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Volume 48, Issue 8
Displaying 1-7 of 7 articles from this issue
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Paper
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Takahiko MORI2012 Volume 48 Issue 8 Pages 451-460
Published: 2012
Released on J-STAGE: September 01, 2012
JOURNAL FREE ACCESSThis paper deals with control of crane tele-operation system considering power assisted conveyance. We design a new crane tele-operation system using zero phase notch filter and apply the system to power assist controller in master enviroment. The system enables to modify frequency characteristics of operating torque without signal distortion on the line in oder to suppress vibration of the load-rope of crane. Furthermore, We design some methods considering power assisted conveyance as controller in master enviroment. Some results of simulation and experiment are given in order to verify the usefulness of our proposed system.View full abstractDownload PDF (2152K) -
—Effects of Pressurization History on the Calibration Results—Hiroaki KAJIKAWA, Tokihiko KOBATA2012 Volume 48 Issue 8 Pages 461-469
Published: 2012
Released on J-STAGE: September 01, 2012
JOURNAL FREE ACCESSThis study focuses on the effects of the calibration protocol on the results for hydraulic pressure transducers. Using a fully-automated calibration system that uses a pressure balance as the standard device, quartz Bourdon-type hydraulic pressure transducers were calibrated at pressures from 10 MPa to 100 MPa. Two kinds of calibration procedures, stepwise and 0-A-0-type procedures, were applied to pressure increasing and decreasing cycles. For the stepwise procedure, the interval between the calibration cycles exerts a strong influence on the results in the pressure increasing process. The preliminary pressurization immediately before the cycle can reduce the effects of the interval. However, in turn, the waiting time between the preliminary pressurization and the main calibration cycle considerably affects the results. Results with the 0-A-0-type procedure differ from those with the stepwise procedure. In particular, hysteresis becomes much smaller because the effect of previously applied pressure is reduced by the pressure release to zero pressure. From the results, possible measures for obtaining reproducible calibration results are presented.View full abstractDownload PDF (1294K) -
Jun-ya NAGASE, Toshiyuki SATOH, Shuichi WAKIMOTO, Norihiko SAGA, Koich ...2012 Volume 48 Issue 8 Pages 470-478
Published: 2012
Released on J-STAGE: September 01, 2012
JOURNAL FREE ACCESSIn recent years, Japanese society has been aging, engendering a labor shortage of young workers. Robots are therefore expected to be useful to perform tasks such as day-to-day work support for elderly people. In particular, robots, which are intended for use in the field of medical care and welfare, are expected to be safe when operating in a human environment because they often come into contact with people. Furthermore, robots must perform various tasks such as regrasping, grasping of soft objects, and tasks using frictional force. Given these demands and circumstances, The stiffness-changeable finger has been developed for the robot hand in such environments. In this study, we have evaluated characteristics of force control of stiffness-changeable finger using balloon actuator by predictive functional control (PFC) system. The predictive functional control is one of the model based predictive control (MPC) schemes, which predict the future outputs of the actual plant over the prediction horizon and compute the control effort over the control horizon at every sampling instance. In this paper, PFC control performances of the finger using balloon actuator are reported.View full abstractDownload PDF (1896K) -
Hideaki TANAKA, Shinji HARA, Tetsuya IWASAKI2012 Volume 48 Issue 8 Pages 479-487
Published: 2012
Released on J-STAGE: September 01, 2012
JOURNAL FREE ACCESSA class of large-scale systems with decentralized information structures such as multi-agent systems can be represented by a linear system with a generalized frequency variable. In this paper, we investigate stability of such systems, which is the most fundamental property from the view point of control. Specifically, we first show that the system is stable if and only if all the eigenvalues of the interconnection matrix are in a region on the complex plane specified by the generalized frequency variable. We then provide an algebraic characterization of the stability region in terms of polynomial inequalities. Finally, the complexity properties of the stability region is examined, and they are illustrated by numerical examples.View full abstractDownload PDF (485K) -
Hiroshi YAMAMOTO, Masaharu MOTEKI, Takashi OOTUKI, Yuji YANAGISAWA, Ak ...2012 Volume 48 Issue 8 Pages 488-497
Published: 2012
Released on J-STAGE: September 01, 2012
JOURNAL FREE ACCESSCivil engineering work still involves many dangerous and grueling tasks. So improving work environments and ensuring safety are important challenges facing in this field. It is also essential to develop to prepare for the aging of construction workers and growing shortage of young skilled workers, which will occur in response to the falling birthrate and aging of the future population. This research project was undertaken as challenges to overcome these problems by developing the basic technologies for automated construction system using the three-dimensional information and achieving self-controlled operation by hydraulic excavators which is a typical general purpose construction machine. The developed prototype excavator has achieved the self-control of soil excavation and loading work, with the almost same speed and with the same precision in finished product to those of normal work by human worker.View full abstractDownload PDF (1948K) -
Keiji WATANABE2012 Volume 48 Issue 8 Pages 498-504
Published: 2012
Released on J-STAGE: September 01, 2012
JOURNAL FREE ACCESSThis paper presents decoupling of complementary sensitivity and robust stabilization on diagonal dominance for MIMO systems. The decoupling can be achieved by model bridge control system with the state feedback for decoupling and the observer for the observable diagonal-model of the nominal plant. The system with uncertainties in the gain and the phase range for diagonal elements and under the maximal gain for non-diagonal ones can be robustly stabilized by adjusting diagonal elements of complementary sensitivity on the basis of diagonally dominant systems.View full abstractDownload PDF (450K) -
Toru KURIHARA, Nobutaka ONO, Shigeru ANDO2012 Volume 48 Issue 8 Pages 505-513
Published: 2012
Released on J-STAGE: September 01, 2012
JOURNAL FREE ACCESSThe photometric stereo method is extended for single-frame, disturbance illumination free measurement of normal vector map. This system uses (1) three-phase amplitude-modulated illuminations at the vertices of a regular triangle and (2) correlation image sensor (CIS). The triangular three-phase amplitude-modulated illuminations are used to encode the surface orientation into the amplitude and phase of the reflected light intensity. The CIS demodulates them and reconstructs the surface orientation. Based on the correlation detection principle, any background illuminations uncorrelated with the modulated light are satisfactorily removed. The normal vector map as well as the intensity image are obtained in a single frame. Several experimental results for the system performance evaluation are shown.View full abstractDownload PDF (1275K)
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