近距离复杂操作过程中航天器相对运动姿轨之间存在耦合，准确分析耦合特性是精准控制系统设计的前提。利用基于对偶四元数得到的航天器相对运动一体化模型，采用参数分析法研究了姿轨耦合特性。首先分析了模型中的耦合项，明确了耦合产生的物理成因，确定了关键耦合参数；之后逐次改变各个参数，联合一体化动力学模型进行求解，获得耦合对航天器相对运动的定量影响。结果表明，推力偏心所产生的附加力矩和重力梯度力矩是产生相对姿轨耦合的主要成因，绝对姿态运动比相对姿态运动对相对轨道的影响更加明显，形成的姿轨耦合特性更为复杂。研究结果可为相对姿轨协同控制系统设计提供参考。%Coupling effect between the spacecraft attitude and orbit influences relative motion of the spacecraft a lot, also influences control. Thus the couple characteristics should be studied before controller design. In this paper, we used relative motion model which is built based on dual quaternion, to analysis coupling effect. We pro⁃posed a new method⁃parameters analysis method, that is, the parameters in the coupling term were changed succes⁃sively, solved the above dynamics equation, get the curves and the laws of the relative motion parameters generated by coupling terms. Based above, we designed control law to prove the coupling impact on control effect. Simulations have been done with the coupling model and the classic model of the relative motion respectively. The results show that coupling effect seriously affects the attitude and orbit of relative motion, especially the attitude influences the orbit motion a lot. In order to make the orbit and attitude control simultaneously, we must consider the coupling effect and coordinated characteristic during the controller design.
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