基于凯恩方程的无人机伞降回收动力学建模与仿真

在无人机的伞降回收过程中，无人机与降落伞一直都处于实时的动平衡状态，两者在伞降回收过程中的耦合关系及其复杂，因此很难建立精准的无人机伞降回收动力学模型。针对该问题，将伞降回收系统划分为降落伞和无人机分别进行处理。针对时变对象降落伞，通过阻力面积随充气时间的变化关系建立其动力学模型。针对无人机，首先，基于多体动力学思路，将其划分为左右机翼和机身的多体系统，通过平板绕流系数优化其伞降过程中的大迎角动力学模型；然后，通过偏速度矩阵将各体的动力学模型引入伞降回收系统质心；最终，基于凯恩方程推导并建立了伞降回收系统六自由度模型，并引入海拔高度和风力对无人机伞降回收的影响。通过数值仿真与实验数据的对比，可以发现两者具有较好的一致性，该动力学模型能够为无人机的伞降回收提供指导。 

Dynamics modeling and simulation of UAV parachute recovery based on Kane equation

In the UAV parachute recovery process, the UAV and parachute are always in real-time dynamic balance state, and the coupling relationship between the two in the parachute recovery process is very complicated, so it is difficult to establish accurate dynamics model of UAV parachute recovery. For solving this problem, the UAV parachute recovery system was divided into the parachute and UAV, and the dynamics model of the parachute was established by the relationship between the drag area and the inflating time. First, based on the method of multibody dynamics, the UAV was divided into a multibody system, including the left wing, right wing and fuselage, and its high angle of attack dynamics model was optimized by the coefficient of flow around a flat plate. Second, the models of each body were introduced into the center of mass of the entire parachute recovery system by the partial velocity matrices. Finally, based on Kane equation, a six-degree-of-freedom model of the parachute recovery system was derived and established and the effects of the altitude and wind on the parachute recovery system dynamics were considered. Through the comparison of numerical simulation and experimental data, it is found that the two have good consistency, and this dynamics model can provide guidance for the UAV parachute recovery.