Author name cluster

Kenji Kawashima

Possible papers associated with this exact author name in Arrow. This page groups case-insensitive exact name matches and is not a full identity disambiguation profile.

21 papers

1 author row

ICRA Conference 2023 Conference Paper

Limit Cycle Generation with Pneumatically Driven Physical Reservoir Computing

Hiroaki Shinkawa
Toshihiro Kawase
Tetsuro Miyazaki
Takahiro Kanno
Maina Sogabe
Kenji Kawashima

One of the recent developments in physical reservoir computing, which uses the complex dynamics of a physical system as a computational resource, is the use of a pneumatic pipeline system as a computational resource. This uses the dynamics of air for computation, and because it is lightweight and power-saving, it is used for gait-assist control using a soft exoskeleton with pneumatic rubber artificial muscles. In this study, we verified that by feeding back the estimated information to a pneumatic pipeline system, the pneumatic physical reservoir computing can generate periodic pressure changes as a stable limit cycle, such as those seen in walking. A pneumatic reservoir with feedback loops was modeled to generate limit cycles in the simulation, and it was confirmed that the system could generate limit cycles with high accuracy even from initial positions far from the target limit cycle. This system is expected to be applied to assist walking movements with a soft exoskeleton with a lightweight computational device.

ICRA Conference 2022 Conference Paper

Online Assistance Control of a Pneumatic Gait Assistive Suit Using Physical Reservoir Computing Exploiting Air Dynamics

Hiroyuki Hayashi
Toshihiro Kawase
Tetsuro Miyazaki
Maina Sogabe
Yoshikazu Nakajima
Kenji Kawashima

Wearable gait assistive devices have been im-proved by soft robotics in terms of safety and physical burden of the wearer. Currently, electrical sensors and computers around the wearer are bottlenecks in enhancing the wearer's activities. In this paper, we present a wearable gait assistive system using soft pneumatic system for all the actuation, sensing, and computation. Pneumatic artifical muscles (PAMs) on the thighs were used to generate assistance force, and thin PAMs on the whole legs were used for sensing the wearer's motion. All thin PAMs were connected to each other by tubes, and the pressure response in the tubes were exploited to compute the wearer's motion in manner of physical reservoir computing. The left thigh angular velocity estimated from the reservoir response was used for control the PAMs for actuation. Our experiment with the use of gait assistance showed that the system worked correctly. This paper shows that the pneumatic analog computation system for sensing soft body can help the functionality of soft wearable assistive devices.

IROS Conference 2020 Conference Paper

Development of Selective Driving Joint Forceps Using Shape Memory Polymer

Katsuhiko Fukushima
Takahiro Kanno
Tetsuro Miyazaki
Toshihiro Kawase
Kenji Kawashima

In this study, we developed a selective driving joint forceps (SDJF) for laparoscopic surgery. The SDJF has a mechanism that the driving joints can be selected arbitrarily, therefore each joint doesn't require an individual actuator for operating. The developed SDJF has six joints that can be operated using only four actuators. Each joint has 2-degrees-of-freedom (DOF) of flexion. Therefore, the SDJF has the same working area as the forceps having six driving joints (each joints can bend ±30° around the X and Y axes). The mechanism of the SDJF is realized by fixing each joint with a collar made of shape memory polymer. The proposed mechanism not only reduces the number of actuators required for joint operation, but also has the rigidity of the forceps, which is important in surgery. In addition, a driving section of the forceps is driven by pneumatic cylinders, therefore, the forceps joint has high-back-drivability, lightweight and high-output. We measured the heating and cooling time required to change the driving joint, dynamic response and rigidity of the prototype SDJF.

IROS Conference 2019 Conference Paper

Development of an Arm Curl Machine with Variable Resistance Using Pneumatic Artificial Rubber Muscle

Tomoya Nakanishi
Toshihiro Kawase
Junya Aizawa
Shintaro Yoshida
Shingo Ohno
Ryo Sakurai
Tetsuro Miyazaki
Takahiro Kanno

A method to improve quality of life of elderly people is to increase muscle strength. The purpose of this study is to develop a machine to improve muscle strength effectively. In this paper, we proposed a muscle strength training machine that exerts variable resistance using pneumatic artificial rubber muscle. In addition, we observed the effect on muscle activity by using the proposed machine with predictable and unpredictable load change patterns. Experimental results showed that there was a difference between the rising time of muscle activity and the maximum amplitude of electromyogram depending on predictability of the load change and showed the possibility of effective muscle strength improvement against unpredictable load using the arm curl machine.

