深空探测器定位在共线平动点附近的线性策略

深空探测器需要定位在日-地(月)系的共线平动点L1或L2附近执行探测任务,但由于共线平动点的不稳定性,必须在运行期间进行轨控。对于条件周期轨道(如晕轨道)必须在控制过程中考虑高次项,控制条件复杂,技术上实现相对困难。而某些探测任务,探测器定位在共线平动点附近的条件拟周期轨道(对应L issajous轨道)上亦可以。这种类型的轨道可以离共线平动点较近,那么只需要在控制过程中考虑线性项即可,控制条件简单。以圆型限制性三体问题作为基本模型,采用预估-校正法逼近线性化模型下的目标轨道,给出在轨运行期间的轨控策略亦是可取的,这种控制措施相对而言较简单,容易实现。仿真计算结果表明是可行的,能够提供较高的位置精度。

Linear Strategy for Positioning of Spacecraft around the Collinear Libration Points

Deep space explorers should be positioned around collinear libration points L_1 or L_2 of the Sun-Earth(Moon) system to carry out exploration missions.Due to instability of collinear libration points,station-keeping must be implemented during operation to achieve this.For conditional periodic orbits(such as Halo Orbits),high-order terms should be taken into consideration in the control process,and,technically speaking,this is complicated to achieve.For some missions,requirements can be met to position an explorer in the conditional quasi-periodic orbits(Lissajous Orbits) around the collinear libration points.Orbits of this type can be positioned near collinear libration points,and for simplicity it is adequate to take linear terms into consideration in the control process.Based on the model of circular restricted three body problem,nominal orbit in a linearized model can be approached by prediction-correction method,and the orbital control strategy is relatively simpler and can be easily realized.Numerical results show that linear strategy is feasible and its precision of positioning is comparatively high.