Measurement system for manipulative motion of human fingers is presented. A human subject wears several clip-on devices on the back of the fingers. Each device has a short stem extending outward from a finger with a light emitter at its end. A stereo vision system measures the three dimensional positions of the light emitters. The positions and the orientations of the fingers are calculated from the light emitters' positions using a kinematic model of the fingers. The protruding stems on the back of the fingers reduce occlusion caused by other fingers. Selection of the stem length, calibration method, and two examples of measurement of manipulation are presented. The overall accuracy of the system was 0.3 to 0.8 mm.

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Dynamic measurements in the order of nanometer by heterodyne laser interferometry for large displacement! comparing them to the unitscale were studied. Two Wollaston prisms were positioned in the back to back arrangement to expand measurable displacements. Frequency dividers were used to enhance the frequency characteristics of the method effectively. Phase unwrapping which is needed in the phase-shift measurements was carried out by using a personal computer and a kind of package software together with our own. The best figure in the present stage is 70 μm in dynamic range, and 100Hz in frequency range respectively. The method was tested in stochastics and results showed the conservative value of coefficient of variable was 1.0%.

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The paper describes a new absolute flatness measurement method by an interferometer. The method uses two surfaces and four interferograms obtained at different positions of a specimen. The principle of the proposed method is based on the autonomous calculation of inclination angles which occur with the lateral displacements of the measured specimen. The total systematic error of each CCD-pixel which includes wavefront error due to the reference mirror and optical path distortion in the interferometer is also calibrated by this method. The influence of the accidental error of the sampled data with CCD-pixels which remains as the only cause of error of the proposed absolute measurement method is estimated by the error propagation rule. The uncertainty amount of the obtained absolute flatness is reduced to about a double of that of the sampled data of each pixel due to the accidental error. The method is available in the aperture expansion by connecting stepwise shifts and measurements of a specimen with an area larger than the aperture of the interferometer.

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A new measuring method is proposed for estimation of robot positioning accuracy. The principle of the method depends on the well-known mathematical fact that one point in 3-dimensional space can be regarded as an intersection of three planes. The coordinates of it can be obtained by solving simultaneous equations of the three planes. The basic system consists of a laser detector on the target point, three laser scanners and a computer. Each scanner is used to rotate the linearly spread laser beam called laser plane. When the detector is on the plane, the rotation angle is measured to decide the equation of the plane. To find the equation of the plane, the unknown parameters have to be decided by given standard points in advance. This procedure is called a calibration. The measurement error depends on the calibration error, arrangement of the scanners and measuring accuracy of a rotation angle. The results on simulation show that the optimum layout pattern of standard points is the cylindrical pattern which includes a measurement cube. The optimum arrangements of scanners are the 2-horizontal and 1-vertical layout and the equilateral triangle layout. The 3-Dimensional measuring accuracy is 0.15 mm within a 1 m cube on simulation.

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When the Knudsen number of fluid increases, the fluid can not be treated as continuum and the conventional fluid dynamics equation is no longer applicable. Therefore, it is necessary to analyze physical phenomenon by chasing the motion of each molecule, and thus the molecular simulation has been developed. The objective of this study is to analyze flow phenomenon at very low spacing by using the molecular dynamics simulation. A magnetic head of a hard disk device is taken as a typical example, because the floating distance between the head and the disk is reduced to 50nm or less and it is said that even modified Reynolds equation can not give appropriate result in this case. In the present paper, the fundamentals of molecular dynamics and boundary conditions are described and discussed.

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The measurement of a diameter of a small hole with low measuring force and a high resolution is one of key issues for evaluating products in the industry of semiconductor and micro machining. However, there is no good sensing system to measure the diameter of a small hole by low measuring force. Therefore, we have developed a novel sensing system using a pneumatic system for measuring the diameter of a small hole. The sensor consists of a small ball, a thin pipe, a vacuum generator and a differential pressure gauge. In this sensor, the small ball is kept at the center of the thin pipe by the vacuum pressure. When the ball touches a wall of a small hole, the ball is shifted from the center of the pipe and it causes the airflow from outside to inside of the pipe. The differential pressure gauge detects the airflow, then the sensor finds the touching between the small ball and the wall of the small hole. A first prototype of the pneumatic ball probe is made and tested. From the theoretical analysis and the experimental tests, the probe is found to detect the touching and to measure the ball shift.

