大空域变轨巡航飞行器变结构控制律研究

摘要

For the perturbation problem of system matrix occurred during the orbital transfer of supersonic large-space cruise vehicle, This paper presents a variable structure control law with strong robustness. Then, through reasonable selection of sliding surface, the variable structure control law designed is perturbation invariable with the change of flight field, thus the robustness of control law is kept. Furthermore, by analyzing the phase plane and using lyapunov theory, the stability of the closed-loop system is proved. By using the saturation function to approximate sign function, the chattering of variable structure control law is eliminat-ed. Finally, the simulation results show the strong robustness of the designed variable structure control law.%针对超声速大空域变轨巡航飞行器在变轨过程中出现的系统矩阵摄动问题,给出了具有较强鲁棒性的变结构控制律.通过合理选取滑模面,使得设计的变结构控制律对由于飞行空域变化造成的系统矩阵的摄动具有不变性,从而保证了控制律的鲁棒性.通过对系统相平面的分析及李亚普诺夫理论证明了闭环系统的稳定性.利用饱和函数来近似符号函数,对变结构控制律的抖振现象进行消除.最后给出了数学仿真校验,结果表明所设计的变结构控制律具有较强的鲁棒性.