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Volume 48, Issue 1
Displaying 1-10 of 10 articles from this issue
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Special Issue on Cutting Edge of System Integration Technology
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[in Japanese], [in Japanese], [in Japanese], [in Japanese]2012 Volume 48 Issue 1 Pages 1
Published: 2012
Released on J-STAGE: March 02, 2012
JOURNAL FREE ACCESSDownload PDF (134K)
Paper
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Keiji MONDEN, Kenichiro NONAKA2012 Volume 48 Issue 1 Pages 2-10
Published: 2012
Released on J-STAGE: March 02, 2012
JOURNAL FREE ACCESSIn this paper, a method for stable path tracking of non-holonomic vehicles with time delays is proposed. Time-state control form, which is suitable to control non-holonomic systems, is adapted for vehicle control, but time delays have not been considered explicitly so far. This study deals with the time delays in time-state control form by transforming time delay factors from time delay into state delay. To deal with the time delay, the proposed method uses Smith predictor which is one of the typical compensator for time delay systems. To apply Smith predictor to time-state control form, the control plant is modified to achieve exponential tracking performance. By the proposed method, it is shown that stable path tracking is achieved under high gain control paprameters.View full abstractDownload PDF (2683K) -
Katsuhiko TABATA, Yoshifumi NISHIDA, Yoshihiro IIDA, Toshiaki IWAI2012 Volume 48 Issue 1 Pages 11-19
Published: 2012
Released on J-STAGE: March 02, 2012
JOURNAL FREE ACCESSWe propose a new navigation system for Automatic Guided Vehicles (AGV) used as a carrier in the factory. The guided marker of the navigation system is composed of ultrasonic transducers instead of the traditional markers such as electromagnetic tape, light reflective tape and so on. The proposed system is available to be used not only indoors but also outdoors and adaptable to a temporary route. The ultrasonic sensor is generically susceptible to noise, so that we make the following propositions. First, a phased array of the ultrasonic sensors is employed in searching a land marker to improve the signal-to-noise ratio. Second, the specific ID with 7bits is assigned as the land marker to avoid the system errors ascribable to an ultrasonic interference. In addition, the proposed system is quite compact in virtue of the embedded technology of a microcomputer and Field Programmable Gate Array (FPGA). This paper reports the development of the proto-type system of navigation system and confirmation of its fundamental performances.View full abstractDownload PDF (4597K) -
Takahiko MORI2012 Volume 48 Issue 1 Pages 20-26
Published: 2012
Released on J-STAGE: March 02, 2012
JOURNAL FREE ACCESSThis paper deals with control of crane tele-operation system considering power assisted conveyance. We design a new optimal servo control system using notch filter and apply the system to feedbak controller in slave enviroment. The system enables to assign poles to desirable locations of a closed loop system exactly 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 experiments are given in order to verify the usefulness of our proposed system.View full abstractDownload PDF (1304K) -
Isao FUJIMOTO, Susumu HARA, Yoji YAMADA, Yoshifumi MORITA, Kiyoshi SES ...2012 Volume 48 Issue 1 Pages 27-36
Published: 2012
Released on J-STAGE: March 02, 2012
JOURNAL FREE ACCESSThis paper shows control methods of the smooth switching from vibration reduction when a worker conveys flexible structures to their positioning. One of the important issues in this study is there are no knowledge of the goal position before conveying an object and the terminal time when worker finishes conveying. Then one of sensors can detect the displacement of the object not anytime but only the time when the position is settled. Additionally, an overshoot has to be prevented when there are other objects at the goal position. For clearing up these issues, we applied an adaptive nonstationary control method and showed its effectiveness. And two methods for determining the goal position with limited sensor signals are proposed. For showing the utility of the proposed methods, we conducted four kinds of experiments of positioning a flexible object: 1) only the power assist control, 2) the vibration control with power assist control, 3) the vibration and position control with power assist control and laser sensor, 4) the vibration and position control with power assist control without laser sensor. The results show that the first method is useful for accurate positioning in a short time. The second method does not need an additional sensor used in the first method. However, this method takes a longer time for accurate positioning settling. Adaptive nonstationary control with smooth mode switching is useful when the additional sensor signal is input in the positioning stage only. Then, the results also show that vibration control is important when not only conveying but also positioning because of preventing the overshoot. The proposed methods are useful because it can position any undetermined goal position before conveying.View full abstractDownload PDF (3023K) -
Takehito KIKUCHI, Sosuke TANIDA, Toshimasa TANAKA, Keigo KOBAYASHI, Ka ...2012 Volume 48 Issue 1 Pages 37-44
Published: 2012
Released on J-STAGE: March 02, 2012
