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Volume 44, Issue 4
Displaying 1-12 of 12 articles from this issue
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Hiroyuki FUKUDA, Hisakazu NAKAMURA, Muneaki HIGUCHI, Hirokazu NISHITAN ...2008 Volume 44 Issue 4 Pages 293-301
Published: April 30, 2008
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSDead reckoning and star reckoning are two basic self-localization methods for vehicles. But each method has inherent weakness. To recover these weaknesses, a sensor-fusion method via an initial state observer was proposed. However, this method can be only applied to the vehicles which move in a limited field. In this paper, we propose a new sensor-fusion method by using a grid point observer. We confirm the effectiveness of the proposed method by computer simulation and experiment of self localization of a two-wheeled mobile robot.View full abstractDownload PDF (8702K) -
Ichijo HODAKA, Ichiro JIKUYA2008 Volume 44 Issue 4 Pages 302-308
Published: April 30, 2008
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSThis paper develops the realization theory for linear periodic continuous-time systems. The substantial difficulty in the period-specific realization problem is that there may be no solution among linear periodic systems whose dimensions are equal to the order of a given weighting pattern matrix, in sharp contrast with realization problems for general linear time-varying systems or linear time-invariant systems. This paper proves the existence of period-specific realizations even when there exists no realization with dimension equal to the order of the weighting pattern matrix. It is finally shown that the realizations obtained in this paper have a minimal dimension among all of possible realizations with a specific period of time.View full abstractDownload PDF (4798K) -
Takashi SHIMOMURA, Masahiro TAKAHASHI, Takao FUJII2008 Volume 44 Issue 4 Pages 309-316
Published: April 30, 2008
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSThis paper addresses strictly positive real H2 controller synthesis with placement of sensors and actuators. Observer-based controllers that satisfy strict positive realness are sought in conjunction with H2-cost minimization. By utilizing the property that controller variables are split from structured variables under constraint of strict positive realness, we consider placement of sensors and actuators while designing controllers. Two problems are formulated via liner matrix inequalities (LMIs). The one is a regulator design problem with placement of actuators. The other is an observer design problem with placement of sensors. Solving these problems alternatively, we attain our main purpose. Through an illustrated example of a simply supported Euler-Bernoulli beam, the applicability of the proposed method is demonstrated.View full abstractDownload PDF (4826K) -
Koichi FUJIWARA, Manabu KANO, Shinji HASEBE2008 Volume 44 Issue 4 Pages 317-324
Published: April 30, 2008
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSSoftsensors are widely used for estimating product quality or other key variables when on-line analyzers are not available. However, their estimation performance deteriorates when the process characteristics change. To cope with the changes in process characteristics and update the model, recursive methods such as recursive PLS and Just-In-Time (JIT) modeling have been developed. However, they do not always function well when process characteristics change abruptly. In the present work, a new method for constructing softsensors based on a JIT modeling technique is proposed. In the proposed method, referred to as correlation-based JIT modeling, the samples used for local modeling are selected on the basis of the correlation among variables. Q statistic is used as an index of the correlation. The proposed modeling procedure is as follows: 1) Divide samples stored in the database into some temporal datasets, 2) Apply Principal Component Analysis (PCA) to the datasets separately, 3) Calculate Q statistic of the query point against each dataset, 4) Select a dataset which provides the smallest Q statistic, and 5) Construct a temporary model from the selected dataset. The proposed method can adapt a model to changes in process characteristics even when operating condition is changed abruptly. It can also cope with process nonlinearity. The usefulness of the proposed method is demonstrated through a case study of a CSTR process whose catalyst deactivation and recovery are considered as changes in process characteristics.View full abstractDownload PDF (16018K) -
Hiroyasu SHIGEMORI, Ryo NAGAO, Naoto HIRATA, Koji NAMBU, Nobuya IKEDA, ...2008 Volume 44 Issue 4 Pages 325-332
Published: April 30, 2008
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSA new automatic control method is proposed for controlling product quality of a complex and nonlinear process. The proposed method is based on a locally weighted regression model, which is a type of Just-In, Time models. A quality control system using the proposed method was developed and has been applied to control of the mechanical properties and the width of steel plates. The proposed method determines the optimum values of manipulated variables of the post-processes from the information of the pre-processes which has actual process data. In the proposed method, only one parameter, which is determined from actual plant data off-line, is necessary to tune a proximity function, and the optimum values of other model parameters can be automatically calculated in real time. Significant effects on reducing product quality deviations and model maintenance load have been achieved in commercial production. The developed system, has made important contributions to product quality improvement, production cost reduction, and employees satisfaction.View full abstractDownload PDF (12655K) -
An Application to Course-changing Maneuver for a ShipFuyuki HANE2008 Volume 44 Issue 4 Pages 333-342
Published: April 30, 2008
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSThis paper proposes designing of reference signals that realize a trajectory planning for course-changing in heading control system for a ship. The trajectory planning sets not only a designated quantity of turning but also the rate of turning with taking the ship characteristics and the steering gear limitation characteristics into account. To realize the trajectory planning, the reference signals are designed by analytical approach, which consist of the reference heading and the feedforward rudder inverting the ship model. The designing specifications consist of the course-changing conditions, the ship characteristics and the steering gear limitation characteristics. The maximum rudder angle and the maximum rudder rate in the feedforward rudder are derived by using relations between the reference heading and the ship model, and correspond to the limitation angle and the limitation rate in the steering gear, respectively. The equations of the reference heading are defined by time function with its initial conditions. First making the initial conditions set into zero, the reference signals are calculated. Secondly using the results, the reference signals which included the initial conditions are calculated. The designing of reference signals were verified by numerical calculations. We can conclude that our proposal method realizes the trajectory planning.View full abstractDownload PDF (5145K) -
