This paper investigates the problem of simultaneous state and unknown input estimation/observation within a prescribed time for a class of descriptor systems with unknown inputs (UIs). Firstly, for the descriptor system with UIs, a new structure decomposition is developed which provides a more straightforward way to estimate the state and UIs. Subsequently, based on the sub-system obtained by the decomposition, new prescribed time unknown input observers (PTUIOs) are developed for both the single-output and the multiple-output cases, which, on the one hand, achieves the simultaneous state and UI estimation within an arbitrarily prescribed time, and on the other hand, breaks through the restriction imposed in the literature that the sub-system should be single-output and meanwhile be in a special canonical form. The necessary and sufficient conditions for the existence of the PTUIO are established in terms of the original system matrices. Finally, two examples are presented to verify the effectiveness of the proposed method.

中文翻译：

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未知输入的描述符系统的指定时间观察器


本文研究了一类具有未知输入 （UI） 的描述符系统在规定时间内同时状态和未知输入估计/观察的问题。首先，对于带有 UI 的描述符系统，开发了一种新的结构分解，它提供了一种更直接的方法来估计状态和 UI。随后，基于分解得到的子系统，针对单输出和多输出情况开发了新的规定时间未知输入观察者 （PTUIO），一方面实现了任意规定时间内的同步状态和 UI 估计，另一方面突破了文献中关于子系统应该是单输出，同时采用特殊规范形式的限制。PTUIO 存在的必要和充分条件是根据原始系统矩阵确定的。最后，提出了两个实例来验证所提方法的有效性。