It is well-known that by the steering control based on exact linearization technique, a car without side skidding in its wheels can achieve globally asymptotically stable trajectory tracking. But actually, real cars always experience side skidding, where their behavior depends on their velocity, roadbed, and property of wheels. In this research, we propose an improved steering controller which prevents skidding and realize the similar tracking performance with that of the car under nonholonomic constraint. We show the stability condition of the closed loop system, and verify the tracking performance through simulations.

View full abstract

[in Japanese]

View full abstract

This paper describes the operation system such as throttle, brake and steering wheel, which were implemented with by-wire technology and were equipped inside the cockpit. Computer was used to control those systems to operate via digital signal processing system and follow the desired command value for the Active Interface Vehicle. This paper proposes the method of the basic control for these by-wire Systems.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

This paper describes a steering control system that realizes zero off tracking for articulated buses. The control system consists of feedforward and feedback controllers. The steering angles as feedforward signal of the controller are calculated by inverse calculation of vehicle dynamics with road geometry and the vehicle characteristics. The controller was confirmed in the simulations and the experiments that the good performance of lane following is realized by means of the feedforward controller and the feedback controller we propose.

View full abstract

Optical disk drives need to be more robust in mobile use, or in high speed use. Various servo technologies are studied, but they need lager circuits and longer computational time. In this paper, high gain servo controller with complex zeros is proposed. It has the same structure with the conventional contrtollers. The robustness of system with this controller will be shown with experimental data.

View full abstract

[in Japanese]

View full abstract

Multirate controllers are widely used for Hard Disk Drives. However, the conventional formulation based on the multirate lifting technique can not express the characteristics over the Nyquist frequency. We propose a new approach for multirate notch filter design considering the margins explicitly by introdusing a virtual sampling point which enables frequency analysis over the Nyquist frequency.

View full abstract

In order to increase the servo-bandwidth in hard disk drives, we developed a simultaneous designing for a controller and a structure of the head positioning system. We showed that the servo- bandwidth limiters are not only peak frequencies of mechanical resonances but also their residues. Moreover, the mechanical system that can achieve high servo bandwidth with low residue of the first resonant mode was developed.

View full abstract

[in Japanese]

View full abstract

A structural health monitoring (SHM) system for the purpose of maintenance cost reduction or performance guarantee of the civil and the building structures were studied. To make the smart structure, development of an active sensing diagnostic technique is needed to predict the location of structure damage during maintenance with a limited number of PZT elements. As PZT elements are inexpensive, small in size, and function as a sensor and actuator, it is possible to integrate them with a structural component without reducing structural performance and also it is suitable for realizing active damage detection on-line.

View full abstract

[in Japanese]

View full abstract

Optical fiber sensing technology for structural health monitoring system is described. FBG-based displacement sensor module was developed and installed for steel framed 12F building with several panel-shape passive dampers for absorbing earthquake input energy.Additionally, metal coated FBG sensor is proposed. Sensor has even performance on optical characteristics of UV-resin coated FBG sensor, and mechanical performances are excellent.

View full abstract

An application of a smart, network-enabled, wireless sensorbased on the Berkeley Mote platform to the next generation ofstructural health monitoring and control was proposed. In thispaper, the performance of the MICA2 Mote as a wireless sensingtool for risk monitoring in buildings is tested.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

We propose a rotor balancing control which can distinguish betweenthe displacement caused by imbalances and the displacement causedby outer vibration.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

When we do a presentation, we often use a method that project a picture of PC to a screen and presenter uses a device to point out like a laser pointer. In this case, there are several problems. For example, unstable light dot. In this paper proposes the system that improve these problems to be flexible to use and also describes its applications.

View full abstract

In this research, we analyzed the user structure by using the questionnaire data in the complex industry composed by two industries such as careers and makers, that is, the cellular phone industry. Moreover, it has aimed to do the user segmentation by using these analysis data, and to propose a method of the corporate-strategy planning. We enabled high-speed processing by making the questionnaire data a bit pattern. In this paper, the analysis result by Majority Algorithm is reported. In the near future, the system that we developed will have the possibility to be able to operate as One-to-One marketing system that operates on the Internet. We can plan the business maneuver by this in real time.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

In this paper, we propose a new grouping method of machines in a factory by using the concept of Grouping Genetic Algorithm(GGA) which is a Genetic Algorithm(GA) modified to suit the structure of grouping problems. The purpose of our research is to step up working efficiency by dividing machines in a factory into any number of groups so as to minimize the number of parts moving between the groups. Simulation results show the efficiency of the proposed method.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

k-certainty exploration method is a very efficient method to construct Markov Decision Process models of unknown environments. However, it is impossible to apply this method to environments which include continuous state space. This paper describes a new exploration method using k-certainty exploration method and Fuzzy-ART to represent these environments as Semi-Markov Decision Process models.

View full abstract

[in Japanese]

View full abstract

Many of traditional works for battery support of mobile robots adopt such way that has to quit their own tasks for the time of battery charge and come back to their battery station. This is one of inefficient factors, in continuously implementing some given tasks. As one way to remedy this problem, we have proposed a battery reloading system that is able to promote the effects of a robot without interrupting the works, by sending an exclusive robot for the battery reloading to a working site. To realize the system, this paper describes a mechanism for the remainder checking of the equipped battery on a robot and for activating other robot to support the robot.

