Research On Loads Alleviation Of Elastic Aircraft

In this paper, at first, the aeroservoelastic equations of the elastic airplane are established and thestability of the airplane is analysized by using the root locus method. Then, the flight dynamic modelfor maneuver analysis is established and the effect of the structural flexibility on the flight parametersand maneuver loads is illustrated. The numerical results show that the structural flexibility can not beignored in the process of maneuver loads design for elastic aircraft. To alleviate the maneuver loads ofthe airplane, an optimal maneuver loads alleviation system is synthesized by using the linear quadraticGaussian (LQG) theory. The simulation results show that the maneuver loads can be effectivelyalleviated by the proposed optimal control system with multi-control surfaces. At last, the gust loadsalleviation is studied. The time responses of the gust loads of the airplane subject to several gustexcitations are illustrated. To alleviate the gust loads, a PID controller is synthesized and thesimulation results show that the control law can alleviates the gust loads effectively.