Voltage control using variable capacitor was applied to multiple electrostatic suspension The multiple suspension indicates the simultaneous control of several electrostatic suspension systems with a single power amplifier In this work the power amplifier is replaced by the voltage control system using a variable capacitor, which is connected in series to the controlled objects and a constant power supply The characteristics of the proposed system were studied analytically Double parallel electrostatic suspension was achieved.

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Variable flux-path magnetic suspension using flux concentration is studied analytically It was shown that flux-concentration type can produce larger suspension force than the conventional variable flux-path system using ferromagnetic control plate. However, it was difficult to achieve stable suspension, since the control (variable) force was not so large, To solve such a problem, the characteristics of the suspension system are studied by finite element analysis. In particular, the effects of the direction of motion, the operating positions and the shape of the control plates were investigated.

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Super elastic alloy has the characteristic of good reversible flexibility and active deformation caused by transformation between austenite and martensite. The alloy has also hysteresis characteristic changed by prestress. Then, the alloy can use as actuator because of the change. In this paper, the active deformation of the alloy wire on the prestressed conditions is experimentally proofed by Joule heating. So a system with 1 DOF using the alloy wire is designed and constructed with measurement system. In conclusion, the alloy can perform very well as actuator under optimum condition. Final goal of this study is that the actuator will be used in domestic robot.

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A new open-loop driving method of piezoelectric actuator is proposed which is characterized by using variable capacitor. The actuator and the variable capacitor is connected m series and a constant voltage is applied to this connection. The charge of the actuator is controlled by adjusting the value of the variable capacitor. In the experiment, the variable capacitor is realized by switching the connections of several prepared capacitors. The Experimental results demonstrate that hysteresis is rather small in the proposed driving system.

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Extra low consumed power suspension in gravitational field is achieved in a power-saving solar photovoltaics magnetic suspension system with a zero-power controller. The zero-power magnetic suspension system needed power becomes statically zero. A fabricated conventional system used 290[mW] total consumed power for the static suspension of 90[g] floator mass. The photovoltaic cells used in the apparatus had a maximum power capacity of about 2[W] in summer sunlight. Therefore, this system can supply the power necessary for static suspension in sunlight. However, most of the power were used in peripheral devices including the displacement sensor. A dedicated power-saving peripheral devices are newly fabricated for this system. The power is reduced from 290[mW] to 50[mW]. The new system achieves stable suspension even under the illuminance of the fluorescent lamp.

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Blood sampling is frequently performed in clinical inspections and blood donations. There are 2 ways to improve the skill of needle puncture: clinical experience and simulation training by using a human phantom. However trainee cannot practice positively in clinical site due to the subjects' burden. In addition, simulation training would not give difference of reaction force of venipuncturing between the subjects. In this study, a haptic device for novel venipuncture simulation training was prototyped. The device of human interface would reproduce various reaction forces of puncturing by using haptic technology. In addition, reaction force of puncturing against a biological tissue phantom has been measured with the device and represented as a restricted numerical model. As the results, the characteristic reaction force of puncturing was reproduced with the restricted numerical model. For the next step, viscoelastic characteristics of the tissue should be integrated to the numerical model to achieve further realistic reaction of needle puncture.

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A localization method based on klinotaxis is proposed to contribute to improve the environment of lakes using the underwater robot that imitates fish. By using the method, the source can be found from the change of stimulation during wave propulsion in a dispersion field. An experiment is performed using a mechanism of sniffing to explore the relationship between sensor response and strength of a diffusion field. In the result of the experience, the sensor response become obvious using the mechanism, and a transient response is also observed clearly. But it is hard to know the distribution of the stimulation if there is the transient response m atmosphere. So, it is problem to improve the transient response in diffusion field for the use of the swing sensing of the propulsion. Then, it is shown that the localization of the source is possible by using the analysis of characteristic response with the swing sensing m the field.

