In this article, the backstepping control scheme is designed for a class of systems with multisource disturbances, actuator saturation, and nonlinearities in the domain of discrete time. To address the multisource disturbances, we put forward a novel discrete-time hybrid observer, which can deal with both modeled and unmodeled disturbances. In virtue of the radial basis function neural networks, the unknown nonlinearities are approximated. In addition, the anti-windup technique is adopted to cope with the actuator saturation phenomenon, which is pervasive in engineering practice. Bearing all the adopted mechanisms in mind, the composite control strategy is designed in a backstepping manner. Sufficient conditions are established to guarantee that the states of the system ultimately converge to a small range with linear matrix inequalities. Finally, the effectiveness of the presented methodology is verified for the spacecraft attitude system.

中文翻译：

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受多源扰动和执行器饱和影响的一类非线性离散时间系统的反步控制


在本文中，反步控制方案是针对一类具有多源扰动、执行器饱和和离散时间域非线性的系统而设计的。为了解决多源扰动，我们提出了一种新颖的离散时间混合观测器，它可以处理建模和未建模的扰动。借助径向基函数神经网络，可以近似未知的非线性。此外，还采用了抗饱和技术来应对工程实践中普遍存在的执行器饱和现象。考虑到所有采用的机制，复合控制策略以反推方式设计。建立了充分的条件来保证系统的状态最终收敛到具有线性矩阵不等式的小范围内。最后，在航天器姿态系统中验证了该方法的有效性。