Automatic Carrier Landing System Design Based On Carrier-based Aircraft Of The Lqg / Ltr Method, Theory And Simulation Study

Aircraft carrier has a developing history of more than 80 years. Aircraft carrier and carrier-based airplane have become a key factor of winning especially in recent years' several modern local war. As the main attack force, carrier-based airplane carrier, in its various stages of flight, landing safety is the most difficult task. The landing environment of the carrier-based airplane is very tough. Limited landing spaces, deck motion together with the airwake disturbance factors have a bad effect on the safety of landing.In order to improve the safety of landing and relieve the burden of the pilot, automatic carrier landing system (ACLS) was born. The goal of ACLS is to help the pilot land on the carrier deck when the landing environment is tough. Therefore the disturbance-rejection ability and robust stability are especially important to ACLS. However, the designing method currently used in ACLS does not work very well when the disturbances are relatively strong. In order to achieve good landing effect, such good abilities mentioned above are demanded for the designing method of ACLS.The designing method used in this thesis is LQG/LTR method. LQG method, namely linear quadratic Guass method, is a state feedback optimal designing method used when stochastic noise disturbance is involved or model states cannot be measured directly. Its nature is the optimal quadratic controller with kalman filter. In order to enhance its robustness, Doyle and Stein proposed the linear multivariable control design method, known as the linear quadratic Gauss/loop transfer recovery (LQG/LTR) method. Essence of the method is to first set a target loop to meet the performance requirements in frequency domain and robustness demand, and then design a model-based compensator, recovering the characteristics of the target loop in the input or output.The main work of this thesis is to apply the LQG/LTR method to the automatic carrier landing system. To this end, this paper firstly outlines the development of aircraft carrier and carrier-based aircraft history; take-off and landing of the aircraft as well as ACLS system design, followed by the discussion of the aircraft landing environment including the movement of the carrier and the model of airwake, carrier-based aircraft dynamic model and the developing history and designing method of LQG/LTR method. Finally design an ACLS based on the LQG/LTR method and carry out the simulation and verification.Simulation results show that the ACLS based on the LQG/LTR has good robust performance, and can guide the aircraft landing precisely in the presence of multiple disturbances, and landing error is very small. To further testing the robustness of the system, this thesis carry out 10 groups of landing simulation with different forms of disturbances, and the statistical result is also good.In order to visualize the landing effect, the thesis finally uses the virtual reality technology in Matlab to import the simulation data to a virtual world established. The whole landing process is shown through a virtual animaion, hence achieving both emotional and direct showing effect.