Design Of Automatic Carrier Landing Fight Control System Of Fixed-wing UAV

Unmanned aerial vehicle landing is difficult and risky.The sea landing environment is complex and changeable.The flight control system in the landing process is the inner ring of the Automatic Carrier Landing System.It has the important role of controlling the attitude of the aircraft and keeping the aircraft falling smoothly.This paper mainly focuses on the research and design of a flight control system for a fixed-wing UAV.Firstly,a six-degree-of-freedom full-quantity nonlinear model of a fixed-wing UAV is constructed.The minimum-energy-function-method is proposed to balance the state quantity of the unmanned aerial vehicle at the landing stage,and the stability of each state quantity is good and precision is high when verifying the equilibrium state.Meet the requirements of the system.Secondly,an autopilot is designed for fixed-wing UAV.The UAV trimming state is used as the reference state for the nonlinear model linearization.The small disturbance linearization method is used to linearize the UAV nonlinear model to determine the control object.The UAV autopilot is designed from the inside to the outside of the circuit structure,and adjusting the parameter,verifying the response of the autopilot to the hop signal.Then,for the characteristics of the fixed-wing UAV body,an APCS of maintaining angle of attact is designed.Improvement of the trimming method based on the minimum energy function balancing method.The multi-group equilibrium state of the UAV nonlinear model is searched,and the velocity-thrust-curve is studied.It is proved that the fixed-wing UAV needs to design the APCS.Structural design and parameter setting are performed for APCS of maintaining angle of attact.Unit step input for altitude change rate.Verify the response curve of the flight control system after the design work.Finally,the random disturbance wind that the UAV may face during the landing process is analyzed.According to the military standard MIL-HDBK-1797,the free atmospheric turbulence and the stern turbulence are extracted.The UAV flight control system designed in this paper can be verified.To a certain extent,resist the interference that may occur during the landing process.Under the wind field,the genetic algorithm is used to optimize the parameters of the UAV flight control system.Finally,compare with the response of the flight control system before the optimization in the spoiler field.The system has a stronger ability to suppress turbulence after the parameters are optimized.