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This paper describes design of a semi-rotary actuator of three-quarter-turn type for water hydraulic robotic arm that will be mounted on the deep submergence research vehicle. This actuator is vane-type, by which oscillating motion can be obtained directly. Also, the actuator is triplicate single vane-type, by which the unbalanced force is not applied to the bearings. Rotation angle of the actuator is 270 degrees. Metal components of the actuator is made of stainless steel. The bearings used are made of plastic. To reduce internal leakage and eliminate metal contact, plastic (UHMW-PE) plates are inserted between the sliding parts as seal material. To design the structure and dimension of the actuator, strength of the parts are analyzed by finite element method.

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This paper describes a cam-drive type proportional valve for water hydraulics and its dynamic characteristics. In the developed valve, the spool is driven by positive cam mechanism, m which a heart-like cam is placed between two cam-followers and the cam is driven by stepping motor. As for measurement of dynamic characteristics, the step and frequency response are measured using the constructed controller with micro computer. In addition, dynamic characteristics using an AC servo motor is also measured for improvement of dynamic characteristics of the developed valve. The 5% settling time of step response was 25 ms with the servo motor. Bandwidth of frequency response using the servo motor was about 30 Hz. Thus the response of the developed valve is better than conventional proportional valves is better than conventional proportional valves.

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A rideable autonomous mobile robot is currently under development in our laboratory. Especially in this research, the rideable autonomous robot is aimed at functioning m various human-robot-environment interactions. The safety for human is of major importance to develop the robot. Hence the robot has a structure based on safety measures and will be embedded with flexible control modes. This paper presents the development concept, the control system the mechanical design process,a prototype robot and the preliminary experiment using the prototype.

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This paper validates a biped robot gait with tiptoe mechanism. Five tiptoe mechanisms were proposed. The robot gait was optimized using the simulated annealing. The robot with tiptoe could walk longer than the robot with no tiptoe. Moreover, center-of-gravity movement of the robot with tiptoe also became smooth. However, model 3 and model 4 could not walk straight. This problem was improved by adding a thumb to mechanism. The number of joints and thumbs are important to walk stable.

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Recently, human and robots share working space. So it is important avoiding collision risk. This report proposes impact force reduction method using humanoid robot arm. We supposed to short impact time and to decrease impact velocity could reduce impact force. To achieve this approach we use "Reduction method based on the acceleration of a collision part". This method is developed type of the method using coupling inertia force. This method selects the motion that makes perpendicular ingredient of collision point acceleration maximum. Also, this method can make offline distribution too. So, computation time of reduction motion can be shorted. Several simulations and experiments using redundant manipulators are performed the effectiveness of this method.

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The measurement of ground reaction forces (GRF) is important in gait analysis. The GRF are normally measured by using some force plates. However, force plates have several problems. First, they are embedded in the floor of the gait laboratory, so that the measurement is limited to the laboratory. Second, subjects have to walk exactly over the force plates. For these reasons, several force sensors which can be attached to a shoe sole have been developed by using some strain gages. However, the strain parts prevent us from developing a thin and compact force sensor. We have developed a wearable sensor device to measure GRF In this paper, first, we present a new structure of the sensor device which makes the device lighter Second, we develop the new device. Finally, we experimentally examine the usefulness of the new device.

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This paper presents an ambulation training robot equipped with mechanical safety devices and torque limiters. The mechanical safety device and the torque limiter consist of only mechanical components without actuators, controllers and batteries. The mechanical safety device locks the robot's wheel after detecting the overdrive on the basis of the wheel's angular velocity. The torque limiter shuts off the robot's motors. First, the ambulation training robot equipped with the mechanical safety devices and the torque limiters is explained. Second, the safety device is explained. Finally, the usefulness of the developed ambulation training robot is experimentally examined.

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Surface models with many rigid plates are investigated by using the canonical Monte Carlo simulation technique. The small rigid plates are included on the triangulated surfaces and are considered to be an analogue of heterogeneous components in membranes. The assumed sizes of rigid plates are negligible compared to the surface size in the thermodynamic limit Three types of density for the total number of rigid plates are assumed. By fixing rigid plates on both ends of the surface, we find that it is possible to calculate the string tension σ and the dependence of a on the distance L between two fixed rigid plates.

