连续地月转移系统动力学研究与能量分析

为了研究新型连续地月转移系统的动力学及能量需求,采用Lagrange方法,在系绳为刚性杆假设的前提下,同时忽略第三体引力、地球扁率和系绳轴向变形等扰动因素的影响,建立了驱动型动量交换绳系卫星(MMET)系统的三维刚性动力学模型。对所建立的动力学模型进行了数值仿真及对比分析,仿真结果验证了所建模型的正确性。研究表明,外力矩对系统轨道运动参数影响甚小,对姿态运动参数影响明显。采用MMET方式进行载荷转移,推导出了实现载荷地月轨道转移所需的入口速度条件以及时间周期条件,并求解出了载荷在2次任务之间的时间间隔。给定初始条件下,当MMET系统以0.231 6 rad/s的旋转角速度绕其质心旋转1 448.5圈,其绕地心刚好运行5圈时,载荷可顺利进入地月转移轨道。最后,对连续地月转移系统实现载荷的地月转移进行了能量对比分析,结果表明,相同条件下,MMET载荷转移方式相比于传统脉冲变轨方式在载荷转移过程中消耗更少的能量。

Dynamics and energy analysis of continuous cislunar transfer system

To study the dynamics and energy of continuous cislunar transfer system, under the conditions of rigid rod presumption and overlooking the perturbations of the third-body gravitation, the oblateness of the Earth and the axial deformation, by using the Lagrange method, a three-dimensional rigid dynamic model of motorized momentum exchange tether (MMET) is built, which has been verified under numerical simulation, comparison and analysis. Studies show that the external torque has less influence on the orbit movement but has evident influence on those attitude parameters. Entry velocity condition and time period condition, which ensure that payload enters the cislunar transferring trajectory successfully, of MMET have been deduced theoretically. Furthermore, the time interval between two payloads transferring missions is solved. Under the given initial conditions, if the rotational angular velocity of MMET is 0.231 6 rad/s, when MMET rotates around its center of mass by 1 448.5 circles and MMET orbits Earth for 5 circles simultaneously, the payload can enter cislunar transfer trajectory successfully. The analysis of energy requirement, which is needed by MMET way or traditional impulse transfer way when transferring payloads from Earth to Moon, has been studied. It is illustrated that under the same conditions, the way of MMET needs less energy.