This paper is devoted to suppressing the lumped disturbance, which is mainly composed of static and dynamic unbalanced disturbance, to ensure the imaging quality of the rotating payload satellite system with a five-degree-of-freedom active magnetic bearing. The dynamic model of lumped disturbance in imaging phase is established to design the balancing error index of payload unbalance, and the effect of bearing mechanical characteristics is analyzed. A novel fixed-time extended state observer is proposed to estimate unknown lumped disturbance and uncertainty. On this basis, a novel quaternion-based fixed-time nonsingular terminal sliding mode controller is presented to achieve high precision, high stability, and chattering-free attitude control. The complete proof on the faster convergence performance of the presented sliding mode surface compared to the existing sliding mode surfaces and the fixed-time convergence of the presented controller is provided. Numerical simulation results are carried out to verify the lumped disturbance modeling accuracy and the effectiveness of the proposed controller.

中文翻译：

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考虑静动不平衡扰动的旋转有效载荷卫星高精度控制

本文致力于抑制主要由静态和动态不平衡扰动组成的集总扰动，以保证五自由度有源磁轴承旋转载荷卫星系统的成像质量。建立成像阶段集总扰动动力学模型，设计有效载荷不平衡的平衡误差指标，分析轴承力学特性的影响。提出了一种新的固定时间扩展状态观测器来估计未知的集总干扰和不确定性。在此基础上，提出了一种新颖的基于四元数的固定时间非奇异终端滑模控制器，以实现高精度、高稳定性、无颤振的姿态控制。提供了与现有滑模面相比，所提出的滑模面更快的收敛性能和所提出的控制器的固定时间收敛性的完整证明。数值仿真结果验证了集总扰动建模的准确性和所提控制器的有效性。