太阳帆航天器姿态机动的复合控制研究

Research on Compound Control for Solar Sail Spacecraft Attitude Maneuvering

输入成型法无法消除姿态机动过程中的柔性振动,残留的柔性振动将改变大柔性太阳帆航天器的结构参数,影响姿态机动的控制精度。为此,基于两种控制手段(作用于太阳帆中心的喷气和作用于支撑杆顶端的电推进)的组合,提出复合控制方法,以消除姿态机动过程中的柔性振动。采用将帆面质量等效到支撑杆的简化方法,建立太阳帆航天器姿态运动与柔性振动的耦合动力学模型,并从减小振动模态的外加激励出发,根据简化的动力学模型,得到了两种复合控制的设计方法:消除某一阶的柔性振动方法和减小前n(n>1)阶的柔性振动方法。仿真结果表明,相比输入成型法,第二种复合控制方法不但机动时间短,还能够将姿态机动过程中的柔性振动抑制到5%,使机动角度精度优于0.003°。由于仅利用已有的控制手段,复合控制方法算法简单,适合于实际应用。

The input shaping methods canrt eliminate flexible vibrations during the attitude maneuvering. The residual flexible vibration will change the structure parameters of the large flexible solar sail spacecraft and influence the control precision of attitude maneuvering. Therefore, the compound control method was proposed to eliminate the flexible vibration during the attitude maneuvering, based on the combination of two kinds of control ways. The coupling dynamic models of solar sail attitude motions and flexible vibrations were established by the method of taking the sail membranes quality equivalent to booms. Considering of reducing the external forces of vibration modes, tWO kinds of compound control strategies were obtained by the simplified dynamic models. According to the simulation results, the maneuvering time of the second compound control method is fewer than that of the input shaping method. The second compound control method can reduce flexible vibrations to 5% during the attitude maneuvering process and make the precision of the maneuvering angle better than 0. 003°. Because of just using those existed control ways, the algorithms of the compound control method are simple and suitable to the practical applications.