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Volume 48, Issue 9
Displaying 1-9 of 9 articles from this issue
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Paper
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Yoichi OKAWA, Chongho YOUN, Yoshinari NAKAMURA, Toshiharu KAGAWA2012 Volume 48 Issue 9 Pages 515-521
Published: 2012
Released on J-STAGE: September 22, 2012
JOURNAL FREE ACCESSThe thesis of this study is to investigate that the measurement accuracy of the isothermal discharge method for hydrogen gas with an isothermal tank which is designed for measuring the flow-rate characteristics of pneumatic components. Compressed gas in an isothermal tank, which is combined three types of orifice, is discharged from 700kPa(abs) to atmospheric pressure. The average temperature in the tank during discharge is measured experimentally. Experimental results and the measurement errors of the isothermal discharge method in hydrogen and air are compared. In consequence, when hydrogen and air is discharged with same pressure drop rate respectively, the temperature change in hydrogen is less than the one in air. When the maximum discharge rate is 35.6kPa/s during discharge hydrogen, the measurement error is less than 3% in whole discharge time. The difference between the temperature change in hydrogen and air is discussed qualitatively in the view point of the relation among Nusselt number, Reynolds number and Prandtl number. As a result, it is investigated that the heat exchange between hydrogen and copper wire is five times larger than the one between air and copper wire.View full abstractDownload PDF (848K) -
Satoshi TSUJI, Akira KIMOTO, Eiji TAKAHASHI2012 Volume 48 Issue 9 Pages 522-527
Published: 2012
Released on J-STAGE: September 22, 2012
JOURNAL FREE ACCESSWe propose a new proximity sensing method using electrodes and photodiode with the LED for simultaneous measurements of electrical and optical properties of object. In this proposed sensor, impedance between electrodes and photodiode is measured while changing light emission of the LED. The electrical property of object is measured by changing the capacitance between the electrodes, and the optical property of object is measured by changing impedance of between photodiode while changing light emission of the LED. In the experiment, discrimination of six kinds of material and detection of distance was possible. This technique may be applicable to proximity sensor for robot and factory automation.View full abstractDownload PDF (829K) -
Keisuke SHIMA, Gaku UENO, Erhan AKDOGAN, Toshio TSUJI, Masaki HASEGAWA ...2012 Volume 48 Issue 9 Pages 528-535
Published: 2012
Released on J-STAGE: September 22, 2012
JOURNAL FREE ACCESSThis paper proposes a novel human-human interface (HHI) using electromyograms (EMGs) and tactile stimulation as an interactive communication tool between human and human. In this system, EMGs is utilized to measure muscle conditions of human, and then the muscle force and muscular coordination are evaluated based on EMGs. Evaluated results are converted to stimulation signals, and then sent to another human as tactile stimulation for interactive communication. For accurately communication, stimulation signals are generated based on human sensory characteristics. In the experiments, utilizing small oscillators as tactile stimulators, human sensory characteristics for stimulation amplitudes and effective oscillation patterns for multi-channel stimulation were investigated. Muscle condition during forearm motions of an imaginary therapist was also evaluated and sent to an imaginary patient for verification of the proposed method. The results lead us to conclude that the proposed HHI could use to communication tool for motor function rehabilitation.View full abstractDownload PDF (1866K) -
— Discrete-time Case —Takashi OKAJIMA, Koji TSUMURA, Tomohisa HAYAKAWA, Hideaki ISHII2012 Volume 48 Issue 9 Pages 536-544
Published: 2012
Released on J-STAGE: September 22, 2012
JOURNAL FREE ACCESSIn this paper, we study an adaptive leader tracking problem for discrete-time multi-agent systems with uncertain heterogeneous dynamics. The proposed distributed controller consists of two components. One is an adaptive controller which modifies the uncertain heterogeneous dynamics of the agent close to a homogeneous model. The other is an ordinary relative state feedback controller which attains leader tracking if the dynamics are homogeneous. An important feature of our approach is that the states of the agents need not be bounded if some parts of their dynamics are known and homogeneous, which is the case with the velocity-to-position integrator in vehicle formation. By constructing a logarithmic Lyapunov function, we show that state tracking is achieved asymptotically and the error system consisting of state tracking errors and parameter errors is Lyapunov stable. We also present a numerical example to demonstrate the effectiveness of the proposed approach.View full abstractDownload PDF (630K) -
Sousuke NAKAMURA, Ryo KOMA, Takashi KUBOTA, Hideki HASHIMOTO2012 Volume 48 Issue 9 Pages 545-552
Published: 2012
Released on J-STAGE: September 22, 2012
JOURNAL FREE ACCESSIn the concept of Intelligent Space, the battery capacity requirements and tasks for self localization in the mobile robot could be relieved by assistance such as wireless power transmission and position sensing from the surrounding space. Wireless power transmission based on magnetic resonance coupling has a effective range of about antenna diameter which is expected to be suitable for charging mobile robots. If the position sensing based on magnetic resonance coupling is also possible, both wireless power transmission and position sensing could be possible by single equipment which is a reasonable system. Therefore, this paper describes the proposal and experimental consideration of novel position sensor based on magnetic resonance coupling. The proposed sensor is composed by transmitter array antenna implemented under the floor and target antenna built into the target. Here, a single transmitter antenna can be selected from the array antenna using the switching unit. There are two big differences from the other sensor systems. First is that the wireless power transmission could be also possible by almost the same equipment. Second is that the sustainable battery-less position sensing is possible since the target does not require any battery. This is possible since the position sensing is based on reflection coefficient which could be measured by transmitter antenna side. The position is estimated by matching the coupling coefficient between antennas calculated from the reflection coefficient with the database of coupling coefficient and position. Finally, the performance of the position sensor is evaluated through experiments.View full abstractDownload PDF (871K) -
