弹性飞机地面滑行随机最优控制

Stochastic Optimal Control of Flexible Aircraft Taxiing

将主动控制缓冲器应用于飞机地面滑行减振。建立了飞机在随机跑道激励下,考虑机身俯仰运动与弹性振动的非线性随机动力学模型。采用统计线性化方法,使模型在平衡点附近线性化。加入前置线性滤波器将随机路面高斯激励转换成高斯白噪声激励。基于随机最优控制理论,设计了线性二次型高斯(LQG)控制器。由Monte-Carlo法模拟了路面随机过程,得到了飞机的动响应。通过主动控制缓冲器与被动控制缓冲器的仿真比较可以看出,主动控制缓冲器能够有效提高飞机地面滑行的舒适性与减振性。

In this article active control landing gears are designed to alleviate vibration during aircraft taxiing. A nonlinear stochastic dynamic model is established which takes into consideration aircraft body pitch movements and the elastic vibration excited by the random runway. The statistical linearization method is adopted to ensure the linearity of the model near the balance point, and the Gaussian random process of the runway is generated from the Gaussian white noise by a shape filter. Based on the stochastic optimal control theory, a linear quadratic Gaussian （LQG） controller is designed with weighted quadratic performance index related to comfort, shock absorption, and less energy spending. The aircraft dynamic responses are obtained through the runway random process modeled by Monte-Carlo method. Simulation results show that, compared with the passive control landing gears, active control landing gears can effectively improve comfort and shock absorption of the aircraft. Finally, the influence of the weighted coefficients on performance index is discussed in detail.