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Volume 41, Issue 9
Displaying 1-8 of 8 articles from this issue
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Fumito ITO, Dauren F. AKHMETOV, Masaaki KOMAZAKI, Hiroto TACHIKAWA, Ma ...2005 Volume 41 Issue 9 Pages 715-723
Published: September 30, 2005
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe characteristics and applications of the “cable sensor, ” a new type of vibration sensor, are considered in this paper. Previous studies by the authors on the practical use of cable sensors in rockfall detection are reviewed. The mechanism of output voltage generation by the sensor is discussed. Methods for analyzing static electricity and molecular dynamics are applied toward elucidating the sensor's measurement principles. The following results were obtained:
1) Alternating output voltage of cable sensor occurs when an external vibration source causes multiple contacts between the conductor part of the sensor and its dielectric material (FEP). 2) The above fact is demonstrated experimentally through a vibration test using an audio speaker and an acceleration sensor. Output waveforms of the cable sensor are similar to those of the acceleration sensor. 3) From molecular dynamics analysis, it was supposed that FEP with a higher electron affinity might be produced by adding a -CF2CF3 group to the main chain of FEP in order to increase the output voltage of the sensor. 4) Output voltage of the sensor decreases with increase in capacitance of the circuit. This means that the output voltage decreases both with an increase in the length of the cable sensor and with the introduction of an extension signal transmission cable. The signal decrement could be compensated by amplification. A transfer function of the measurement circuit is derived, which enables evaluation of the necessary amplification gain. The results of the analysis of material combination for the sensor components and the proposed solutions to the equation describing the measurement circuit have deepened the understanding of the voltage output mechanism and measurement principles of cable sensors.View full abstractDownload PDF (4170K) -
Ippei TORIGOE2005 Volume 41 Issue 9 Pages 724-728
Published: September 30, 2005
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA new flowmeter is proposed in which the stream to be measured is divided into two branch conduits, a main conduit and a smaller bypassing conduit. The total flow rate through the flowmeter is calculated based on the flow rate reading of the flowmeter installed in the bypass conduit and the bypass rate; this rate -the ratio between the total flow rate and the flow rate through the bypass conduit- is obtained, using Bernoulli's equation, from the pressure difference measured in the main conduit at positions upstream and downstream from the branch point of the bypass. An experimental apparatus was constructed and several water flow experiments were performed. The results indicate the following: (1) as the total flow rate increases the bypass rate increases or decreases depending on the conditions in the main and bypass conduits; (2) the total flow rate can be measured by the proposed method independent of changes in the bypass rate.View full abstractDownload PDF (884K) -
Yutaka SAITOU, Jun-ichi IMURA2005 Volume 41 Issue 9 Pages 729-738
Published: September 30, 2005
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper proposes a novel efficient algorithm for model predictive control (MPC) of discrete-time linear systems subject to input constraints. As is well known, the MPC problem is reduced into the problem of calculating the solution trajectory of the discrete-time linear complementarity (D-LC) systems. Based on this fact, the algorithm fully exploits the information on the solution of the problem at the previous time step, as like the difference technique used in the calculation of the solution trajectory of the dynamical system. Efficiency of the proposed algorithm is shown by a numerical example.View full abstractDownload PDF (2269K) -
Stabilization Based on Minimum Phase Property and High Gain FeedbackKiyotaka SHIMIZU, Kenichi TAMURA2005 Volume 41 Issue 9 Pages 739-746
Published: September 30, 2005
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper is concerned with stability analysis for PID control of multi input and multi output system. The purpose is to determine PID parameter values which asymptotically stabilize the closed-loop system for regulation problem. Main idea is to determine PID parameters based on the minimum-phase property and Lyapunov's direct method. By making zero dynamics asymptotically stable and peforming high gain output feedback we can stabilize the closed-loop system with PID control. The effectiveness of the proposed method is confirmed by simulation results for various plants.View full abstractDownload PDF (1252K) -
Effect of Presentation Method, Recall Type, and Time Period for AnalysisKazumoto MORITA2005 Volume 41 Issue 9 Pages 747-753
Published: September 30, 2005
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe author conducted a laboratory experiment to estimate the mental workload of subjects as they acquired visual and auditory information. The following factors were examined using a within-subjects design experiment.
•Presentation method: The 3 modes of presenting both auditory and visual information simultaneously, presenting only auditory information, and presenting only visual information;
•Whether information was recalled vocally or silently after it was presented; and
•Three time periods for analysis: before, during, and after presentation.
As a subsidiary task, subjects were made to rotate a mounted disk 6cm in diameter one full turn every 2s. The variance in time to rotate the disk was examined to clarify the differences in mental workload between experimental conditions. The results were as follows. No difference in mental workload was found among the 3 presentation modes. Moreover, it was clearly shown that mental workload was highest when subjects replied vocally.View full abstractDownload PDF (2510K) -
Naoyuki YAMADA, Tatsuya SUZUKI, Shinkichi INAGAKI2005 Volume 41 Issue 9 Pages 754-762
Published: September 30, 2005
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a parameter identification technique for a stochastic switched ARX model. The developed algorithm can be regarded as a natural extension of the learning algorithm for Hidden Markov Model (HMM), which is based on the EM algorithm. The results of the estimation of the parameter in the ARX model at each discrete state can be comprehended as a solution for the weighted least mean square estimation problem. The usefulness of the proposed technique is verified through some numerical experiments for the switched impedance model with and without existence of the modelling error.View full abstractDownload PDF (1909K) -
Shohei TANIGUCHI, Ryuta OZAWA, Norimitsu SAKAGAMI, Sadao KAWAMURA2005 Volume 41 Issue 9 Pages 763-771
Published: September 30, 2005
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe propose a new method to decompose joint torque of multi-joint structures such as humans and robots. In the proposed method, joint torque is decomposed into three components based on time-scale transformation at first. Next, the torque pattern from a rigid body model and the torque patterns from viscosity and elasticity of muscles and reflections are obtained. In this paper, we have described the detail of the proposed method and verified its validity through experimental results. In the experiments, measurement accuracy of the experimental system and the proposed method is confirmed by basic experiments using a dummy arm. Moreover, human torque patterns obtained by two subjects are measured and decomposed into three components though the proposed method.View full abstractDownload PDF (1774K) -
Ichiro IIMURA, Toshiya ITO, Koji HAMAGUCHI, Shigeru NAKAYAMA2005 Volume 41 Issue 9 Pages 772-774
Published: September 30, 2005
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper proposes a distributed parallel processing of Queen Ant Strategy named “ASqueen” which imitated an ant society which a queen ant governs. It is noted that the proposed processing method satisfies “shortening of average time for search” and “improvement of searching ability” at the same time in the seventy-six cities' configuration of TSPLIB.View full abstractDownload PDF (578K)
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