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DOI： 10.1109/ROBOSOFT.2018.8405387

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Other Link： http://orcid.org/0000-0002-3036-6447

Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.1109/LRA.2018.2803204

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Other Link： http://orcid.org/0000-0002-3036-6447

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Institute of Electrical and Electronics Engineers Inc.  

As a part of our research on several different types of Giacometti robots, a 20-m-long, considerably light, and simple robot arm, referred to as the Giacometti arm, is developed in this study. Even though the Giacometti arm is not suitable for precise positioning, rapid motion, and high load capacity, which are the aspects most conventional robots focus on, it is designed for extremely specific purposes such as the inspection of otherwise unreachable regions using a small camera at the arm's tip. In addition, it is designed to be essentially safe even if it falls down or hits an object. This aspect is realized using helium-filled balloon bodies and thin pneumatic muscles. In this paper, we designed new Giacometti arm which is 20-m-long, weighs 940 g, and has 20 degrees of freedom. To realize this long arm, we derived a kinematic model of the 20-m-long Giacometti arm, factoring in the air resistance. We verified the model using the arm, and its utility was confirmed at a mock-up facility.

DOI： 10.1109/IROS.2017.8206097

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DOI： 10.1109/SII.2017.8279206

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DOI： 10.5739/jfpsij.10.38

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE Computer Society  

Hydraulic actuators has been utilized for various types of robots. However, hydraulic control system for multiple degrees of freedom mechanisms has a large volume because such system needs many control components. The purpose of this research is to develop a small hydraulic flow control valve. In the previous research, we have developed a small flow control valve using particle excitation by a piezoelectric transducer [1], and applied this valve to a hydraulic system. In this research, we have fabricated and evaluated a small three-way valve for further miniaturization.

DOI： 10.1109/ULTSYM.2017.8091956

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DOI： 10.5739/jfpsij.10.38

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DOI： 10.1109/ULTSYM.2017.8091956

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Other Link： http://orcid.org/0000-0002-3036-6447

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Institute of Electrical and Electronics Engineers Inc.  

This paper introduces a quadruped soft-Amphibious robot using 4.0 mm diameter thin and soft McKibben actuator. The robot utilizes its leg and body bending mechanism to locomote. For each leg, three links of the actuators are arranged in parallel with fixed upper and bottom part. Then, four actuators are arranged in parallel and fixed with a thin plastic plate in between the actuators for the body motion. The elastic deformation of the plastic plate actuated by the actuators assist in the side-To-side motion of the robot mimicking the gait of the biological creature like lizard/salamander during walking motion. FEM simulation studies were performed in Marc Mentat® to evaluate the bending behaviors and validated with an experimental test. Walking experiment was tested on a flat surface and on sand using two different gaits of trot and crawl gait. On the other hand, swimming experiment was tested inside water using only crawl gait. Different input pressure and frequency were varied to study the walking behavior. The robot successfully walks on a flat and 10° incline plane with a maximum speed of 0.056 m/s using trot gait and robust to move on sand and in water using the crawl gait at 0.041 m/s and 0.022 m/s, respectively.

DOI： 10.1109/AIM.2017.8014146

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Institute of Electrical and Electronics Engineers Inc.  

This paper describes an analytical study undertaken on an electromagnetic actuator design with a displacement amplification mechanism by explaining the physical modeling and formulizing the actuation time of the actuator in terms of physical model variables. This is followed by an experimental investigation on the actuation time of the electromagnetic actuator. Increasing the gap between the electromagnet and armatures to increase the stroke of the electromagnetic actuator resulted in a drastic loss of the thrust force. The displacement amplification mechanisms were used to increase the stroke of the actuator without incurring high levels of loss in the thrust force. For the same load and final stroke of the actuator, the actuation time was observed to model the effect of amplification ratio on the actuator. Using the physical and mathematical modeling of the displacement amplified electromagnetic actuator and by formulating the actuation time, simulations were implemented that revealed the relationship between the actuation time and amplification ratio. The design of the experimental setup and methodology of the experimentation are explained to verify the simulation results and calculated relationship between the amplification ratio and actuation time in practice. The results of simulations and experimentations showed that there is an optimum point until which the amplification ratio can be increased while advancing from actuation time for the same load and final stroke of the actuator. The similarity between the simulation and experimental results proved that the value of this optimum point could be formulized and expressed in terms of other variables used to simulate the actuator.

DOI： 10.1109/AIM.2017.8014143

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Institute of Electrical and Electronics Engineers Inc.  

