Nozaki, Takahiro

写真a

Affiliation

Faculty of Science and Technology, Department of System Design Engineering (Yagami)

Position

Associate Professor

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Career 【 Display / hide 】

  • 2012.04
    -
    2014.03

    The Japan Society for the Promotion of Science, Research Fellow (DC1)

  • 2014.04
    -
    2015.03

    Yokohama National University, Assistant Professor

  • 2015.04
    -
    2018.03

    Department of System Design Engineering, Keio University, Assistant Professor

  • 2018.04
    -
    2022.03

    Department of System Design Engineering, Keio University, Assistant Professor

  • 2019.10
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    2021.04

    Department of Mechanical Engineering, Massachusetts Institute of Technology, Visiting Scientist

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Academic Background 【 Display / hide 】

  • 2006.04
    -
    2010.03

    Keio University, Faculty of Science and Technology, Department of System Design Engineering

    University, Graduated

  • 2010.04
    -
    2012.03

    Keio University, Graduate School, Division of Science and Engineering, School of Integrated Design Engineering

    Graduate School, Completed, Master's course

  • 2012.04
    -
    2014.03

    Keio University, Graduate School, Division of Science and Engineering, School of Integrated Design Engineering

    Graduate School, Completed, Doctoral course

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Academic Degrees 【 Display / hide 】

  • Ph. D., Keio University, Coursework, 2014.03

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Research Areas 【 Display / hide 】

  • Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Power engineering

  • Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Control and system engineering

  • Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Electron device and electronic equipment

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Research Keywords 【 Display / hide 】

  • Robotics

  • Control Engineering

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Books 【 Display / hide 】

  • Force/Tactile Sensation for Contact Task

    K Ohnishi, T Nozaki, Y Saito, H Asai, T Kitamura, Emotional Engineering: Vol.10: Emotional Engineering as a Culture for 22nd Century Civilisation, 2025.01

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    The sensation of the contact is indispensable for the contact task. In this chapter, the instantaneous value of the force/tactile sensation is defined and quantified as the ratio of the force and the velocity. The absolute value is also defined by the rms value with the definition of the time window. This value is extended to the frequency domain with the four parameters, which are also the admittance of the contact object. The operating point of the contact task in the force–velocity plane should be the crossing point of the characteristics of the actuation and the mechanical load. This is the same as the coincidence of the force/tactile sensation with the admittance of the contact object. Since the admittance of the contact object is varied according to the motion, such a coincidence should be maintained by the feedback mechanism. As a result, the feedforward system to define the mission of the contact and the feedback system for the matching the admittance is the essential structure of the contact task. That is shown by the figures and the experimental results.

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Papers 【 Display / hide 】

  • Thrust Control with Switching in Electrodynamic Propulsion Systems with Corona Discharge

    S Yashita, H Katagiri, T Kitamura, T Nozaki

    2025 IEEE International Conference on Mechatronics (ICM), 1-6  2025

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    Electroaerodynamics (EAD) is one phenomenon that manipulates gas with high voltage. Corona discharge is a typical example and is known to produce thrust quietly without moving parts. Therefore, it is expected to be utilized in various ways, such as a thrust source of drones. As thrust with corona discharge depends on the applied voltage, it is necessary to manipulate the applied voltage for thrust control. However, large-scale systems require several tens of kV, and there is little adequate research on these systems. Thus, an adequate switching method is essential, and it is also crucial to elucidate the effect of switching on thrust. Hence, this study conducted thrust control with corona discharge and analyzed the influence of switching on thrust. Specifically, a resistor is connected in series to the electrode, and a switching element is connected in parallel with the resistor. The proposed method stabilizes and limits the voltage applied to the switching element and effectively controls the thrust and the voltage applied to the electrode. Two experiments were conducted to reveal the electrical characteristics of the electrode in corona discharge and confirm the effectiveness of the proposal. The first experiment showed the potential of switching for the electrode with corona discharge on the collector side. Moreover, the second experiment demonstrated that the proposed switching method worked properly, and thrust can be controlled by changing the duty ratio of switching. The achievements of this study are expected to control levitation systems EAD, such as corona discharge, and realize stable control.