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In epidural anesthesia, dural puncture is a serious medical accident. Then, we are studying the needle and the puncture method for preventing this medical accident. As a fundamental examination of failure analysis when sticking a biomechanical material with a needle, failure analysis at the time of applying load to the filmy natural rubber by the sharp bar was carried out with the finite element method. The influence on the failure by the difference m the tip form of a stick and the prediction by the nonlinear finite element analysis was possible m a certain domain was confirmed.

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The electronic properties of SiC nanoribbons are investigated by the first principles calculation. Their atomic structure is assumed to be the same as the structure of graphene nanoribbons, viz., the honeycomb structure. The influences of the width and edge state of the nanoribbons on their density of states and band structures are examined. The result suggests the bandgap of a SiC nanoribbon depends on the geometry of its stable structure rather than whether it is hydrogen-terminated or not.

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This report shows fatigue evaluation of the circular notched plate under the interlaminar shear loading at elevated temperature. Test specimen made of SUS304 were prepared to added double notch to circular notched plate. FEM analysis of a specimen made to distribution of stress under the interlaminar shear loading. Fatigue tests were conducted, and compared with results of analysis. The results, stress distribution of the circular notched plate under the interlaminar shear loading shows unique compared to the plate under the interlaminar shear loading, or the circular notched plate under the tensile loading. And also consistent with experimental results.

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In current time, fracture toughness of biomass based plastics that consist of poly (latic acid), PLA and kenaf short fibers, which absorbs its CO_2 efficiently is evaluated. Adding this fiber to PLA greatly increase its fracture toughness. Compared with the precedence research, we got the result a little better than precedence research. From these results, increase of the mechanical property by kenaf content is certainly observed, and application for a structural material use is shown to be possible.

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In this study, composites of poly(lactic acid), PLA, reinforced with kenaf fibers were molded through twin-screw kneading process followed by hot-pressing. Micro-bond / monofilament tests and static tensile test were conducted to the present composites. By comparing the present test results with rule-of-mixture estimations, the overall trends for mechanical properties of the present biomass-based composite were found to be explained by the rule of mixture. However further modifications to the theory may be beneficial.

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CFRP pressure vessels are used as a hydrogen storage system of fuel cell vehicles (FCVs). The FCVs are expected to increase a driving distance of at least 500 km as same as conventional gasoline-fueled vehicles. Therefore, the storage pressure of hydrogen must be raised from 35MPa to 70MPa. However, CFRP is expensive material, although these have good mechanical properties. In this study, in order to decrease the use of CFRP, pressure vessels reinforced with CFRP grids were examined. We selected five variables as the design parameters and executed optimum designs by using response surface method and genetic algorithm under the constraint condition the same burst pressure as the original pressure vessel.

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Recently, carbon fiber reinforced plastic (CFRP) material has been used in structural element of transport vehicles. Besides, adhesive bonding is known as better method for joining the CFRP structures The purpose of our work was to examine the characteristics of strength for CFRP composite structures. We modeled single-lap adhesive joints composed of quasi-isotropic CFRP laminates having various lay-up pattern subjected to static tensile load to carry out finite element method analysis, and compared the analysis results of stress distribution at adhesive layer. In addition, failure load of various adhesive joint specimens were measured. As a result, it was found that the stress distributions on adhesive layer and failure load for joints were affected by each lay-up patterns of CFRP adherends.

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This paper proposes a novel lightweight robot arm for astronautical development by using honeycomb structure. A robot arm is an arm of the machine which works holding, releasing, carrying, etc. It is used not only on the ground, but is used in space. In the space aeronautics field, all the launched objects should possess lightweight and compact to save launch cost. For this purpose various lightweight materials have been developed. Honeycomb structure is one of such lightweight material and already used in astronoutical field mainly for large panels. In this study, we propose to appliy honeycomb structure to realize lightweight and compact arm.

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The objective of this study was to develop new forming methods making use of undesirable phenomena caused by bending for aluminum alloy extruded sections. In this report, we examined the deformation properties in press bending of channel by a finite element method and an experiment. The deformations of the cross section in channel were grouped into inner falling and outer falling. Then, it was clarified that the thickness of the channel, the bend degree, and the distance between dies influence the cross-sectional deformation.

