This paper describes tribological issues in micromachines and possible solutions to them. In microsystems, surface forces such as capillary force, electrostatic force and van der Waals force become dominant compared to the gravitational force because of the scale effect. Since the surface forces often cause increase in adhesion, friction and wear, tribological consideration is important in designing -the microsystems. Texturing and hydrophobic coating of surfaces are effective to reduce the adhesion and friction. Air bearings are also effective for preventing the friction and wear of high-speed sliding elements such as rotors of micro rotating machinery and sliders in hard disk drives. To investigate structures and functions of insects or other small living creatures provides many suggestions to the tribological issues in micromachines because they have solved many of the same issues during their evolution.

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This paper describes friction characteristics of a water droplet on hydrophobic surfaces and effects of geometry of hydrophobic surfaces on friction are investigated. Sliding angle at which a droplet begins to fall down on a tilted surface and shear resistance of a droplet confined between two hydrophobic surfaces were measured. The results show, that on hydrophobic surfaces with small raised patterns, the sliding angle and the shear resistance are both small and symmetrical convex shape of the droplet is maintained during the sliding. The friction force between two hydrophobic surfaces is proportional to the peripheral length of the solid-liquid interface.

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Direct visualization method for molecularly thin lubricant films on magnetic disks is presented. Visualization of a molecularly thin film is an extremely useful technique for the investigation of replenishment and retention of thin lubricant films. Ellipsometry can provide thickness and refractive index of a molecularly thin film. We demonstrated ellipsometric microscopy using a white light source could provide improvement of signal to noise ratio of images. However, measurement of absolute thickness of films has not been established, although the relative thickness can be obtained by intensity of images. In this report, method for measuring the absolute thickness of films has been presented.

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The spreading of a non-functional polymeric liquid film on a solid surface was studied at molecular resolution by using Monte Carlo simulations. As model molecules, a linear chain polymer perfluoropolyether Z was employed and simplified as a set of beads connected by springs. Movement of the beads was made in an off-lattice three-dimensional space following the law of energy minimization. By introducing a method for identifying film surface from molecular number density, spreading profile of the polymeric film was obtained, showing similarity to the experimental measured result.

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In order to polish the glass substrate for HDD, new novel polishing system with electric field was proposed. Electric field provides kinetic energy to abrasives. These abrasives scratch and rub the glass Surface and realized the super smooth glass substrate that surface roughness is less than 0.5nmRa. In order to realize this system, the movements of abrasives are observed. The effect of frequency and the strength of electric field on mean velocity are elucidated. After the decision of optimum electric field, glass plate was polished. After 60 min of polishing time, surface roughness of glass plated was reduced from 5.1nmRa to 0.49nmRa.

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In order to evaluate surface properties as wettability and surface energy, novel surface analysis method was proposed with the observation of condensed liquid drops on the specimen in an ESEM. In the present study, we try to measure surface energy on the specimens that has micro size monotectic area or that has micro size geometric shapes area to establish this novel method. As a result, micro size drops selectively condensed on the monotectic area or geometric shapes area. And this method could measure surface energy on the individual micro size area in the specimens.

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As for a perspective view with the future of intelligent machinery systems, this paper suggests some possibilities of an application to the field of e-learning. That is, computer vision technologies looking at human are expected to be potent tools for the improving the quality of education. There are proposed a couple of systems as concrete examples: (1) multimedia self-study support system distributing lecture-video by on-demand base, and (2) classroom scene monitoring system. Although these two systems involve a lot of difficult problems, some of which are yet impossible to solve, they would contribute to enhance computer vision technology farther and to meet social demands for the level-up of higher education that are recently greatly increased.

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We developed a new method for accurate estimation of the excitation force of an electric motor by inverse system using measured acceleration response. Usually, an electric motor is attached to a supporting structure in some points. Therefore, we have to estimate the amplitude and phase of motor excitation forces. The amplitude and phase of motor excitation forces were estimated by solving an inverse dynamical problem with measured values of the acceleration. To solve this inverse problem, we employed an accelerometer to measure the accelerations of the supporting beams of the motor. In the experiment, the acceleration of a beam was measured when the motor was in operation. Additionally, the inverse system was created by using the equations of motion for both the motor and the supporting beams. The results obtained by this method agreed well, with the results of the excitation force measured by using a load cell directly.

