【作者】 刘亚静；

【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】 卫星姿态控制系统是一个多输入多输出、耦合的不确定非线性系统。在轨运行的卫星不可避免地受到各种干扰力矩的影响,并且这些干扰力矩的大小也是变化的。干扰不确定性的存在使得卫星姿态控制问题进一步复杂化。因此,为了完成姿态控制任务,需要所设计的控制律具有较高的鲁棒性。本文就是在这种背景下,从理论和应用两个方面对卫星姿态控制系统的控制算法进行了深入的研究,并将提出的姿态控制方案用于某型在研卫星的姿态控制中。主要完成了以下几个方面的工作:针对常值干扰下的卫星姿态控制问题,给出了一种基于LQR的线性控制方法。先将建立的卫星动力学模型进行线性化,并根据LQR方法中对参数的要求形式进行状态变量的选取,设计合适的反馈增益,以实现对常值干扰的抑制,从而实现姿态控制。针对形式已知的周期干扰力矩,在已建立的刚性卫星姿态动力学模型的基础上简化方程,可以得到独立的俯仰回路方程,和相互耦合的滚动/偏航回路方程,对形式已知的周期干扰力矩对卫星姿态的影响进行理论分析。对于独立的俯仰回路可以进行单独的补偿设计。对于相互耦合的滚动/偏航回路采用滚动/偏航轴的反作用飞轮对形式已知的周期干扰力矩进行最大限度的补偿,以实现高精度姿态控制。针对有界不确定性干扰设计了几种具有鲁棒性的控制器。首先设计了一基于Lyapunov方法的四元数反馈非线性控制律,并且在理论上证明了控制律的正确性。其次设计了一个具有良好的鲁棒性和快速性的滑模变结构控制律,采用了反双曲正切函数,避免了滑模变结构控制中的抖振问题。最后针对角速度敏感器失效状态下的姿态控制问题,设计了一个基于干扰观测器的输出反馈姿态控制器,实现了对不确定性干扰的有效抑制。更多还原

【Abstract】 Satellite attitude control system is a multi-input multi-output coupled uncertain nonlinear system. For any on-orbit satellite, it is inevitable to be influenced by some kinds of disturbance torques. Furthermore, these disturbances are uncertain. This uncertainty makes the attitude control problem further complicated. Therefore, to accomplish attitude control mission, it is necessary to design attitude control laws with high robustness. On this background, this thesis investigated attitude control algorithms for satellite attitude control system in detail, from both theoretical and applicable aspects, and applied the proposed control schemes to certain satellite control system. The main contents of this thesis are as follows.A linear control method based on LQR is given in accordance with the attitude control problem with constant value disturbance. At first, we linearize the kinetic model of the satellite. Then we select state variables according to the requirements of parameters’ form in the LQR method, design appropriate feedback gain to implement disturbance suppression and attitude control.According to the known form periodic disturbance torque, we can get the independent pitch loop equation and coupled roll/yaw loop equation after we simplify the established rigid satellite attitude kinetic model. And then we theoretically analyze the impact of known form periodic disturbance torque to the satellite attitude. We carry out a separate compensation design for the independent pitch loop. For the intercoupling roll/yaw loop,the reaction flywheels on this loop are used to make maximum compensation to the known form periodic disturbance torque in order to realize high-precision attitude control.According to the bounded uncertain disturbances, we design several controllers with robustness. First,we design a quaternion feedback nonlinear control law base on Lyapunov method and prove the correctness of the control law theoretically. Secondly,a sliding mode variable structure control law with good robustness and rapidity is designed. We use reverse hyperbolic tangent function to aviod the chattering problem in sliding mode variable variable structure control. Finally, we design a output feedback disturbance observer without angular rate in accordance with the control problem in the state of angular velocity sensor failure.更多还原