Kyushu University Academic Staff Educational and Research Activities Database
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Kenji Tahara Last modified date:2018.06.07

Associate Professor / Control Systems
Department of Mechanical Engineering
Faculty of Engineering

Graduate School
Undergraduate School
Other Organization

Academic Degree
Ph. D (Eng.)
Field of Specialization
Research Interests
  • Robust motor control strategy to delay and noise of sensory information in sensory-motor integration
    keyword : Sensory-motor integration, delay, noise
  • Soft human support device using polymer artificial muscle
    keyword : polymer artificial muscle
  • Compound mobility using soft and hemispheric foot with torsional motion
    keyword : Compound mobility
  • Dexterous object manipulation by fusing a sensory feedback manner with proprioceptive information
    keyword : Virtual frame
  • On control of musculoskeletal systems by combining a feedfoward and feedback control manners
    keyword : musculoskeletal system
  • A high-backdrivable manipulator with variable stiffness mechanism
    keyword : Variable stiffness
  • Development and analysis of an intelligent motor control strategy for whole body musculo-skeletal system model to generate a smooth and natural human-like movement.
    keyword : Muscul-skeletal system
  • Development of a human-like nursing care robotic system that can lift up a human being
    keyword : nursing care robot
  • Dynamic object manipulation using a multi-fingered robotic hand
    keyword : Dynamic Grasping and manipulation
Academic Activities
1. K. Tahara and Z.W. Luo, "On dynamic control mechanisms of redundant human musculo-skeletal system,", Springer-Verlag, S. Kawamura and M. Svinin (Eds.): Advances in Robot Control -From Everyday Physics to Human-Like Movements-, pp. 217–247, 2011.10.
1. Ken Masuya, Shu Ono, Kentaro Takagi, Kenji Tahara , Feedforward Control of Twisted and Coiled Polymer Actuator Based on a Macroscopic Nonlinear Model Focusing on Energy, IEEE Robotics and Automation Letters, 10.1109/LRA.2018.2801884, 3, 3, 1824-1831, 2018.07, This letter proposes a feedforward (FF) controller for the twisted and coiled polymer actuator (TCPA), the so-called fishing line/sewing thread artificial muscle, based on its macroscopic nonlinear model. TCPA is an artificial muscle, and it contracts up to 50% in response to heating. Although several methods considering Joule heating as the input have been proposed to control the TCPA displacement, the FF controller based on the linear model shows the nonnegligible offset error. Therefore, the FF controller should be designed based on a nonlinear model, e.g., the model constructed by the authors. However, computing the inverse of the nonlinear model for the FF controller is difficult. Even if the inverse can be computed under static conditions, the problem of how to compensate the dynamics still remains. For this problem, we compensate the dynamics based on the idea of the Hammerstein model, namely we divide the inverse dynamics into the nonlinear transformation part and linear dynamics part. The former part consists of a converter from the displacement to temperature and a ratio adjuster for the squared voltage. Meanwhile, the latter is represented by the linear model of TCPA temperature. Through experiments, it is verified that the proposed FF controller can reduce the offset error of the displacement compared with the linear controller..
2. Y. Matsutani, Kenji Tahara, H. Kino, H. Ochi, Complementary compound set-point control by combining muscular internal force feedforward control and sensory feedback control including a time delay, Advanced Robotics,, 32, 8, 1-15, 2018.03, This paper proposes a new set-point control method for a musculoskeletal arm by combining muscular internal force feedforward control with feedback control including a large time delay. The proposed method accomplishes robust and rapid positioning with a relatively small muscular force. In the positioning by the muscular internal force feedforward controller, a large muscular force is required to achieve good performance. On the other hand, in the positioning by the feedback controller including the large time delay, the system can easily fall into an unstable state. A simple linear combination of these two controllers makes it possible to improve the control performance and to overcome the drawbacks of each controller in a complementary manner. First, a two-link six-muscle arm model is considered as a musculoskeletal system in this study. Second, the new set-point control method, which consists of the feedforward control signal and the feedback control signal including the time delay, is designed. Third, the stability of the proposed method is investigated using the Lyapunov–Razumikhin method. Finally, the results of numerical simulations and experiments are presented to demonstrate the advantages of the proposed method..