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Abstract An optical three-axis tactile sensor is comprised of a silicone-rubber sheet, an acrylic plate, a CCD camera and a light source. A silicone-rubber sheet has an array of 8×9 sensor cells consisting of a columnar feeler and conical feelers. Since the 2-by-2 conical feelers were detached from the acrylic board under too large horizontal force, the three-axis tactile sensor could detect friction coefficient of the object surface with limited range of shearing force only in the preceding authors' studies In the present paper, the authors proposed a new sensing element which has a columnar feeler and 8 conical feelers. The authors formulated a set of equations which could evaluate normal and shearing forces from integrated gray scale value and centroid displacement caused by conical feeler's contacts. To evaluate these sensing elements, we conducted a series of experiments using an x-z stage and a two-axis force sensor. It was found that relationship between centroid displacement and shearing force does not depend upon applied normal force, and that the present equations can estimate variations in normal force induced by increase of shearing force.

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In order to investigate effects on presentation tactile-haptic reality, the authors developed two multi-modal displays A and B. Display A was able to stimulate muscle-tendons of forearms and fingers. Display B was able to simulate mechanoreceptors of fingers in addition to the muscle-tendons. Display A was constituted of a manipulator having three-degrees of freedom and a gripping force display. Display B was constituted of a tactile display having an 8-times-8 array of stimulus pins and the above-mentioned manipulator. A psychophysical experiment was performed using an adaptive method. In the adaptive method, a human subject adjusted a crossing angle of a comparison texture to be equivalent to a standard texture fixed during the experiment. As the result of the experiment, we obtained a threshold of 16.8 degrees of crossing angle. Since the value of the threshold is similar to the threshold obtained by similar experiments using a mouse-mounting typed tactile display that has adequate capability to present virtual textures, it guarantees presentation capabilities of the present displays.

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The authors developed a mental image creation support system, a 3-DOF manipulator for teaching strokes of presented images. It is composed of a 2-DOF quadrilateral parallel-link manipulator and a 1-DOF rotational actuator, the rotational axis of which a knob is attached to. The former is driven by a couple of servomotors and controls the manipulator-arm end position. The latter is driven by a servomotor attached to the manipulator-arm end, and controls the knob orientation. The positioning accuracy of this manipulator is affected according to the manufacture errors of parts, the modeling errors of kinematics, and the attachment errors of servomotors. This paper presents a method of the calibration of parameters of the parallel mechanism, and it was confirmed that the calibration greatly reduced the positioning errors from 10 to 2 mm.

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The underground radar is used as a method for imagining complicated underground structures, such as a stratum and a buried target, with un-destroying and un-contacting. However, in order to find an object from an underground radar image with sufficient accuracy, a lot of experience or knowledge of an expert is necessary. Therefore, various kinds of signal processing have been studied aiming at making an image clear. The key techniques generally used in an underground radar are the synthetic aperture processing and the FFT. The crucial point is as follows. There is an important characteristic that the hyperbola of the received wave form measured by the underground radar varies with the depth of a buried target. Then, the authors propose an underground imaging algorithm for synthetic aperture processing considering the characteristic of the depth-induced change of underground-radar signal image.

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This paper presents a method of detecting vehicles located around the host vehicle by using cameras having different fields of view to generate a surrounding map. T method of generating a surrounding map incorporates new algorithms that include two key technologies. One is the sensor integration of t e camera data The second key point is a method of checking error detection using traffic-flow-context based knowledge. The results of experiments conducted with a real vehicle are described. It is shown that this method is helpful in improving detection accuracy.

