A model-free tuning method for proportional-multi-resonant controllers

TL;DR

This paper introduces a simple, model-free tuning method for proportional-multi-resonant controllers that relies on a single frequency response measurement, making controller design easier and more accessible for various linear plants.

Contribution

The paper presents a novel, easy-to-implement tuning approach for resonant controllers that does not require detailed plant models or complex calculations.

Findings

Method successfully tuned controllers in three example cases

Approach simplifies the tuning process similar to Ziegler-Nichols methods

Applicable to general linear time-invariant plants

Abstract

Resonant controllers are widely used in applications involving reference tracking and disturbance rejection of periodic signals. The controller design is typically performed by a trial-and-error approach or by means of time and resource-consuming analytic methods that require an accurate plant model, intricated mathematics and sophisticated tools. In this paper, we propose an easily implementable, model-free method for tuning a proportional-multi-resonant controller applicable to general linear time-invariant causal plants. Just like the Ziegler-Nichols methods, the proposed methodology consist in identifying one specific point of the plant's frequency response -- which is easily obtained in a relay with adjustable phase experiment -- and then designing the controller with simple tuning formulas and tables. The method is analyzed in detail for three examples, showing its practical appeal and wide applicability.