In this paper, we address the problem of disturbance estimation for a class of linear systems with both fast time-varying uncertainty and measurement noise. A novel bi-bandwidth extended state observer (BESO) is proposed to achieve fast disturbance tracking and satisfactory noise suppression. The direction information of the estimation errors is used through a directional switching operator (DSO) to dynamically tune the bandwidth of the BESO. Sufficient conditions for the stability of the BESO are given, and the error dynamics are proven to be bounded and to converge in finite time. A comprehensive comparison of the BESO and three other representative approaches is presented, which shows that the BESO achieves a performance improvement of greater than 13%. A closed-loop control application for a structurally damaged aircraft is also provided to demonstrate the effectiveness and efficiency of the BESO.

在本文中，我们解决了一类同时具有快速时变不确定性和测量噪声的线性系统的干扰估计问题。提出了一种新颖的双带宽扩展状态观测器（BESO），以实现快速的干扰跟踪和令人满意的噪声抑制。估计误差的方向信息通过定向切换算子（DSO）用于动态调整BESO的带宽。给出了BESO稳定性的充分条件，并且误差动态被证明是有限的并且在有限的时间内收敛。对BESO和其他三种代表性方法进行了全面比较，结果表明BESO的性能提高了13％以上。