The paper proposes non-destructive inspection methods using ultrasonic and electromagnetic wave radar. That is, it presents first, for ultrasonic sensor, two types of detection methods of a multi-reflective wave model method and a stationary wave model method. And, next an electromagnetic wave radar inspection method based on a signal propagaion model. All these methods are based on the physical model of the object and thus they guarantee a high reliable and high accurate defect's detection and measurement. In this respect, it entirely differs from the conventional methods based on the human's five senses.

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Lamb waves are normally utilized for inspecting thin metal sheets. Recently, an electromagnetic acoustic transducer (EMAT) has been developed and is beginning to be used as a Lamb wave detector. The EMAT offers the advantage of inspection without using a couplant. The EMAT generates Lamb waves with fixed wavelengths determined by the interval between the meander lines in the sensor coil that constitutes the EMAT. We have studied an EMAT consisting of a meander line coil with intervals from 1mm to 4mm and having a paired structure symmetrically embraced with a thin steel sheet on opposite sides.

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In order to disseminate distributed energy systems, an autonomous abnormal diagnosis is imperative. The purpose of this study is to develop the abnormal diagnosis method using the fieldbus technology, which makes it possible to share much information of field devices. At the first stage, the authors constructed a experimental apparatus of a heat exchanging process and a measurement and control system with fieldbus devices. Through experiments of the process characteristics, the abnormal diagnosis method for the air retention to the shell of the heat exchanger, in which the overall heat transfer coefficient is always monitored as the representative process parameter, was developed and its effectiveness was confirmed.

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Significant pressure fluctuations were observed in suction water tunnels when an axial flow pump was operated without anactual head at some blade angles. To identify the causes, investigations were done by measuring acoustic natural frequencies andpressure fluctuations in the tunnels, lateral and torsional vibrations of the pump shaft, and pressure fluctuations of the oil in thehydraulic system to control the blade angle. Measurements were also taken by inserting air into the suction tunnels with acompressor and by setting air bags inside the tunnels. The results showed that acoustic resonance occurred in the tunnels, but itwas not a simple resonance. The dominant frequency, which was neither the blade passing frequency nor its higher harmonics,depended on rotating speed in the reverse way: it decreased when rotating speed increased, and vice versa. The pressurefluctuations and vibrations of the pump shaft had a strong relationship. However, they had different dominant frequencies andoccurred at different blade angles. Several measurements were made in different seasons and it was found that the phenomenawere season-dependent. The causes are discussed. It is believed that the excitation source was vortex shedding from the blades,which locked into the acoustic resonance in the water tunnels via vibration of the blades.

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The three dimensional characteristics of multi-surface liquid motion in a rectangular tank are investigated. The rectangular tank is divided into two parts by a baffle, which is vertical to the bottom of the tank and does not reach the bottom. The modified Helmholtz equation is derived from Laplace equation by separation of variables, and solved by boundary element method. A good agreement was found between the theoretical and experimental results. Effects caused by the position of the baffle, and the distance between the baffle and the bottom, upon the natural frequencies and corresponding mode shapes are discussed.

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This paper presents the model test results of coupled-mode self-excited vibration of Folsom dam Tainter-gate at its large openings. The Folsom gate was represented by a 1/31-scaled model, where the whole gate vibrates around the trunnion pin and the skinplate vibrates in the streamwise direction. Both the vibration modes couple well through hydrodynamic and inertial forces. This type of coupled-mode vibration is accompanied by the flow-rate variation under the gate, and under certain conditions a violent self-excited vibration is induced. In the present model tests, the Froude number was fixed at 6.67, the reduced gate opening height relative to the gate submergence depth was adjusted up to 11.9%, and the whole gate vibration frequency was varied. As a result, it was concluded that the gate dynamic instability decreases in its intensity, with increasing the gate opening, and the fluid excitation effect disappears at the reduced gate opening of about 14%.

