多控制面飞机的全机颤振主动抑制设计

Active Flutter Suppression of Airplane Configuration with Multiple Control Surfaces

以仿F/A-18A外形的全机模型为对象,研究多输入/多输出(MI MO)飞机颤振主动抑制(AFS)设计方法和特点。控制律采用线性二次型高斯(LQG)方法,结合平衡截断法降阶。首先,仅用机翼舵面对机翼部件和全机设计AFS控制律;然后,全动平尾参与AFS控制;最后,机身额外加装小翼,与机翼舵面联合控制,考察AFS效果。研究发现:单独机翼AFS效果显著,颤振速度提高28%;全机构型有机身模态参与颤振,仅用机翼舵面,低阶控制律颤振速度增量仅为4.6%;全动平尾参与控制可改善低频颤振,但存在低速的高频不稳定模态;机身小翼与机翼舵面联合控制,AFS控制效果可达14.9%。最终,筛选出机翼后缘内侧舵面与机身小翼两组控制面进行AFS设计,即可达到14.5%的颤振速度增量,是较为理想的AFS方案。

Active flutter suppression（AFS） of a multi-input/multi-output（MIMO） airplane configuration is studied on an imitational F/A-18A model.The controllers are designed by linear quadratic Gaussian（LQG） method truncated by a balanced truncation method.First,by merely using the wing flaps,the AFS of the wing and the airplane are performed.Then,all-moving horizontal empennage are involved into flutter control.Finally,a pair of fuselage flaps is combined with the wing flaps for AFS.It is found that the AFS of the wing is effective with the flutter speed increasing by 28%.However,the increment is only 4.6% for the airplane because of the fuselage modes coupling into flutter.The addition of all-moving horizontal empennage can improve low-frequency flutter,but it can also cause low-speed high-frequency instability.Combining the fuselage flaps with the wing flaps can increase the flutter speed by 14.9%.Finally,the trailing-edge in-board flaps and the fuselage flaps are selected to achieve a 14.5% flutter speed increment,which is a satisfactory AFS design.