Papers - Ohnishi, Kouhei

Evaluation of Gait Phase Detection Methods for Walking Assist Robot

Tawaki Y., Okano T., Murakami T., Ohnishi K.

IEEE International Symposium on Industrial Electronics (IEEE International Symposium on Industrial Electronics)  2018-June   1051 - 1056 2018.08

ISSN  9781538637050

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© 2018 IEEE. Lower paralysis interrupts the mobility and depresses quality of life. Some incomplete paraplegia have an ability to walk in rehabilitation. However, incomplete paraplegia consumes larger energy for the gait motion than able-bodied people. Therefore, it is difficult for them to walk a long time. To solve this problem, many walking assist exoskeletons have been developed. In the case of walking assist, assist timing is one of the essential factors. The mismatch of assist timing interferes user's motion, thus it is required to adjust the assist timing. To control the assist timing, gait phase detection methods are used. Gait motion is divided into several phases. Many researchers introduce the gait phase detection method to control the assist timing. However, there is a mismatch between assist torque and ideal torque which is required by the user. There are no researches to evaluate the gait phase detection methods based on the analysis of the transition of assist torque required by the user. The purposes of this research are to propose the novel FSBM and evaluate the gait phase detection methods. In the experiment, a subject walks on the treadmill with wearing knee exoskeleton. The motor of the exoskeleton is controlled by the bilateral controller. Therefore, the assist torque can be adjusted to be suited to the user by manipulating master side motor. After the experiment, the assist torque and detected gait phases of proposed FSBM are compared to the conventional methods.

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Time delay compensation for force controller in bilateral teleoperation system under time delay

Tashiro T., Shimono T., Mizoguchi T., Ohnishi K.

Proceedings - 2018 IEEE 15th International Workshop on Advanced Motion Control, AMC 2018 (Proceedings - 2018 IEEE 15th International Workshop on Advanced Motion Control, AMC 2018)     649 - 654 2018.06

ISSN  9781538619469

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© 2018 IEEE. Time delay compensation is very important in the teleoperation field because time delay deteriorates the system performance and stability. Therefore, a lot of research about time delay compensation have been proposed and developed. One of the effective methods, communication disturbance observer (CDOB) has realized the time delay compensation for the position tracking in bilateral teleoperation. Thanks to CDOB, the smooth operation has been achieved. However, the precise force matching has not been achieved yet by any methods. To solve this problem, the time delay compensation method for the force control system has been proposed. This method realizes the precise contact force control under time delay. Therefore, the time delay compensation method is extended to bilateral teleoperation in this paper. In other words, the time delay compensation for the force controller in the bilateral teleoperation system is proposed toward the precise force matching. The validity is confirmed by the experiments.

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Artificial Replacement of Human Sensation Using Haptic Transplant Technology

Fukushima S., Sekiguchi H., Saito Y., Iida W., Nozaki T., Ohnishi K.

IEEE Transactions on Industrial Electronics (IEEE Transactions on Industrial Electronics)  65 ( 5 ) 3985 - 3994 2018.05

ISSN  02780046

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© 2018 IEEE. This study proposes a novel prosthetic hand that can artificially replace human sensation using haptic transplant technology. Conventional motorized prostheses are unable to precisely control the grasping force of the hand due to the lack of force sensation. In this paper, a haptic prosthetic hand is developed that allows for intuitive operation and precise force adjustment. These functions are realized by artificially transplanting the tactile sensation of a healthy part of the user's body to the amputated part of their body. The haptic transplant technology transmits the force sensation of the prosthesis to the master interface attached to the amputee's healthy part of body using bilateral control without a force sensor. Furthermore, variable compliance control is proposed for flexible adaptation to the shape of the object being grasped. The effectiveness of the proposed system was experimentally verified by comparing the controllability of the proposed system with that of a myoelectric prosthesis. In summary, an artificial replacement for human sensation was developed, and the intuitive operability and flexibility of the proposed system were confirmed.

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Disturbance observer and kalman filter based motion control realization

Phuong T., Ohishi K., Mitsantisuk C., Yokokura Y., Ohnishi K., Oboe R., Sabanovic A.

IEEJ Journal of Industry Applications (IEEJ Journal of Industry Applications)  7 ( 1 ) 1 - 14 2018

ISSN  21871094

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© 2018 The Institute of Electrical Engineers of Japan. Many effective robot-manipulator control schemes using a disturbance observer have been reported in the literature in the past decades. Besides, the disturbance observer combined with the Kalman filter has attracted the attention of researchers in the field of motion control. The major advantage of a motion control system based on the Kalman filter and disturbance observer is the realization of high robustness against disturbance and parameter variations, effective noise suppression and wideband force sensing. This paper presents a survey of motion control based on the Kalman filter and disturbance observer, which have been previously introduced by the authors. Several control schemes, as well as formulations and applications of the Kalman filter and disturbance observer, are described in the paper. The performance and effectiveness of the control schemes are evaluated to give a useful and comprehensive design of the Kalman filter and disturbance observer in various motion control applications.

