This study presents the vibration control method of a lightweight car supported with active suspensions. As the car body is lighter for energy saving, it alters a flexible structure. Therefore it is difficult to apply the vibration control method of high stiffness cad body to a flexible one. A plate structure replaces an elastic car body as a fundamental approach. It has a distributed parameter system. Hence, we designed a control system based on LQ control theory, with a reduced order model that controls the six-degree modes of bouncing, rolling and pitching that including vibration modes of bending and torsion. These multiple modes were controlled in this experiment, which verified that vibration in active suspension system could be controlled.

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In vibration isolation control problem, semi-active control methods in which coefficient of viscous damping is varied effectively have been proposed and expected to realize a high performance. However, the semi-active system is classified into a bilinear system which belongs to a nonlinear system. In this study, the switching hyperplane of sliding mode control is designed by the disturbance-accommodating bilinear optimal control theory and it is applied to a semi-active vibration base isolation problem. The proposed method adopts the damping force in criteria function, and the controller takes into account the disturbance dynamics by difining an augemented bilinear system. This study deals with a ten-degree-of-freedom structural model with base isolation. And the computer simulation is carried out by taking account of the delay of switching the coefficient of dampers. As a result, the usefulness of the present method was demonstrated.

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This paper describes velocity feedback control with variable gain for a vibratory machine which has a nonlinear resonance curve. Vibration of the vibratory machine and movement of a work are coupled through normal force and friction force. The coupled vibration is nonlinear, and the resonance frequency changes according to the work mass and vibration amplitude. Self-excited vibration by positive velocity feedback follows the resonance frequency change automatically. In changing from positive feedback gain to negative feedback gain in velocity feedback control, self-excited vibration is suppressed actively. Self-excited driving starts up vibration and transportation quickly, and active vibration control stops those quickly. The mathematical model of the vibratory machine simulates the behavior of the actual vibratory machine exactly.

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This paper presents the dynamic characteristics of the seated human body and a method for the evaluation of ride comfort by using the multiple regression analysis under the load condition of biaxial vibration. At first, the vertical and horizontal frequency responses of the head, shoulder, and waist were measured by exciting subjects with three kinds of biaxial sine wave vibrations including 0, 45, and 90 [deg]. Out of phase components or the reproductive wave of the floor vibration of high speed train running at 275 km/h. Secondly, the subjects were required to compare the vertical and the biaxial vibrations, and also to answer questionnaire. Base up the results of the experiment, the estimated equation between the human dynamic characteristics as explanation variable and the sensitivity parameters as criterion variable was established by using the multiple regression analysis. As a result, it was clarified that the sensitivity was related to the dynamic characteristics of the head, shoulder, and waist under the effect of biaxial vibration.

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This paper deals with the mechanism of damping and excitation force acting on a vibrating tube in two-phase flow. The gas phase flows faster than the liquid phase in two-phase flow. This relative velocity can cause turbulence and momentum diffusivity which induce pressure fluctuation and additional viscosity. The investigation of the relationship between tube vibration and two-phase flow showed that damping ratio and excitation force are closely related to the drift flux of the gas phase. From these results it was found that damping ratio ζ is given by ζ∝ρ_L(1-α)√j_GL, and excitation force √Φ_eq is by √Φ_eq∝ρ_L(1-α)j_GL, where, ρ_L is liquid density, α is void fraction, j_GL is drift flux.

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Precise measurements of added fluid forces acting on a circular cylinder in in-line direction were conducted with some different forcing amplitude conditions in a water tunnel to investigate their nonlinear characteristics. In the previous report, characteristics of added fluid forces were reported in the case that forcing amplitude is 5%. In this report, the experimental results in the case that forcing amplitude is 2.5% and 10% are described and compared with those of 5% amplitude condition. As a result, it was found that added damping forces are strongly dependent on cylinder amplitude, while added mass coefficient is insensitive to it. The measured added damping force was reduced to exciting parameter, which denotes dimensionless exciting fluid force. The characteristics of the exciting parameter agree quantitatively with the in-line oscillation behavior of an elastically supported cylinder in a cross flow obtained by previous free oscillation tests. Furthermore, the effects of fluid damping to the exciting parameter were discussed on the basis of the experimental results in detail.