The vehicle using omnidirectional wheels has ability to move in all directions without changing the body direction unlike a normal four wheel drive vehicle. However most of omnidirectional vehicle are designed for using only on flat ground. In this paper, we propose a new type of omnidirectional wheel, 'Spiral Mecanum Wheel', which enables vehicle climb the step. This new wheel consists of spiral beams and many small rollers, and these small rollers are arranged along the spiral beams. When the vehicle with this spiral Mecanum Wheels moves in normal direction, the edge of the spiral moves to cover the step from above. We have performed the experiments using Spiral Mecanum Wheel and showing the wheel works very well. As a result, in the experiment using single Spiral Mecanum Wheel, this Spiral Mecanum Wheel climbed the step about 83% of the wheel diameter in normal direction motion. The vehicle with Spiral Mecnaum Wheel climbed the step about 37% of the wheel diameter in tangential direction motion and 59% in normal direction.

DOI： 10.1109/AIM.2017.8014195

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE SA  

Current McKibben muscles are usually 10-40 mm in diameter, which makes them very stiff during contraction and difficult to deform rendering them unsuitable for dense mounting with shape adaptability in small spaces. In this research, to solve these problems, our group has developed the thinnest McKibben muscle reported until now. Bundling the muscles results in a multifilament muscle of the desired shape and flexibility. This paper reports the design of the thin McKibben muscle and the multifilament muscle and their static characteristics. In addition, we propose two theoretical models of multifilament muscles and derive their theoretical characteristics. The static characteristics of multifilament muscles with various design parameters have been evaluated through experiments and modeling. As a result, the greater contraction ratio of the multifilament muscles compared to that of the single muscle was demonstrated both theoretically and experimentally. (C) 2017 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.sna.2017.04.047

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers Inc.  

As part of our research on developing different types of Giacometti robots, the potential of a very long, very light, and very simple robot arm with a balloon body is discussed in this paper. Although this robot arm is not suitable for precise positioning, rapid motion, and high load capacity, which are the aspects most conventional robots focus on, it is designed for very specific purposes, such as inspection using a small camera at its tip and is designed to be essentially safe even if it falls down or hits an object. This robot arm is realized using helium-filled balloon bodies and thin pneumatic muscles. The arm achieves self-weight compensation, and the possibility of designing a very long arm is confirmed theoretically and experimentally. A prototype of a 7-m-long cantilever arm is designed, developed, and tested.

DOI： 10.1109/LRA.2017.2655111

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Other Link： http://orcid.org/0000-0002-3036-6447

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer International Publishing  

This paper presents a redundant musculoskeletal robot using thin McKibben muscles that is based on human anatomy. The purpose of this robot is to achieve motions and characteristics that are very similar to a human body. We use a thin McKibben muscle, which is compliant and flexible, as the actuator of a musculoskeletal robot. Using a bundle of thin McKibben muscles, we develop a multifilament muscle that has characteristics similar to those of human muscles. In contrast, the actuators of conventional musculoskeletal robots are very heavy, not densely attached and have poor backdrivability. Because multifilament muscles are light and can be densely attached, we can attach them to the musculoskeletal robot as skeletal muscle and achieve a redundant system that is equivalent to a human drive mechanism. In this paper, we report a method for fabricating multifilament muscles that imitate various muscles, the development of a lower-limb muscle mechanism for the redundant musculoskeletal robot with thin McKibben muscles and experimental results showing that the proposed musculoskeletal robot achieves humanlike motions that have not yet been reported for other robots.

DOI： 10.1186/s40648-016-0061-3

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Other Link： http://orcid.org/0000-0002-3036-6447

DOI： 10.1109/SII.2016.7844067

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DOI： 10.1109/SII.2016.7844064

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DOI： 10.1109/IROS.2016.7759106

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Other Link： http://orcid.org/0000-0002-3036-6447

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE SA  

Pneumatic actuators in general require an air-compressor, valves, and pneumatic hoses. This makes them difficult to be used on mobile apparatus. To solve this problem, we previously developed a new gas source that uses the electrolysis/synthesis of water through an ion-exchange membrane. The developed gas source uses a gas/liquid reversible chemical reaction and controls the generation/absorption of gas through an electric current supplied to the membrane.
In this paper, we present a control method for the energy-regeneration cycle and perform theoretical and experimental studies to verify its power consumption. This energy-regeneration control method is applied to an actuator, and it works successfully with a power consumption improvement of approximately 20% compared to that without energy-regeneration. Furthermore, we successfully develop a hose-free pneumatic rubber actuator with this control method. (C) 2016 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.sna.2016.07.004

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DOI： 10.1109/IROS.2016.7759181

