Ohnishi, Kouhei

写真a

Affiliation

Keio Frontier Research & Education Collaborative Square (K-FRECS), K-FRECS at Shin-Kawasaki ( Mita )

Position

Project Professor (Non-tenured)

External Links

Career 【 Display / hide 】

  • 1980.04
    -
    1982.03

    慶應義塾大学工学部電気工学科 ,助手

  • 1982.04
    -
    1988.03

    慶應義塾大学工学部電気工学科 ,専任講師

  • 1988.04
    -
    1996.03

    慶應義塾大学理工学部電気工学科 ,助教授

  • 1992.04
    -
    1993.03

    兼慶應義塾大学就職部(矢上支部) ,委員

  • 1993.10
    -
    1995.09

    慶應義塾大学学生部(矢上) ,委員

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Academic Background 【 Display / hide 】

  • 1975.03

    The University of Tokyo, Faculty of Engineering, 電気工学科

    University, Graduated

  • 1977.03

    The University of Tokyo, Graduate School, Division of Engineering, 電気工学専門課程

    Graduate School, Completed, Master's course

  • 1980.03

    The University of Tokyo, Graduate School, Division of Engineering, 電気工学専門課程

    Graduate School, Completed, Doctoral course

Academic Degrees 【 Display / hide 】

  • 工学 , The University of Tokyo, 1980.03

 

Books 【 Display / hide 】

  • Force/Tactile Sensation for Contact Task

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

     View Summary

    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.

  • Mechatronics and Robotics: New Trends and Challenges

    Ohnishi K., et al, CRC Press, 2020.11,  Page: 266

    Scope: 12 Human–Robot Interaction

  • Motion Control Systems

    ASIF SABANOVIC OHNISHI KOUHEI, John Wiley, 2011.02

    Scope: 364

  • 「コンピュータの数理」

    矢向 高弘,村上 俊之,大西 公平 , 朝倉書店, 2000.10

     View Summary

    コンピュータの構造を論理的かつ数学的に理解するすることに主眼を置き,ハードの基礎からCの活用までを解説した。

  • 丸善

    堀 洋一、大西公平, 1998.06

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Papers 【 Display / hide 】

  • Remote Catheter System With Enhanced Haptic Feedback for Use in Endovascular Procedures

    Akiyama T., Kitamura T., Nogawa H., Iwama T., Saito Y., Asai H., Shibao S., Mizutani K., Ohnishi K.

    IEEE Transactions on Medical Robotics and Bionics 8 ( 3 ) 1428 - 1437 2026.08

     View Summary

    We propose a sensorless remote catheter control system that delivers real-time haptic feedback. Bilateral control combined with a reaction force observer estimates contact forces and transmits them to the operator in real time, while frequency-shaped feedback improves the perceived sensitivity and reduces fatigue. Using three catheter types and three operators, we evaluated position-force synchronization, loop delay, and vessel-wall load relative to manual manipulation. The average position error was approximately 2.14× 10<sup>-5</sup>m, and the force error was 0.493 N. Cross-correlation (≤ 1Hz) showed no measurable lag in the low-frequency synchronization analysis within the 1 ms resolution. For force equivalence, the prespecified primary analysis employed a two one-sided tests (TOST) procedure based on estimates obtained from a linear mixed-effects (LME) model, with the smallest effect size set to ±10% of the manual mean; equivalence was supported (b = -0.029, 90% confidence interval [-0.119, 0.061]), whereas a stricter ±5% sensitivity analysis was not supported. All operators completed the tasks after minimal system familiarization. These findings indicate that the system replicates manual precision in a benchtop phantom setting while enabling real-time haptic feedback and maintaining vessel-wall loading comparable to that of manual manipulation. Our sensorless haptic technology represents a promising step toward future clinical translation of remote catheter systems, with applications in safer, standardized, and more intuitive endovascular procedures.

  • DecompGrind: A Decomposition Framework for Robotic Grinding via Cutting-Surface Planning and Contact-Force Adaptation

    Araki S., Hachimine T., Saito Y., Ohnishi K., Morimoto J., Matsubara T.

