【作者】 郭延宁；

【导师】 马广富；

【作者基本信息】 哈尔滨工业大学 ， 控制科学与工程， 2008， 硕士

【摘要】 由于具备了“更快、更好、更省”等优点,近年来小卫星的研究受到了世界各国的高度重视,成为航天发展的一个重要方向。另一方面,由于磁力矩器具有结构简单、质量轻、功耗低、成本低等特性,直接使用磁力矩器对小卫星进行姿态控制也成为当前的研究热点。本文就对三轴稳定小卫星的姿态磁控制方法进行了研究。与传统控制器不同的是,磁控制力矩受地磁场限制,只能在与地磁场正交平面内产生,即系统在任意时刻都是不完全可控的,致使姿态磁控制没能在实际中得到广泛应用。本文则考虑了磁控制力矩产生的方向性约束和所受到的空间干扰力矩,建立了磁控小卫星的系统模型,分别针对不同飞行任务设计了四种磁控制律,并对它们进行了数学仿真验证和结果分析对比。首先,本文在研究了周期线性系统特性的基础上,针对卫星的周期线性系统模型,基于LQR方法设计了周期时变控制律并通过数学仿真验证了其控制性能;接着为了减少计算量,同样基于LQR方法设计了定常增益反馈控制器,并利用周期系统的Floquet定理对其稳定性进行了分析,仿真结果同样表明了该控制器的有效性和实用性。为了增强系统的鲁棒性,本文结合预测控制中的在线滚动优化原理,针对卫星的离散系统模型,设计了控制力矩受地磁场线性约束时的预测控制律,并分析了其稳定性。数学仿真表明了该控制算法有着稳态精度高,干扰抑制能力强等优点。考虑卫星在完成姿态机动任务时的强非线性,本文最后研究了滑模控制在卫星姿态磁控制中的应用。通过研究滑模控制原理和周期非线性系统稳定性定理,针对卫星的非线性系统模型设计了工程实用的滑模控制律,并结合磁力矩产生的方向性约束对其进行了修正。仿真结果表明,该控制律具有较强的鲁棒性和快速性。更多还原

【Abstract】 In recent years, research on small satellites has been paid great attention, and has become an important research area of space technology due to some“Faster Better Cheaper”characteristics for small satellites. Magnetic control system is attractive for small satellites, since the magnetorquers are relatively simple and lightweight, require low power and are inexpensive. The primary purpose of the work is to develop control laws for three axis stabilization of small satellites.The magnetic control torques are different from the traditional controller, which can only be generated perpendicular to the local geomagnetic field vector, and hence the satellite is instantaneously under-actuated. So far, this has prevented the application in practice using magenetorquers only. However, this paper presents the satellite model of a small magnetic actuated satellite with the constrainted control torques and environment model. Four magnetic controller designs are implemented for different missions, and their pros and cons are discussed via simulation.After provided the introduction to periodic linear system and the periodic linear model of satellite, a periodic time varying controller is presented based on LQR method and then examined its performance via simulation; At the same time a constant gain LQR controller is designed in order to reduce the computer burden on satellite, the stability of which can be checked by means of Floquet theory. The controller is also effective and with certain utility according to simulation results.Online receding horizon optimal strategy in Model Predictive Control is applied to magnetic attitude control problems in this paper to enhance the robustness of the system, a predictive control algorithm is designed with constraints on the control torque based on the discrete model of satellite, afterwards its stability is also analyzed. The simulation results showed that the control law designed has high steady precision and strong ability to mitigate interference.The last approach to the attitude control for a magnetic actuated satellite is based on sliding mode control considering the strong nonlinear in attitude maneuver missions. A stable controller is applied which can be easily used in practical based on the nonlinear model of satellite, and then a modification has been done on it combined with the constraints of magnetic control torque. The analysis of simulation results showed that the control law designed has fast dynamic response and strong robustness.更多还原