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

This paper introduces an approach for manipulating bodily self-consciousness, in particular, senses of body ownership and illusory self-touch by using a robotic/haptic technology. This study especially focuses on the rubber hand illusion (RHI). In the classic RHI paradigm, an invisible participant's hand and a visible fake rubber hand are manually stimulated by an experimenter. However, our approach, which is termed active self-touch, allows the participants to administrate the tactile stimulation with variable force feedback by using a robotic master-slave system. Three RHI experiments with active self-touch were performed to demonstrate the utility of the proposed approach for assessment of bodily self-consciousness. The embodiment of a fake hand was assessed with the classic RHI paradigm, and the RHI paradigm with somatic sensation was applied to examine the effect of variable force feedback on the sense of illusory self-touch. These experiments verified that active self-touch allows participants to experience the classic RHI. In addition, the results implied that the sense of illusory self-touch can be induced, even if force feedback is absent in the dynamic self-touch condition, and that illusory sensation is easily modulated by variable force feedback during quasi-static self-touch rather than during dynamic self-touch. These findings suggest that our proposed approach has the potential to reveal relationships between action/haptic perception and the sense of body ownership.

DOI： 10.1109/THMS.2015.2487499

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DOI： 10.1109/SII.2015.7404892

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Other Link： http://orcid.org/0000-0002-3036-6447

Language：English   Publisher：The Japan Society of Mechanical Engineers  

Hydraulic proportional valves generally suffer from their large size due to their complicated structures using large solenoids or motors. Therefore, they have some limitations of design or decrease mobility of hydraulic systems. In this paper, we present a small hydraulic flow control valve using particle excitation by a PZT vibrator. This valve can control the flow rate of water by the applied voltage to the PZT vibrator. The prototype of the proposed valve evaluated the relationship between the applied voltage, the impressed pressure, and the flow rate. This fundamental evaluation successfully indicated the flow-controllability of the proposed valve.

DOI： 10.1299/jsmeicam.2015.6.221

CiNii Books

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE SA  

This paper introduces an impact drive mechanism (IDM) that utilizes the rapid contraction property of shape memory alloy (SMA) wire. In this study, possible structures for an SMA-wire-based IDM actuator are investigated, and a prototype actuator comprising a main body, an inertia body, an SMA wire, and a bias spring is developed. To verify the applicability of the prototype actuator as a positioning device, driving experiments were conducted under various conditions. The experimental results demonstrated that the prototype actuator enables bidirectional step-like movement with several step sizes by changing the profile of applied voltage, such as amplitude, duty cycle, and frequency. In addition, we developed PI-controller-based position control systems by using these three parameters as control input; the control characteristics and potential applications of each method were discussed. These results implied that the SMA-wire-based IDM actuator has the potential to be used as a new linear actuator in sub-millimeter order driving. (C) 2014 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.sna.2014.08.013

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J-GLOBAL

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Bodily self-consciousness has become an important topic in cognitive neuroscience aiming to understand how the brain creates a unified sensation of the self in a body. Specifically, full body illusion (FBI) in which changes in bodily self-consciousness are experimentally introduced by using visual-tactile stimulation has led to improve understanding of these mechanisms. This paper introduces a novel approach to the classic FBI paradigm using a robotic master-slave system which allows us to examine interactions between action and the sense of body ownership in behavioral and MRI experiments. In the proposed approach, the use of the robotic master-slave system enables unique stimulation in which experimental participants can administer tactile cues on their own back using active self-touch. This active self-touch has never been employed in FBI experiments and it allows to test the role of sensorimotor integration and agency (the feeling of control over our actions) in FBI paradigms. The objective of this study is to propose a robotic-haptic platform allowing a new FBI paradigm including the active self-touch in MRI environments. This paper, first, describes the design concept and the performance of the prototype device in the fMRI environment (for 3T and 7T MRI scanners). In addition, the prototype device is applied to a classic FBI experiment, and we verify that the use of the prototype device succeeded in inducing the FBI. These results indicate that the proposed approach has a potential to drive advances in our understanding of human body ownership and agency by allowing novel manipulation and paradigms. (C) 2014 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jneumeth.2014.05.038

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PubMed

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

Our previous study has proposed a novel approach with a robotic/haptic technology to tactile rubber hand illusion (TRHI) paradigm in order to open new discussions about the manipulation of human body-parts ownership. The results demonstrated that the use of master-slave system can cause the TRHI, enabling a unique condition-active self-touch. As an advanced approach, this study examines the effect of force feedback on the TRHI under the active self-touch. We hypothesize that appropriate force feedback plays an important role to determine our body-parts ownership; people would not experience the TRHI if the force feedback from a fake hand largely differs from the contact force on a real hand. This paper, in particular, discusses how the force feedback affects the TRHI under the active self-touch by variously changing force rendering on the master device.

DOI： 10.1109/SMC.2013.97

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Language：Japanese  

CiNii Books

J-GLOBAL

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