This brief is concerned with the design of the disturbance observer (DOB) in the presence of uncertain delay. The stability, robustness, and output performance of the DOB-based control system are studied. First, the zero exclusion criterion is used to study the stability of the characteristic equation with uncertain delay, and a method is proposed to determine the range of the uncertain delay that a given DOB-based control system can tolerate. The effect of the DOB on the stability is analyzed, and some guidelines are proposed to design a DOB-based control system for a process with a given range of uncertain delay. In addition, the disturbance rejection performance and robustness are analyzed. As a result, the method to design a DOB-based control system satisfying multiple objectives in the presence of uncertain delay and disturbance is proposed. Simulation examples show the effectiveness and merits of the proposed method, and the method is successfully used to control the fuel flow of a glass furnace.

中文翻译：

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低阶过程不确定时滞下基于DOB的控制系统设计

本摘要与存在不确定延迟的干扰观察器（DOB）的设计有关。研究了基于DOB的控制系统的稳定性，鲁棒性和输出性能。首先，使用零排除准则研究具有不确定延迟的特征方程的稳定性，并提出一种确定给定基于DOB的控制系统可以容忍的不确定延迟范围的方法。分析了DOB对稳定性的影响，并提出了一些指导原则，以针对给定范围的不确定延迟，设计基于DOB的控制系统。此外，还分析了抗干扰性能和鲁棒性。结果，提出了一种在不确定的时延和扰动存在下设计满足多个目标的基于DOB的控制系统的方法。