Modeling And Simulation Of Long Rail Launcher For Unmanned Aerial Vehicles(UAVs)

With the layout of the national strategy,unmanned aerial vehicles(UAVs)have been gradually moving from military to civilian use.Fixed-wing UAVs have faster speeds and longer distances than rotary-wing UAVs and have been widely used in government agencies and enterprise departments to reduce labor costs.Because of the small size and low cost of UAVs,the UAVs market is in the ascendant,and the research on the mode of UAVs take-off and launch is booming.So far,the UAVs takes off in the form of take-off on the ground,catapult-assisted take-off,rocket-assist,hand throwing,aerial launching,vertical take-off and submarine launching and so on.This topic captures the demand of the market,designs and studies the15kg-20kg-level UAVs catapult.Based on the reference of the structure of pneumatic catapult,hydraulic catapult,electromagnetic catapult,rubber band catapult and electro-mechanical power catapult,the UAVs catapult of this thesis is designed.Firstly,the sub-system of the launcher system is determined,and then the parts of the sub-system are designed.The design of the components includes the design of the sliding rail system,the design of the catapult car,the design of the buffer system,the design of the loading trolley for the UAV release arm structure and the design of other related accessories.After basically determining the function and shape of these components,the part model is drawn in the SolidWorks platform and assembled into a complete launcher model in the SolidWorks assembly platform.Secondly,the fluid dynamics software FLUENT is used to analyze the lift-drag characteristics of the launching UAV.It is important to estimate the lift-drag characteristics of the UAVs to be launched,which is related to the design of the sliding rail length and the improvement of the structure of the trolley release arm.In addition,the data of the UAV lift-drag characteristic is an important basis for optimizing the launching angle of the launcher,which can ensure that the speed of UAVs can reach the expected target during the launch.Thirdly,the mechanical model in the process of UAVs launching is established.After studying the lift-drag characteristics of the UAV,the dynamic model of UAVs emission process is established,which is the foundation of ADAMS dynamic simulation,and the strength checking of key components is the prerequisite to test whether the launcher design satisfies the success of UAVs launching.According to the established launcher model,the finite element model of key components is established according tothe need,and then the stress distribution of the components is obtained by static stress analysis under the ANSY Workbench Static Structural module.Strengthening thin structure and optimizing and improving redundant designs are carried out.Finally,the ADAMS simulation model is established in SolidWorks platform,and then the dynamics simulation of the UAVs launching is carried so as to verify whether the mechanical model of the UAVs launcher is reasonable.