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This paper was reported relationship between deformation of press forming die with asymmetric rib and formability. At the press forming, die and mould are deformed by forming load. This elastic deformation makes forming defects. It may be effective to increase ribs on a die and mould, although those thickness and layout are restricted by temperature stress at casting. To research the effect of asymmetric rib, we simulated a structural analyses and using the small press model for forming experiment. As the result of these, deformation of design surface is very small, and same trend were exited at analyses and forming experiment.

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Floating-Expanding-Plug-Bending of pipe is characterized by expanding and shifting of floating plug, both of which are helpfully functioning to the bending, reducing working force and realizing severe bending with high-precision cross section profile. By using this method, a circular pipe is deformed to triangle section with triangle-shape plug In order to obtain the basic characteristics of bending to polygonal section pipe, geometric shapes of triangle plug which produce triangle section were investigated. In the experiments, it was realized that the plug should not have sharp edge and circular aspect to form triangle bent pipes. Both bending and expanding completed at the same time on the bending method. In this research, deformation behavior of metal materials in Floating-Expanding-Plug Bending was also analyzed with FEM analysis and experiment.

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In recent years, minute bellows tube is expected to be utilized in the electronics and medical sectors. As a general forming method to bellows include spinning and hydraulic-forming. However, huge pressure is necessary, to forming bellows for thin-walled minute tube by hydraulic-forming. On the other hand, spinning using a side roll is advantageous for forming minute bellows, because the forming force is low and the forming limitation is high. The purpose of this research is to establish the forming method of the micro-bellows by spinning with side roll. At first, the influence of bellows shape exerted on the characteristic was analyzed in FEM. Then, the experiments were carried out, in order to realize the optimum forming conditions such as roll displacement, side pressure and pitch of bead. As a result of experiment, the product under the optimum condition was manufactured.

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The purpose of this study is to develop the new multipurpose roll forming system named Flexible Roll Bending System. In particular, to product taper spiral pipe is ultimate target. This system which consists of feeding rolls and forming rolls can bend and twist the thin metal plate according to the forming roll moment in vertical direction and inclining. The relative height of the forming roll to the feeding roll level affects the feeding roll direction curvature, and the angle of forming rolls affects the torsion ratio of the spiral. By adding a unit of in-plane bending between feeding roll and forming roll, arc-shaped strip was could be bent to taper spiral tube.

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Shock wave caused by automobile exhaust system, etc are mainly factors of vibration and noise. Since the magnitudes of vibration and noise are dependent on strength of the shock wave, it is important to measure accurately strength of the shock wave. In this research, installing experimental apparatus with share force sensors (i. e. strain gages), the shear forces after passing though the shock wave are measured. Experimental results show that the behavior of flow can be successfully estimated by analyzing the measured shear forces.

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The characteristics of wind power generation by the flexible sheet flutter were investigated. In the present experiment, the effects of sheet length and wind velocity are examined. The sheet displacement, the angular frequency and the generated power were measured temporally to investigate the characteristics of power generation In addition, the high-speed camera was used to obtain the sheet behavior, especially modes and mode change. Power generation efficiency was roughly as a ratio of the measured electric power to the rotational kinetic energy calculated based on the moment of inertia, the rotational angular amplitude and the angular frequency. The results show that the rotational angular amplitude has the largest effect on the generated power.

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The SCRAM jet engine is characterized by supersonic combustion. In supersonic combustion, one of the most important issues is supersonic mixing. The main purpose of the present study is to find mixing enhancement methods in supersonic mixing. One method utilizing the flexible sheet flutter for supersonic mixing enhancement is proposed and investigated. As a flexible sheet, rubber thin sheets were examined with several elasticity moduli and flow direction lengths. Water was injected just upstream of a flexible sheet to in the supersonic flow. The flow and mixing fields were visualized by schlieren method and a high-speed camera. The frequency and modes of flutter and the mixing were calculated based on captured images. The results show that the flutter frequency decreases as sheet length increases. The flutter frequency decreases slightly with water injection compared to that without the injection. An increase of sheet length enlarges the diffusion region of water.

