Transfer Function Analysis and Implementation of Active Disturbance Rejection Control

TL;DR

This paper enhances understanding and implementation of active disturbance rejection control (ADRC) in industrial settings through transfer function analysis, frequency-domain insights, and a novel discrete-time implementation emphasizing practicality.

Contribution

It introduces a realizable transfer function model for continuous-time ADRC, provides a frequency-domain analysis of ADRC components, and presents the first exact discrete-time transfer function implementation emphasizing efficiency and robustness.

Findings

Transfer function implementation enables direct comparison with classical control.

Frequency-domain analysis offers insights into ADRC performance and sensitivity.

Discrete-time implementation improves practicality for industrial applications.

Abstract

To support the adoption of active disturbance rejection control (ADRC) in industrial practice, this article aims at improving both understanding and implementation of ADRC using traditional means, in particular via transfer functions and a frequency-domain view. Firstly, to enable an immediate comparability with existing classical control solutions, a realizable transfer function implementation of continous-time linear ADRC is introduced. Secondly, a frequency-domain analysis of ADRC components, performance, parameter sensitivity, and tuning method is performed. Finally, an exact implementation of discrete-time ADRC using transfer functions is introduced for the first time, with special emphasis on practical aspects such as computational efficiency, low parameter footprint, and windup protection.