    IEEE Transactions on Automation Science and Engineering 23   15384 - 15397 2026

    ISSN  15455955

     View Summary

    Robotic grinding is widely used for shaping workpieces in manufacturing, but it remains difficult to automate this process efficiently. In particular, efficiently grinding workpieces with different shapes and density-dependent removal resistance is challenging because removal resistance varies with local contact conditions. Moreover, it is difficult to achieve accurate estimation of removal resistance and analytical modeling of shape transition, and learning-based approaches often require large amounts of training data to cover diverse processing conditions. To address these challenges, we decompose robotic grinding into two components: removal-shape planning and contact-force adaptation. Based on this formulation, we propose DecompGrind, a framework that combines Global Cutting-Surface Planning (GCSP) and Local Contact-Force Adaptation (LCFA). GCSP determines removal shapes through geometric analysis of the current and target shapes without learning, while LCFA learns a contact-force adaptation policy using bilateral control-based imitation learning during the grinding of each removal shape. This decomposition restricts learning to local contact-force adaptation, allowing the policy to be learned from a small number of demonstrations, while handling global shape transition geometrically. Experiments using a robotic grinding system on 3D-printed workpieces with different shapes and densities under fixed belt conditions demonstrate reduced grinding time while maintaining safe levels of contact force.

  • Teleoperated Orthopedic Drill System Presenting Haptic Information Extended by Bur Tip Position

    Matsunaaa T., Takano S., Shimono T., Ohnishi K., Yagi M., Nakamura M.

    2025 IEEE International Conference on Mechatronics Icm 2025  2025

     View Summary

    In orthopedic surgery, robotic technologies to assist surgeons operating surgical drills to cut bones are being de-veloped, since there is a risk to injure delicate tissues around bones. Penetration detection is useful for surgical drills to enhance safety. However, there is still a risk to damage delicate tissues, even if penetration is detected to stop drills. In this study, a teleoperated haptic drill system implementing a safety enhancement system which extends haptic sensation according to the end effector position is presented. The presented method is composed of the object detection phase and the operator assist phase. In the object detection phase, the position and posture of an object are acquired by the drill system which has the shape model of the object. In the operator assist phase, haptic sensation is extended based on the acquired object information to prevent penetration of the object, while the state of the controller of the drill system is visualized by CG images created by a cutting simulator. The feasibility of the method is confirmed by cutting a pseudo bone.

  • Effectiveness Evaluation of Penetration-Detection Scheme for Surgical Drill Using Thrust Force and Positional Information

    Takano S., Shimono T., Matsunaga T., Yagi M., Ohnishi K., Nakamura M., Mima Y., Yamanouchi K., Ikeda G.

    IEEE Access 13   125594 - 125605 2025

     View Summary

    The risk of spinal cord injury when cutting into the spine is a particular concern in orthopedic surgery. Surgeons must rely entirely on their haptic senses to determine bone penetration. Therefore, surgeons incur heavy burdens. Some studies have introduced penetration-detection systems using torque information. However, these method requires obtaining the characteristics of the bone before the actual cutting. Our previous study introduced an orthopedic haptic drill equipped with a penetration-detection system. This drill detects penetration by monitoring changes in the force of a linear motor. In this study, the advantage of using force over torque for penetration detection was verified through theoretical modeling and experiments. The theoretical model indicates that the thrust force reacts more sensitively than the torque at penetration. The detection methods using the force-based and torque-based methods were compared through experiments. The experimental results verified that the force-based detection method has advantages in terms of detection accuracy and detection time. The results demonstrated the efficacy of the proposed method, highlighting its potential utility in improving the accuracy and safety of orthopedic procedures.

  • An Environment-Adaptive Position/Force Control Based on Physical Property Estimation

    Kitamura T., Saito Y., Asai H., Ohnishi K.

    IEEE Access 13   34200 - 34210 2025

     View Summary

    The current methods to generate robot actions for automation in significantly different environments have limitations. This paper proposes a new method that matches the impedance of two prerecorded action data with the current environmental impedance to generate highly adaptable actions. This method recalculates the command values for the position and force based on the current impedance to improve reproducibility in different environments. Experiments conducted under conditions of extreme action impedance, such as position and force control, confirmed the superiority of the proposed method over existing motion reproduction system. The advantages of this method include the use of only two sets of motion data, significantly reducing the burden of data acquisition compared with machine-learning-based methods, and eliminating concerns about stability by using existing stable control systems. This study contributes to improving the environmental adaptability of robots while simplifying the action generation method.