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The vibration characteristics of dangerous kind of coupled-mode self-excited vibrations have been investigated in detail using a 1/31-scaled model of Folsom dam Tainter-gate, where it has been revealed that an intensive instability is induced under small gate openings, but never under large gate openings of 14% relative to the gate submergence depth. This paper presents major flow-rate variation characteristics obtained by a 1/27-scaled model of Folsom dam Tainter-gate at its large openings. The reduced gate openings were adjusted at 2 to 8% in its mean value, and the Froude number was from 3 to10. The discharge flow velocity induced by the periodic change of gate opening height was measured along the discharge opening, using an LDV, thus resulting in the resultant fluctuating flow-rate coefficient. As a result, it was concluded that as the gate opening increases, the reservoir flow field is getting released from its tight shutting up the discharge flow, thus resulting in larger fluctuating flow-rate coefficient, but in less dynamic gate instability.

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Recently, research and development of micro co-generation system is conducted actively. However, few studies were reported on the combined thermal efficiency based on the actual data measured all through the year. In this paper, firstly, we report actual data based combined thermal efficiency evaluation of micro gas turbine centered micro co-generation system especially focused on ambient temperature effect. During the measurement we found temperature fluctuation of heat transfer medium under the condition that the ambient temperature is less than 28 degree Celsius. Then, secondly, we report the analysis of this phenomenon by formulating the relation of heat balance taking account of nonlinearity of valve characteristics.

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The DEM (discrete element method) simulations for cohesive fine particles were carried out with the representative particle model. In order to simulate the process of surface improvement the liquid bridging force which depends on temperature was considered. From the calculations, hot fluid occupied the central region near the inlet of particles. On the other hand, cool fluid occupied the downstream region. Agglomerated particles took place in the central region near the inlet of particles and they were maintained in the downward region where the temperature was low. This was caused by the condition of cohesive force corresponding the solidification of liquid bridging.

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This paper deals with a theoretical analysis and experimental study of combination resonance of the flexible bellowssubjected to oscillating internal fluid pressure excitation. The governing equation of the bellows is expressed with theMathieu's type equation. The parametric instability boundaries of bellows are calculated by the first-order approximationanalysis using perturbation method. As a result, it is clarified that combination resonance occurs in the bellows due to theoscillating internal fluid pressure excitation. And the theoretical results of the parametric instability boundaries agree wellwith the experimental results.

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In this paper, the mechanism and dynamic stability of gas-lubricated bearing are considered. The pressure distribution which is generated in compressible fluid at the gap of bearing is calculated. The equation of motion is derived using the fluid force acting on a journal which is calculated from the pressure distribution. Based on the derived equation, the numerical simulation of the dynamic behavior of the journal is performed and the stability of the behavior of the journal is investigated. Finally parameter studies are shown.

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This paper describes the feature reducing drag of rotating cylinders in atmospheric air, by the way of wearing floating shrouds covered on the rotor in coaxial. We established the new theory enable to rotate cylinders higher velocity in atmospheric air up to supersonic velocity. We eliminated vacuum containers, vacuum pumps, super conducting magnetic bearings, and other demerits concern to THE VACUUM from flywheels. This new theory have disclosed by us at first in the world in 2002. We will give a full detail of the new theory and instruments for examinations, experimental data and several difficulties on the experiment and phenomena on aerodynamics have come across to the New Floating Shroud Technology.

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Recently, Pressure Sensitive Paint Technique (PSP) has been being developed to measure 2-dimensional pressure filed quantitatively. It has been applied to aerodynamics due to high spatial resolution and low cost. However, it cannot reduce the effect of temporal illumination light source variation and it is hardly applicable to moving test surface to be measured. Furthermore, pressure sensitive dyes generally depend strongly on temperature as well. It, therefore, has been quite difficult to apply it to thermal acoustic phenomenon, which is caused by the interaction between pressure and temperature. In the present study, 2-Color Laser Induced Fluorescence method is proposed, in which 2 dyes are used to simultaneously obtain two fluorescence-intensity images emitted at different wavelength. Hence, this can resolve some above-mentioned problems of PSP, i.e. the reduction of illumination noise and applications to moving body. Some promising dyes were investigated to apply to this technique. Consequently, PtTFPP and Pyrromethene 546 combination was found to enhance temperature sensitivity, resulting in one of the best temperature sensitive paint (TSP). In the combination of Ru(dpp) and Pyrromethene 546, its fluorescence intensity at green range becomes more blunt, so temperature-independent pressure sensitive paint can be instrumented.