View full abstract

This paper introduces a position sensor-less control technique making use of mechanical springs. It proves that the presented method fits for practical use on real electro-mechanical systems.Additionally, It is examined what occurs when the system collides with an object.

View full abstract

Recently, much attention has been paid to the study of estimating the direction of sound sources. This paper proposes a servo system which always tracks the direction of a sound source.

View full abstract

Exact recognition of outside is indispensable for autonomous walking of legged locomotion robot to in the real environments. Our aim is stable walking of the robot that has the stereo vision system and regards the real environments as 3D frames with it. A hierarchical navigation is adopted in the trajectory plan. It is composed of the following four parts which are measure of surrounding environment, map making, trajectory plan and moving by repeating this execution.

View full abstract

This study aims at establishing an advanced visual feedback control method by extending the Cubic Neural Network (CNN) intelligent method. In this study, a qualitative controller was designed in consideration of the system characteristics, especially observational noise by using the genetic algorithm. This study deals with a problem of stabilizing a two-dimensional inverted pendulum by feedback control using stereo camera. To verify the noise tolerance of the proposed method, the computational simulations and the experiments using a real apparatus were carried out. It was confirmed that the designed CNN controller has noise tolerance.

View full abstract

The shaking table is need of lightweight for reproducing the variety of input signal exactly. However, the natural frequencies of vibration modes of the table appear on operating frequency region. Such vibration modes get into problem that may cause spillover instability. So, the research purpose is to control such vibration and motion of the shaking table by using the reduced order modeling technique. And Two degree-of-freedom control system is introduced.

View full abstract

Considering the recent earthquake disasters, Japanese government is now constructing a three- dimensional large-scale shaking table.In order to develop a control method for the shaking table operation,we have been paying attention to the Minimal Control Synthesis (MCS) procedure for applying to the shaking table.This paper reports the simulation studies of enhancing control procedure for the medium-scale shaking table with the bi-linear specimen.Control simulations were carried out for acceleration type demand signals by means of the designed controller with the MCS procedure.Performance improvement by the Three Variable Control with the MCS procedure is discussed.

View full abstract

The largest 3-dimensional vibration test facility is now being constructed. So far, we had constructed the numerical simulator in order to make sure the performance of the facility. It is important for anyone to easily calculate the response of a model beforehand after the test facility is officially operated. Therefore, we have constructed the graphical user interface intended for the numerical simulator since 2002. This paper describes the outline concept of the graphical user interface of the numerical simulator for the 3-dimensional vibration test facility.

View full abstract

The three-dimensional full-scale earthquake testing facility (E-Defense) is now under construction in Miki city. This facility has 24 actuators and those actuators can supply enough power to the shaking table. The control system of E-Defense is designed by Three Variable Control (TVC) Technique. This study shows control simulation results of the shaking table - test model coupled system with TVC.

View full abstract

[in Japanese]

View full abstract

Servo type velocity sensor has been used to observe an earthquake because this sensor is high sensitivity. This paper proposes to implement the velocity sensor to the vibration control of isolated table, because this sensor can detect the velocity and acceleration signals at the same time. The frequency response of velocity sensor can be improved by using notch or inverse notch filter. As a result, this velocity sensor can improve the frequency response of isolated table.

View full abstract

In this paper, for 2-DOF anti-vibration unit with both piezo actuator and VCM, the complete isolated condition, which is based on the full-state feedback control using velocity sensor, is derived. A simulation result of isolated characteristics considering the dynamics of actuators and velocity sensors is described. The complete isolated condition can be realized, because the piezo actuator and the VCM show the realistic response.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

A new active six-axis vibration isolation system (VIS) is proposed which uses zero-power magnetic suspension and a parallel mechanism. The parallel mechanism consists of direct acting links, a table and a base. An active single-axis VIS unit that works as a direct acting link is equipped with a zero-power magnetic suspension system. Several experiments are carried out with the developed single-axis VIS unit.

View full abstract

Microvibration control technology has been rapidly becoming more important in a number of fields including superfine technology in semiconductor manufacturing and bio-technology in gene analysis. In the previous study, we proposed the system which carries out vibration control of concrete foundation using the piezoelectric actuator to improve isolation performance at a low cost. The vibration control experiments of proposed control system were carried out with generally better results in isolation performance. However, for practical us, the new approaches are required, because there is unknown dynamics which exist in the concrete foundation. In this study, in order to solve this problem, an adaptive digital filter is applied to the control system. The effectiveness of the proposed control system is verified through vibration isolation experiment.

View full abstract

[in Japanese]

View full abstract

This report introduces the outline of a PBL class "Experiments I" carried out in Okayama Prefectural University. The communication using light was tried with mirror, lamp, etc. In the class, students learn what is needed when sending a message to a distant place, through an experience of creating a kind of communication protocol. In this report, the schedule of the experiment including a communication contest and a presentation is briefly described.

View full abstract

"Mechanical Design and Drafting" is positioned as a comprehensive exercise which organically combines "Machine Element Design", "Drafting", "Working Technology" and so on. However, each student is not fairly evaluated on originality and creativity. Moreover, they are mainly evaluated qualitatively, and the rate of quantitive evaluation becomes quite small. In this paper, a new quantitive evaluation scheme is considered using a genetic algorithm(GA) which is one of the evolutional computation. That is, the optimal form is generated using the GA, and the difference between the optimal form and the form designed by the student is evaluated quantitively.

View full abstract

[in Japanese]

View full abstract