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Volume 39, Issue 1
Displaying 1-12 of 12 articles from this issue
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Isao KAWANO, Masaaki MOKUNO, Toru KASAI, Hiroshi KOYAMA, Takashi SUZUK ...2003 Volume 39 Issue 1 Pages 1-10
Published: January 31, 2003
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSEngineering Test Satellite-VII (ETS-VII) successfully performed the first autonomous Rendezvous Docking (RVD) flight using an image sensor with 6 degree-of-freedom (6 DOF) control in the world. ETS-VII is a test satellite to perform in-orbit demonstration of the autonomous RVD technology. Proximity Sensor (PXS) is the image sensor which measures relative position and attitude, and PXS navigation is used primarily in a docking approach phase (within 2m from target satellite). In this paper, we introduce ETS-VII PXS design and evaluation results of its in-orbit performance. In-orbit performance is evaluated in comparison with another navigation sensors such as Rendezvous Radar (RVR). Measurement accuracy of PXS is better than its requirement. And it is shown that image sensor is useful for rendezvous navigation sensor.View full abstractDownload PDF (3559K) -
Kenichi HASEGAWA, Kuniko MAEDA, Hiromi HAMANAKA2003 Volume 39 Issue 1 Pages 11-17
Published: January 31, 2003
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAn area detector system for a wavelength-dispersive crystal spectrometer has been constructed for rapid chemical state analysis by external beam PIXE. Five position-sensitive proportional counters (PSPCs) are stacked and operated as a 2D detector. Each PSPC has a carbon fiber resistive anode. Pulses from the five PSPCs are converted into digital signals with a 512×5 channel charge-division analyzer. Five spectra are simultaneously obtained. A software converts this 2D data set into one spectrum after adjusting the offset channels. The spatial resolution of this system is somewhat larger than that of our single PSPC system previously developed. However the counting efficiency is five times higher than that of the single one.
Chemical state analysis in atmospheric air within several seconds to several minutes has been realized. Usefulness of this system for time-resolved chemical state analysis was demonstrated by measuring sulfur Kα spectra from a marine sediment sample.View full abstractDownload PDF (1989K) -
Extension of the Case of Relative Degree One to Multivariable SystemsMitsuaki ISHITOBI, Kouta KASHIWAMOTO2003 Volume 39 Issue 1 Pages 18-24
Published: January 31, 2003
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper analyzes the asymptotic properties of zeros of discrete-time systems corresponding to continuoustime multivariable plants with pure imaginary zeros. A condition that ensures the stability of the limiting zeros of the discrete-time systems for sufficiently small sampling periods is derived.View full abstractDownload PDF (1447K) -
Naohisa OTSUKA2003 Volume 39 Issue 1 Pages 25-34
Published: January 31, 2003
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, the concept of generalized (Cγ(·), Aα(·), Bβ(·))-pairs for linear uncertain ω-periodic discretetime systems is introduced and its properties are investigated. Further, the parameter insensitive disturbancerejection problems with dynamic compensator for uncertain linear ω-periodic discrete-time systems is formulated and its solvability conditions are presented.View full abstractDownload PDF (2041K) -
Koji KINOSHITA, Takuya SOGO, Norihiko ADACHI2003 Volume 39 Issue 1 Pages 35-42
Published: January 31, 2003
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIterative learning control (ILC) obtains a desired input that exactly generates a desired output through repetitions of the similar tasks. The adjoint-type ILC, which is based on the gradient method, can obtain the bounded desired input for a finite dimensional and non-minimum phase system. This aspect suggests that the adjoint-type ILC can achieve good output tracking for a flexible arm, which is a infinite dimensional and non-minimum phase system. In this paper, we propose an update law and give a convergence condition for the adjoint-type ILC applied to a single-link flexible arm. In order to verify the effectiveness of the adjoint-type ILC for the single-link flexible arm, an experiment is carried out. Several researchers have proposed a iterative learning controller for the flexible arm by using assumed modes method. In this paper, a simple model of the single-link flexible arm is used because ILC dose not require the accurate model. Experiments result show that, even if the single-link flexible arm is modeled by the simple method and has some uncertainties, good output tracking is achieved. Moreover, pre-actuation, which is remarkable aspect of the adjoint-type ILC, is observed.View full abstractDownload PDF (1439K) -
Utility of Fly-Wheel Angular Velocity MeasurementsShigemune TANIWAKI, Yoshiaki OHKAMI2003 Volume 39 Issue 1 Pages 43-50
Published: January 31, 2003
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA real-time attitude estimation filter for the gyroless spacecrafts is proposed. In this method, outputs from a fly-wheel tachmeter is used. Attitude angular velocity is estimated from wheel angular velocity with use of algebraic relation between them based on angular momentum equation. Extended Kalman filter is used for compensation of sensor noises and drift of total angular momentum caused by external disturbances. The estimator's performance is demonstrated via numerical simulations.View full abstractDownload PDF (1664K) -
