Stability Analysis And Augmentation Controller Design Of Large Airship

Large airship can be used to complete the strategic task of space probe, high altitude endurance platform and communication relay. It also can be used as a communications relay, geodetic survey, environmental monitoring, which has important military significance and society value. In order to better complete the long-endurance flight task, it is important to have the capability of position and attitude hold. Therefore, the stability analysis for large airship and the design of augmentation control system are key technology both in the process of its development and application. It’s a challenge mission that due to the large volume, large hysteresis, low speed, and its weight and gravity center have large change because of ballonets.According to this phenomenon, this article is taken large airship as the research object, analyzed the stress relationship and established the nonlinear airship model of 6 degree freedom. Based on the stability analysis, it is proposed the LMI eigenstructure assignment algorithm and Backstepping algorithm to design the augmentation controller. The main research contents include:(1) Through the complex stress relationship and based on the Newton’s laws of motion, it isestablished the nonlinear airship model of 6 degree freedom and converted the nonlinear model into the general expression.(2) It is made the model linearize into the horizontal and lateral equation. And it is analysed the performance of airship. Then it is studied the stability of the longitudinal motion with considering the coupling ballonet.(3) It is used the LMI eigenstructure assignment algorithm and Backstepping algorithm to design the augmentation controller. Through the simulation analysis, it is proved that the linearized augmentation controller can improve the stability of the airship longitudinal motion and realize the control of different movement modal coupling degree between different directions. The nonlinear augmentation controller can restrain the oscillatory motion like the pendulum and improve the closed-loop system robustness.