Title: Data-driven controller design in the frequency domain to achieve specified stability margin

Authors: Kota Jinai; Yusuke Tsunoda; Takao Sato

Addresses: Graduate School of Engineering, University of Hyogo, 2167, Shosha, Himeji, Hyogo, 671-2280, Japan ' Graduate School of Engineering, University of Hyogo, 2167, Shosha, Himeji, Hyogo, 671-2280, Japan ' Graduate School of Engineering, University of Hyogo, 2167, Shosha, Himeji, Hyogo, 671-2280, Japan

Abstract: Data-driven control design is an effective approach for directly synthesising controllers from experimental data, without requiring explicit system identification. While tracking performance is often the primary focus, guaranteeing system stability is equally essential. Conventional data-driven design methods typically address tracking performance and stability margins separately in the time and frequency domains, respectively. However, integrating both aspects within the frequency domain offers a more coherent and practical framework. Despite its advantages, no unified method has been established to achieve this integration. This paper proposes a novel frequency-domain data-driven control design method that simultaneously ensures specified stability margins and optimises tracking performance. The proposed method enforces stability margins as constraints based on the sensitivity function, while minimising an objective function that quantifies the tracking error. Since both the objective function and constraints are formulated in the frequency domain, the proposed approach facilitates intuitive analysis of performance and robustness. Moreover, it enables a structured trade-off between control performance and stability margins through explicit specification. The effectiveness of the proposed method is demonstrated through numerical simulations comparing servo and regulator control designs.

Keywords: frequency domain; robust stability; data-driven; trade-off design; servo; regulator.

DOI: 10.1504/IJAMECHS.2026.153252

International Journal of Advanced Mechatronic Systems, 2026 Vol.13 No.2, pp.133 - 142

Received: 05 Jun 2025
Accepted: 13 Oct 2025
Published online: 29 Apr 2026 *

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