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ITS (intelligent transport system) has been expected to support drivers operation or operate vehicle instead of drivers and provide comfortable vehicle travel and reduction of traffic accidents. ACC (adaptive cruise control) has also been focused as safety and comfortable system, especially in a heavy duty vehicle. However it is difficult for PID throttle controller to recognize unspecified disturbances, for example uphill/downhill road environment, variation of engine performance and vehicle weight depending on load, and achieve robustness. In this paper a new adaptive cruise control of self-tuning algorithm using neural network emulator and fuzzy logic is introduced. Simulation and experimental results show the effectivity of this system for great robust performance of speed control.

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A mechanism of leaning blade squeaking due to the friction between the photoreceptor drum and the blade in a copy machine are presented. Although this problem has been known for many years, the details of oscillation mechanism are not clarified, so we have not found out the fundamental solution method yet. Here, in order to clarify this oscillation mechanism, we took notice of the feature of the oscillation that the frequency changed discretely with a normal force of the blade. In other words, we found out that the oscillation is caused by couple of immanent modes in the cleaning blade, and it was, dependent on a friction force which mode became unstable coupling. As a result, we confirmed that the discrete change of oscillation frequency was explained by the unstable coupled modes of the cleaning blade.

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Skew phenomena of a flat belt running between cylindrical rollers with out-of-plane angular misalignment were simulated by means of the FEM software MARC. The effects of roller misalignment angle, belt initial tension, coefficient of friction, and an added tension roller on the belt skew were investigated. The FEM results indicate that the skew transient state disappears very quickly and the skew rate is proportional to the roller misalignment angle and is about 60% in magnitude compared with the in-plane misalignment case. Moreover, when the tension roller is placed in a suitable position with a certain in-plane angular misalignment, the belt skew is greatly reduced due to the out-of-plane misalignment. The skew generating mechanism with out-of-plane angular misalignment was also investigated.

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A printing-belt is widely used for a color printer. It is necessary to have a highly precise printing-belt feeding system for a high-quality color image. A printing-belt, usually wide and inelastic, has a complex behavior; the finite element method (FEM) is usually conducted for analyzing the complex behavior of the printing-belt. However, due to its complex behavior and the use of FEM, designing the optimal printing-belt feeding system consumes a vast amount of time. It is therefore necessary to have a simple model for determining the belt behavior. A simple model for determining the behavior of a printing-belt was used to estimate the characteristic of belt-walk. It was found that the model-simulated belt-walk is in good agreement with the experimental measurements. This agreement confirms the validity of the model for estimating belt characteristics more quickly and easily than by FEM. It is thus expected that it will speed up the design process for an optimal printing-belt feeding system.

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Paper skew is one of the serious problems for feeding papers in printers and copiers. The paper skew observed when rubber rollers feed a paper is simulated by using the FEM soft ware MARC and a three dimensional model. Effects of a front tension acting at a leading corner of a paper and difference in the friction coefficient on divided paper areas are investigated. The result show that the paper skews to the lower friction coefficient area

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Paper handling system, which carries paper sheet at a high speed such as ATM, requires steady operation at all times, and it is important in their design to prevent the machine from trouble during carrying the paper. In this study, the investigation of a relation between physical conditions of device or paper and its behavior during its carrying has been conducted. This report describes the evaluation results of phenomena relevant to.handling error such as jam by experiment and FEA.

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A page turning roller which has two driving rollers and a sensing roller in the same axis can sense the length of page feed, and to set a threshold against the page feed length enables to sense a turn of page for various kind of books. In this study, the turnpage using this roller and the way to sense the failures of turnpage are presented. Influences of diameter difference between sensing roller and driving rollers as well as the condition of operation against turnpage are clarified by experiments.