ICRA Conference 2019 Conference Paper

Robotic Forceps without Position Sensors using Visual SLAM

Takuya Iwai
Takahiro Kanno
Tetsuro Miyazaki
Toshihiro Kawase
Kenji Kawashima

In this study, a robotic forceps with a wrist joint using visual SLAM for joint angle sensing was developed. The forceps has a flexible joint connected to the wrist joint at its rear end and the motion of the rear joint is driven by a parallel linkage. A monocular camera attached on the rear of the parallel linkage is in charge of position sensing, and the joint angles are estimated from the pose of the camera. The pose of the camera is obtained by a visual SLAM. The visual servo system realizes a simple attaching mechanism. The static and dynamic positioning experiments are conducted. We confirmed that the visual servoing system controls the forceps tip within the error of 3 deg in the motion range of 50 deg.

IROS Conference 2018 Conference Paper

Development of Master-slave Type Lower Limb Motion Teaching System

Toshihiro Tagami
Toshihiro Kawase
Daisuke Morisaki
Ryoken Miyazaki
Tetsuro Miyazaki
Takahiro Kanno
Kenji Kawashima

Motor skill learning is fundamental in many physical activities of human. In the processes of learning of motor skills, learners often receive visual or physical information about postures from teachers. However, the information about postures usually cannot be transmitted precisely. In this paper, we propose a motion teaching system to transmit teachers' motion to learners directly by using a motion capture and an assist suit. The assist suit, which has a pneumatic artificial rubber muscle (PARM) as an actuator, was designed to move a learner's hip joint with less loss of assistive force and less constraint of motion. Hip joint motion of a teacher can be transmitted to the assist suit by master-slave control. In addition, to compensate the delay of the PARM, posture of the teacher is predicted before the occurence by a recurrent neural network by using electromyogram signals and the past joint angle. We confirmed the system can transmit a teacher's motion to a learner in real time, and with the neural network, the delay of the learner's motion could be suppressed to approximately 0. 1s, which is enough to feel visual and physical information synchronous. Therefore, the proposed motion teaching system would have the ability to transmit teachers' motion to learners visually and physically with precision sufficient to facilitate skill transmission.

ICRA Conference 2016 Conference Paper

Thin-diameter chopsticks robot for Laparoscopic Surgery

Haruka Sakurai
Takahiro Kanno
Kenji Kawashima

Surgical robot systems increase the operability and efficiency of laparoscopic surgery. Forceps manipulators with the diameter less than 3mm can drastically reduces the invasion to the patient, compared to those used in current robot systems with the diameter of 5mm or more. In this paper, we propose a novel surgical manipulation system with Φ3mm forceps. Instead of introducing costly grasping mechanisms, the proposed system consists of a pair of rods driven by two robotic forceps holders, so that they can synchronously grasp, move, and rotate objects, in manner of a chopstick. Five-DOF kinematic model is constructed, which includes three-DOF translational motion, a sliding motion, and a grasping motion. A master-slave system is constructed and the tracking performance of the controller is validated. We also experimentally confirmed that the proposed system can perform the block-transfer task, which is common in training of surgeons, and the block-rotation task.

IROS Conference 2015 Conference Paper

Compact haptic device using a pneumatic bellows for teleoperation of a surgical robot

Ryoken Miyazaki
Tomohisa Terata
Takahiro Kanno
Toshiaki Tsuji
Gen Endo
Kenji Kawashima

In this paper, a lightweight master interface for a surgical robot system is proposed. The position of the human hand is measured by a non-contact motion tracker, but the force feedback is realized by a handheld haptic device. A gripping force is displayed by a pneumatic bellows, which is smaller and more lightweight than electric motors. As for the slave manipulator, the gripper of a surgical forceps is actuated using a pneumatic cylinder. Force estimation is possible due to the back-drivability of the pneumatic actuator. Experimental results show the control performance of the haptic device and a constructed master-slave system.

