| The work presented in the paper is to research the flight simulation of gust response and gust load alleviation technology. When encountering gust, the airplane appear bump,and the load acting on aircraft wing changes rapidly, which decreases aircraft ride quality and reduces structural life-time. Especially for the future flexible aircraft, due to the significant flexibility effect, the body movement and the structure movement appear dynamic coupling, which has a greater impact on flight safety. As a consequence, the gust load alleviation system based on active control technology is introduced, which can inhibit the response of the aircraft against the gust, slow wing flutter intensity, improve the fatigue strength of the wing structure, and improve the ride quality. The research in this paper could be divided into three parts. Firstly, the atmospheric turbulence model based on the rational spectral theory is established in both frequency domain for flight control law design and time-domain for flight simulation. Secondly, the flight dynamic model considering flexible structure is established, which is used to analyze the dynamic characteristics of the airplane. Finally, based on LQG/LIT methods, the optimizing design for gust alleviation system is established in order to minimize the comprehensive goal considering the aircraft flying qualities, performance and vibration reducing. The simulation results show that the proposed atmospheric turbulence model is fit for gust alleviation system design, and the designed flight control law based on multi-objective optimization method has great positive effects on reducing the airplane's gust load. |
