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Volume 47, Issue 10
Displaying 1-12 of 12 articles from this issue
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Special Issue on Sensing Innovation
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[in Japanese], [in Japanese], [in Japanese], [in Japanese]2011 Volume 47 Issue 10 Pages 421
Published: 2011
Released on J-STAGE: January 21, 2012
JOURNAL FREE ACCESSDownload PDF (165K)
Paper
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Kenbu TERAMOTO, Ryoji INOUE2011 Volume 47 Issue 10 Pages 422-429
Published: 2011
Released on J-STAGE: January 21, 2012
JOURNAL FREE ACCESSLamb waves have been used for non-destructive inspection of thin-plate-like structures. However, the conventional time-of-flight technique is not reliable for locating the defects even in isotropic plates because of the dispersiveness in the Lamb wave propagation. Avoiding difficulties caused by the dispersiveness, this paper proposes a novel dynamic shear strains analysis which has an ability to localize defects with reconstructing near-field images. The proposed imaging method utilizes the determinant of the dynamic shear strains covariance matrix which are defined over the object surface. The determinant denotes the distribution of correlated intensity modulation of the incident wave fronts with scattered ones. The value of the determinant, therefore, increases significantly in the near-field of the defects. In this study, the computational process in the wave field near the defects is discussed and their physical meanings are investigated through FDTD-simulations and acoustic experiments.View full abstractDownload PDF (928K) -
Koichi KURITA, Kazumasa IMAI, Tatsumi IKE, Toru NONAKA2011 Volume 47 Issue 10 Pages 430-434
Published: 2011
Released on J-STAGE: January 21, 2012
JOURNAL FREE ACCESSIn this study, an effective noncontact technique for the detection of free-living human locomotion is proposed. The technique involves the measurement of the electrostatic induction current flowing through a measurement electrode. Further, an occurrence model for the electrostatic induction current generated due to a change in the electric potential of the human body is proposed. This model effectively explains the behavior of the waveform of the electrostatic induction current flowing through the measurement electrode. The obtained results show that the presence of a gait cycle is directly reflected in the electrostatic induction current generated due to walking motion. This suggests that subtle differences in the walking condition can be detected using the proposed technique.View full abstractDownload PDF (865K) -
Masato SUGIURA, Michitaka SAKAIDA, Yohichi FUJIKAKE, Keisuke IRIE2011 Volume 47 Issue 10 Pages 435-441
Published: 2011
Released on J-STAGE: January 21, 2012
JOURNAL FREE ACCESSMetallurgical coke is needed as reducing reagent and energy source in blast furnaces. Most of coke ovens in Japan have been working over 30 years and have become gradually decrepit. A coke oven consists of many coking chambers, and each chamber is 6 m high, 16 m long and 0.4m wide. Uneven damage at the chamber-wall surface such as brick erosion and carbon deposition disturbs production because the coke is pushed horizontally when discharged from the chamber. To diagnose the chamber wall which is constantly sustained at a high temperature, we have developed a water-cooling heat-resistance probe. Line scan cameras mounted in the probe obtain thermal images of the entire chamber-wall surfaces with high resolution. In addition, to measure topographical information of the wall, a laser light-section method combined with line-scan-camera imaging has been considered. It is emphasized that the diagnosis probe works under enormously severe conditions, such as at a temperature of over 1000°C and inside a width of only 0.4m. Clarifying the appearance of chamber-wall damages in operating aged coke ovens, we proposed the index relating unevenness of a chamber-wall surface to pushing load. The index is utilized for the guidance enabling effective repairs of damaged oven walls.View full abstractDownload PDF (2792K) -
Norimasa KOBORI, Daisuke DEGUCHI, Tomokazu TAKAHASHI, Ichiro IDE, Hiro ...2011 Volume 47 Issue 10 Pages 442-449
Published: 2011
Released on J-STAGE: January 21, 2012
JOURNAL FREE ACCESSIn order to estimate accurate rotations of mobile robots and vehicle, we propose a hybrid system which combines a low-cost monocular camera with gyro sensors. Gyro sensors have drift errors that accumulate over time. On the other hand, a camera cannot obtain the rotation continuously in the case where feature points cannot be extracted from images, although the accuracy is better than gyro sensors. To solve these problems we propose a method for combining these sensors based on Extended Kalman Filter. The errors of the gyro sensors are corrected by referring to the rotations obtained from the camera. In addition, by using the reliability judgment of camera rotations and devising the state value of the Extended Kalman Filter, even when the rotation is not continuously observable from the camera, the proposed method shows a good performance. Experimental results showed the effectiveness of the proposed method.View full abstractDownload PDF (1424K) -
Masato MUKOYAMA, Jun-ya TAKAYAMA, Shinji OHYAMA2011 Volume 47 Issue 10 Pages 450-458
Published: 2011
Released on J-STAGE: January 21, 2012
JOURNAL FREE ACCESSIn this paper, a measurement method for cross-sectional temperature distributions is considered. A novel method based on an acoustic computed tomography (CT) technique is proposed. Specifically, the temperature distributions are estimated using the time of flight data of many ultrasonic propagation paths. The Maximum Likelihood - Expectation Maximization (ML-EM) method is proposed to reconstruct the temperature distributions in a square area properly. The effectiveness of the proposed reconstruction method is confirmed by both numerical experiments and fabricated experimental system.View full abstractDownload PDF (1983K) -
Naoki SUNAGUCHI, Tetsuya YUASA, Qingkai HUO, Shu ICHIHARA, Masami ANDO2011 Volume 47 Issue 10 Pages 459-467
Published: 2011
Released on J-STAGE: January 21, 2012