ICRA Conference 2015 Conference Paper

Pneumatically driven handheld forceps with force display operated by motion sensor

Ryoken Miyazaki
Takahiro Kanno
Gen Endo
Kenji Kawashima

Development of intuitive user interface of a dexterous forceps with wrist joint for minimally-invasive surgery (MIS) is important for reducing the surgeon's confusion and fatigue. In this paper, a wearable robotic forceps manipulator is proposed. By measuring the wrist attitude of the surgeon by a motion sensor and driving the forceps tip by actuators, intuitive operation is realized, compared with fully mechanical forceps. A compact and lightweight system is achieved since we adopt pneumatic actuators to drive the manipulator. In order to help the force sensing of the surgeon, the external force is measured from the air pressure and displayed in a visual way. Experimental comparison with a conventional handheld forceps and a teleoperation system is conducted and its results show the effectiveness of the proposed handheld forceps.

IROS Conference 2011 Conference Paper

A prototype of pneumatically-driven forceps manipulator with force sensing capability using a simple flexible joint

Daisuke Haraguchi
Kotaro Tadano
Kenji Kawashima

This paper presents the first prototype of pneumatically-driven forceps manipulator using a simple flexible joint with intrinsic force sensing. A high performance spring component with wire actuation is employed for two-degree of freedom (DOF) bending joint, and two-DOF tendon drive system is implemented by four pneumatic cylinders. Using a continuum model for the kinematics, a PD controller with static and dynamic compensation is designed for the position control, which shows a good performance at the sufficient working frequency for surgical operations. The forceps manipulator can estimate external forces using a disturbance observer. A link approximation model is introduced to design the observer as the first intuitive approach. The force estimation can be achieved with an accuracy of 0. 2 N in the basic straight posture.

ICRA Conference 2010 Conference Paper

Development of grip amplified glove using bi-articular mechanism with pneumatic artificial rubber muscle

Kotaro Tadano
Masao Akai
Kazuo Kadota
Kenji Kawashima

In this paper, a grip amplified glove using pneumatic artificial rubber muscles (PARMs) which are covered with a exoskeleton structure is developed. A bi-articular mechanism with a PARM that is suitable for bending finger is realized. The glove has totally 10 DOFs consist of four units. To achieve power-assist motion properly, the PI control, which is based on the pressure value from the balloon sensor, is performed. This sensor makes the applied part free from electricity. To evaluate the validity of glove, the skin surface electromyography (EMG) signals of muscles are measured during grasping. These results demonstrate that the effectiveness of the power amplified glove.

ICRA Conference 2010 Conference Paper

Plugfest 2009: Global interoperability in Telerobotics and telemedicine

Hawkeye H. I. King
Blake Hannaford
Ka-Wai Kwok
Guang-Zhong Yang
Paul G. Griffiths
Allison M. Okamura
Ildar Farkhatdinov
Jee-Hwan Ryu

Despite the great diversity of teleoperator designs and applications, their underlying control systems have many similarities. These similarities can be exploited to enable inter-operability between heterogeneous systems. We have developed a network data specification, the Interoperable Telerobotics Protocol, that can be used for Internet based control of a wide range of teleoperators. In this work we test interoperable telerobotics on the global Internet, focusing on the telesurgery application domain. Fourteen globally dispersed telerobotic master and slave systems were connected in thirty trials in one twenty four hour period. Users performed common manipulation tasks to demonstrate effective master-slave operation. With twenty eight (93%) successful, unique connections the results show a high potential for standardizing telerobotic operation. Furthermore, new paradigms for telesurgical operation and training are presented, including a networked surgery trainer and upper-limb exoskeleton control of micro-manipulators.

