某无人机前起落架摆振动力学研究

Shimmy dynamics study of a UAV nose landing gear

针对某小型轮式起降无人机前起落架在滑跑过程中可能存在的摆振问题,首先,考虑其支柱前倾角、结构扭转及侧摆柔性、轮胎与地面作用特性等多个耦合因素,建立了前起的摆振动力学模型。其次,采用Matlab/Simulink对动力学模型进行了仿真分析,以阻尼参数的确定为例,得到了不同阻尼形式下的扭转、侧摆自由度的时域响应曲线,对比了库伦阻尼、线性阻尼、平方阻尼分别作用及组合作用下减摆效果。最后,研制了减摆器及无人机前起样机,并进行了外场滑跑试验。研究结果表明,无人机运行平稳,未发生摆振。线性阻尼和平方阻尼具有较好的减摆效果,既能够较快地耗散摆振能量,又不会产生过大阻尼力矩。

In order to solve the shimmy oscillation problem of the UAV nose landing gear during taxing,the dynamic model of a UAV nose landing gear was established,considering strut rake angle,torsional and lateral stiffness of strut. The model was solved by numerical simulation with Matlab / Simulink,and the time domain curve of torsional and lateral degree was obtained. The anti-shimmy effect of dry friction,linear damping and square damping was contrasted. The shimmy damper and nose landing gear was developed. The results show that it run well during the taxing experiment and linear damping or square damping is better.