JOURNAL FREE ACCESSCaster walkers are supporting frames with casters and wheels. These tools are regularly utilized as life support tools or walking rehabilitation tools in hospitals, nursing homes and individual residences. Users of the walkers can easily move it thanks to its wheels and casters. However falling accidents often happen when it moves without users. The falling accident is very serious problem and one of leading causes of secondary injuries. In the other case, it is hard to move to desired directions if users have imbalance in their motor functions or sensory functions, e.g., hemiplegic patients. To improve safeness and operability of the walkers, we installed compact MR fluid brakes on the wheels and controlled walking speed and direction of the walker. We named this intelligently controllable walker, “i-Walker” and discussed on the control methods and experimental results in this paper. Preliminary trials for direction control of the first-generation of the i-Walker (i-Walker1) are presented. On the basis of the results, we improved the control method and hardware of the i-Walker1, and developed the second-generation (i-Walker2). System description and experimental results of the i-Walker2 are also described. The i-Walker2 has better operability and lower energy consumption than that of the i-Walker1. The line-tracing controller of the i-Walker2 well controls human motions during walking experiments on the target straight line.View full abstractDownload PDF (3556K) -
Minami SHIBAGAKI, Noboru HAYASAKA, Minoru HASHIMOTO2012 Volume 48 Issue 1 Pages 45-50
Published: 2012
Released on J-STAGE: March 02, 2012
JOURNAL FREE ACCESSA polyvinyl chloride (PVC) gel actuator shows great potential because of such positive characteristics as movement in the air, large deformation, and being lightweight. We have proposed a structure of a contraction type actuator and investigated various characteristics of this actuator. In order to use this actuator as a control element, we propose a mathematical model. Based on these results, we develop a position feedback control method of the actuator and investigate the validity of the control method in this paper.View full abstractDownload PDF (1439K) -
Tomoki YAMASHITA, Motomasa TANAKA, Satoshi YAMAMOTO, Shigehiko HAYASHI ...2012 Volume 48 Issue 1 Pages 51-59
Published: 2012
Released on J-STAGE: March 02, 2012
JOURNAL FREE ACCESSWe are now developing the strawberry harvest robot called “M-3” prototype robot system under the 4th urgent project of MAFF. In order to develop the control software of the M-3 robot more efficiently, we innovated the RT-middleware “OpenRTM-aist” software platform. In this system, we developed 9 kind of RT-Components (RTC): Robot task sequence player RTC, Proxy RTC for image processing software, DC motor controller RTC, Arm kinematics RTC, and so on. In this paper, we discuss advantages of RT-middleware developing system and problems about operating the RTC-configured robotic system by end-users.View full abstractDownload PDF (8432K) -
Satoru FUJISAWA, Takahiro WADA, Hiroyuki KONNO, Shun'ichi DOI2012 Volume 48 Issue 1 Pages 60-66
Published: 2012
Released on J-STAGE: March 02, 2012
JOURNAL FREE ACCESSThe driver tilts his/her head to the direction of the curve center while the head movement of the passenger is opposite to the driver. Moreover, it is known that the driver does not get carsickness comparing with the passenger. Thus, we hypothesize that driver's head-tilt strategy has the effect to reduce motion sickness. So far, we proposed a mathematical model of the motion sickness incidence caused by the head movement in 3D space based on subjective vertical conflict theory. In this paper, we, thus, investigate motion sickness incidence of the head movements measured in the real car experiments using the proposed model. The results demonstrate that the head tilts against centrifugal acceleration have the effect to reduce motion sickness. Based on the results, we propose a novel posture control device for decreasing the passenger's head roll in curve driving. It is shown that the proposed device potentially has the effect to decrease the passenger's head roll angle, which is expected to reduce the motion sickness.View full abstractDownload PDF (2222K) -
Naohiro UENO, Daisuke ONO, Chao-Nan XU2012 Volume 48 Issue 1 Pages 67-72
Published: 2012
Released on J-STAGE: March 02, 2012
JOURNAL FREE ACCESSMechanoluminescent (ML) materials are attractive smart materials that can emit light induced by mechanical deformation. The ML sensing devices of SrAl2O4:Eu have been developed to make possible to visualize dynamic stress. Dynamic stress distributions are visualized as patterns of mechanoluminescence by painted micro-particle mixtured with paint on surface of the structure. In this paper, we attend that patterns in mechanoluminescence images reflect the distribution of stress on the structures. A method of mechanoluminescence pattern detection is divided into two steps. First step is image filtering in which the euclid distance and correlation coefficient between each frame images are applied for detection of mechanoluminescence patterns. Sencound step is detailed analysys of mechanoluminescence pattern by using Higher Order Local Autocorrelation (HLAC). Developed method is inspected by using some experimental results.View full abstractDownload PDF (1866K)
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