论文标题
对替代算法的不稳定性的调查
Investigation of Instabilities in Detumbling Algorithms
论文作者
论文摘要
驱动是指削弱卫星角速度的行为。此操作至关重要,因为实际上不可能在没有某种程度的态度控制的情况下名义上执行任何其他操作。用于挖出卫星的常见方法通常涉及磁性致动,并与不同类型的传感器配对,这些传感器用于提供角速度反馈。本文介绍了时间浪费对两种驱动算法的稳定性的不利影响。广泛的文献综述表明,两种算法都可以为涉及持续反馈和输出的系统实现绝对稳定性。但是,物理组件涉及对算法的最大频率施加限制,从而使任何此类系统都无法想象。这断言需要进行离散的时间稳定性分析,因为它更适合反思这些算法的实际实现和动态。本文从当前的理论开始,并观察这些算法的稳定性。接下来的部分描述了团队执行的连续和离散时间稳定性分析以及从中得出的结论。理论研究导致在角速度和硬件的工作频率上发现了多种条件,该算法是不稳定的。然后,通过MATLAB和PYTHON3.6.7上的各种模拟来验证这些结果。本文结束了关于时间限制和驱动算法不可行的条件所构成的各种不稳定性的讨论。
Detumbling refers to the act of dampening the angular velocity of the satellite. This operation is of paramount importance since it is virtually impossible to nominally perform any other operation without some degree of attitude control. Common methods used to detumble satellites usually involve magnetic actuation, paired with different types of sensors which are used to provide angular velocity feedback. This paper presents the adverse effects of time-discretization on the stability of two detumbling algorithms. An extensive literature review revealed that both algorithms achieve absolute stability for systems involving continuous feedback and output. However, the physical components involved impose limitations on the maximum frequency of the algorithm, thereby making any such system inconceivable. This asserts the need to perform a discrete-time stability analysis, as it is better suited to reflect on the actual implementation and dynamics of these algorithms. The paper starts with the current theory and views on the stability of these algorithms. The next sections describe the continuous and discrete-time stability analysis performed by the team and the conclusions derived from it. Theoretical investigation led to the discovery of multiple conditions on angular velocity and operating frequencies of the hardware, for which the algorithms were unstable. These results were then verified through various simulations on MATLAB and Python3.6.7. The paper concludes with a discussion on the various instabilities posed by time-discretization and the conditions under which the detumbling algorithm would be infeasible.