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In the present research, the vibration intensity was measured by the three-channel method on air-conditioner compressor casings, and the vibration energy flow pattern was analyzed. Distributions of the vibration energy sources and sinks on the casing were identified using the time-averaged vibration intensity and the envelope vibration intensity. The vibration-energy flow pattern and energy source distribution were compared between compressors with and without noise-vibration reduction measures to discuss whether the measures were effective. The results showed that energy sources existed near the lower edge of the stator, and then the energy flowed into compressor lower part with low rigidity. The results showed also the magnitude of energy sources for the compressor with noise-vibration reduction measures were much smaller than that without the measures.

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In rotating machineries, resonance phenomena occur with large amplitude in the vicinity of the major critical speed. In this paper, a new vibration suppression method utilizing the discontinuous spring characteristics are proposed. This spring characteristics are made by additional springs with preload and additional dampers. This method has the following advantages: In designing these additional springs, we need not adjust their parameter values to the rotor stiffness and the system damper. The amplitude of vibration can be suppressed arbitrarily. This method is applicable not only to the stationary vibration but also to the nonstationary vibration. We clarified these phenomena theoretically and experimentally.

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This paper deals with a newly developed damper, called a keel damper, used to reduce bridge vibration caused by wind or vehicles passing over it. The keel damper consists of a combination of steel plates and damping resin, and is attached to the girder edge of the bridge. It can provide high damping performance for the bridge vibration in spite of the simple structure. In this paper, the basic structure of this damper is introduced. In addition, a scale model and numerical analysis results for a model bridge are also discussed.

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In this paper, the plastic deformation characteristics of axially compressed tubes that have steps on the inside, slits along tubes and flanges at both ends were investigated experimentally. The experimental results were compared with the calculated results obtained by FEM analysis, and the energy absorbing and dissipating characteristics of those tubes were discussed.

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The machines which cause an impact such as a press machine and forging machine carry down impact to the ground, so sometimes adjoining machine's accuracy is worsened, and vibration pollution is brought about. Though heretofore floating foundation has been used to isolate vibration, here we propose a momentum absorbing damper as a new vibration isolator. This damper is composed of an auxiliary mass, a spring and a dashpot. The auxiliary mass contacts with the platform of the press machine and it leaves from the machine by an impulse. By this motion of the auxiliary mass, the momentum of the machine is absorbed. In this paper, the effect of vibration isolation of this damper is examined through experiments and numerical simulation.

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Damping ratio which shows damping of the vibration system composed of loading mass added on spring and dashpot is the importance, when it is designed in vibration isolation. Half-power method is used in order to identify damping ratio using resonance curve of forced vibration. Half-power method is an approximation calculated from the approximate analysis result using natural angular frequency. And, it is known that the error increases, when damping ratio consists over 0.1. The development of various high damping vibration proofing material advances recently, and the derivation of exact equation which can be applied to the case with big damping ratio is desired. This study proposes method to derive of exact equation of damping ratio. Then, it was rewritten in resonance curve which described resonance curve using natural angular frequency in the peak angular frequency, and exact equation of half-power point was required from this resonance curve, and exact equation of damping ratio was calculated. In addition, the relation between error and exact equation of damping ratio estimated equation by half-power method is explained in detail.

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The purpose of this work is to identify the characteristics of a nonlinear vibration system subjected to a random input. In a general, a statistical technique of a higher order spectra(HOS) could be used for non-gaussian data analysis. Here, numerical simulation and experimetal model was executed for symmetrical and an asymmetrical nonlinear vibration system.

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A method for estimating each story damping coefficient of a building, along with each story stiffness, is proposed based on the probabilistic damage estimation framework, which evaluates not only estimates but also their reliability quantitatively. The effectiveness of the method is investigated through response simulation data of buildings with various damping distribution, compared to other damping estimation methods. The estimated values of damping coefficient by the proposed method correspond very well with the true values with small estimation errors, which shows the advantage of the proposed method over the others.

