Research On Key Technologies Of Adaptive Landing Gear Of Shipborne Helicopters

As a rotorcraft,helicopter has the characteristics of flexibility and convenience of taking off and landing.Compared with land-based helicopters,shipborne helicopters have to face a dynamic and swaying ship surface when taking off and landing,which causes a very large flight burden for pilots.Once the ship shaking violently or the pilot misoperates,it is easy to cause accidents.At present,the landing of shipborne helicopter is usually assisted by the landing system,which requires supporting devices for both the ship surface and the helicopter,and increases the structural complexity and helicopter’s load.Therefore,this project focuses on the landing gear,designs an adaptive landing gear which can actively adapt to the terrain and solve the problem of landing difficulty of shipborne helicopter.First of all,according to the landing requirements of shipborne helicopters and the differences between the new adaptive landing gear and the traditional landing gear,the landing process planning of shipborne helicopters in different conditions is carried out to maximize the function of the adaptive landing gear and reduce the burden of pilots.Meanwhile,according to the design requirements and landing characteristics of the adaptive landing gear,the adaptive landing gear system is constructed,and the overall design scheme and system composition of the adaptive landing gear are determined.The structure of adaptive landing gear is functional.This paper designs an adaptive landing gear of shipborne helicopter with three-point plane hinge.Then the forward and inverse kinematics of the landing gear are calculated and verified.In order to ensure the good comprehensive performance of the landing gear,genetic algorithm is used to optimize its configuration from two aspects,transfer performance and working space.In addition,the single leg dynamics analysis is carried out by using Lagrange method,the landing gear ground contact model is established and the ship surface contact force is analyzed.The control system of adaptive landing gear plays a decisive role in its flexibility and response speed.This paper designs the position feedback control strategy and the body level control strategy based on the position control respectively for the landing gear before landing and after landing.According to the control requirements,a vertical terrain tracking autonomous positioning algorithm based on laser ranging is proposed,and a horizontal controller based on strapdown inertial navigation system is designed.At the same time,a joint simulation model ofadaptive landing gear MATLAB and ADAMS is established to simulate and analyze the designed control strategy.The simulation results show the effectiveness and rapidity of the control strategy.Finally,an adaptive landing gear simulated landing experiment system is built,the development of electrical system and control software are completed,and the research of signal filtering processing,landing gear attitude measurement and other experimental related technologies are completed.Finally,the simulated landing experiment of the adaptive landing gear shows that the adaptive landing gear design is reasonable,the control method is effective,and it can land safely on the dynamically swinging ship surface.