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

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Reviews, Commentaries, etc. 【 Display / hide 】

Presentations 【 Display / hide 】

  • 精子形成能判定のための精巣の硬さ測定装置の開発~ハムスター精巣を用いての検討

    OHNISHI KOUHEI

    [Domestic presentation]  日本コンピュータ外科学会 (東京、日本) , 

    2016.11
    , 

    Oral presentation (general), 日本コンピュータ外科学会

  • The Control Scheme of Underactuated Master System in Bilateral Control for Operation of Fragile Environment

    OHNISHI KOUHEI

    The 41st Annual Conference of IEEE Industrial Electronics Society,IECON (横浜) , 

    2016.11
    , 

    Oral presentation (general), IECON

  • Development of haptic prosthetic hand for realization of intuitive operation

    OHNISHI KOUHEI

    [International presentation]  The 42nd Annual Conference of the IEEE Industrial Electronics Society,IECON 2016 (Firenze,Italy) , 

    2016.10
    , 

    Oral presentation (general), IEEE

  • Simultaneonus Locomation of Biped Robot with the Transmission of Human Motion

    OHNISHI KOUHEI

    [International presentation]  The 42nd Annual Conference of the IEEE Industrial Electrnics Society,IECON 2016 (Firenze,Italy) , 

    2016.10
    , 

    Oral presentation (general), IEEE

  • Robotic Finger Rehabilitation System for Stroke Patient Using Surface EMG Armband

    OHNISHI KOUHEI

    [International presentation]  The 42nd Annual Conference of the IEEE Industrial Electronics Society,IECON 2016 (Firenze Italy) , 

    2016.10
    , 

    IEEE

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

  • Real haptics system without any sensors at slave side

    2018.04
    -
    2021.03

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

  • Revolution of integrated platform on medicine and engineering by haptic technology

    2013.05
    -
    2018.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (S), Principal investigator

Awards 【 Display / hide 】

  • Fujihara Award

    大西公平, 2019.06, 藤原科学財団

    Type of Award: International academic award (Japan or overseas)

  • 電気学会功績賞

    2017.06, 電気学会

    Type of Award: Award from Japanese society, conference, symposium, etc.

     View Description

    ハプティクス通信技術の発展とその産業応用への貢献

  • 紫綬褒章

    大西公平, 2016.11, Japanese Gavernment, 多年学術の分野においてよく努め発展に寄与したことについて

    Type of Award: Other

  • 産業応用部門賞

    嶌本慶太・谷田和貴・野崎貴裕・大西公平, 2014.08, 電気学会, 腱駆動型球体間接機構による力覚伝達

    Type of Award: Award from Japanese society, conference, symposium, etc.

  • 日本学術会議会長賞

    青山藤詞郎・柿沼康弘, 2013.09, 日本学術会議 産学官連携推進会議, 「外乱オブザーバー応用技術」の開発

    Type of Award: Award from publisher, newspaper, foundation, etc.

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Social Activities 【 Display / hide 】

  • IEEE 'Transactions on Industrial Electronics'

    1988.05
    -
    Present

Memberships in Academic Societies 【 Display / hide 】

  • IEEE Industrial Electronics Society, 

    2010.01
    -
    Present
  • Institute of Electrical Engineers of Japan, 

    2009.05
    -
    2010.05
  • 日本コンピュータ外科学会, 

    2008.10
    -
    Present
  • 電気学会, 

    2008.05
    -
    2009.05
  • IEEE Industrial Electronics Society, 

    2008.01
    -
    2009.12

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Committee Experiences 【 Display / hide 】

  • 2015.05
    -
    2016.05

    会長, 電気学会

  • 2014.12
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    2016.11

    委員, 電気学会実世界ハプティクスの高度化に関する協同研究委員会

  • 2014.05
    -
    2016.05

    有識者会議役員, 電気学会

  • 2014.05
    -
    2015.05

    会長代理, 電気学会理事会

  • 2014.02
    -
    Present

    代議員, 電気学会

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