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Damping ratios of structures are generally scattering under the influence of various excitations. Wind excitation is one of those excitations. Wind excitation is involved in microtremor data for tower-like structures such as high rise stacks. It is necessary that damping ratios for high rise reinforced concrete stacks are calculated using data of removing wind excitation. The purpose of this study is to propose the method to remove wind excitation involved in microtremor data. And relationship between displacement amplitudes and first mode damping ratios is examined using data of removing wind excitation involved in microtremor data.

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The possibility for the force sensing by the change of the fingernail color was investigated. The fingernail color was classified into white an d red area. It was found that the fingernail color shows the high sensitivity to the applied force of 0N-5N. When the higher force was applied, the white area gradually increased and the change of density of a red color was observed. There are the sensitiv e change region of the binary analised data of white area at the force less than 5N. .

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This study was to investigate the relationship between the optimum diameter of hand rim and the ability of operation of wheelchair. The diameters of tested hand rims were 16, 22. 32 and 42mm. The optimum diameter of hand rim was 32mm. The ability tests were performed for 5m sprint on a level and a sloping floor, corner operation, meandering operation and tern operation, these tests were estimated the ability for muscle power, agility and dexterity. The operation of wheelchair improved at the optimum diameter compare with the pessimum diameter. The exerted force of the hand estimated from acceleration characteristics of the wheelchair was largest in operating the wheelchair with the optimum diameter. It was consider that the wheelchair with the optimum diameter surpassed in the ability of operation.

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Sensory evaluation of the optimum diameter was performed in grasping baseball bat grip, and the grasping pressure at finger and hand were measured during bat swing movement. The optimum diameter of bat grip was similarly to the diameter of the bat grip used in daily practice. During bat swing, the integrated pressure exerted in the finger and hand showed high value especially at the middle, ring and little fingers. At the ball impact, the fluctuation of the bat head of the optimum grip diameter was smaller than that of pessimum grip diameter. It was considered that the bat with optimum grip diameter is suitable for smooth bat swing.

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This paper presents the numerical model of multiaxle vehicles running on level ground. Considering possible factors related to turning motion such as vehicle configuration and tire slip velocities, we constructed equations of motion to predict steerability and driving efficiency of such vehicles. In order to reveal the turning characteristics of multiaxle vehicles, the effect of fundamental parameters such as vehicle speed, steering angles and type of driving system were examined on a sample of multiaxle vehicles. Additionally, field tests using full-scale vehicles were carried out to evaluate the basic turning characteristics on level ground.

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In large-sized plant construction work, apparatus is modularized at a factory and the method of construction carried into the transportation contemptuous glance-ground is enforced. If a module is enlarged, the deviation of load occurs at two or more supporting points under the inclination and the uneven influence of a run road surface, and a possibility of damaging an inside is during the conveyance work. This equipment has controlled change of the supporting point load generated at the time of module conveyance.

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Integration of traction/braking force distribution and active front steering is discussed. Based on an active front steering control to respond D^* command input by the driver, effects of traction/braking force distribution to generate direct yaw moment is investigated. A model following controller is designed to attenuate fluctuation of the sideslip angle. Two objective functions are defined to determine the traction/braking force distribution. The optimum distributions for these objective functions are derived in the form of simple algebraic expressions. Their effects on SBW vehicle driveablity and stabilities are tested through detailed numerical simulations using CarSim vehicle model.

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A design method of the high speed bogie suspension is proposed in this report. For improve the vertical oscillation of high speed Shinkansen vehicles, caused by the first order body bending, the primary and secondary suspension and damping should be optimized for avoiding the resonance between the bogie-bouncing, bogie-pitting and the body bending motion, in case that the bending stiffness of the car body could not be rised.

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This paper studies the effects of the time delay on the stability of a finite element method (FEM in short) model of a plate with a self-sensing actuator, in which the controlled voltage is delayed to apply to the piezoelectric actuator. It focuses on the problem how the delay affects the stability of the controlled system as the delay varies. The analysis reveals that even a very small delay can destabilize the smart board controlled by a self-sensing actuator, whereas a board delayed controlled by PD control is insensitive to the displacement gain of mechanical strain voltage. On the other hand, it shows that the feedback gains can be chosen so as to render the system delay-independent stable, namely asymptotically stable for all given delay.

