KEIO RESEARCHERS INFORMATION SYSTEM

Papers 【 Display / hide 】

Papers 【 Display / hide 】

• Robust Control of an Electrical Drive with a Flexible Joint Using PI Controllers Based on Torsional Torque Derivative Feedback

  Kahsay A.H., Derugo P., Shikata K., Katsura S., Szabat K.

  Energies 19 ( 1 )  2026.01

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  Electric drives are responsible for torque generation in most industrial processes and devices, including electromobility. The operational performance of industrial drives is often limited by torsional vibrations and time-varying load inertia. To address these challenges, this paper proposes and compares three robust control structures based on PI controllers augmented with additional feedback from the first and second derivatives of torsional torque. A higher-order integral disturbance observer (IDO) is employed to estimate the unmeasurable derivatives of torsional torque, enabling accurate compensation. Furthermore, a bio-inspired optimization algorithm (Britch-inspired Optimization Algorithm, BiOA) is utilized to determine the optimal gain coefficients for the PI controller and the additional feedback loops. The proposed methodologies are validated through simulations and experimental testing on a physical setup, demonstrating improved reference-trajectory tracking and enhanced torsional vibration suppression under varying load conditions.

  • Access to Document (DOI)

• Vibration Suppression in Torsional Systems Robust to Load-Inertia Variations Using Wave Control

  Shikata K., Szabat K., Katsura S.

  IEEE Transactions on Industry Applications  2026

  ISSN  00939994

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  This paper presents a vibration suppression approach for systems with elastic couplings, which combines standard control and observation structures with a novel wave-space transformation. By formulating the system dynamics as a wave system and designing a traveling wave controller to reject reflected waves, the proposed method achieves robust vibration suppression against variations in load-side inertia. Unlike conventional approaches that rely on online identification or adaptive mechanisms, which inherently require persistent excitation and may compromise suppression performance, the proposed method eliminates the need for such estimation. The paper details the modeling, controller design, and state-estimation scheme. Experimental results validate the effectiveness of the proposed method, showing superior immunity compared with conventional ones under varying load-side conditions and discussing the criteria for parameter selection for the observers and controller.

  • Access to Document (DOI)

• Application of higher-order disturbance observer in the control structure of the two-mass system

  Derugo P., Haftu Kahsay A., Szabat K., Zawiślak R., Shikata K., Katsura S.

  Przeglad Elektrotechniczny 101 ( 6 ) 112 - 117 2025

  ISSN  00332097

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  The article presents issues related to vibration damping in a dual-mass system. A control structure with a PI controller and with additional feedback from the torsional torque and its derivative is used for the study. A higher-order integral estimator is proposed to obtain information on these variables. Results showing a significant improvement in the quality of estimation of these quantities compared to the classical observer are presented. Theoretical considerations are confirmed by simulation and experimental studies.

  • Access to Document (DOI)

• Quasi-Real-Time Motion Control via Measured Sampling Periods

  Shikata K., Katsura S.

  IECON Proceedings Industrial Electronics Conference  2025

  ISSN  21624704

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  This study introduces quasi-real-time (QRT) motion control, explicitly incorporating measured sampling periods into the digital control loop. Digital control in mechatronic systems typically relies on the assumption of fixed sampling periods. However, practical systems often experience sampling fluctuations due to hardware limitations, sensor-related interrupt processing, and communication delays. To address this issue, a systematic discretization method for continuous-time transfer functions is proposed to enable controller, observer, and filter design under sampling fluctuations. Experimental results demonstrate that the proposed approach performs more robustly than conventional fixed-sampling implementations. QRT motion control relaxes stringent real-time (RT) constraints and is a foundation for user-friendly, general-purpose operating system (GPOS)-based RT execution frameworks in advanced mechatronic applications.

  • Access to Document (DOI)

• A Novel PI-Based Control Structure with Additional Feedback from Torsional Torque and Its Derivative for Damping Torsional Vibrations

  Derugo P., Kahsay A.H., Szabat K., Shikata K., Katsura S.

  Energies 17 ( 19 )  2024.10

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  This paper presents issues related to the damping of torsional vibrations in a system with elastic coupling. A novel PI-based control structure with additional feedback from torsional torque and its derivative is proposed. For the estimation of the required variables, the integral observer is proposed. Analytical expressions are presented to enable the selection of parameters of the control system. The relationship between the considered system and popular structures with a PI controller and one additional feedback from torsional torque and the derivative of torsional torque is pointed out. The proposed control structure is tested under simulation and experimental studies.

  • Access to Document (DOI)

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Courses Taught 【 Display / hide 】

Courses Taught 【 Display / hide 】

• LABORATORIES IN SCIENCE AND TECHNOLOGY

  2026

• COMPUTER PROGRAMMING EXERCISE

  2026

• LABORATORIES IN SYSTEM DESIGN ENGINEERING 2)

  2026