非线性气动弹性模型参考自适应控制

Model Reference Adaptive Control of Nonlinear Aeroelasticity

首先将含有前/后缘双控制面二元机翼的动态方程以状态空间形式描述,然后考虑俯仰方向的迟滞非线性模型存在参数不确定性的情况下,利用Lyapunov稳定性理论进行了结构化模型参考自适应控制律设计。仿真结果显示:所设计的控制律能够使开环不稳定的气动弹性系统快速地达到稳定状态。由于最大控制面偏转的存在,来流速度较高时闭环系统仍会发生颤振;根据控制面最大偏转的不同取值,文中给出了闭环临界颤振速度的变化曲线。

The dynamic equations of a two-dimensional airfoil with leading and trailing edge control surfaces are described in state space. Then it is considered that there exists parametric uncertainty in the hysteresis nonlinearity in pitch. Based on Lyapunov stability theory, a structured model reference adaptive control law is designed. The simulation results show that the open-loop aeroelastic system is unstable and exhibits limit circle oscillation, while the closed-loop system reaches to stable state quickly. As the existence of hard constraint on the control inputs, the closed-loop system becomes unstable when the freestream velocity is higher. The effects of maximal control inputs on the closed-loop critical flutter velocity are investigated, and a stable boundary is obtained.