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Mechatronic servo systems such as industrial robot arms and NC machine tools are used as actual production lines and assembly lines. Accurate modelling is required for controller design of the mechatronic servo systems. In this paper, a model for the controller design of industrial mechatronic servo systems is derived. Based on the proposed model, a method for determining the servo parameters in the servo controller of industrial mechatronic servo systems is proposed. The method is based on a model of the mechatronic servo systems and the effectiveness of the method is assured by the experimental results.

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A newly proposed method in ISO for calibration of vibration pick-up sensitivity is performed and compared with conventional methods experimentally. The proposed method is called sine-approximation method which is described in ISO/CD5347-1. The conventional methods are fringe counting method and minimum point method which are described in IS05347-1. Each method is carried out simultaneously on a same experimental setup using modified Michelson-type interferometer. Signal process procedures for sine-approximation method, such as phase unwrapping and uncertainty in approximation are proposed. A guide for uncertainty estimation in each method is presented. From the experimental results at 10 m/s² in acceleration, sine-approximation method can be obtained up to 2000 Hz and its expanded uncertainty is estimated as 0.16-0.9 % at coverage factor 2. The main source of uncertainty is voltage measurement of the pick-up output. The new method has advantage on both the operational scope and its uncertainty. Obtained calibration results from each method are agreed within each uncertainty. The experimental results also show that electric and mechanical noise affect to the difference of each result. Those noises lead to inconsistency of calibration results on each method.

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This paper describes a grating projection method for three-dimensional profile measurement of specular objects. This method is principally available for any reflective objects without limitation of sizes restricted by the lens size of optics. A “deformed grating pattern” is observed when the reference grating is projected onto a mirror-like surface. This deformed pattern reflected by the surface is captured by a CCD camera and analyzed on the basis of phase shifting technique to give three-dimensional profile of the specimen. The reflection type of grating projection method attains such high accuracy in profile measurement as 1/35000 in relative accuracy to the measuring field size. Experimental results are shown with respect to a Si-wafer and a curved glass plate to verify the principle proposed here.

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A nondestructive detection technique and a high-speed inspection system for a narrow crack appearing at random on a ferrite surface have been developed. When a specimen is sprayed with ethanol, the ethanol on the surface evaporates quickly but the ethanol that has penetrated into a crack evaporates slowly. A crack is recognized by detecting the evaporated ethanol using FID (Flame Ionization Detector). In this system, 66 probes, each with a small area, are settled on to the specimen with narrow gaps between them. The gas on the surface is simultaneously held in 66 containers, each with a small capacity of 1× 10^-6 m³. The gas in these containers is led to the FID and the ethanol in the gas is detected. The minimum detectable mass flow rate of ethanol is 5.7×10^-10 g/s and the detection time for one container is 0.2s. The experimental results using this system show that the minimum detectable crack width is 3μm, and the expected detection time is 2.2s.

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This paper describes that a new type unconstrained surface method for micro stereolithography which can harden ultraviolet solidified resins selectivity by gathering ultraviolet rays under the surface of resins is proposed. The stereolithography method is roughly classified in two methods; one is a constrained surface method, the other is an unconstrained surface method. The constrained surface method has been used to fabricate microstructures using stereolithography because it is easy to obtain high accuracy microstructures than the unconstrained surface method. The proposed method has advantages of decreasing in a harmful influence of the fabrication accuracy for generated unsolidified layer for oxygen and for surface tension. The analyses of the shape of hardened resin are calculated the light energy distribution considering to an aberration of an object lens. The resin was hardened selectivity under the surface of the resin that is recognized. The results of the shape of curing resin which are compared with simulation analyses and curing experiments are in approximately agreement with the height of experimental structures.

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Stainless steel pipe with fine hole and long size has recently needed for the flow line of pure gas and liquid, which is used in the field of precision machinery. Inner wall of such a pipe should be finished with high precision. Stainless steel pipes with different size of inner diameter are polished by flowing slurry at high velocity through the capillary. Finishing modes are examined in detail by scanning electron microscopy and profilometry. It is found from the experiments that the surface roughness of inner wall of as-received stainless steel pipe is reduced gradually with slurry passes, in which larger inner diameter of pipe has very enormous reduction rate in early stage of finishing. Usage of larger grain becomes to yield higher reduction of surface ròughness. It is said that concentration of grain has a great effect on small inner diameter of pipe, but less effect on larger ones. Optical and scanning electron micrographs of the polished surface indicate that texture pattern of the inner wall disappears with slurry pass number, in which texture disappear in early stage of low pass number in small inner diameter of pipe, but not in larger ones.