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Active motion evaluation by mechanical power factor analysis based on specific frequency component

Osada S., Shimono T., Mizoguchi T., Ohnishi K.

IEEJ Journal of Industry Applications (IEEJ Journal of Industry Applications)  7 ( 3 ) 244 - 249 2018

ISSN  21871094

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© 2018 The Institute of Electrical Engineers of Japan. This paper proposes a new approach of mechanical power factor analysis for evaluating human active motion. The mechanical power factor is affected by the motion trajectory of an evaluation object. Therefore, in active motion, unified evaluation is difficult using the conventional analysis method. In this study, the power factor evaluation of active motion is realized by applying the perturbation from the evaluation system and using its frequency component for power factor calculation.

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Frequency-Based Analysis of the Relationship between Cutting Force and CT Number for Inplant-Surgery-Teaching Robot

OHNISHI KOUHEI

IEEJ Journal of industry Applications(accepted for publication) (IEEE)   2017.12

Research paper (scientific journal), Joint Work

軟性内視鏡ロボットに搭載可能な小型ハプティック鉗子ロボットの開発

OHNISHI KOUHEI

日本コンピュータ外科学会論文誌(accepted for publication) (日本コンピュータ外科学会)   2016.12

Joint Work

A Bilateral Control System to Synchronize with Haptic and Visual Sense for Teleoperation over Network

OHNISHI KOUHEI

IEEJ Journal of industry Application 5 ( 5 ) 370 - 377 2016.09

Joint Work

An Allocation Method of High Pass Filter for Bilateral Teleoperation System Over Network Considering Stability and Performance

OHNISHI KOUHEI

IEEJ Journal of industry Applications (IEEJ)  5 ( 3 ) 199 - 205 2016.05

Research paper (scientific journal)

Vompensation of Backlash for Geared Drive Systems and Thrust Wires Used in Teleoperation

OHNISHI KOUHEI

IEEJ Journal of Industry Applications (IEEJ)  4 ( 5 ) 514 - 525 2015.09

A Two Flow Expression Method of Four-Channel Bilateral Control System with Time Delay and Validation of Model-Free Time Delay Compensator

OHNISHI KOUHEI

IEEJ Journal of Industry Applications 4 ( 5 ) 574 - 581 2015.09

Joint Work

A Structural Approsch to Improve the Stabilith of Bilateral Control System wiht Time Delay

OHNISHI KOUHEI

IEEJ Journal of Industry Applications (IEEJ)  4 ( 5 ) 526 - 534 2015.09

力センサレス臓器触診デバイスによる生態の硬さ測定法

OHNISHI KOUHEI

日本コンピュータ外科学会論文誌 (日本コンピュータ外科学会)  17 ( 2 ) 91 - 100 2015.08

Joint Work

官能評価に基づく機能モードごとの通信遅延補償設計法

OHNISHI KOUHEI

電気学会論文誌産業応用部門誌 (電気学会)  135 ( 7 ) 755 - 764 2015.07

Joint Work

力触覚通信ー超成熟社会発展を後押しする新しい通信

OHNISHI KOUHEI

電子情報通信学会誌 (電子情報学会)  98 ( 5 ) 361 - 368 2015.05

Joint Work

An Adaptive Reaction Force Observer Design

OHNISHI KOUHEI

IEEE Transaction on Mechatronics (IEEE)  20   750 - 760 2015

Joint Work

Electro-Hydraulic Transmission System for Minimally invasive Robotics

OHNISHI KOUHEI

IEEE Transaction on Industrial Electronics (IEEE)   2015

Joint Work

Heartbeat Synchronization with Haptic Feedback for Tele-surgical Robot

OHNISHI KOUHEI

IEEE Transaction on industrial Electronics (IEEE)  61 ( 7 ) 3753 - 3764 2014.07

Joint Work

A Guide to design Disturbance Observer

OHNISHI KOUHEI

ASME Journal of Dynamic System, Measurement and Control 136 ( 2 ) 1 - 10 2014.03

Joint Work

Decoupling Strategy for Position and Force Control Based on Model Space Disturbance Observer

OHNISHI KOUHEI

IEEE Transaction on Industrial Elecronics (IEEE)  61 ( 2 ) 1022 - 1032 2014.03

Joint Work