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The evaluation methodologies for the flow-induced vibration instability of a long flexible beam due to the axial leakage-flow are reported. In the previous papers, the axisymmetric bodies are regarded as a rigid body not as a continuous body. In this paper we deal with the body as a continuous flexible beam. The equations of motion for the fluid and the structure are coupled analytically and the added mass, added damping and added stiffness are derived by considering the unsteady pressure acting on the beam. The relation between the axial velocity and the unstable phenomena is clarified. Concerning the critical flow velocity, the root locus is shown. We compare our results with the experimental results which one of the authors reported before. As a result, the design criteria for the axial leakage flow are discussed.

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In the previous paper, the authors proposed a new type of magnetic damper using a lever-type displacement magnifying mechanism and rare-earth magnets. In this paper, a viscoelastic-friction damper and a viscoelastic damper using the lever-type displacement magnifying mechanism and viscoelastic material are proposed in order to obtain a passive damper which gives damping and stiffness within a relative displacement in the region of about 0.1∼20 mm. Denoting the magnifying ratio by λ, the damping force and the spring force of the viscoelastic material are increased λ² times and the friction force is increased λ times by the magnifying mechanism. The trial dampers were made and the resisting force characteristics were measured. To describe the mathematical properties of the viscoelastic material, a four-element viscoelastic model was used, and the parameters of the model were identified using the experimental results. The frequency responses and the seismic responses of a three-dimensional piping system supported by each damper were measured using an electrohydraulic type shaking table. The experimental results are compared with the calculated results obtained by the finite element method (ANSYS), and the effects of vibration suppression of the dampers are discussed.

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The purpose of this study is to develop a procedure for performing a dynamic analysis on a beam supported with nonlinear distributed spring by the MLPG method. Equations of motion on a beam supported with nonlinear distributed spring have been derived using the MLPG method. The computational programs for statics, eigen-value analysis and time history responses were developed using the derived equations. Appropriate values on the order of a basis vector used in an approximate displacement, the number of nodal points and the sizes of local domains were found under carrying out static analyses. Then the validity of the formulations and the computational programs were verified by comparing the numerical solutions obtained using the developed computational programs with the analytical solutions and the numerical ones by the finite-element analysis.

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Centering (skew) characteristics of flat belt running between crowning rollers together with conical rollers are investigated by using FEM software MARC. Changing roller misalignment, belt initial position and main parameter values, the belt skew is simulated. The results indicate that the belt always skews to the center position of the parallel crowning rollers independent of the belt initial position. During the skew, the belt wraps spirally around the rollers coming into contact at the larger diameter side of the rollers and separating at the smaller one. When the belt moves with the rollers with negligible small slip, the belt moves to the top of the crowning. This is the belt centering mechanism. As the crowning radius becomes smaller, the centering gets faster.

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Recently, requirement for performance specifications of the control systems has been very severe with the advance of industry. For instance, in the case of control of the light weighted train, vibration caused by an influence on a disturbance and resonance of flexible body should be reduced not only at a single frequency but also on the wide range of frequency. For this problem, disturbance observer has been used traditionally. However, in many cases of industrial systems such that the light weighted train, disturbance frequency is varied for some frequency range. Therefore, it may be difficult to reduce the adverse effect of the disturbance by the use of the traditional disturbance observer. In this study, we implement the vibration suppression control system using disturbance observer to cope with frequency variation to reduce the adverse effects of periodic disturbances. In order to demonstrate the usefulness of the proposed disturbance observer, we applied it to the vibration control system for a flexible beam where disturbance force whose frequency is varied for some range is imposed. It can be shown by numerical simulations and experiments that the proposed control scheme has superior performance of disturbance reduction as compared with the traditional disturbance observer and the H_∞ controller.