Kayo YOSHIMOTO, Mitsuru HIGASHIMORI, Kenjiro TADAKUMA, Makoto KANEKO2012 Volume 48 Issue 9 Pages 553-562
Published: 2012
Released on J-STAGE: September 22, 2012
JOURNAL FREE ACCESSThis paper discusses a shaping strategy of a rheological object. We first introduce a seven-nodes viscoelastic model for approximating the outline and the dynamic characteristics of the object. Then, we show a shaping method of the object's outline, where the proportion of the input axis to another one, which is perpendicular to the input one, is controlled by using a parallel jaw gripper. Based on the plastic deformation distribution for the integrated input stress, the proposed method can actively manage the object's final outline. In addition to the contribution on simplifying the gripper's degree of freedom, this method has an advantage that the handling time is drastically reduced, compared with the position based passive method. We finally show the experimental results for confirming the validity of the proposed method.View full abstractDownload PDF (2749K) -
Tetsuya HORIUCHI, Abdugheni KUTLUK, Harutoyo HIRANO, Yuichi KURITA, To ...2012 Volume 48 Issue 9 Pages 563-570
Published: 2012
Released on J-STAGE: September 22, 2012
JOURNAL FREE ACCESSThis paper proposes a method for qualitatively estimating the mechanical properties of arterial walls on a beat-to-beat basis through noninvasive measurement of continuous arterial pressure and arterial diameter. First, in order to describe the nonlinear relationships between arterial pressure waveforms and arterial diameter waveforms as well as the viscoelastic characteristics of arteries, we developed a second-order nonlinear model (called the log-linearized arterial viscoelastic model) to estimate the viscoelasticity of arterial walls. Next, to verify the validity of the proposed method, carotid viscoelastic indices were estimated based on arterial pressure waveforms measured using an ultrasonic device, and on arterial diameter waveforms measured using a noninvasive sphygmomanometer. The results showed that the proposed model could be used to accurately approximate the mechanical properties of arterial walls, and it was confirmed that the viscoelastic indices of arterial walls were proportional to age (stiffness: r=0.870; viscosity: r=0.668; and modified viscosity: r=-0.720). It was therefore concluded that the proposed model can be used to qualitatively evaluate arterial viscoelastic properties based on noninvasive measurement of arterial pressure and arterial diameter.View full abstractDownload PDF (1934K) -
Masakazu TAKAHASHI2012 Volume 48 Issue 9 Pages 571-579
Published: 2012
Released on J-STAGE: September 22, 2012
JOURNAL FREE ACCESSThis paper proposes a method to prove that working drug manufacturing computerized systems using Programmable Logic Controller (PLC) have adequate functions and performance. Drug companies are required to prove the adequacy of functions and performance by regulatory authorities, because these systems make significant impacts for the drug quality. Especially, tasks that adequacy of working system is proved by existing documents and operational records are called Retrospective Computerized System Validation (RCSV). But no description about RCSV procedures using PLC exists. This makes the drug companies to confuse. Therefore we propose RCSV procedures that can be conducted adequately and efficiently. As a result of trials, we can confirm that the quality and efficiency of RCSV is improved.View full abstractDownload PDF (1343K) -
Taro SHIBANOKI, Keisuke SHIMA, Takeshi TAKAKI, Yuichi KURITA, Akira OT ...2012 Volume 48 Issue 9 Pages 580-588
Published: 2012
Released on J-STAGE: September 22, 2012
JOURNAL FREE ACCESSWhen a user has no experience of controlling devices using bioelectric signals, for instance controlling a prosthetic hand using EMG signals, it is well known that voluntary generation of such signals might be difficult, so that the classification issue of multiple motions thus becomes problematic as the number of motions increases. This paper proposes a novel class selection method based on the Kullback-Leibler (KL) information measure and outlines its application to optimal motion selection for accurate bioelectric signal classification. In the proposed method, the probability density functions (pdfs) of recorded data are estimated through a multidimensional probabilistic neural network (PNN) trained based on the KL information theory. A partial KL information measure is then defined to evaluate the contribution of each class for classification. Effective classes can be selected by eliminating ineffective ones based on the partial KL information one by one. In the experiments performed, the proposed method was applied to motion selection with four subjects (including an amputee), and effective classes were selected from all motions measured in advance. The average classification rate for selected motions under the proposed method was 93.03±1.25%. These outcomes indicate that the proposed method can be used to select appropriate motions for accurate classification.View full abstractDownload PDF (1714K)
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