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This paper deals with a motion control problem of a uniaxial ball-screw slide system driven by an AC servomotor. The objective is to control the motion specified by the trapezoidal velocity profile, using the multi segment sliding mode control method. The method that has been originally proposed by Shyu et.al is modified and used in the present study to simplify the control law and to alleviate the chattering phenomenon. The validity of the control law is examined by numerical simulation.

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As areal recording density and read/write frequency have been increasing rapidly, mechanical structure to clamp head gimbals assembly (HGA) at the top of a magnetic recording test stand is required for the multi-degree-of-freedom alignment to correspond to various HGA and for achieving higher head-positioning servo performance by increasing servo bandwidth by additional actuator. A new mechanical structure of additional actuator with PZT as displacement expander has been proposed. This paper discusses the integrated design of the mechanical structure and active controller for the proposed actuator. The robust performance is examined with the uncontrollable modes in relation to the structure perturbations.

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In the production factories and the construction site, as workers become older and the number of workers decrease, the demand for the automation of physical tasks is strong. Focusing on the automation of plant construction sites, one of the most laborious tasks is positioning pipes, valves, and accessories. Specifically, this work contains operations of lifting the object to be installed via multiple manual winches. To automate this task, a parallel wire mechanism, that must be using inverse kinematics or a Jacobian matrix, can be applied. However, these methods need information of position and posture of the actuators and the objects before using systems. In this study investigates the feasibility of a power-assisted lifting device that directly detects the applied human force using load sensors, without using inverse kinematics or a Jacobian matrix, and that operates the actuators according to the detected force.

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This paper presents a vibration control method for a wire with time-varying length such as an elevator cable and a crane wire. The characteristics of the wire is varying with time, hence, a nonstationary controller which is designed depending on the time variation of controlled object is effective. Furthermore, since a wire is flexible structure, a spillover due to uncertainties and ignored high order modes is caused. Therefore, we propose the controller considering the robustness for the uncertainties of controlled system and its usefulness is verified through a numerical calculation.

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This paper presents a synthesis method of nonstationary sliding mode controller with time-varying switching hyperplane for reducing the vibrations of wire changing its length. The proposed method deals with a change of system in time domain continuously. First, we construct the model of controlled system including a wire and two mass points at both ends by non-dimensional synthesis method. Then the controller with time-varying hyperplane is designed with the time-varying Riccati equation. Finally, the performance of this controller is verified through the simulation in the two cases that the length is getting long and short.

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Wire-Driven Parallel Mechanism (WDPM) is similar to a parallel link mechanism, except that it employs wires instead of links. The mechanism has the advantage of simple structure and light weight. This mechanism has been used only in small vibration environment until now, therefore vibration control of WDPM was not important research subject. However, in future we will use this mechanism on bad condition such as the monitoring system in a flow of a gas in electrostatic precipitator. In this paper, we propose the vibration control technique in the case of containing disturbance.

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This paper deals with transversal motion and vibration control for a flexible tower-like transportation system taking account of elevator to lift payloads vertically. Applying a lumped modeling method presented by Seto and LQI-based control system, two controllers which achieve good performance are designed. As well, this research investigates problems which may occur in actual transportation systems through control experiments. The purpose of this research is to control motion and vibration under moving flexible transportation systems. It is demonstrated that this transport system moves without vibration from one side to another at a high speed, and that the multimode-vibration of the flexible structure are controlled without spillover caused by neglected higher modes.

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We must try high gain of the control with mechatronics systems to realize high speed, high precision positioning. But, the ball screw drive mechanism used for mechatronics systems becomes unstable when its control gains become high to have some mechanical resonance frequencies. In this paper, it aims at designing a filter for resonance repression. The adjusting method to set up some resonance repression filters and the positioning reference filter are proposed, and shortening of the settling time for positioning is realized.

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For simple harmonic vibration systems, this paper proposes a new vibration damping method utilizing the velocity reduction by addition of Masses. In this method, the damping effect can be acquired by making the primary mass added an auxiliary mass at the equilibrium position Furthermore, we also apply the above proposed method to the vibration suppression problem of conveyance equipments, so-called stacker cranes, and propose a new lift-up method of platform for damping the vibration occurred in the body. This paper examines the effectiveness of the proposal through several experiments.