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A smart structure is composed of the piezoelectric film sensor and actuator in order to reduce the structural vibration. H₂ controller is designed with the reduced order model of the smart structure which is obtained by finite element and modal analyses. The control force is applied by the piezoelectric film actuator and the feedback signals are detected by the piezoelectric film sensor and the accelerometer in the system. The vibration response is suppressed by the displacement control and the modal control in which the spatial displacement and the modal coordinate displacement are taken as the controlled variable. The shape/placement of the piezoelectric actuator and the H₂ control system are simultaneously optimized to achieve an enhanced vibration control performance. Efficient optimization algorithm based on a two-step procedure is employed in the simultaneous optimization. It is verified by some applications that the enhanced performance for the vibration suppression can be achieved by the presented optimal design.

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This paper presents a method for vibration control system of one-link flexible arms. This method is based on the robust model following control scheme that has been proposed by the authors. This scheme can robustly control the nominal model in the presence of unmodeled dynamics and achieve the desired model following simultaneously. Therefore, this method is suitable for controls of plants that are difficult to model like flexible arms. Furthermore, a sufficient condition for stabilizing the nominal model in the presence of unmodeled dynamics is derived and the existence of bounds for all signals is proved. Finally, the results of computer simulation and flexible arms' vibration control experiment are presented to show the effectiveness of the proposed method.

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A magnetic bearing system using forces of repulsion between permanent magnets was developed. In the developed magnetic bearing, the radial motions of the rotor were passively supported by repulsive forces. The motion in the axial direction, which is inherently unstable, was stabilized by using the motion control of the permanent magnets for passive radial suspension with a piezoelectric actuator. The maximum displacement of the actuator was 200 μm. The developed magnetic bearing suspended a rotor without any mechanical contact. Its dynamic characteristics were studied experimentally. It was demonstrated that the rotor could follow stepwise command signal whose magnitude was within ±60 μm when I-PD control was applied.

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A hybrid magnetic damper composed of a ball screw, rare-earth magnetic and electromagnets is discussed experimentally, and a switching control law for a single-degree-of freedom system consisting of a mass, a spring and the hybrid magnetic damper is also discussed in this paper. Karnopp switching law is explained in terms of Lyapunov theory. From this consideration, a new control law suitable for hybrid magnetic damper is given. The frequency and seismic responses are discussed analytically and experimentally.

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We have developed an objective lens actuator for slim DVD drives to improve the vibration characteristics, so that the servo-control range can be expanded. To reduce the higher-order resonance peak resulting from elastic deformation of the moving part, we took the vibration modes into consideration in designing the actuator structure. Thus, we could lighten the actuator and reduce the resonance peak without increasing its stiffness. Our experiments showed that the amplitude of higher-order resonance at 16 kHz in the auto-focusing direction was reduced to less than 3 dB. The acceleration sensitivities in the auto-focusing and tracking directions were 97 and 92 m/s²/V, respectively. These values meet the requirements for 8X DVD-ROM and 32X CD-ROM drives.

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The future SELENE (SELenological and ENgineering Explorer) mission is planned to make a soft-landing on the lunar surface. The lunar lander is called "SELENE-B." For preliminary terrestrial landing experiments, the flying test bed (FTB) was developed and the first flight experiment finished, which was aimed at validation of the whole FTB flight system. Other experiments are planned for validation of the SELENE-B onboard hardwares, such as sensor systems, and softwares for control systems. In order to validate those systems, it is desirable for the FTB to have the same dynamic characteristics as the SELENE-B. In this paper we are concerned with the controller of the FTB which achieves the SELENE-B model-following system using the FTB. Some numerical simulations are provided to show the effectiveness of the proposed SELENE-B model-following system.

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A tactile display device is effective in the virtual reality and remote control systems. In the present paper, a matrix-type tactile display device is mounted on a computer mouse so that a human subject can feel virtual textures and defects by manipulating the mouse and keeping his finger on the tactile display. In order to establish a design method for the tactile display device, the arthors developed a matrix-type experimental tactile display device having a 4×6 array of stimulus pins using bimorph piezoelectric actuators. In the tactile display device, 1.2, 1.9, 2.5 mm were utilized as the distances between adjacent stimulus pins. Using this tactile display device mounted on a mouse, we performed a series of psychophysical experiments with five male subjects in their twenties. It is found that distance between adjacent stimulus pins should be equal to the human two point threshold (1∼2 mm) and that the present display device can display virtual figures which are more than double area of the mouse cursor.