ICRA Conference 2009 Conference Paper

Bilateral teleoperation with time delay using modified wave variable based controller

Kenji Kawashima
Kotaro Tadano
Cong Wang
Ganesh Sankaranarayanan
Blake Hannaford

Force-reflecting teleoperators in which the remote environment is kinesthetically coupled to the operator can considerably increase task performance. Wave-variable-based controllers can support the stable operation of force-reflecting teleoperators under arbitrary communication delays. Transparency in such systems is compromised in order to maintain stability. We had previously proposed a modified wave variable controller that implemented additional wave impedance in the wave variable transformations in order to focus more closely on force tracking. In this paper, we present a new controller for bilateral teleoperators based on the modified wave variable control method which provides superior position and force tracking performance compared to the traditional wave-variable-based method. Moreover, the method has high stability. Theoretical investigation and experimental results confirm the performance of this new controller.

IROS Conference 2008 Conference Paper

Bilateral teleoperation with time delay using modified wave variables

Kenji Kawashima
Kotaro Tadano
Ganesh Sankaranarayanan
Blake Hannaford

Force-reflecting teleoperators in which the remote environment is kinesthetically coupled to the operator can considerably increase task performance. However, wave-variable-based controllers can support the stable operation of force-reflecting teleoperators under arbitrary communication delays. Transparency in such systems is compromised in order to maintain stability. In this paper, we present a new controller for bilateral teleoperators based on the wave variable control method which provides superior force tracking performance compared to the traditional wave-variable-based method. Additionally, this method also improves the phase delay induced by the latency in the communication network. Both simulation and experimental results confirm the performance of this new controller.

IROS Conference 2008 Conference Paper

Model-based passivity control for bilateral teleoperation of a surgical robot with time delay

Kenji Kawashima
Kotaro Tadano
Ganesh Sankaranarayanan
Blake Hannaford

In minimally invasive telesurgical systems, displaying the forces measured at the slave side is an important issue. Latency in communication lines limits the transmission of vivid tactile sensations and drives the system unstable. In this paper, we propose a new model-based approach for the bilateral control of a telesurgical robot using time-domain passivity control. This method consists of a virtual slave model implemented at the master side to estimate the force on the slave side. During the operation, the estimated force from the virtual slave is added to the actual measured force transmitted from the slave in order to maintain the passivity of the system. Both simulation and experimental results confirm the performance of this new controller.

ICRA Conference 2007 Conference Paper

Development of a Master Slave System with Force Sensing Using Pneumatic Servo System for Laparoscopic Surgery

Kodak Tadano
Kenji Kawashima

In the teleoperated minimally invasive surgery systems, measurement and display of sense of force to the operator is a problem. In this paper, a manipulator for supporting forceps has been developed which has 3-DOFs actuated by pneumatic cylinders. We also developed a master manipulator using a delta mechanism and a gimbal mechanism with a force sensor and motors with reduction gears. In the developed master-slave system, we applied different impedance control to each manipulator. The force control type of impedance control is adopted without force sensor for the pneumatic slave manipulator. For the master manipulator the motion control type of impedance control is implemented. The experimental results indicated that the operator could feel the force at the slave side to a satisfactory extent.

ICRA Conference 2006 Conference Paper

Development of 4-DOFs Forceps with Force Sensing using Pneumatic Servo System

Kotaro Tadano
Kenji Kawashima

In the teleoperated minimally invasive surgery systems, measurement and display of sense of force to the operator is a problem. In this paper, we proposed a master-slave system for laparoscopic surgery, which can provide force feedback to the surgeon without using force sensors. Pneumatic cylinders were used as the actuator of the manipulators to achieve this. First, we developed two forceps manipulators to construct a master-slave system which have 4-DOFs at the tip. A bilateral dynamic control system was then designed using a neural network for acquisition of the inverse dynamics. The obtained inverse dynamics was used as a feedforward controller and to estimate the external force from the differential pressure of the cylinders. Experimental results showed that the developed system successfully display the contact force on the slave side to the operator on the master side

