Research On Automatic Carrier Landing Technology Based On Direct Lift Control

The automatic carrier landing system(ACLS)can increase the success rate of carrier-based aircraft landing,it can also realize the true all-weather and unmanned landing under all sea conditions.This is the future trend of carrier-based aircraft landing and it is also the basis for realizing UAV landing,so it is necessary to research the technology of ACLS.In view of the disadvantages of using elevator as actuator to generate lift indirectly,this paper designs a new type of ACLS based on the direct lift control.And in order to better cope with the influence of air-wake and deck motion,the fuzzy auto-disturbance rejection controller(Fuzzy-ADRC)of ACLS based on the direct lift control is designed.Firstly,in order to analyze the shortcomings of the existing ACLS and for subsequent comparative analysis,the model of approach landing is established and the traditional H-dot ACLS is established.The six-degree-of-freedom nonlinear model of the carrier-based aircraft is established.In order to make the landing environment more realistic,the aircraft carrier deck motion and air-wake model are established respectively.After that,the H-dot ACLS based on the indirect lift control is designed.Mainly referring to the American F/A-18 carrier aircraft,the autopilot of the example carrier-based aircraft is established.At the same time,the approach dynamic compensation system(APCS)is designed to keep the angle of attack constant,and the longitudinal guidance law adopt the PID controller.Through the simulation of the ACLS,the response performance of the carrier aircraft is verified.Secondly,a new type of ACLS based on the direct lift control is designed.The autopilot of the ACLS consists of a main control channel with direct lift and an attitude auxiliary control channel.The lift is generated directly by manipulating the flap in the main control channel,and the pitching moment is balanced by manipulating the elevator in the attitude auxiliary control channel,the cooperation of the two channels can realize the stability of the angle of attack while tracking the track quickly.Since the autopilot can keep the angle of attack constant,the APCS is designed to keep the speed constant;For the height control loop,a longitudinal guidance law adopting PID controller is designed.Through the simulation,the ACLS based on the direct lift control has faster height step response.Finally,in view of the random and irregular disturbances encountered by the carrier-based aircraft during the landing,the Fuzzy-ADRC of ACLS based on the lift control is designed.In the attitude auxiliary control channel of the autopilot,the second-order Fuzzy-ADRC with the angle of attack as the control target is designed;for the APCS,the second-order fuzzy autodisturbance-rejection controller with the speed as the control target is designed;for the longitudinal guidance law,a first-order Fuzzy-ADRC with the height as the control target is designed.The comprehensive landing environment including the deck motion model and airwake model is established for the simulation,and the simulation results show that the FuzzyADRC has the advantage of reducing the height error and the better ability of keeping the angle of attack and speed constant under the influence of air-wake and deck motion.