This paper investigates an attitude control technique for a low Earth orbit nanosatellite with moving masses based on the active use of aerodynamic forces. A speed-adaptive dynamic surface control scheme is designed to comprehensively solve the practical problems of aerodynamic model error, the dynamic effect of movement, stroke limitation, and slow convergence. Multiple constraints are imposed on the inputs to reduce the fast-varying dynamic effect of the masses to be negligible. Other slow-varying disturbances are precisely estimated by a nonlinear observer. In particular, to resolve the contradiction between the overshoot and the attitude convergence speed, a novel adaptive law is designed based on the smooth hyperbolic tangent function to adjust the convergence parameter within the given boundary. Moreover, considering the actual physical limitation, hard constraints are imposed on two actuators. Finally, by using the Lyapunov approach, it is proven that, despite uncertain dynamics, unknown disturbances and input constraints, the attitude error can be adjusted to be arbitrarily small by choosing the proper parameters. A semi-physical simulation platform is built to verify the feasibility of the moving mass actuator and the effectiveness and robustness of the proposed control scheme.

中文翻译：

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输入约束下运动质量卫星的速度自适应动态表面姿态控制

本文研究了一种基于主动利用空气动力的具有移动质量的低地球轨道纳米卫星的姿态控制技术。设计了一种速度自适应动态曲面控制方案，综合解决气动模型误差、运动动态效应、行程限制、收敛慢等实际问题。对输入施加了多种约束，以将质量的快速变化动态影响降低到可以忽略不计。其他缓慢变化的干扰由非线性观察者精确估计。特别是为了解决超调量与姿态收敛速度之间的矛盾，设计了一种基于光滑双曲正切函数的自适应律，在给定边界内调整收敛参数。而且，考虑到实际的物理限制，对两个执行器施加了硬约束。最后，利用李雅普诺夫方法证明，尽管存在不确定的动力学、未知的扰动和输入约束，但通过选择合适的参数可以将姿态误差调整到任意小。搭建了半实物仿真平台，验证了移动质量执行器的可行性以及所提出控制方案的有效性和鲁棒性。