连续地月载荷转移系统二维柔性动力学建模与分析

The 2D flexible dynamic model and analysis of continuous cislunar transfer system

摘要:

为研究系绳柔性对连续地月载荷转移系统(continuous cislunar payloads transfer system, CCPTS)动力学的影响，利用Lagrange方法建立了CCPTS二维柔性动力学模型，并对所建立的二维柔性动力学模型进行了理论及仿真分析.通过对系绳为柔性绳与刚性杆两种情况下的动力学进行仿真对比分析表明:系绳柔性对CCPTS轨道、姿态参数有一定的影响，而这种影响表现为变量变化的时间不同步，并且会随着时间的推移逐渐增大；系绳的柔性特性导致母星径向加速度以及真近角加速度出现“毛刺”现象；由系绳长度所产生的重力梯度力矩对刚性杆和柔性绳产生了不同程度的影响；当外力矩不存在时，系绳旋转角速度随时间周期变化，当外力矩不为零时，旋转角速度随时间近似线性增加，增加的快慢由外力矩的大小决定.此外，系绳初始旋转角速度以及系绳长度对系绳的横向、纵向振动的幅值和周期均产生了一定的影响.

Abstract:

In order to analyze the impact of tether flexibility on the dynamics of CCPTS (Continuous Cislunar Payloads Transfer System) the 2D flexible dynamics of CCPTS is built by using Lagrange method and the numerical simulations are presented. Firstly, the comparison analyses between the 2D flexible model and the 2D rigid model show that the flexibility of the tether affects the orbital elements and attitude elements of CCPTS, and makes these elements of CCPTS out-of-step and increases with increasing time. The chief satellite’s radial acceleration and true anomaly angular acceleration produce some burr due to the flexibility of the tether. The gravity gradient torque caused by the tether affects the CCPTS differently. The angular velocity of tether by the gravity gradient torque regularly varies with time when external torque is zero. However, the angular velocity increases linearly with time while external torque is nonzero and the increasing speed is decided by the magnitude of the external torque. Moreover, the transverse vibration and longitudinal vibration of the tether are affected by the variations of the initial tether angular velocity and tether length.