设计观测器的目的是利用系统的输出量和输入量来重构状态。在设计观测器过程中，除了要求状态估计值ｘ渐近逼近真实值ｘ外，还希望两者间有一个合理衰减率，而这与观测器系统的极点位置密切相关。精确配置极点的观测器难以满足其它期望性能指标约束，将观测器系统矩阵的极点配置于一指定区域内，可使极点的选取获得较大的自由度。该文对线性定常系统的降维状态观测器区域极点配置问题进行了研究，通过对观测器增益隈的分析设计，给出了极点位于圆形区域内的一类降维状态观测的存在条件及解集 The purpose of designing the observer is to use the system output and input to reconstruct the state. In the process of designing the observer, in addition to requiring the state estimate x to approach the true value x asymptotically, it is also desirable to have a reasonable decay rate between the two, which is closely related to the pole position of the observer system. It is difficult to satisfy the constraints of other expected performance indicators by precisely observing the poles of the observer. When the poles of the observer system matrix are arranged in a designated area, greater freedom of selecting poles can be obtained. In this paper, the problem of pole placement in reduced-order state observer region of linear steady-state systems is studied. By analyzing and designing the observer gain 隈, the existence conditions of a class of state-preserving observer in a circular region are given Set solution