摘要
超近程逼近过程中,服务航天器为刚柔液耦合的复杂系统,单摆等液体晃动模型不再适用,对这种工况下的航天器进行了动力学建模与控制的研究。采用虚功率原理推导了一种新的适用于三轴推力作用下的液体晃动等效模型,通过引入相对位置导引矢量与相对位置误差矢量,建立了相对轨道误差动力学模型,结合相对姿态动力学模型,得到超近程逼近段的刚柔液耦合的相对轨道姿态动力学模型。针对模型存在的不确定性和未知干扰,设计了基于滑模估计器的相对姿轨耦合控制律。通过数学仿真验证了控制律的有效性,仿真中的晃动结果与Flow-3D结果能够吻合,验证了晃动模型的合理性。
In close proximity,the servicing spacecraft is a complex system with rigid-flexibleliquid coupled,and the liquid sloshing model,such as pendulum,isn′t applicable.The dynamics modeling and control of this spacecraft were studied.Firstly,a kind of new liquid sloshing equivalent mechanical model was derived by virtual work principle,and it could be applied to the situation of tri-axial thrust.Secondly,a relative position guidance vector and a relative position error vector were defined,and a relative position error dynamics model was derived.Thirdly,combining the relative position error dynamics with the relative attitudedynamics,a coupled relative attitude-orbit dynamics model was established, which was suitable for the process of close proximity in rendezvous and docking.The model was also rigid-flexibility-liquid coupled.Finally,a control law based on the slide-mode-control was designed to estimate the unknown but bounded disturbances,system uncertainties and measurement noise.The effectiveness of the control law was validated by numerical simulation.The results of the sloshing in the simulation agree well with the Flow-3 Dresults,which indicates that the liquid sloshing equivalent mechanical model is reasonable.
出处
《中国空间科学技术》
EI
CSCD
北大核心
2017年第4期1-9,共9页
Chinese Space Science and Technology
基金
上海市科学技术委员会资助项目(14XD1423400)
关键词
在轨服务
超近程逼近
轨迹导引
刚柔液耦合
相对姿轨耦合
滑模估计器
on-orbit servicing
close proximity
trajectory guidance
rigid-flexible-liquid coupled
relative attitude-orbit coupled
sliding mode estimator