3. Miao Li, Kenji Tahara, Aude Billard, Learning task manifolds for constrained object manipulation, Autonomous Robots,, 42, 1, 159-174, 2018.01, Reliable physical interaction is essential for many important challenges in robotic manipulation. In this paper, we consider Constrained Object Manipulations tasks (COM), i.e. tasks for which constraints are imposed on the grasped object rather than on the robot’s configuration. To enable robust physical interaction with the environment, this paper presents a manifold learning approach to encode the COM task as a vector field. This representation enables an intuitive task-consistent adaptation based on an object-level impedance controller. Simulations and experimental evaluations demonstrate the effectiveness of our approach for several typical COM tasks, including dexterous manipulation and contour following..
4. Ken Masuya, Shu Ono, Kentaro Takagi, Kenji Tahara, Modeling framework for macroscopic dynamics of twisted and coiled polymer actuator driven by Joule heating focusing on energy and convective heat transfer, Sensors and Actuators, A: Physical,, 267, 443-454, 2017.11, In this paper, a nonlinear dynamics model of the twisted and coiled polymer actuator (TCPA) driven by Joule heating is proposed. TCPA is an actuator based on the phenomenon that the twisted and coiled polymer contracts by heating. TCPA has received considerable research attention after the discovery of this phenomenon. Although several conventional models were proposed to explain TCPA behavior, they do not address several characteristics of a real TCPA, namely, the delay of the displacement to the temperature, temperature behavior to the input (Joule heating), and effect of the convective heat transfer on the relationship between the displacement and temperature. The macroscopic modeling framework presented herein explains these properties. The main ideas of the proposed model are (1) the energy relating to TCPA, and (2) the temperature and velocity dependence of the convective heat transfer coefficient. Experiments were conducted for three kinds of TCPA. It was verified that the proposed model is more viable than a conventional model. In particular, the proposed model reduced the prediction errors of the displacement by more than 50% compared with the conventional model..
5. Ryuta Ozawa, Kenji Tahara, Grasp and dexterous manipulation of multi-fingered robotic hands
a review from a control view point, Advanced Robotics,, 31, 19-20, 1030-1050, 2017.10, Manipulation is one of the most important fields in robotics. Nevertheless, even given the long history of manipulation research, technologies for multi-fingered robotic hands are still in development. This paper investigates past research studies on control systems of multi-fingered robotic hands for grasping and manipulation..
6. Akihiro Kawamura, Kenji Tahara, Ryo Kurazume, Tsutomu Hasegawa, Dynamic grasping of an arbitrary polyhedral object, Robotica,, 31, 4, 511-523, 2013.07.
7. Hitoshi Kino, Shiro Kikuchi, Yuki Matsutani, Kenji Tahara, Takahiro Nishiyama, Numeracal Analysis of Feedforward Position Control for Non-pulley Musculoskeletal System: a Case Study of Muscular Arrangements of a Two-link Planar System with Six Muscles, Robotics Society of Japan, 10.1080/01691864.2013.824133, 27, 16, 1235-1248, 2013.03.
8. Akihiro Kawamura, Kenji Tahara, Ryo Kurazume, Tsutomu Hasegawa, Robust visual servoing for object manipulation against temporary loss of sensory information using a multi-fingered hand-arm, Journal of Robotics and Mechatronics, 25, 1, 125-135, 2013.01.
9. K. Tahara, S. Arimoto, R. Ozawa and Z.W. Luo, Bio-mimetic pinching movements of musculo-skeletal dual finger model, Advanced Robotics, 25, 1-2, 175-204, 2011.01.
10. K. Tahara and H. Kino, Reaching movements of a redundant musculo-skeletal arm: Acquisition of an adequate internal force by iterative learning and its evaluation through a dynamic damping ellipsoid, Advanced Robotics, 24, 5-6, 783-818, 2010.04.
11. K. Tahara, S. Arimoto, M. Sekimoto and Z.W. Luo, On control of reaching movements for musculo-skeletal redundant arm model, Applied Bionics and Biomechanics, 6, 1, 57-72, 2009.03.
12. H. Kino, T. Yahiro, S. Taniguchi and K. Tahara, Sensorless position control using feedforward internal force for completely restrained parallel-wiredriven systems, IEEE Transactions on Robotics, 25, 2, 467-474, 2009.02.
