挠性航天器浮动质心动力学建模

为提高挠性卫星的姿轨耦合控制精度,针对挠性卫星的姿态动力学建模问题展开研究.采用有限元与牛顿力学相结合的方法,提出一套体现卫星真实质心的浮动运动的浮动质心模型及建立在卫星浮动质心上的高精度动力学模型.利用此模型描述挠性卫星的姿态运动状态,能够准确反映出卫星的姿态运动与轨道运动之间的耦合关系以及卫星附件的挠性振动对卫星质心位置、速度的影响,进而准确估计出在挠性卫星有姿态机动的情况下各动力学要素与动态性能指标受挠性振动的影响,为提高卫星控制精度提供依据.通过仿真计算可知,应用该模型对卫星姿态机动过程进行动力学仿真所得到的结果符合实际工程约束,具有良好的可行性.

Dynamic modeling of flexible spacecraft based on floating centroid system

In order to improve the accuracy of the attitude-orbit coupling control problem of spacecraft with flexible attachments, a study on dynamic modeling of flexible spacecraft is conducted. As a result, a high-precision dynamic model based on the floating centroid frame system(FCFS) which can describe the attitude movement of spacecraft as well as the coupling relationship between the attitude maneuvering and the orbit movement better than the old ones is proposed by using the method of Finite-element along with Newton mechanics.The simulation result demonstrates that the FCFS model fits the practical restraint well and thus is applicable. The dynamic influence on the spacecraft caused by the vibration of the flexible attachments during the attitude maneuvering procedure can be calculated accurately by using the FCFS model and so is the changing of dynamic factors, such as the the velocity and the displacement of the centroid.The research results can provide theoretical basis for attitude-orbit coupling control problem of flexible spacecraft and thus achieve the purpose of improving control accuracy.