Research On Adaptive Control Method Of Aircraft Landing Gear

As an important structural component of the helicopter,the landing gear directly affects its take-off and landing performance.The final landing effect of the aircraft is also closely related to the performance of the landing gear control system.Traditional PID control is widely used because of its simple and better control effect,but its adjustment performance is mainly determined by the specified control parameters,which makes it difficult to meet the needs of some special and time-varying operation processes.As a new control method,fuzzy PID control realizes the adaptive control of the parameters in PID through fuzzy reasoning ability.It has strong adaptability,but the control accuracy is insufficient and the stability is poor.This thesis presents a PID control method based on fuzzy neural network.By applying the learning ability of neural network,the adjustment of fuzzy rules can be realized,and the system has strong data processing ability and learning ability,which improves the response speed and stability of the control system.Finally,the specific effect of this new control method in the adaptive landing simulation test is verified by experiments.The main research contents and results are as follows:(1)According to the landing gear mechanical performance and landing planning,an adaptive landing gear model is established.Based on the analysis of the motion characteristics of the landing gear,the mathematical model of the motion control system of the single leg structure of the aircraft landing gear is established,that is,the mathematical model of the double closed loop control is established,and then the mathematical model of the motor and the screw is established.The kinematics analysis of the single leg structure of the landing gear is carried out by using the complex vector method,and the mathematical model is obtained.Finally,the motion control model of the single leg structure of the landing gear is obtained.(2)In order to verify the good characteristics of the fuzzy neural PID control method,the mathematical models of the three control methods are established by using the Simulink toolbox in Matlab,and the dynamic simulation under different conditions is carried out.By comparing the simulation results of traditional PID,fuzzy PID and fuzzy neural PID under step signal,disturbance signal and sinusoidal signal,it is concluded that the fuzzy neural PID control system has better control performance.(3)The aircraft landing gear simulation operation test platform is designed and built to analyze the actual effect of the control method in the landing process.The test results show that after the fuzzy neural PID control method is applied in the landing gear control system,the motion curve is more stable,the overall jitter is smaller,and the running time meets the actual requirements.In the landing gear adaptive landing simulation test of different terrains,the application of this PID control method can realize the smooth landing of the landing gear structure in complex terrain,which further verifies the practicability of this control method.In summary,in the aircraft landing gear control system,the application of fuzzy neural PID control method can improve the safety factor of helicopter landing,meet the response speed of the system,make it more stable and robust,and enhance the adaptability of the aircraft landing gear to complex terrain.