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The experiments on the burden measurement of human and a transfer aid system were presented to develop a self-transfer aid system. A person with weak leg muscle who uses a wheel chair is assumed to be a target user. By using the transfer aid system, a user can transfer between a wheel chair and a toilet. The mechanical concept is that a user puts his/her belly on a saddle of a robotic arm, and then the robotic arm raises a user. The experimental setup was fabricated to investigate the burden to human and the transfer aid system. It is confirmed that a long robotic arm is better to decrease the human's burden; however the robotic burden is increased. The opposite phenomena were obtained using a short robotic arm. By using the experimental results, a test system of a self-transfer aid system was fabricated.

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Although such functions as Bezier, B-Spline and NURBS are widely used in Computer Graphics for generating any freeformed surfaces, they are not necessarily appropriate for describing the existing surfaces; They need structured data sets according to a grid. Their mathematical structures make it almost impossible to obtain entirely smooth surface. To overcome these problems, an application of parametrized polynomial functions was proposed in this study. By using our parametrized polynomial, the artificial knee joint surface was described mathematically and the results were fully compared with those from B-Spline with respect to accuracy and smoothness. Computer generated images were made to demonstrate that our parametrized polynomial was superior to the B-Spline.

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This paper introduces two types of self-bearing motor which uses Lorentz force. The rotor has eight strong permanent magnets on the surface of it. The stator has six concentrated windings. Hence it has merits of good dynamic response, good linearity and high reliability. First, the fundamental principle is introduced how the motor produces linear rotating torque and radial levitation force. Then the fundamental characteristics of slot type and slotless type are compared. Finally an experimental setup is fabricated to confirm the characteristics of this motor. The application of both types are described according to the measured characteristics.

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Generally, a redundant robot has been used to avoid a static obstacle in industrial production systems. In this paper, a control method of a redundant robot for avoidance of a moving obstacle using visual impedance is proposed. Two CCD cameras are used to construct a stereovision, and a high-speed image processing board with a built-in DSP processor is used for image input and real time processing. When an obstacle moving into a previously established virtual potential field around the links of a robot is detected, a virtual torque is generated by the proposed method. A criterion function including the manipulability of arm and the distance between obstacle and the link is proposed for selection of a redundant joint. A control algorithm is also developed to complete both a tracking task by an end-effector and a task of obstacle avoidance by a redundant joint at same time. The effectiveness of the proposed method has been demonstrated through the avoidance experiments.

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In this paper, we discuss about motion planning for hand-over between human and robot. In constructing an algorithm to generate receiver's motion, we aim at reproducing a human-like robot motion in order to reduce human physical and mental burden. First we analyze trajectories and velocity patterns of a hand-over motion performed by two humans. From this experimental results we extract some conditions to realize safety and kind receiver's motion. We then plan the robot's motion considering these conditions based on an instantaneous optimal control method. This algorithm updates the performance function evaluating the error and torque energy at each sampling step. Therefore we can design the weight matrix concerning the error as time-varying form to bring the characteristics of robot motion close to that of human motion. Finally, we execute some kinds of simulation which generates robot receiver's motion by inputting real human deliverer's data into proposed algorithm. These results shows that the robot motion realize safety and kind receiver's motion reflecting human receiver's characteristics.

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In the present study, following efforts have been made, relating to the unsteady straight running stability of a passenger car. To build a model, on-road vehicle experiment is performed and the straight running stability of a vehicle is verified. Also, to investigate a driving index, sensory test and evaluations of heart rate variability by a driver are performed. To investigate the relationships between vehicle dynamics and tire characteristics, a model for the straight running stability has been built. A 3-degree-of-freedom vehicle model together with a general drivers model are utilized for the analysis. Next, the proposed human-vehicle-model is investigated and the index to quantify straight running stability is determined. Also, by identifying the tire characteristics that improves straight running stability, the effectiveness of the proposed human-vehicle-model is demonstrated. Lastly, tire test is performed against the same operational conditions used for the on-road vehicle test, to verify the validity of the developed human-vehicle-model.