13. K. Tahara, Z.W. Luo, S. Arimoto and H. Kino, Sensory-motor control mechanism for reaching movements of a redundant musculo-skeletal arm, Journal of Robotic Systems, 22, 11, 639-651, 2005.11.
14. S. Arimoto, K. Tahara and J.-H. Bae, A stability theory on a manifold: Concurrent realization of grasp and orientation control of an object by a pair of robot fingers, Robotica, 21, 2, 163-178, 2003.03.
15. S. Arimoto, M. Yoshida, J.-H. Bae and K. Tahara, Dynamic force/torque balance of 2D polygonal objects by a pair of rolling contacts and sensorymotor coordination, Journal of Robotic Systems, 20, 9, 517-537, 2003.09.
16. S. Arimoto, K. Tahara, M. Yamaguchi, P.T.A. Nguyen and H.-Y. Han, Principle of superposition for controlling pinch motions by means of robot fingers with soft tips, Robotica, 19, 1, 89-98, 2001.01.
1. Ken Masuya, Shu Ono, Kentaro Takagi, Kenji Tahara, Nonlinear Dynamics of Twisted and Coiled Polymer Actuator made of Conductive Nylon based on the Energy Balance, 2017 IEEE International Conference on Advanced Intelligent Mechatronics, 2017.07.
2. Kentaro Takagi, Takeshi Arakawa, Jun Takeda, Ken Masuya, Kenji Tahara, Kinji Asaka, Position control of twisted and coiled polymer actuator using a controlled fan for cooling, SIPE, 2017.03.
3. Takeshi Arakawa, Kentaro Takagi, Kenji Tahara, Kinji Asaka, Position control of fishing line artificial muscles (coiled polymer actuators) from nylon thread, SIPE, 2016.03.
4. Kenji Tahara, Yuki Matsutani, Daisuke Nakagawa, Masataka Sato, Hitoshi Kino, Variable combination of feed-forward and feedback manners for set-point control of a musculoskeletal arm considering the maximum exertable muscular force, 42nd Annual Conf. of the IEEE Industrial Electronics Society, 2016.10.
5. Hiroaki Ochi, Hitoshi Kino, Kenji Tahara, Yuki Matsutani, Geometric conditions for feedforward positioning of musculoskeletal tendon-driven structure, 41st Annual Conf. of the IEEE Industrial Electronics Society, 2015.11.
6. Tetsuya Morizono, Kenji Tahara, Hitoshi Kino, Experimental investigation of contribution of biarticular actuation to mappings between sensory and motor spaces, 41st Annual Conf. of the IEEE Industrial Electronics Society, 2015.11.
7. Tokuo Tsuji, Kosei Baba, Kenji Tahara, Kensuke Harada, KEN'ICHI MOROOKA, Ryo Kurazume, Grasp stability evaluation based on energy tolerance in potential field, IEEE⁄RSJ Int. Conf. Intell. Robots, Syst., 2015.09.
8. Tomofumi Okada, Kenji Tahara, Development of a two-link planar manipulator with continuously variable transmission mechanism, 2014 IEEE/ASME International Conference on Advanced Intelligent Mechatronics, 2014.07.
9. Miao Li, Hang Yin, Kenji Tahara, Aude Billard, Learning object-level impedance control for robust grasping and dexterous manipulation, 2014 IEEE International Conference on Robotics and Automation, 2014.06.
10. Yuki Matsutani, Kenji Tahara, Hitoshi Kino, Hiroaki Ochi, Motoji Yamamoto, Set-point control of a musculoskeletal arm by the complementary combination of a feedforward and feedback Manner, 2014 IEEE International Conference on Robotics and Automation, 2014.06.
11. Kenji Tahara, Yuta Kuboyama, Ryo Kurazume, Iterative learning control for a musculoskeletal arm: Utilizing multiple space variables to improve the robustness, IEEE/RSJ Int. Conf. Intell. Robots, Syst., 2012.10.
Membership in Academic Society
  • IEEE Robotics and Automation Society
  • The Robotics Society of Japan
  • The Society of Instrument and Control Engineers
  • The Japan Society of Mechanical Engineers
  • RI-MAN