Interval estimation for discrete-time linear time-delay systems based on state augmentation

This paper investigates an interval estimation method for discrete-time linear time-delay systems sub-ject to unknown but bounded disturbances and noise. We utilize the state augmentation technique to decouple the time delays. The interval estimation problem for the time-delay system will be transformed into that for a delay-free state augmented system. We then propose a two-step method which consists of robust observer design and zonotope-based interval analysis to achieve interval estimation. In observer design, a T - N - L observer is used to provide more degrees of design freedom, whose robustness is characterized by H & INFIN; performance. Finally, a numerical example is provided to demonstrate the effective-ness and superiority of the proposed method.& COPY; 2023 European Control Association. Published by Elsevier Ltd. All rights reserved.