Exponential Convergence Analysis of Serial Differentiators for Robust and Accurate Estimation of High-Order Derivatives

This paper presents a rigorous mathematical analysis of the higher-order serial differentiator (HOSD), originally proposed by the authors for estimating time derivatives of time-varying signals. Unlike previous studies that partially relied on numerical simulations to demonstrate asymptotic converge...

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Bibliographic Details
Main Authors: Jang-Hyun Park, Dong-Ho Lee
Format: Article
Language:English
Published: IEEE 2025-01-01
Series:IEEE Access
Subjects:
Online Access:https://ieeexplore.ieee.org/document/11005536/
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Summary:This paper presents a rigorous mathematical analysis of the higher-order serial differentiator (HOSD), originally proposed by the authors for estimating time derivatives of time-varying signals. Unlike previous studies that partially relied on numerical simulations to demonstrate asymptotic convergence of the estimation error, this work provides a complete analytical proof that both first- and higher-order derivative estimates converge exponentially fast to an arbitrarily small neighborhood of zero. Furthermore, it is analytically shown that replacing the discontinuous sign function in the differentiator dynamics with a smooth saturation function effectively mitigates chattering while preserving convergence to a small neighborhood around zero. The proposed analysis significantly strengthens the theoretical foundation of the HOSD and enhances its robustness and practical applicability in real-time control and estimation systems.
ISSN:2169-3536