JOURNAL FREE ACCESSWe have proposed a tomographic x-ray imaging system using DFI (dark field imaging) optics along with a data-processing method to extract information on refraction from the measured intensities, and a reconstruction algorithm to reconstruct a refractive-index field from the projections generated from the extracted refraction information. The DFI imaging system consists of a tandem optical system of Bragg- and Laue-case crystals, a positioning device system for a sample, and two CCD (charge coupled device) cameras. Then, we developed a software code to simulate the data-acquisition, data-processing, and reconstruction methods to investigate the feasibility of the proposed methods. Finally, in order to demonstrate its efficacy, we imaged a sample with DCIS (ductal carcinoma in situ) excised from a breast cancer patient using a system constructed at the vertical wiggler beamline BL-14C in KEK-PF. Its CT images depicted a variety of fine histological structures, such as milk ducts, duct walls, secretions, adipose and fibrous tissue. They correlate well with histological sections.View full abstractDownload PDF (3435K) -
Yusuke KONNO, Shohei HASHIGUCHI, Syuji NAITO2011 Volume 47 Issue 10 Pages 468-476
Published: 2011
Released on J-STAGE: January 21, 2012
JOURNAL FREE ACCESSOnline 3D profile measurement is required for various production lines. Light section method is well-known and easy to apply for getting surface profile. But the light section method does not meet speed requirement for online measurement in steel industry. We developed high speed 3D surface profile measurement system based on light section method. By using Time Delay Integration (TDI) camera and modulated light source, profile information is coded as phase shift of fringe. Phase of fringe image is recovered by quadrature demodulation and phase unwrapping. We apply this method to measure steel strip shape and successfully build online measurement system.View full abstractDownload PDF (3275K) -
—Processing in Measurement Time—Toshitaka UMEMOTO, Morihito KAMON, Yoichiro KAGAWA2011 Volume 47 Issue 10 Pages 477-484
Published: 2011
Released on J-STAGE: January 21, 2012
JOURNAL FREE ACCESSAs manufacturing processes are steadily automatized, quick and accurate mass measurement systems are in great demand. In this respect, recently, active belt conveyer ‘checkweigher’ is used by many enterprises. This system possesses a serious technical problem, in which three types of mechanical noises, that is, proper vibration, motor vibration, and belt pulley vibration, are included in detection signals. The noises should be removed to increase the accuracy. In the current mass measurement system, ‘moving average method’ is applied for the aim. However, it is not enough to realize the quick and accurate measurement. Very recently, we applied ‘frequency analysis method’ using the complex LMS algorithm for this problem. Only a signal in the stable time had to be used for real-time processing with this method. In this study, therefore, we decreased the moving average filters and increased the adjustment notch filters.View full abstractDownload PDF (596K)
Paper
Control
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Jun SHIMODAIRA, Yuki AMAOKA, Shinsuke HAMATANI, Masahiro TAKEUCHI, Hir ...2011 Volume 47 Issue 10 Pages 485-492
Published: 2011
Released on J-STAGE: January 21, 2012
JOURNAL FREE ACCESSBased on Generalized Motor Program, we analyzed the skill of human's table-tennis movement We hypothesized that it can be divided into arm swing and translational movements by upper and lower body movements, respectively. We expressed 3D position of the racket by only one parameter resulted from the analysis using Principal Component Analysis. Body trunk position measurement attested the lower body plays the role of keeping fixed relative-position between the ball and the body trunk at any hitting time. By applying human skills in upper and lower body movements, we could make the robot properly play table-tennis with a human.View full abstractDownload PDF (1368K)
System Integration
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Tomoaki YOSHIDA, Kiyoshi IRIE, Eiji KOYANAGI, Masahiro TOMONO2011 Volume 47 Issue 10 Pages 493-500
Published: 2011
Released on J-STAGE: January 21, 2012
JOURNAL FREE ACCESSThis paper proposes a light-weight navigation platform that consists of gyro-assisted odometry, a 3D laser scanner and map-based localization for human-scale robots. The gyro-assisted odometry provides highly accurate positioning only by dead-reckoning. The 3D laser scanner has a wide field of view and uniform measuring-point distribution. The map-based localization is robust and computationally inexpensive by utilizing a particle filter on a 2D grid map generated by projecting 3D points on to the ground. The system uses small and low-cost sensors, and can be applied to a variety of mobile robots in human-scale environments. Outdoor navigation experiments were conducted at the Tsukuba Challenge held in 2009 and 2010, which is an open proving ground for human-scale robots. Our robot successfully navigated the assigned 1-km courses in a fully autonomous mode multiple times.View full abstractDownload PDF (1091K)
Industrial Application
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Masatoshi OGAWA, Yasumasa SUZUKI, Harutoshi OGAI, Jin KUSAKA2011 Volume 47 Issue 10 Pages 501-510
Published: 2011
Released on J-STAGE: January 21, 2012
JOURNAL FREE ACCESSWith the problem of environmental pollution and energy depletion in recent years, a control technology which improves the performance of automobile engine has been demanded. This paper presents a method for construction of response surface model and a control parameter optimization method for automobile diesel engine in order to develop a model-based control system and the early development technique based on the model. The proposed method for construction of response surface model is able to efficiently-develop the response surface model that describes the multiple control parameters in relation to the characteristic value such as fuel consumption and emission. The proposed control parameter optimization method is able to quickly and efficiently calculate optimal control parameters to optimize evaluation item such as fuel consumption and emission based on the model.View full abstractDownload PDF (2120K)
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