充液航天器的姿态控制与液体燃料晃动抑制研究

发布时间：2018-04-14 17:21

本文选题：充液航天器 + 滑模观测器　；参考：《南京航空航天大学》2016年硕士论文

【摘要】：液体燃料作为一种广泛使用的航天能源,其晃动不可避免地对航天器姿态稳定造成负面影响,而充液航天器作为一类固-液耦合的复杂模型,其动力学建模研究涉及到流体力学、经典力学等,系统中存在的强非线性、强耦合性、零动态不稳定等问题都是控制领域研究的重点和难点。首先,介绍了课题的研究背景和研究意义,综述了充液航天器动力学建模研究及姿态控制技术研究现状。其次,针对一类在二维平面内平动的充液航天器模型,在其等效控制输入的简化模型基础上提出了一种滑模状态观测器的设计方法,通过选取可测状态航天器姿态角间接估计出了晃动角状态,并通过有界性证明及误差分析得出晃动估计角在一定误差范围内可以快速逼近真实值的结论。该方法有效解决了液体晃动角度实际中无法测量的情况,具有一定的工程意义。再次,本文直接针对充液航天器实际控制器设计了滑模控制器。相比于采用等效控制输入的简化模型方法,由于不存在等效控制器与实际控制器的转换误差问题,因此在滑模控制器作用下充液航天器的姿态能够快速稳定,系统鲁棒性较强。随后,针对航天器实际控制器出现的未知推力及扭矩故障,采用自适应方法估计了未知故障信息,所设计的容错滑模控制器也能够在故障存在的情况下稳定充液航天器姿态。最后,针对三维面内的充液航天器进行了建模研究。首先,在建立的地心惯性坐标系、轨道坐标系、航天器体坐标系及液体晃动坐标系的基础上采用角动量守恒定律建立了充液航天器各个部分对其质心的惯性力矩,并将其与三轴充液航天器的拉格朗日方程相结合,得出完整的动力学方程,完成了建模工作。最后,在三轴充液航天器模型上采用滑模控制方法,保证了航天器三轴的姿态稳定,令充液航天器在轨道坐标系上稳定飞行。
[Abstract]:As a widely used space energy, liquid fuel sloshing inevitably has a negative impact on spacecraft attitude stability, while liquid-filled spacecraft is a complex model of solid-liquid coupling.The research of dynamic modeling involves hydrodynamics, classical mechanics and so on. The problems of strong nonlinearity, strong coupling and zero dynamic instability in the system are all the key points and difficulties in the field of control.Firstly, the research background and significance of the subject are introduced, and the research status of liquid-filled spacecraft dynamic modeling and attitude control technology is summarized.Secondly, a design method of sliding mode state observer is proposed for a liquid-filled spacecraft model with translational motion in two-dimensional plane, based on the simplified model of equivalent control input.The sloshing angle state is estimated indirectly by selecting the attitude angle of the measurable state spacecraft, and the conclusion that the sloshing estimation angle can quickly approach the real value within a certain error range can be obtained by the boundedness proof and error analysis.The method can effectively solve the problem that liquid sloshing angle can not be measured in practice, and has certain engineering significance.Thirdly, a sliding mode controller is designed for the liquid filled spacecraft controller.Compared with the simplified model method using equivalent control input, the attitude of liquid-filled spacecraft under the action of sliding mode controller can be quickly stabilized and the system robust because there is no conversion error between the equivalent controller and the actual controller.Then, for the unknown thrust and torque faults occurred in the actual spacecraft controller, the unknown fault information is estimated by adaptive method. The designed fault-tolerant sliding mode controller can also stabilize the attitude of the liquid-filled spacecraft in the presence of the fault.Finally, the modeling of three-dimensional liquid-filled spacecraft is studied.First of all, based on the inertial coordinate system of geocentric, orbit coordinate system, spacecraft body coordinate system and liquid sloshing coordinate system, the inertia moment of each part of liquid-filled spacecraft to its center of mass is established by using the law of conservation of angular momentum.By combining it with Lagrange equation of triaxial liquid-filled spacecraft, the complete dynamic equation is obtained, and the modeling work is completed.Finally, the sliding mode control method is applied to the three-axis liquid-filled spacecraft model, which ensures the stability of the three-axis attitude of the spacecraft and makes the liquid-filled spacecraft fly stably in the orbital coordinate system.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V448.2

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