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Volume 43, Issue 8
Displaying 1-14 of 14 articles from this issue
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Koichi YOSHIDA, Takeshi TSUJIMURA2007 Volume 43 Issue 8 Pages 625-631
Published: August 31, 2007
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSThis paper proposxs a tracking oontrol method for an active free space optics (FSO) telecommunication system that enables a mobile terminal to be tracked in user networks of short-range coverage. The active FSO Spitem consists of a transmitting terminal with an LD and a receiving terminal with a PD. Each terminal incorporates a mecbanism that controls the path of the laser beam emitted from the LD so as to align to the optical axis of the PD regardless of position changes between the terminals. This provdes the system with a high-speed and ubiquitous optical communication capability over a oonvcntional wireless network with a loWer bit rate for control signal transmission. The axis. atignment control requires the relative position and orientation between the terminals, which can be estimated on-line through the proposed method using an extended Kalman filter. The performance of the tracking control mcthod is verified by experiments using a prototype of the active FSO System.View full abstractDownload PDF (17222K) -
with a Design Example for the Lateral-directional Motions of an Aircraft and Its Verification ExperimentsMasayuki SATO2007 Volume 43 Issue 8 Pages 632-640
Published: August 31, 2007
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSThis paper proposes a vehicle controller design for two design requirements; variable maneuverability and disturbance rejection, where the meaning of variable maneuverability is defined as, roughly speaking, matching of plant outputs with model outputs in some frequency range for many models, possibly infinitely many models, without changing the controller. The proposed controller is composed of a feedback controller and a feedforward controller; the feedback controller is a disturbance rejection controller which minimizes the H∞ norm of the transfer function from disturbance inputs to controlled outputs, and the feedforward controller is a right inverse system of the closed-loop system composed of the plant and the feedback controller. With using our proposed method, we design a controller for the lateral-directional motions of a research aircraft. We conducted hardwarein-the-loop simulations and flight tests to verify the simultaneous realization of variable maneuverability and disturbance rejection. These experiments have shown that the controller has satisfying performance under real conditions; that is, variable maneuverability and disturbance rejection are simultaneously realized under real conditions.View full abstractDownload PDF (8546K) -
Hidenori SHINGIN, Yoshito OHTA2007 Volume 43 Issue 8 Pages 641-645
Published: August 31, 2007
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSThis paper considers the reduction of the quantization bit number of feedback in disturbance rejection. The plant is affected by bounded disturbances and controlled by a single input determined by observed state. The output amplitude is reduced by keeping the state in an appropriate polyhedral set. The bit number is evaluated by the number of control values required to keep the set invariant. A method to compute the controller with minimum bit number for a given polyhedral set is proposed as the iteration of linear programs. With some assumptions, finite bit number can always be achieved by degrading achievable performance arbitrarily.View full abstractDownload PDF (4208K) -
Gou NAKURA2007 Volume 43 Issue 8 Pages 646-655
Published: August 31, 2007
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSIn this paper we study the H∞ tracking problems with preview for linear jump systems considering time-varying uncertainties. We adopt a game theory approach for them and present a saddle point strategy. We consider three different tracking problems depending on the property of the reference signals. In order to solve these tracking problems, we introduce the auxiliary systems with no uncertainties and the auxiliary performance indices, and solve the auxiliary game problem. Numerical examples demonstrate that increasing the preview lengths improves the tracking error.View full abstractDownload PDF (5272K) -
Kenji KASHIMA, Kazunori NISHIO2007 Volume 43 Issue 8 Pages 656-662
Published: August 31, 2007
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSThis paper provides an analytical expression of the discrete-time H2performance limit based on state space representation. The obtained formula, similarly to its continuous-time counterpart, clarifies performance degradation caused by non-minimum phase properties of the plant. The derivation is not so strainghforward because of the theoretical difficulty arising from the definition of H2-space on the unit disc. The result can be interpreted intuitively by introducing the class of strictly causal controllers.View full abstractDownload PDF (14480K) -
Yuichi KOBAYASHI, Kyouji OTSUBO, Shigeyuki HOSOE2007 Volume 43 Issue 8 Pages 663-671
Published: August 31, 2007
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSThis paper discusses the design of decentralized capturing behavior by multiple mobile robots. The design is based on a gradient descent method with local information. The task of capturing a target is divided into two problems, enclosing behavior and grasping behavior. We give analysis on convergence of the local control policy in enclosing problem. In grasping behavior, we consider the force-closure condition in decentralized form for designing a local objective function. The proposed local control policies wereevaluated in simulations, where the flexibility of the system was verified caused by the decentralized nature of the system.View full abstractDownload PDF (11642K) -
Yeboon YUN, Hirotaka NAKAYAMA, Min YOON2007 Volume 43 Issue 8 Pages 672-678
Published: August 31, 2007
