某无人机弹射起飞动力学分析与安全性研究

Dynamic Analysis and Safety Study of Catapult Launch for UAV

针对新型无人机设计初期技术人员关心的弹射方式的结构参数与布局形式的选型问题,以某无人机为研究对象,建立了无人机弹射起飞动力学模型。在此基础上分析了弹射杆长度、弹射杆机身安装点等主要参数对无人机弹射起飞安全性的影响,仿真结果表明:弹射杆长度增加、安装点距无人机质心水平距离减小、垂直距离增加均可增加弹射过程无人机俯仰角,减小前起落架轴向载荷及振荡,能够有效提高弹射起飞安全性;当弹射杆长度增加至800 mm,安装点距无人机质心水平距离减小至289 mm,垂直距离增加至365 mm,会有前起落架提前离地的风险;当安装点距无人机质心水平距离增加至589 mm,垂直距离减小至265 mm,前起落架会出现突伸现象。

Aiming at the selection of structural parameters and layout of the launch method,which are concerned by technicians at the initial stage of designing a new unmanned aerial vehicle(UAV),a dynamic model of catapult launch is established by taking a UAV as the research object.On this basis,the influence of the main parameters such as the length of the launch bar and the installation point of the launch bar on the fuselage on safety of the UAV catapult launch is analyzed,and the simulation results show that increasing the length of the launch bar,decreasing the horizontal distance and increasing the vertical distance between the installation point and the centroid of the UAV can increase the pitch angle of the UAV,reduce the axial load and slow down the oscillation of the nose landing gear during the process of catapult launch,which can effectively improve safety of catapult launch.When the length of the launch bar is increased to 800 mm,the horizontal distance is decreased to 289 mm or the vertical distance is increased to 365 mm,there is a risk that the nose landing gear will leave the track surface in advance.When the horizontal distance is increased to 589 mm or the vertical distance is decreased to 265 mm,the sudden-extension of the nose landing gear will appear.