Masao SUGI, Hideo YUASA, Tamio ARAI2003 Volume 39 Issue 1 Pages 51-58
Published: January 31, 2003
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA new method is proposed for controlling a large number of traffic signals, which are represented by nonlinear oscillators, each governed by a reaction-diffusion equation at a node of a graph. The behavior of each signal is determined only by the states of its neighbors, with the system as a whole being also organized globally. In this report, both offsets between neighboring signals and phase splits of them are controlled according to the traffic condition. The simulation results are exemplified to show the validity of the method.View full abstractDownload PDF (2036K) -
Fumihiko ISHIDA, Yasuji SAWADA2003 Volume 39 Issue 1 Pages 59-66
Published: January 31, 2003
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe report the global features of recently observed results of phase lead phenomena of human hand-tracking experiments, i.e. the hand motion precedes the target motion in the frequency range 0.4Hz<f<1.7Hz, and the amount of precedence approximately corresponds to the value for which the amount of the error of the hand position occurring at sudden frequency change of the target motion is minimum. A delayed feed-forward model with a properly chosen value of a feed-forward parameter roughly reproduced the two main features of the experimental results simultaneously. These results suggested that the phase in the human percepto-motor control system might be chosen to an operational point to minimize the transient error in a certain frequency range determined by physical parameters.View full abstractDownload PDF (2240K) -
Description of System Generation ProcessSatoshi MURATA, Kohji TOMITA, Haruhisa KUROKAWA2003 Volume 39 Issue 1 Pages 67-73
Published: January 31, 2003
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA variety of models of self-reproduction process have been proposed since von Neumann initiated this field. Almost all of them are described within the framework of two-dimensional cellular automata. They are heavily dependent on or limited by the peculiar properties of the two dimensional lattice spaces, but such properties are irrelevant to the essential nature of self-reproduction. In this paper, we introduce a new framework called “graph automata” to obtain a natural description of complicated spatio-temporal developmental processes. As an illustrative example, a self-reproduction of Turing machine, which requires very long description by conventional cellular automata, is shown in a simple and straightforward formulation.View full abstractDownload PDF (3580K) -
Hideya TAKANASHI, Yoshihiro MIYAKE2003 Volume 39 Issue 1 Pages 74-81
Published: January 31, 2003
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWalk training for elderly people is carried out by using the cooperative walk between human and human. In such care relationship, both walk movements are mutually adapted and walking itself is co-emerged in real-time. However, such co-emergence process has not been realized by the present welfare apparatus, and our group have proposed Walk-Mate which is the walking support robot to realize such process in human-machine relationship. In this research, we applied Walk-Mate to the elderly people who actually have walk handicaps. Then, balance and smoothness of walking were analyzed as an index of the effectiveness of Walk-Mate. As the first phase, it was shown that the system was effective for the modeled disabled person that was constructed by attaching a load to one leg and fixing a knee joint. In the following phase, effectiveness for elderly people who have handicaps of neural and muscle skeletal system was studied, and consequently sufficient effects were shown from the viewpoint of stability of walking.View full abstractDownload PDF (3941K) -
Min YOON, Hirotaka NAKAYAMA, Yeboon YUN2003 Volume 39 Issue 1 Pages 82-84
Published: January 31, 2003
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSGeneralization error bounds in Support Vector Machines (SVMs) are based on the minimum distance between training points and the separating hyperplane. Especially, the error of soft margin algorithm can be bounded by a target margin and some norms of the slack vector. In this paper, we formulate a soft margin algorithm considering the corruption by noise in data directly. Additionally, through a numerical example, we compare the proposed method with a conventional soft margin algorithm.View full abstractDownload PDF (461K) -
Nobumasa TAKAHASHI, Hideo SAITO2003 Volume 39 Issue 1 Pages 85-87
Published: January 31, 2003
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe aim of this paper is to develop of the 3-D human interface system via hand motion recognition. We built a multiple camera system mounted on a display. For natural interface to computers, the images of the user's hand motion are captured by the multiple camera system. For estimating the 3-D coordinates of the indicating position, 3-D shape model is generated using the images. Stable estimation of indicating position becomes possible by using an effective combination of 2D image features and 3-D model. We compared the finger tip locus estimated by the proposed system with the locus estimated by human. Those two kinds loci are close so that the efficacy of the proposed method can be demonstrated.View full abstractDownload PDF (2041K)
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