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The authors previously reported a remarkable current fluctuation was observed in the axles of the running wheelsets when a track circuit was shunted by the pair of wheelsets. To investigate into the behavior of the fluctuation, they applied a bio-electric amplifier to detect minute voltage potential difference caused by the electric current in the wheelsets. As the results, they found the fluctuation was caused by an electric resonance which was originated in the circuit, composed of the pair of axles and the pair of rails. Analyzing the frequency, they also found the resonance current contained an AF band used for the control device of the grade crossing alarm system.

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In this study, piezoelectric elements are applied to passive vibration suppression of beam structure, or a primitive model of railway carbody. Piezoelectric devices are electrically shunted by an external electric circuit, e.g., a serial connected inductor and resistor. Results of excitation tests show that piezoelectric elements more effectively increase the loss factor of the structure than damping layers that have already been put into practical use. According to simulation results, it is expected that the 1st mode bending vibration can be suppressed successfully even if the structure is as large as an actual railway carbody.

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A robust optimal design method based on the minimax regret criterion is proposed for multistage expansion planning of energy supply systems. Under uncertain energy demands increasing stepwise, equipment capacities and utility contract demands as well as energy flow rates for each expansion period are determined in consideration of their hierarchical relationships to minimize the maximum regret in the annual total cost and satisfy all the possible energy demands for the whole planning period. This optimization problem is formulated as a kind of multilevel linear programming problem, and its solution is derived by repeatedly evaluating upper and lower bounds for the optimal value of the maximum regret. Through a numerical case study on a cogeneration system for district energy supply, features of the economic robustness and multistage expansion planning are clarified in relation to the uncertainty in energy demands and the number of years for expansion periods.

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The home care equipments to assist the elderly or handicapped person are usually used by one or more limited family persons in their house. The controller of them therefore must be designed to be usable by all people. However, it is independently designed by each manufacturing company. In this work, the authors have investigated not only the mechanical properties of button switch, as pressing force, size and stroke, but the cognition of button switch as the size, color and character type. Furthermore, a new controller of care bed was designed functionally based on the universal design concept. Seven types of mock-up for controller were made using the stereolithography system. The operating feeling of them was examined by younger persons. As a result, the property of controller which can be easily used for everyone was proposed in this work.

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We have designed a new prototype knee joint, which utilizes a hydraulic cylinder in the stance phase and a microprocessor-controlled pneumatic cylinder in the swing phase. In this study, the gait performances of this knee joint were tested in 3 trans-femoral amputees, comparing with a commercially available knee joint, Otto Bock 3R60, which is at present alleged to provide a higher gait performance. An electronic metronome was used for step duration so as to make the subject with cadences of 88, 96 and 104 steps/min. Vicon 140 system was used, particularly forcusing on the motion measurements of hip and knee flexion angles as well as hip moment in a sagittal plane. As results, this knee joint showed stabler and superior in terms of gait performance rather than Otto Bock 3R60 at different cadences. The newly designed knee joint appears promising to serve as a superior prosthesis for the trans-femoral amputees.

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A 3-D motion analysis of the artificial knee joint is expected, as one of important techniques for geometrical design of the artificial knee joint. This study aimed to develop a 3-D motion analysis with high precision by using pattern matching (PM) technique with wide-spreading high-resolutional computed radiography (CR). We report the method for calculating the geometry of the X-ray source and the evaluation of PM. The full six degrees of freedom (DOF) pose of prosthetic component were calculated by matching computer-synthesized projection images with experimentally acquired 2-D CR image. The 3-D geometry of prosthetic component was reconstructed using a curved surface by B-spline. PM was done using the parametrically calculated the six DOF in order to minimize the exclusive OR (XOR) between both of the binarized image. Further, some objective windows were set up on the screen to make reference time shorten. The femoral component was rotated in the center of calibration flame to examine accuracies of the PM technique. The numbers of pixels of XOR became zero by making the stop of 6-D parameters smaller. The accuracies of below 0.7mm for translation and 0.7° for rotation were confirmed.