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSMany decision making problems are formulated as multi-objective optimization problems so as to satisfy diverse demands of decision maker. One of main issues in multi-objective optimization is how to find a Pareto optimal solution which meets decision maker's demands. To the end, interactive optimization methods, for example aspiration level methods, have been developed. On the other hand, several methods using genetic algorithm have been researched for generating the whole set of Pareto optimal solutions. However, those conventional methods have some problems when applying them to real practical problems considering the number of function evaluations. In many engineering design problems, generally, there are black-box objective functions whose forms are not explicitly known in terms of design variables. Under this circumstance, given design variables, the values of objective function can be obtained by sampled real/computational experiments such as structural analysis, fluid-mechanical analysis, thermodynamic analysis, and so on. These analyses are expensive and time consuming, and it is an important issue in real application problems how to make the number of necessary analyses as few as possible. In this paper, we suggest a sequential approximation method for solving multi-objective optimization problems, which is composed of two stages; i) the first stage is to predict the form of each objective function by using support vector regression on the basis of some experimental data, ii) the second stage is to find the Pareto optimal solution closest to the given aspiration level of decision maker using thepredicted objective functions, and in parallel, to generate the whole set of Pareto optimal solutions. Also, we discuss a way how to select additional experimental data for revising the form of objective function by relearning step by step. Finally, we illustrate the effectiveness of the proposed method through some numerical examples.View full abstractDownload PDF (11162K) -
Kentaro OHNUMA, Ken MASAMUNE, Teruyoshi SADAHIRO, Kitaro YOSHIMITSU, J ...2007 Volume 43 Issue 8 Pages 679-688
Published: August 31, 2007
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSThe main purpose of this study is to develop a human-adaptive surgical robot system for laparoscopic surgery that is controlled according to a surgical scenario. This study is intended to contribute to development of a Scrub Nurse Robot (SNR) for the OR, which hands surgical instruments to surgeons and receives them. Additionally, we construct a surgical scenario model for laparoscopic cholecystectomy surgery with timed automata. It is important to obtain effective intraoperative informations for the appropriate interactive control of surgical robots. This paper proposes an overview of the“Human Adaptive Mechatronics”-based surgical system and a construction method of an algorithm recognizing the intraoperative actions of a surgeon.View full abstractDownload PDF (27951K) -
Takeo OOMICHI, Tatsuru NAGAI, Kazuhiro MORI, Yoshinori ADACHI, Takashi ...2007 Volume 43 Issue 8 Pages 689-698
Published: August 31, 2007
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSAutonomous mobile robots moving under various environments are required to integrate a lot of techniques. This paper presents the system integration concept of the mobile robot architecture based on RFID tag system for realizing control condition, distributing autonomous control system for highly reliable operation and fusion control of autonomous and teleoperation. Effect of the system for various conditions is verified by the mobile robot that is designed as the proposal system concept.View full abstractDownload PDF (19972K) -
Ayaka OHTAKE, Masayuki HARA, Jian HUANG, Tetsuro YABUTA2007 Volume 43 Issue 8 Pages 699-701
Published: August 31, 2007
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSThis paper especially discusses the passive-type size-weight illusion in which the weights of objects are given forcibly. We attempted to examine the illusion in virtual reality and found that the characteristics differ between the normal and passive types. The results imply that the illusion does not appear in the early stage due to the reflective action. However, the size weight illusion becomes to appear by adapting to sudden loads after few trials.View full abstractDownload PDF (11123K) -
Chang-Jun LIN, Hiroaki OZAKI, Hua QIU2007 Volume 43 Issue 8 Pages 702-704
Published: August 31, 2007
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSIn this paper, based on a very simple physical principle, a simple and convenient speed sensor for a gasoline engine used is developed. The sensor has several favorable features, i.e. small, light, taking little space, sufficient accurate and handling easy in control operation, especially, easy and low-cost in produce. Moreover, the sensor with the same principle and structure is also applicable to a general gasoline engine. The experimental results with an actual in a portable unmanned helicopter (PUH) have sufficiently demonstrated the effectiveness and practicability of the sensor for the application of PUH control.View full abstractDownload PDF (427K) -
Masahiro TAKEKAWA, Tsuyoshi KIYAMA2007 Volume 43 Issue 8 Pages 705-707
Published: August 31, 2007
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSThis paper considers a decentralized anti-windup stabilizing control synthesis problem with a non-zero feedthrough matrix from output to input of saturation via the generalized sector approach.The sufficient solvability condition can be recast as a linear matrix inequality (LMI) one.View full abstractDownload PDF (416K) -
Yuichiro TAIRA, Shinichi SAGARA2007 Volume 43 Issue 8 Pages 708-710
Published: August 31, 2007
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSThe kinematics and dynamics for free-floating space robot manipulators have nonlinear parameterization properties that make it difficult to develop adaptive controllers.This paper deals with the kinematics problem.View full abstractDownload PDF (450K) -
Kenji FUJIMOTO, Satoshi SATOH2007 Volume 43 Issue 8 Pages 711-713
Published: August 31, 2007
Released on J-STAGE: February 25, 2013
JOURNAL FREE ACCESSIn this paper, a repetitive control scheme for a class of Hamiltonian control systems is proposed. The proposed method is based on the symmetric property of the variational systems of Hamiltonian systems. It does not require precise knowledge of the plant system. A repetitive control framework is proposed to solve an optimal control problem with a certain cost function generating a periodic optimal trajectory. In addition, numerical simulations of a 2- link robot manipulator demonstrate the effectiveness of the proposed method.View full abstractDownload PDF (4006K)
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