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Direct numerical simulation (DNS) of compressible turbulent channel flow with uniform blowing (UB) or uniform suction (US) is performed aiming at skin friction drag reduction. The Mach numbers, based on the bulk velocity and sound speed at the walls, of 1.5 and 3 are considered. The Reynolds numbers, based on the bulk velocity and channel half-width, is 3000. The DNS results show that skin friction drag is reduced on the blowing side, while increased on the suction side. The local skin friction coefficient c_f using the complessible flow version of the FIK identity reveals that the main contributors to drag modification are the Reynolds shear stress and mean wall-normal convection, similarly to the case of incompressible flow.

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In order to achieve increase of power outputs of an ABWR, it is extremely important to evaluate coolant flow in a lower plenum. Numerical simulation is helpful to predict the coolant flow. However the simulation results considerably depends on models, thus verification experiment is needed. Hence, the objective of the present study is the construction of the benchmark of CFD code for clarification the flow structure of a lower plenum. We constructed a 1/10 model of a lower plenum to conduct flow experiment for validation of CFD analysis. In the experiment, it turned out that coolant flow distribution becomes to be uniform at core support beam, and there are complicated flows around side entry orifices. These flow structures are also described by CFD analysis. As good performance of analysis, we investigated flow distribution to the core particularly by using CFD results, and mechanisms of these flows were discussed.

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The pressure loss characteristics of a dispersion liquid flow containing the organic nanotube in the circular pipe are investigated experimentally. The volumetric flow rate and the pressure difference are measured. The dispersion concentrations of 1000 to 6000ppm are examined Up to the concentration of 3000ppm, the drag reduction increases with an increase of concentrations. At the concentration of more than 3000ppm, however, the drag reduction becomes almost constant, in spite of an increase of the concentration, i.e. saturated. As the Reynolds number increases, the drag reduction decreases. In addition, the electron microscope observation shows that the network structure of the organic nanotube in the dispersion liquid hardly alters after 42 days.

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The pressure loss characteristics were investigated for the water flow with the water and the air cavities in the rectangular duct. The pressure loss coefficients obtained by the experiments were compared with the total loss based on the typical minor losses. The semi-empirical losses of the friction, the sudden expansion, the sudden contraction and the hydraulic jump are considered as the typical minor losses. The semi-empirical total losses show differences of 24-27% from the experimental ones. For the case with the air cavity, the hydraulic jump loss increases as the Reynolds number increases. At relatively low Re, the loss coefficients with the air cavity become lower than those with the water cavity. On the other hand, at relatively high Re,the ones with the air cavity are almost same as those with the water cavity.

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A SDBD plasma actuator with pulse modulation has been proposed to increase the efficiency of the performance. A flow induced in still air by the SDBD plasma actuator with pulse modulation synchronizes with modulation frequency and forms vortexes. We need to measure two dimensional velocity and vorticity, so we measured them by PIV. We compared measurement results by PIV and a hot-wire anemometer to evaluate validity of the PIV measurement. As a result, the PIV measurements are roughly valid.

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An experimental study is performed for a channel flow with the dielectric barrier discharge plasma actuator (DBD-PA). The plasma actuator is an electric device designed for flow control using electrohydrodynamic effect. A very thin jet flow can be induced by the plasma actuator, and it has no moving parts, simple structure and high frequency response. The actuator is installed in the bottom of a channel passage. The wall static pressure is measured in the upper wall of the channel. The Reynolds number based on hydraulic diameter is varied from 600 to 7000. The velocity profiles are measured by a PIV system at the Reynolds number of 2000. The result shows that the pressure loss decreases by the effect of induced flow with the plasma actuator. The effect is remarkable in the laminar flow region.

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In the present study, active control of the diffusion of a circular jet is attempted by the application of a secondary film flow around the jet. The secondary film flow is a thin annular flow around the circumference of the circular jet. In this report, it was described two sentences. First, it was visualized the circular buoyant jet (Carbon dioxide and helium) with acoustically driven secondly film flow, and extracted advection velocity from time series images. Secondary, it was examined the relationship between preferred frequency and density ratio and difference in density which is ratio of the density of a jet fluid and ambient fluid.

