基于滚动优化的模块航天器姿轨协同控制

Relative Cooperative Attitude and Position Control of Fractioned Spacecraft Based on Iterative Optimization

在近程导引段,采用偏心连续小推力矢量推进器和力矩输出装置,实现对特定目标的直线逼近、绕飞,同时完成轨道控制和视线姿态稳定。基于T-H方程和误差四元数建立相对姿轨耦合动力学模型,分别对直线逼近段和绕飞段设计相对位置期望轨线,期望姿态由视线方向计算得到。经典θ-D方法仅在起点处线性化动力学方程,稳定邻域范围有限,不能满足逼近和绕飞相对状态大范围变化的要求。因此基于滚动优化思想,提出分段线性化θ-D次优控制器设计方法,实现相对运动姿轨协同控制。其中姿态直接采用误差四元数矢量部分作状态反馈,降维处理姿轨耦合状态方程。仿真结果表明了该方法的有效性和实用性。

In short range guidance stage,eccentric low-level continuous vector thruster and transformed torque equipment were used to maintain the close approaching and circling of specific object,and complete simultaneously orbit control and light of sight（LOS） stabilization.Relative coupling attitude and orbit dynamic model was established based on T-H equation and error quaternion.Expected relative position gaits were designed respectively for close approaching phase and circling phase.Expected attitude was computed based on LOS angles.Traditional θ-D method can only linearize dynamic equation at start point which hold limited neighbor stable area that can not cover large alteration of relative states during the process.Piecewise linearized θ-D suboptimal controller was proposed based on iterative optimal theory and utilized in relative attitude and orbit control,in which vector part of error quaternion was directly used for state feedback.Decent dimension alternation was made for coupling attitude and position state equation.Simulation results demonstrate that this method are effective.