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This study aims at a system to measure pressures and temperatures of tires of a car and forces acting between the tires and the road surface, and to transfer the body the measured data by real-time wireless communication. The real-time measurement of the forces between the tires and the road surface will greatly improve performance and reliability of the vehicle dynamics control systems including antilock breaking systems, traction control systems, and vehicle stability control systems.

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This study aims at a system to measure 6 force components acting between a tire and the road surface by measuring strains in the wheel of the tire module. The measurement method was developed based upon the least square method. Static tests were carried out, showing effectiveness of the method. It is expected that the real-time measurement of the 6 force components will greatly improve performance and reliability of the vehicle dynamics control systems..

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This paper shows a control method which enables a suspension mechanism with an air actuator to have negative stiffness. An experimental apparatus is manufactured for experimental study, in which the table is suspended and drived by an air actuator. Applying the proposed control method to this apparatus , we have confirmed that the steady-state displacement of the table is in the direction opposite to load, that is, the system has negative stiffness.

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This report is concerned with an active vibration suppression by adaptive output feedback (Simple Adaptive Control : SAC) utilizing ASPRness of the plant. Several problems concerning the realization of ASPRness in the controlled plant and the use of an acceleration as an output feedback signal are considered. These problems are discussed by using a model of 4-DOF experimental structure. Results are examined through simulations and experiments.

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A simplified method to assess the seismic performance of structures with additional viscous or viscoelastic dampers is proposed. It is based on the momentary energy dissipated in structures with/without additional dampers and evaluates the reduction factor of maximum acceleration of earthquake ground motions. The changes in structural stiffness, damping factor and momentary induced seismic energy are considered to relate the proposed method to the maximum displacement response of damped structures. Extensive time history analyses on the single-degree-of-freedom system with additional viscous or viscoelastic dampers are performed and results have shown a good agreement with those predicted by the proposed method.

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This paper proposes a new vibration control method for multiple tall buildings connected with active controlled bridges. Although the method to control the vibration of multiple tall buildings with a different height and dynamic property has been already established, it is difficult to control these buildings with the same height and dynamic property, because a reaction force is not obtained by each building. To solve this problem, the new method to set the active controlled bridge by different height is introduced. The method is confirmed by simulation to be effective.

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This paper describes an application of an air-jet actuator for vibration control of a framed structure. The air-jet actuator that works for suppressing only the first vibration mode is used for the purpose of making the vibration control actuator small-sized and lightweight. A conventional active mass actuator is also used for suppressing the remaining higher order vibration modes. In this research, a five-story structure is treated as a controlled object. The reduced mathematical model consisting of the first to fifth vibration modes of the structure is constructed based on the FEM modal analysis. The control law is designed based on the sliding mode control theory, because the actuator has nonlinear dynamic characteristics.

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Comprehensive active microvibration control system will be required in base-isolated precision manufacturing facilities, in order to control both microvibrations generated by equipment and persons in the buildings and excited by external disturbances such as ambient ground vibrations and winds. A smart structure using piezoelectric actuators was tested for the overall active microvibration control in a base-isolated 2-story steel frame building model of a 5×3×4H m external size and a 6,900 kg total mass which was supported by 4 multistage rubber bearings. The tests showed that the smart structure could effectively control three-dimensional microvibrations generated in the building model.

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It has been a problem in some hospitals that operations using surgical microscopes of suspension type become more difficult due to microvibrations of the microscopes caused by human walks and building equipment such as air conditioning machines. For a practical solution to it, an active microvibration control system was developed, in which magnetostrictive actuators were used because of their large stiffness. A control law based on a model matching method was used to control of microvibrations of the microscopes having various dynamic characteristics corresponding to their attitudes. Tests showed that the microvibration control system using the control law was effective.

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Recently, the number of earthquake isolation structure has been increased. The most of earthquake isolation structure is applied the rubber bearings. However, light-weight structures such as wooden houses were not applied the isolation device, because it is difficult to apply the rubber bearings, for example, the diameter of the rubber bearing narrows according to extension of the natural period of the rubber bearing, and the device can not support superstructure. In this study, the purpose is development about isolation system for Light-Weight Houses. In this paper, result of numerical analysis in this system was reported.

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