Study On Adaptive Landing Gear Control Technology Of Helicopter

Helicopters have very flexible air mobility performance,can achieve short take-off,mainly used for hovering in the air,long-distance transport of supplies and personnel and other tasks.However,due to its unique body structure,when it takes off and lands(VTOL),it has to be very careful,slow and can only choose some relatively flat,stationary ground or ship deck that does not shake violently.However,it is difficult to find the landing point suitable for stable take-off and landing in the complex and changeable disaster areas or in the complex sea.Therefore,to enhance the stability and adaptability of the helicopter during take-off and landing has always been the focus of research in various countries.At present,there is still a big gap in the research on the control system of the strong adaptive helicopter landing gear,compared with the advanced technology and the entity prototype abroad.Therefore,the development of helicopter landing gear which can adapt to the complex environment is of great significance to the development of China’s helicopter aviation industry.Based on the research work of helicopter landing gear system for taking off and landing in complex terrain,this paper designs the helicopter adaptive landing gear system structure,constructs the landing gear related system,establishes the kinematics mathematical model,designs the power system control strategy,and verifies the control system through the simulation test.The main work of this paper is as follows:Firstly,this paper introduces the working principle of the helicopter adaptive landing gear control system.The previous three-point helicopter landing gear structure is the basic design model,and the design meets the system requirements of the adaptive control system.According to the system requirements,the shaking ship surface take-off and landing control mode is designed,and the servo system is designed.Secondly,the forward and inverse kinematics mathematical model of the adaptive landing gear was established,and the forward and inverse pose mathematical model of the fuselage was deduced through the forward and inverse kinematics analysis.Thirdly,the load independent flow distribution system(LUDV)is designed and the mathematical model of the landing gear hydraulic servo system is established,and the mathematical model of the hydraulic servo system is systematically analyzed.The load of the actuator is analyzed and the mathematical model is established.Based on the above analysis,a BP feedforward neural network is designed to optimize the speed feedforward PID controller.Firstly,genetic algorithm(GA)is used to initialize the speed feedforward PID controller parameters,and then the tuned BP network is used to continuously optimize the controller parameters in the control process according to the system’s expected value,actual value and error.The convergence speed,stable state and control precision of the controlled object can be improved obviously,which can meet the design requirements of the preset system and realize adaptive control.Finally,the simulation and experiment were carried out,and the 3D adaptive landing gear mechanical model was established by Solid Works,and the system simulation of the adaptive landing gear was carried out by Matlab and ADAMS to verify the real-time control strategy,and the experimental results were in line with the expected goals proposed in the paper.