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Volume 52, Issue 5
Displaying 1-7 of 7 articles from this issue
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Paper
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Yuki ISHII, Shiro MASUDA2016 Volume 52 Issue 5 Pages 249-256
Published: 2016
Released on J-STAGE: June 29, 2016
JOURNAL FREE ACCESSThis paper considers Fictitious Reference Iterative Tuning (FRIT) for disturbance attenuation based on variance evaluation for non-minimum phase (NMP) plants. The disturbance attenuation FRIT for minimum phase plants based on variance evaluation has already been proposed. However, this method can not be applied to NMP plants because occurrence of pole-zero cancellation results in internally unstable. This paper employs an H2 optimal controller with the help of a generalized interactor which was introduced in the context of control performance assessment for NMP plants by Huang and Shah (1999). In addition, we prove that optimization of a data-driven cost function results in obtaining simultaneously both the optimum controller and the plant model. A numerical example is shown to demonstrate the validity of the proposed method.View full abstractDownload PDF (998K) -
Takayuki NIIZATO, Hisashi MURAKAMI, Kazuki SANGU, Takenori TOMARU, Yut ...2016 Volume 52 Issue 5 Pages 257-263
Published: 2016
Released on J-STAGE: June 29, 2016
JOURNAL FREE ACCESSIn this study, we examine the radical difference between a single and a few individuals behavior. To investigate this difference, we use a fish (Plecoglossus altivelis, ayu or sweetfish) in an unfamiliar environment. We allow the fish to swim freely in a large shallow tank in a controlled laboratory and we track the fish's trajectories. In our experiment, although all trajectories of individuals show Lévy walk behavior, which is known as the optimal strategy for resolving the trade-off between exploration and exploitation, those trajectories of individuals were markedly different depending on whether they were alone or in a group. Our result suggests that the concepts of “whole” for a single fish and a group may be different. Furthermore, we also find that a leader of a group frequently changes though a trial.View full abstractDownload PDF (2850K) -
Kazuki URABE, Daiki NAKAMURA, Shunji SATOH, Xuehua HAN2016 Volume 52 Issue 5 Pages 264-275
Published: 2016
Released on J-STAGE: June 29, 2016
JOURNAL FREE ACCESSThe brain is a typical complex system that executes visual information analysis, motor control, selective allocation of memories, and so on. We have developed a software platform to simulate the complex brain system numerically by computational models, especially focused on vision. Our platform for vision simulation bases on RT-middleware and OpenRTM-aist, which is a software platform to develop robotic system. A new datatype as a common interface of various vision models is provided. The new datatype and our software library enable automatic switching of transformation method of input/output data between vision models, i.e., shared memory or via computer network. We also provide a software package named by OpenCV-RTC which converts a lot of image processing functions of OpenCV into RT-components executable on OpenRTM-aist. We show that a novel model for estimation of fixation location of humans' eye is efficiently developed on our platform by parallel connection of existing models for eye fixation, and show that the new model significantly outperforms the existing models.View full abstractDownload PDF (2055K) -
Takaya TSUKAGOSHI, Takeshi AKEHI, Mitsunori KITAMURA, Taro SUZUKI, Yos ...2016 Volume 52 Issue 5 Pages 276-283
Published: 2016
Released on J-STAGE: June 29, 2016
JOURNAL FREE ACCESSThis paper describes the localization method based on global navigation satellite systems (GNSS) technology for autonomous navigation of mobile robots. The accurate and robust position estimation of the robot is the key to the autonomous navigation. GNSS was usually not used in localization in urban environments because its positioning has multipath errors and problems in availability. In this paper, we propose the GNSS positioning technique that is suitable for the autonomous navigation of mobile robots. We use an open source GNSS positioning library to compute the GNSS fix solutions. The techniques, which select the GNSS observations using the GNSS signal strength and validate GNSS fix solutions, are proposed. Then the GNSS fix solutions are integrated with inertial sensors and an odometer through the extended Kalman filter. From the experiment in the “Real World Robot Challenge (RWRC)”, it was confirmed that the effectiveness of our proposed technique and the feasibility of its highly accurate positioning.View full abstractDownload PDF (3722K) -
Akira YANOU, Kenta YONEMORI, Shintaro ISHIYAMA, Mamoru MINAMI, Takayuk ...2016 Volume 52 Issue 5 Pages 284-291
Published: 2016
Released on J-STAGE: June 29, 2016
JOURNAL FREE ACCESSThis paper studies a control characteristics of visual-servo type underwater vehicle system using three-dimensional (3D) marker under air bubble disturbance on real-time pose tracking for visual servoing. The recognition of vehicle's pose through three-dimensional marker is executed by Genetic Algorithms (GA). The proposed system does not merely calculate the position and orientation information, but can recognize the target position and orientation information through GA while visual servoing, because the system utilizes a three-dimensional marker shape and color to recognize the marker. In our previous research, a regulator performance of the system about the vehicle's pose to 3D marker is explored under the condition that there is no disturbance on images. Therefore this paper explores the control results the robustness of the proposed system for air bubble disturbance on the image, aiming at confirming the control characteristics of the proposed visual servoing system. The following results were derived; (1) The proposed system is robust to time-variant target position in x-axis (front-back direction of the vehicle). (2) Although the fitness value of GA is influenced by disturbance, the system can keep recognizing the position and orientation of 3D marker, and tracking by visual servoing could be maintained under the air bubble disturbances.View full abstractDownload PDF (6271K) -
Kouichi WATANABE, Yosuke ASANO, Ikusaburo KURIMOTO, Tsunaki NUKAYA, At ...2016 Volume 52 Issue 5 Pages 292-298
Published: 2016
Released on J-STAGE: June 29, 2016
JOURNAL FREE ACCESSWe report the construction of temperature and VPD (Vapor Pressure Deficit) control system. In the plant factory with solar light, the control method for temperature and VPD using fogging system was not confirmed in the previous research. We propose the control method for temperature and VPD using variable rate fogging system by VPD feedback control to improve the growing environment of the plant. We subjected evaluation and review of the system that adjusts the fogging rate based on the VPD, and performs variable fogging. As a result, it increased the tomato fruit yield about from 10% to 20% more than the control area by proposed system in summer and winter.View full abstractDownload PDF (1842K)
Short Paper
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Kengo URATA, Masaki INOUE, Dai MURAYAMA, Shuichi ADACHI2016 Volume 52 Issue 5 Pages 299-301
Published: 2016
Released on J-STAGE: June 29, 2016
JOURNAL FREE ACCESSWe propose a modeling method of the wind power output for very short-term prediction. The model has cascade structure composed of two parts: One is a linear dynamical part that is driven by a white Gaussian noise and described by an auto regressive model. The other is a nonlinear static part that is driven by the output of the linear part. This nonlinear part is designed such that the distribution of its output matches with that of the wind power output. The constructed model is utilized to one-step ahead prediction of the wind power output. Furthermore, we evaluate the relation between the prediction accuracy and the sampling period for modeling.View full abstractDownload PDF (620K)
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