ICRA Conference 2006 Conference Paper

Remote Control of Backhoe for Rescue Activities using Pneumatic Robot System

Takahiro Sasaki
Takayuki Nagai
Kenji Kawashima

In this paper, we describe the development of master-slave pneumatic robotic system and its ability to remotely control some functional tasks of backhoe machines during operation on construction sites. The functional tasks include (i) excavating (loading), (ii) lifting, (iii) transporting loads, and (iv) unloading. Pneumatic actuators and grippers, CCD cameras and a control box containing power source, PC and wireless LAN boards are integral part of our pneumatic robot system. During operation, images from the CCD cameras are transported to the master side with a wireless LAN, and then display visually on the laptop PC. Using joysticks, an operator can manipulate the synchronized activities of the system and backhoe machines with or without the CCD cameras. Tests were conducted on some local construction sites to evaluate the effectiveness of the system to control the functional tasks of the backhoe machines. It was found that the use of CCD cameras by the operator to monitor the synchronized activities was more effective than having a direct face to face operator contact with the activities. Disasters caused by environmental changes and man-made actions are increasing worldwide. The safety for rescued workers and investigative officials in disaster areas is a growing concern. Our system provides an opportunity to improve safety

ICRA Conference 2004 Conference Paper

Application of Robot Arm using Fiber Knitted Type Pneumatic Artificial Rubber Muscles

Kenji Kawashima
Takahiro Sasaki
Ai Ohkubo
Toshiyuki Miyata
Toshiharu Kagawa

In the restoration work from disasters, the remote control of construction machine is required to ensure the worker's safety. However, conventional remote-controlled construction machine is larger than ordinary ones and limited in types and numbers, so there is a problem that the transportation to the destructed sites takes time and is troublesome. We have been developing the pneumatic humanoid type robot arm, which can be installed in any models of construction machine. In consideration of portability, the lightweight fiber knitted type pneumatic artificial rubber muscle (FARM) was adopted as the actuator. In this paper, we developed the static and dynamic characteristic models of the FARM taking the effect of elasticity of rubber and frictional force into consideration. Then we realized the remote control of the construction machine using the pneumatic robot that has 6 degree of freedom using the FARM. Moreover, we did some experiments on the remote control of the construction machine. Experimental results show that the developed system is available in remote control of a construction machine.

IROS Conference 2004 Conference Paper

Development of remote control system of construction machinery using pneumatic robot arm

Takahiro Sasaki
Toshiyuki Miyata
Kenji Kawashima

In the restoration work from disasters, the remote control of construction machinery is required to ensure the worker's safety. However, only limited numbers of remote controlled construction machinery exist and they are typically larger than conventional machinery. After a disaster, the transportation of such machinery takes additional times and is often troublesome. Therefore, it would be desirable to develop a remote control system that could easily be installed on ordinary construction machinery. We have been developing a pneumatic robot system, which can be installed in any models of construction machinery, with the aim of easy installation and portability. In consideration of portability, the lightweight pneumatic artificial rubber muscle (PARM) was adopted as the actuator of the robot arm. In this research, we developed a remote control system of construction machinery using the 6-DOF pneumatic robot arm. We used a wireless LAN for the remote control. We did experiment on the remote control of construction machinery and showed that the developed system is available for remote control of construction machinery.

IROS Conference 2003 Conference Paper

Application of robots using pneumatic artificial rubber muscles for operating construction machines

Kenji Kawashima
Naohiro Nakamura
Toshiyuki Miyata
Toshiharu Kagawa

In the restoration work from disasters, the remote control of construction machine is required to ensure the worker's safety. However, conventional remote-controlled construction machine is larger than ordinary ones and limited in types and numbers, so there is a problem that the transportation to the destructed sites takes time and is troublesome. Therefore, the development of the remote-control system using a robot, which can be easily installed in ordinary construction machine, is desired. We have been developing the pneumatic humanoid type robot arm, which can be installed in any models of construction machine, and realizing remote control of construction machine with the aim of easy installation and portability. In consideration of portability, the lightweight pneumatic artificial rubber muscle (PARM) was adopted as the actuator. In this research, we realized the remote control of the construction machine using the pneumatic robot that has 6 degree of freedom using the fiber knitted type PARM. We experimented in order to measure the static characteristic of the fiber knitted type PARM. Then we did experiment on the remote control of the construction machine. Experimental results show the developed system is availability in remote control of a construction machine.