Shingo MABU, Kotaro HIRASAWA, Hiroyuki HATAKEYAMA, Takayuki FURUZUKI2008 Volume 44 Issue 4 Pages 343-350
Published: April 30, 2008
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSGenetic Network Programming (GNP) has been proposed as a new graph-based evolutionary algorithm. GNP represents its solutions as graph structures which contribute to improving the expression ability of the programs. GNP with Reinforcement Learning (GNP-RL) was also proposed as an extended algorithm of GNP and its effectiveness has been confirmed. Because GNP-RL executes reinforcement learning during task execution in addition to evolution after task execution, it can search for solutions efficiently. In this paper, GNP with Actor-Critic (GNP-AC) is proposed to enhance the effectiveness of GNP-RL. Actor-Critic can adjust numerical values appropriately during task execution, i. e., online learning, and use them for determining actions. To confirm the effectiveness of the proposed method, GNP-AC is applied to the controller of the Khepera simulator and its generalization ability is evaluated.View full abstractDownload PDF (12894K) -
Akihide UTANI, Eisuke ORITO, Ayako KUMAMOTO, Hisao YAMAMOTO2008 Volume 44 Issue 4 Pages 351-360
Published: April 30, 2008
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSWireless sensor networks (WSNs) have attracted significant interests of many researchers because they have great potential as a means of obtaining information of various environments remotely. WSNs have their wide range of applications, such as natural environmental monitoring in forest regions and environmental control in office buildings. In WSNs, many sensor nodes with such resource limitation as battery capacity, CPU, and communication capacity are deployed in a region and used to monitor and gather sensor information of environments. Therefore, scalable and efficient network control for saving energy consumption is needed to prolong the lifetime of WSNs. Ant-based algorithms have attracted attentions as routing algorithms for energy consumption savings because they are more robust, efficient, and scalable than other conventional routing algorithms. This paper proposes a new advanced ant-based routing algorithm for large scale WSNs, which is more efficient and scalable than conventional ant-based routing algorithms. We evaluate the proposed algorithm using computer simulations and verify its effectiveness.View full abstractDownload PDF (9807K) -
Masahito YASHIMA, Tasuku YAMAWAKI2008 Volume 44 Issue 4 Pages 361-367
Published: April 30, 2008
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSThe present paper introduces an evaluation of the manipulation performance of a robotic arm with respect to control accuracy, taking into consideration the effects of gravity and the dynamic process between inputs and outputs in the robotic system. A measure based on the output controllability ellipsoid is proposed, which shows the relationship between the end-effector motion and the joint driving force. Computer simulations demonstrate the effects of gravity on the manipulation performance and the benefits of the proposed measure for the trajectory planning.View full abstractDownload PDF (6011K) -
Takeshi SASAKI, Hideki HASHIMOTO2008 Volume 44 Issue 4 Pages 368-376
Published: April 30, 2008
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSIn this paper, we investigate a mobile robot navigation system which can localize the mobile robot correctly and navigate based on observation of human walking in order to operate in a space populated by humans with minimal disturbance to them. To realize this system, we utilize multiple intelligent devices embedded in the environment. The human walking paths are obtained from a distributed vision system. We extract important points from observation and build a topological map of nodes which are important points and of edges which are added based on the presence of paths between important points. In addition, the human walking paths between two important points are averaged to get frequently used paths. The averaged paths are utilized as paths of the mobile robots. The mobile robot navigation based on observation of human is also performed with the support of the system. The position and orientation of the mobile robot are estimated from wheel encoder and distributed vision system measurement data using an extended Kalman filter. The system navigates the mobile robot along the frequently used paths by tracking control.View full abstractDownload PDF (12846K) -
Naohiko SUGITA, Yoshikazu NAKAJIMA, Mamoru MITSUISHI2008 Volume 44 Issue 4 Pages 377-383
Published: April 30, 2008
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSAdaptive control of the machining process in orthopedic surgery will increase not only productivity but also the safety issues of tool usage. The authors have developed a technology for an adaptive control system. The system has two modes, the “predictive mode” and the “adaptive mode.” The predictive mode is used to shorten the air cutting time. In the adaptive mode, the system monitors the cutting force and the cutting temperature, and controls the feed override according to the difference between the real and the desired cutting force. The software is implemented on the robot controller and its effectiveness is evaluated with a urethane bone.View full abstractDownload PDF (19568K) -
Fumio NISHIYAMA, Hideo MURAKAMI2008 Volume 44 Issue 4 Pages 384-386
Published: April 30, 2008
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSThis paper proposes a method of designing a matched filter for stepped-FM radars. The proposed method estimates an autocorrelation function of signals reflected from a target and then derives the matched filter by taking discrete-Fouriertransform of the estimated autocorrelation function. Computer simulation results show that the proposed method outperforms the conventional synthetic bandwidth method in terms of signal-to-clutter ratio.View full abstractDownload PDF (553K)
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