Robust Control Study Of Ski-Jump Takeoff Of Carrier-Based Aircraft

Aircraft carrier which uses carrier-based aircraft as its major weapon is a large surface ships. It provides the takeoff and landing platform for carrier-based aircraft, and it had become main combat force in modern sea war. As the key part of aircraft carrier combat system, whether the carrier-based aircraft could launch fast and safely affect the operational efficiency directly. Conditions for carrier-based aircraft takeoff are more complex than land runway, because of more short deck runway and six degree of freedom motion of the aircraft carrier. So, it has important theory and engineering value to research the robust control of takeoff of carrier-based aircraft.The analysis about the models in this paper is based on ramp ski-jump takeoff pattern. At first, this paper introduces and analyzes the whole process of ramp ski-jump take-off of the carrier-based aircraft. Then the process of take-off is divided into three stages according to the difference of stress state. At last, the dynamics models for different stage were established respectively.To solve the accurate control problem of carrier-based aircraft, the paper converts the nonlinear model into equivalent linear model for controller design by input-output linearization method. Finally, the system realizes decoupling control via dynamic inversion.For matching uncertain control problem of the carrier-based aircraft, a terminal sliding mode control based on variable structure theory is proposed. This method uses nonlinear sliding surface by joining nonlinear polynomial. It realizes both robust control when the matching uncertainties exist and track control of the states in finite time. Simulation results show that:the output of the system can track command signal quickly and accurately, and the controller keeps robustness well.For mismatching uncertain control problem of the carrier-based aircraft, a variable structure control method based on back-stepping is proposed. Considering variable structure control restrict nothing to mismatching uncertainties and back-stepping can solve mismatching uncertainties, this paper designs a back-stepping sliding mode controller by borrowing from the advantage of two methods. In order to weaken chattering phenomenon of sliding mode control, the paper designs an improved adaptive controller based on back-stepping sliding mode method. Because the uncertainties are tracked by adaptive laws, chattering of the system is weakened obviously and the steady state error of output keeps small in result.At last, the conclusion of the whole thesis is provided, and research points in the future are pointed out.