飞机结构模态耦合现象的抑制方法

Preventing Methods of Airplane Structural Mode Coupling

某型飞机试飞中出现了高频振荡现象,该振荡属于伺服弹性振荡,产生该振荡的原因是飞控系统对传感器测量的结构弹性频率段的振动信号衰减程度不足。为了抑制该振荡的发生,对主控系统的纵向通道控制律进行了适当的调整,并对调整前后控制系统的频域特性进行仿真对比。在此基础上,进行试飞现象重现并验证控制律更改的有效性,这些仿真表明,控制律更改可以实现对伺服弹性振荡的抑制。

High-frequency oscillation occurred during the flight test of some airplane, this oscillation was servo-elastic oscillation. The cause was that the flight control system hadn＇t attenuated enough the oscillation signal in the structural elastic frequency range. To avoid this oscillation, the longitudinal control law of primary control system and was adequately adjusted. Frequency characteristic of control system was compared between before and after modification. Then, the phenomenon during flight test was repeated and the modification of control law was validated. The simulation indicated that the new control law was able to prevent servo-elastic oscillation.