基于奇异摄动的三轴稳定挠性卫星姿态控制系统研究

【作者】 丁雯；

【导师】 郭毓；

【作者基本信息】 南京理工大学 ， 控制理论与控制工程， 2010， 硕士

【摘要】 随着空间任务需求的不断增长,越来越多的卫星采用大尺寸挠性附件,并且要求高精度姿态控制。然而,挠性卫星的刚体运动与挠性附件的振动存在耦合,影响卫星本体运动。本文以“空间智能控制技术国家重点实验室项目”为依托,对带挠性帆板的三轴稳定卫星进行了姿态控制和帆板抑振研究。本文首先对某型号三轴稳定挠性卫星的模型进行分析,表明了挠性帆板对卫星的姿态控制影响较大,进行帆板抑振的必要性。其次针对挠性卫星高阶、非线性、非定常的特性,将其当作一个含小摄动参数的多时标系统,应用奇异摄动理论,对挠性卫星数学模型进行降阶分解,得到了代表挠性卫星刚性本体运动的慢变子系统和描述挠性帆板振动的快变子系统。利用奇异摄动模型,根据快慢子系统不同特性和控制要求,设计了基于PID和线性二次最优(LQR)的复合控制器,以及基于滑模变结构和LQR的复合控制器。仿真结果表明,两种复合控制器都能够在较好地进行姿态控制的同时,抑制了帆板的弹性振动,但在PID-LQR复合控制下系统的姿态角具有一定的超调量,利用滑模变结构控制对这一点进行了改进,兼顾了系统的快速性和稳定性,具有较强的鲁棒性,表明了奇异摄动理论应用于三轴稳定挠性卫星姿态控制的可行性。更多还原

【Abstract】 With the development of aerospace mission, more and more satellite adopts large scale flexible structure. However, rigid body motion of flexible spacecraft in orbit is strongly coupled with elastic vibration of flexible body. The dissertation, supported by a grant from National laboratory of space intelligent control, studies the design and realization of attitude control and vibration suppression for the three-axe stabilized satellite with flexible solar-array appendages.By model analyzing of a specific satellite with flexible solar-array appendages, it proved the importance of vibration suppression in attitude control of flexible satellite. Then, taking the flexible satellite as a singular perturbation system, a singular perturbation model is developed to reduce the order of dynamics model. The slow subsystem represents the rigid body motion while the fast subsystem describes the elastic vibrations.Based on the singular perturbation model, two composite controllers are adopted:one is PID and LQR composite controller and the other is SMC and LQR composite controller. The simulation results show that both of the two methods can approve the attitude control precise requirement and suppress the vibration of flexible solar-array appendages efficiently. However, there is small overshoot exists under the control of PID and LQR composite controller. The composite SMC and LQR controller improves it and has good robustness. The feasibility of singular perturbation method used in three-axe stabilized satellite attitude control is proved.更多还原