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In this study, we measure drag torque on a flow between rotating disks in order to clarify a flow around a hydraulic clutch. We simulate a shape of the hydraulic clutch by a rotating disk on which a clutch is stuck and a fixed disk. The drag torque become larger in the case that the slit width of the clutch becomes larger. This is because that the radial flow velocity between the disks becomes smaller. In the case that the geometry of slit of clutch varied, such as with 45 degrees slope, the drag torque become larger because of reduction of the radial flow velocity in the slit of clutch.

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In recent years, energy saving of fluid machinery, such as a centrifugal compressor, is desired, and the improvements of efficiency for each part are demanded. In a vaneless diffuser of a centrifugal fan and compressor, however, a rotating stall may occur and result in an unstable operation. Accordingly, various degradations may appear, e. g. a pressure performance drop, noise/vibration occurrences and damage of machines. The rotating stall is one of rotational flow instability, i.e. is induced by a rotating fluid. Therefore, in this research, the flow around the rotation circular cylinder between two stationary circular disks was investigated by experiments, which is a model of a centrifugal vaneless diffuser without discharge from and suction in an impeller. The experimental FFT results show several peaks with small frequencies, which indicates the flow instabilities can occur with neither discharge nor suction.

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The aim of the present study is to clarify the flow characteristics of the narrow gap between the inner rotating cylinder and the stationary coaxial cylinder which simulates the geometry of the rotor and the stator of an electric vehicle motor. In the present study, the flow of the rotor cylinder surface and the stator edge face are visualized with Kalliroscope flakes. The trajectory of particles at the end of the rotor is visualized. As a result, it is suggested that the flow of the stator edge face influenced the flow on the rotor cylinder surface with Re applied the experimental parameter increasing. Particles passed through the boundary of the gap and the region of the rotor end part which is the space between rotor edge face and stator edge face is observed at Re = 140-1784.

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Due to that high current density on the component compared with other industrial motor is applied, one must take care on heat transfer system to design motor of an Electric Vehicle (EV). Excessively heat generation may cause irreversible fail effect such as demagnetization and burnout of mounted coils. We attempted to simulate flow inside model of an EV motor according to the way that field of the flow can be separated into narrow "gap" and "rotor end part" focusing to pressure on boundary of the system. Pressure field of flow shows that possibility to control heat transfer between both regions because of sensitively with boundary wall on which vortex seemed like Taylor-Couette flow is generated.

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In the photoresist stripping process of semiconductor manufacturing, a method with the ozone water and a disk-shaped nozzle is proposed in authors' previous studies. Moreover, it is suggested that the three-dimensional flow structure of the ozone water between a rotating silicon wafer and the disk-shaped nozzle affects the photoresist stripping rate. The purpose of the present study is to reveal this flow structure. In order to reveal this flow structure, the visualization experiment is conducted with dye and with stereoscopic micro PTV method. As a result, the injected dye forms a high concentrated area near the disk end Furthermore, it is cleared that the injected dye stays between two disks for more than 14 seconds. Besides, it is cleared that the circulation in r-z cross section is formed near the disk end.

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This paper describes wave control of cantilevered beam by controlling the bending moment near free end boundary. The basic fact the equation of motion of beam is the balance of distributed force per unit length and the second derivative of bending moment is equivalent to the distributed force is used. The equation of motion is approximated by finite difference (FD) method. The equations of boundary node are compensated to be same as that of interior nodes in terms of bending moment where virtually existing bending moments are realized as no boundary exists. The wave traveling characteristics between the adjacent FD bending moment is same as that of the adjacent FD displacement when the bending moment is expressed by three adjacent FD displacements. The control bending moments are calculated by the convolution integral of the sensing moment. The numerical bending moment simulates piezoelectric elements. We have conducted numerical simulation of control and found that our method has vibration suppression effect.

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This method to reduce low frequency noise of an interior space in an enclosed space excited by multiple force inputs was suggested based on the mass addition. Because, it is difficult to suppress all of vibration paths by a treatment at single union point therefore the identification of contribution of each path is important in Transfer Path Analysis(TPA). In this paper, the resonance sensitivities and anti-resonance sensitivities at the union point which has high contribution were used as an observation parameter of iteration process. By making the vibration node coincide with the union point, it was possible to removed the resonance peaks. The suggested method was applied to the acoustic cavity model and the reduction of noise level was achieved with small amount of mass addition.

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