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This paper deals with a new seal system between flange joints without using gasket. This gasketless flange includes a groove and an annular lip that is machined in one of the flange being in contact with the other flange to form a seal line when the flanges are assembled. In this study, first, fundamental dimensions are examined for PVC-U to obtain the best sealing performance. Then, the effects of material difference and flange nominal size on the sealing performance of new gasketless flange are investigated for two types of materials, 0.25% carbon steel (S25C JIS) and unplasticized polyvinyl chloride (PVC-U JIS). It is found that the critical internal pressure where leakage appears is mainly controlled by the maximum normal stress at the annular lip for each material even if the flange nominal sizes are different. The gasketless flange made by PVC-U shows the higher critical internal pressure compared with the case of S25C if the same clamping forces are applied. The effect of stress relaxation for PVC-U on the sealing performance is also considered. Then, it may be concluded that this PVC-U gasketless flange also has good sealing performance.

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Previously proposed "Planetary Conical Rolling" (PCR) is a new ironing process carried on between a cylinder die and rollers supported by inner race. Excellent features of PCR such as extremely high thickness reduction, mirror finishing of outer tube surface, no sliding between tool and material, supplement of high pressure in the radial direction were demonstrated. It was also reported that this process could be applied to pressure welding and thread forming. However, inner surface of tube after PCR was considerably rough because of indentation of roller edge on the material. In order to overcome this defect, "Planetary ball rolling", in which rollers in PCR tools were replaced with balls, is proposed. Performance of PBR was compared with PCR by the use of aluminum alloy tubes. As a result, roughness of inner surface of the tube was extremely improved by PBR. Influence of ball diameter on forming limit and surface finishing was investigated. It was found that forming limit was assumed with maximum contact angle and large ball. diameter was advantageous. Additionally, large ball was also effective to reduce surface roughness of both the inner and outer sides of tube. This was due to enlargement of deformation zone, which caused sufficient deformation on outer tube surface and reduced pilling up on the inner tube surface. Obtained tube had good quality and simultaneous finishing of inner and outer surfaces of a tube by PBR was demonstrated.

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In the construction of reactors or pressure vessels for oil chemical plants and nuclear power stations, mono block open-die forging rings are often utilized. Generally, a large forged ring is manufactured by means of enlarging forging with reductions of the wall thickness. During the enlarging process the circular ring is often distorted and becomes an ellipse in shape. However the shape control of the ring is a complicated work. This phenomenon makes the matter still worse in forging of larger rings. In order to make precision forging of large rings, we have developed the forging method using a v-shape anvil. The v-shape anvil is geometrically adjusted to fit the distorted ring in the final circle and reform automatically the shape of the ring during enlarging forging. This paper has analyzed the reforming process of distorted ring by computer program based on F.E.M. and examined the effect on the precision of ring forging.

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Various kinds of micro-cutting simulations based on molecular dynamics (MD) have been proposed in which the temperatures of the outer boundary were assumed to be steady states. Considering both heat and force boundary conditions is necessary in the MD simulations for the limited size of the model. To investigate the influence of the size of the model on behaviors of the workpiece, two dimensional cutting MD simulations for copper single-crystals are carried out using four kinds of models in which the restricted boundary of different sizes and the unsteady heat boundary are included. It was obtained that the boundary conditions exert the influence on both sub-surface damage and the temperature distributions in the workpiece when the boundary is close to the tool edge. Appropriate temperature distributions in the workpiece near the boundary are exhibited to provide the heat conditions at the boundary.

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The present paper describes the influences of the valve roundness and corner dullness to a gasoline leakage, after analyzing them with the shape preciseness of valve-seat system. Moreover, the influences of CBN wheel grinding conditions on the preciseness of valve are discussed. In order to decrease a gasoline leakage from valve-seat clearance, it is necessary to decrease the roundness and corner dullness of valve, as well as the roundness and average clearance of seat. For the small roundness of valve, valve should be fed at the minimum feed rate to CBN wheel under the low eccentricity. The resin-bonded CBN wheel provides the small roundness without sharp scratching under the large wheel speed. The vitrified-bonded CBN wheel with grain size over #800 improves the corner dullness of valve by the sharp edge of wheel formed by the diamond truer of #600 grain size.

