Research On Pneumatic And Hydraulic Lanch System Of UAV

Pneumatic and hydraulic launch technology of the UAV (unmanned aerialvehic le) which is powered by gas-hydraulic is used to accelerate the UAV to takeoff on an inclined orbit. It is an advanced launch technology of the UAV in theworld, which has the advantage of high emission speed, high output power, low costof launch and good mobility. Pneumatic and hydraulic launch system has two typesof driving mode: hydraulic cylinder drive and hydraulic motor drive. This papermainly studied hydraulic launch system by hydraulic motor drive.According to the design parameters, this paper put forward an overall scheme.According to the function of the launch system, the system was divided intomechanical subsystem and hydraulic subsystem.For the mechanical subsystem, this paper used PROE software to establishthree dimens ional models of the launcher, carriage, locking devices and wind ingdrum，then overall assembled these models. According to the security requirements，this paper analyzed the deformation under dynamic load, modal, vibration underwind load of the launcher by using the finite element method. A statics analysis wasgiven to the winding drum and the locking devices.For the hydraulic subsystem， hydraulic system schematics was designedaccording to the energy storage and control requirement and appropriate hydrauliccomponents were chosen. Then this paper established the mathe matical model ofthe hydraulic component and analyzed the effect of components parameters onHydraulic system output energy theoretically.Finally, this paper researched the take-off process of UAV. This paper set upthe simulation model of UAV launching and simulated the accelerating process ofthe UAV and the deceleration process of the carriage, got the parametric curve ofthe UAV and the hydraulic system,then used the simulation result to find out thesystem parameter which influences the take off speed of the UAV and confirmed thepressure of accumulator to launch UAV of different weights.