿态稳定控制问题,提出了一种新的具有鲁棒性滑模姿态控制系统。一方面考虑到平流层飞行环境对飞艇姿态产生了许多不确定性因素,另一方面考虑到飞艇的建模误差和通道耦合,综合建立平流层飞艇姿态控制系统的非线性模型。基于反演法来设计自适应动态滑模,利用Lyapunov稳定理论设计得到了具有鲁棒性的滑模姿态控制系统,不仅消除了系统非匹配不确定性对系统性能的影响,同时避免了反演法的微分膨胀问题。仿真结果表明,这种控制器能够适应平流层环境和未知干扰的影响,满足姿态控制稳定性要求。

For the case of attitude control for stratospheric airship, a new robust nonlinear sliding mode control system is proposed. Firstly, the nonlinear dynamics is built with the consideration of the uncer- tainties due to flight environment and the model error and couplings among different channels. Secondly, several sliding modes and control law with robustness are derived by applying the backstepping method, and the reachability and stability of sliding mode is strictly proven by Lyapunov stability theory. The in- fluence of mismatched uncertainties on system performance is eliminated, and the problem of differential expansion in traditional backstepping is avoided. Finally, the simulation results demonstrate that the con- troller could meet the performance of control system and adapt well to stratospheric environment and un- known disturbances.