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Slipping or wrinkling of web is serious -problems in web handling system such as a paper engineering manufacture machine, a print machine etc. These phenomena in web handling are called web-defects and have the possibility that has given a fatal defect to a product. Elucidating mechanism of various kinds of web-defects and preventing it beforehand is an important technology problem. This paper describes a theoretical prediction model of friction coefficient between uncoated paper and steel roller and outbreak condition of web wrinkling. It is cleared that the friction coefficient between web and roller and outbreak condition of web wrinkling receive influence of parameters such as web tension, web width, web wrap angle and roller radius. Then the relation of friction coefficient and outbreak condition of web wrinkling is trade o f and the prevention of slipping and wrinkling of web simultaneously by adjusting a few parameters is difficult. So using these theoretical models and the optimum design technique, each parameter was optimized.

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This paper describes the measurements of traction coefficient between paper-web and steel roller under various operation conditions. The four kinds of web such as uncoated paper (newsprint), light coated paper, heavy coated paper and PET are used as test webs. In the measurements, the web is wrapped over the rotating roller with the surface velocities from 0 to 40 m/s. The web tension is applied by the weight at the edge of web and the traction force between web and roller is measured by the load-cell at the other edge of the web. The traction coefficients are, then, obtained based on the Euler's belt theory. The flat type steel roller is used, and the web-wrap angle, web tension, web width, roller diameter are changed as operation parameters. From the measured results, the effects of such various operation parameters on the traction coefficient between web and roller are clarified.

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This paper describes the. measurements of traction coefficient between paper-web and steel roller under various operation conditions. The uncoated paper (newsprint) is used as test web. In the measurements, the web is wrapped over the rotating roller with the surface velocities from 0 to 40 m/s. The web tension is applied by the weight at the edge of web and the traction force between web and roller is measured by the load-cell at the other edge of the web. The traction coefficients. are, then, obtained based on the Euler's belt theory. The two types of grooved steel roller are used, and the web-wrap angle, web tension, web width, roller diameter are changed as operation parameters. From the measured results, the effects of such various operation parameters on the traction coefficinet between web and grooved roller are clarified.

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This paper is desmibed the pressure characteristics of the transporting web handling roller with different permeabilities. In the experiments, for web of two types such as newspaper and PET film used. the pressure distribution of rotating guide roller is measured for using a pressure transducer for behavior combination of web wrap angle, web tension, web width and rotating roller speed. Moreover, velocity distribution between the web and rotating roller was measured in the inlet and outlet region by PIV. From the experimental results, the hydrodynamic behavior for two types of webs with different permeabilites are clarified. The vortexes generate in the inlet region and the reverse flow occurs in the outlet region. The change of pressure like spike was considered base on these phenomena

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Experimental and numerical investigations have been carried out on a dynamics of conductive particles in an electric field between parallel plate electrodes to clarify the mechanism of charging process and an action of electrostatic force. Velocities and electric charges of particles were quantified by the experimental observation. Then saturation charge, pull-off charge and charge considering elastic contact between particle and electrode were estimated numerically and the results were compared to the experimental results. These investigations show that the elastic contact plays an important role on the charging of particles.

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A basic research is being carried out on the transport of particles in electrostatic traveling field. A particle conveyor that consists of parallel electrodes was constructed and four-phase traveling electrostatic wave was applied to the electrodes. The following were clarified by experimental and numerical investigations: (1) The mode of particle transport was classified into four: passing region that the transport speed was higher than the wave, synchronous region that particle motion was synchronized with the wave, backward region that particles moved backward to the wave, and vibration region that particles only vibrated but not transported. (2) Numerical 'calculation was conducted based on the three-dimensional Hard Sphere Model. Calculated results qualitatively agreed with experiments.

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A preliminary investigation was conducted on electrostatic inkjet phenomena. High voltage was applied between an insulative capillary tube filled with ion-conductive water and a plate electrode. At the beginning of corona discharge, a Taylor cone was formed at the tip of the tube and the top of the cone was broken to form a very.small droplet that was dispersed like mist at wide angle due to the Coulomb repulsive force of charged mist. When the applied voltage was further increased, water droplet was formed periodically. The charge to mass ratio of the drop was measured and compared with the Rayleigh's and Vonnegut's limits. It was less than the Rayleigh's limit but agreed fairly well with the Vonnegut's limit.

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