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A polishing pad has so far been indispensable in conventional polishing method for most industrial materials. However, many problems, such as wear and glazing of pad surface, variation in removal rate over time, poor repeatability and difficulty in process control, and necessity of in-situ conditioning of pad surface, remain to be solved. A mirror polishing method using no polishing pad is therefore proposed, in which polymer particles are supplied together with abrasive grains on to a tool plate that could be made of hard materials. The polymer particles serve as countless micropads in the work-to-plate gap for polishing action, as well as spacers preventing contact between the tool plate and the workpiece. The feasibility of this method has been verified through polishing experiment of silicon wafers. Higher removal rate of material and higher form accuracy, easier process control and higher stability at less polishing resistance, and hence lower power consumption have been obtained than using a polishing pad. Also it is found that the properties of polymer particles and the surface roughness of tool plate have very important effects on polishing characteristics.

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In order to make a highly integrated LSI, the circuits of patterned metal layers are constructed on a semiconductor-wafer as three-dimensional structure. In the processes of constructing three-dimensional circuits, the dielectric films that should be planarity before depositing patterned metal layers on it are made between the circuit layers. CMP (Chemical Mechanical Polish) is the most effective technology for planarizing semiconductor-wafer surfaces. For improving the functions and performance of a CMP machine, the various items such as polishing pressure, polishing pad, retainer ring, backing film and ingredients of slurry have to be taken into consideration. More efficient processing conditions for CMP and machine parameters to be designed are decided by know-how and knowledge obtained by repeating basic experiments. However, since it takes much time and manpower to get them via experiments, it is required to determine by computer analyses. Since pressure applied on a semiconductor-wafer surface is the most essential factor about the rate of mechanical polish, it is indispensable to obtain pressure distribution on the wafer-surface in order to estimate the rate. In this paper, pressure distribution given to the wafer-surface is computed by FEM (Finite Element Method) to estimate the polishing rate in order to determine optimum machine parameters to be design.

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This paper presents a new and effective assembly model by using a fixture with passive RCC function. Previously, in a peg-in-hole task, such functions for skillful assembly as RCC, contact force sensing and so on have been supplied to a "peg-device" like a hand-manipulator, not a "hole-device" like a fixture. Therefore the characteristics of a fixture with passive RCC function in this task is investigated in this paper. The peg-in-hole task model by using the "RCC fixture" is constructed on vertical (x-z) plane. And the performance of this task is investigated by the quasi-static analysis, which was proposed by Whitney, to evaluate the characteristics of it. From the results of the analysis, it has been made clear that the RCC fixture has shown the insertion behavior unlike conventional RCC applied to a peg near the entrance of hole.

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This paper describes insulation characteristics of slit resonator that a single channel ANC system for silencing leakage noise at ventilation aperture of package. The circular slit resonator composed of thin air layer that is radial expansion with very short axial length was set up package wall. The circular thin air layer is driven by one to four speakers that are controlled using Filtered-X-LMS algorithm to minimize sound power at error microphone. The experimental results show that the noise reduction region spreads to the high frequency side, as the slit depth decreases. The noise reduction quantity increases, as the slit width widens. Visualization of SPL and phase on the circular slit resonator indicate that the noise reduction mechanism is the interference of control sound and noise.

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This paper deals with the behavior of the balls that exist between the grooves of the hypotrochoid plate and the epitrochoid plate in a standard ball reducer. As a first step to elucidate the behavior of balls in a standard ball reducer, we measured and analyzed the ball center locus, the ball passage period, and the ball orbital period. From the results of measurements and analyses, the conclusions were obtained as follow: (1) The ball center locus is hypotrochoid, which is fixed on a coordinate system at rest. The wave number of the ball center locus is equal to that of the groove of the hypotrochoid plate. (2) The ball passage period is equal to the rotational period of the input shaft. (3) The ball orbital period is the product of the rotational period of the input shaft and number of the halls.

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