  • Positioning Control for Voice Coil Motor Using Unbalanced Multilevel Inverter Topology

    G Takei, H Obara, R Haneda, T Nozaki

    2025 IEEE International Conference on Mechatronics (ICM), 1-6  2025

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    This article proposes a new multi-level inverter (MLI) based on flying capacitor inverter (FCI), with focused on high-precision positioning control for a voice coil motor (VCM). Multi-level inverters (MLIs) have the characteristic that increasing the number of output voltage levels reduces the output voltage error. However, as the number of levels increases, the number of circuit elements increases, and the circuit becomes more complex. In addition, the output voltage amplitude for each level is constant in conventional inverters. As a result, such as high-precision positioning control of VCM, designing an appropriate inverter for a reference wave that contains a large amount of low-voltage components increases the number of circuit elements. Therefore, this paper proposes a MLI with two unbalanced dc-input voltages, referred to as unbalanced MLIs (UMLIs) hereinafter. This topology uses two different dc-input voltages, and it is possible to reduce the output voltage level in extremely low-voltage range compared to other voltage levels. Simulation results when the high-precision positioning control of the VCM confirm that the proposed UMLIs improves the control performance compared to the conventional FCIs with equal number of output voltage levels and uniform level widths.

  • Control Stiffness-Based Motion Reproduction for Environmental Impedance Variation

    A Takakura, T Nozaki

    2025 IEEE International Conference on Mechatronics (ICM), 1-6  2025

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    Motion generation technology contributes to the automation of the robots, especially in the industrial field. Imitation learning and motion reproduction system (MRS) are one of the motion generation methods that widely applied. However, machine learning-based methods require a large amount of data and are weak against extrapolation. Although MRS has merit in terms of the data number, it is weak regarding environmental variation. In particular, the environmental impedance variation have occurred, both position and force tracking are impossible. As several conventional studies have been done to reduce only position or force tracking errors, they can not adapt force or position priority tasks, respectively. Therefore, this paper proposes a novel compensation law based on designed control stiffness using the hybrid angle. The validity of this proposal is confirmed by simulation. This paper contributes to the MRS expansion of the environmental impedance variation with consideration of the task's priority physical value.

  • Investigation of Relationship between Electrode Integration Method and Force-to-Volume Ratio in Force Generation System Using Corona Discharge

    H Katagiri, S Yashita, T Kitamura, T Nozaki

    2025 IEEE International Conference on Mechatronics (ICM), 1-6  2025

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    A force generation mechanism utilizing corona discharge has the advantages of being lightweight, compact, and having no moving parts. The general structure of an electrode used to generate corona discharge is a wire on the high-voltage side and a flat plate on the ground side. To gain greater force generated by corona discharge, it is necessary to install and integrate a large number of electrodes. However, if a large number of electrodes are integrated, the required volume will increase. Therefore, a method of integrating the electrodes to increase the force-to-volume ratio is needed. Therefore, this paper comprehensively examines the two-dimensional arrangement of electrodes on the ground side and investigates the relationship with the force-to-volume ratio. Specifically, the force-to-volume ratio was investigated when the ground side was made of hollow hexagons, squares, or triangles compared to the wire-plate electrode. Also, since it is known that the force is more significant when needles are used on the high-voltage side rather than wires, the high-voltage side was made into a needle for electrodes with hollow polygons. The experimental results show that the force-to-volume ratios of the needle-hollow polygon electrodes were larger when the applied voltage was low, around 20 kV, and that of the wire-plate electrode was larger when the applied voltage was higher than 30 kV. These results show the relationship between the method of integrating the electrodes and the force-to-volume ratio, which was unknown in corona discharge. They can be used as a reference in the design of actuators.

  • Performance prediction of fully three-dimensional solid-state propulsion systems by eigenvalue problem decomposition

    H Shibata, T Nozaki

    arXiv e-prints, arXiv: 2503.17910  2025

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Papers, etc., Registered in KOARA 【 Display / hide 】

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Research Projects of Competitive Funds, etc. 【 Display / hide 】

  • Development of a robot for single-cell surgery with tactile feedback

    2024.06
    -
    2027.03

    Grants-in-Aid for Scientific Research, Grant-in-Aid for Challenging Research (Exploratory), No Setting

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    細胞やその小器官から情報を得る手段として、単一細胞手術が近年注目されている。しかし、これまでに研究されてきた方法では、人の手で直接複雑な操作を施すことはできない。本研究は、触覚フィードバック付き単一細胞手術用ロボットの開発を目的とし、研究代表者らが培ってきた力触覚伝送技術（リアルハプティクス）による超微小手術用ロボット開発のノウハウをもとに、まずは基礎的知見を得ることを目指す。本研究の遂行により、複雑な細胞手術や新たな細胞手術法の開発への道が開ける。さらに、細胞研究を起点に生命科学全体の体系や方向性を大きく変革させること、およびロボット工学へ再応用することが期待できる。

  • Development of dental implant drill with bone quality change detection mechanism

    2023.04
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    2027.03

    Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), No Setting

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    歯科インプラント治療は、天然歯への負担が少なく、咀嚼機能や審美性に多くの利点を持つ優れた治療法である。しかし、歯槽骨高の低い上顎臼歯部の埋入においては、上顎洞粘膜損傷の危険性を伴う。そこで本研究では、上顎洞底の皮質骨のみを貫通した時点で上顎洞粘膜の損傷なく停止する新たなサイナスリフトシステムを構築する。目的達成のためA. 切削抵抗とドリル形状・回転速度との関係性解明、B. 切削抵抗測定アルゴリズムの開発、C. 骨質変化検出機構の開発、D. ハンドピース型歯科インプラントドリル機器のハード製作、E. 自動停止制御の実装を実施したのち、F. in vivo 実証実験により、有用性を確認する。

  • 電気的特性に基づく再生誘導血小板の品質評価に基づくパーソナル治療薬の開発

    2023.04
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    2026.03

    Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), No Setting

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    血小板は核を持たないことから、再生医療材料の分野において、臨床応用面で有利である。皮下脂肪組織由来血小板は、iPS細胞由来血小板より、安全面・費用面で、より臨床応用のハードルが低い素材として注目されている。これまでの成果を元に、われわれはは、いち早く皮下脂肪組織由来血小板を創傷治癒薬として臨床応用するため、治験を前提としており、具体的な治験プロトコールの策定・必要な客観的評価基準の確立・治験で使用する脂肪細胞ソースの確保を進めている。本研究では、特に誘導血小板の製品としての品質保証による安全性を担保する技術開発を行い、第一種再生医療等技術として完成させる。

  • Development of a neurorehabilitation system using haptic substitution and motion substitution as external stimuli

    2020.05
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    2022.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, Nozaki Takahiro, Fund for the Promotion of Joint International Research (Home-Returning Researcher Development Research (A)), Principal investigator

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    We conducted research on robot-assisted neuro-rehabilitation with Dr. Hermano Igo Krebs and colleagues at the Massachusetts Institute of Technology in the United States. Three types of tests, Discrete Movement, Rhythmic Movement, and Target Transition, were conducted to clarify the mechanism of human force generation. The results suggest that "the differential value of the force that humans can generate is sufficiently large, and that the response speed is due to visual information," "humans anticipate slight future movements and try to improve their movements," and "the law of superposition holds for the differential value of force. In addition, we succeeded in developing a new proximity sensor that can simultaneously measure distance, angle, and force. The research results were published in an international journal with Impact Factor 8.236 and received an award from the Institute of Electrical Engineers of Japan.

  • Development and control of a new haptic system that brings dexterity to hydraulically driven manipulators

    2020.04
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    2024.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, Nozaki Takahiro, Grant-in-Aid for Scientific Research (B), Principal investigator

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    In this study, we proposed a method to give a robot a force-tactile sensation by installing a multi-degree-of-freedom force sensor at the base of a manipulator. When a force is applied to the manipulator from the external environment, the contact position and contact force can be calculated from the ratio of the force and moment in each axis direction. We implemented the proposed method on a commercial 6-DOF manipulator and confirmed that it is possible to calculate and control the contact position and contact force.

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Courses Taught 【 Display / hide 】

  • SEMINAR IN SYSTEM DESIGN ENGINEERING

    2025

  • POWER ELECTRONICS

    2025

  • LABORATORIES IN SYSTEM DESIGN ENGINEERING 2)

    2025

  • LABORATORIES IN SCIENCE AND TECHNOLOGY

    2025

  • INDEPENDENT STUDY ON INTEGRATED DESIGN ENGINEERING

    2025

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