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It is known that tool-work thermo-electromotive force (E.M.F.) includes the information on chip treatment or vibration frequency in turning. On the other hand, in case of interruptive cutting, reports on E.M.F. which aim to use the signal for monitoring tool failure are few. The present paper deals with a relation between tool wear of face mill and thermo-electric characteristics. Wave form of electric voltage and current in the workpiece which is caused by E.M.F.were observed and analyzed. The results obtained are as follows. In case of single tooth cutting, the rise time of E.M.F.is prolonged in accordance with the width of tool flank wear. In case of double tooth cutting, the wave form of composite E.M.F. at the time when the second tooth begins to cut is changed widely in accordance with the tool wear.Also electric current in the tool-workpiece closed circuit increases remarkably due to tool wear. This phenomenon is remarkable in light cutting. Theoretical analysis shows that main factor influenced is the change of junction electric resistance due to tool wear.

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Mirror-like surfaces obtained by the ultra-precision turning using diamond cutting tools are smooth to the eye, but rough under a microscope. Although a lot of work has been done on the roughness of the mirror-finished surface, its inhomogeneous static structure is not yet well analyzed. This has led to attempt to discuss quantitatively whether the surface texture was indeed chaotic or not. In the paper, the trajectory on the attractor reconstructed in phase space from a measured surface profile was characterized by the Lyapunov exponent and the correlation dimension. The characterization shows that the mirror-finished surface has the strange attractor, the positive Lyapunov exponent and the finite correlation dimension and hence it has the chaotic characteristics. Further, the mirror-finished surface produced by the ultra-precision turning becomes more chaotic as the feed rate and the cutting speed decrease.

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This paper deals with experimental analysis of thermal behavior of vacuum chuck for a basic investigation to design a chuck with very little flatness change due to thermal deformation. It is clarified that the temperature rise of chuck is nearly the same as that of spindle. And the free thermal expansion of aluminum alloy chuck in radius is larger than that of steel spindle. But chuck and spindle are bolted together, and then radial thermal displacement of chuck is constrained. The sliding distance between chuck and spindle and the ratio of sliding distance to difference between radial free thermal expansions of chuck and spindle are strongly influenced by bolt thrust and chuck thickness, not by bolt material.

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This paper describes the development of a system for pocket shaping with sharp-edged corners by use of a non-rotational cutter and a 6-axis control machining center. With a rotational tool, the remains take place at the pocket corners due to the configuration of tool, therefore, it is usually impossible to create the pocket shape with sharp-edged corners. In regard to the above problem, this paper proposes the new method to remove the remains from the corners and to form the pocket shape without round corners by the nonrotational tool. Thus, the non-rotational cutting tool is designed and a CAM software is developed to realize the proposed method. The sharp-edged corner lines consisting of the intersection of side surfaces of pocket shape are machined by use of the side cutting edge of the non-rotational tool, and the sharp edged bottom lines consisting of the intersection between the side surface and the bottom surface, by use of the top cutting edge after the rough cutting by 5-axis control machining with conventional rotational tools such as end mills. The system is applied to finish two kinds of pocket shape; one is composed of only planes, and the other of sculptured surfaces. As a result, the pocket shapes with sharp-edged corners are created, and the validity of the system is experimentally confirmed.

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The micro precise aspherical molding dies have been increasingly required. A new grinding method and a grinding system with 45 degrees inclined rotational axis of micro grinding wheel were developed. In the grinding test, a micro wheel of resinoid bonded diamond wheel was developed and WC (tungsten carbide) aspherical molding die were tested. By the developed system, the form accuracies of about 0.1 μm P-V and the surface roughness of less than 0.03 μ m Rmax were obtained and its machining feasibility was clarified. In this report, the effects of the wheel radius error and the wheel positioning errors (horizontal and vertical directions) on the workpiece form accuracies are simulated and its compensation methods are discussed. Finally, in the aspherical grinding tests, the grinding examples of tungsten carbide by using a proposed compensation methods are examined.

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The NURBS curves and surfaces have become the standard descriptions in the field of CAD and computer graphics. They have several problems, however, such as numerical instability, limited convex hull property, and inefficiency of computing points on a curve or a surface. In this paper, it is shown that these problems can be resolved by using our newly proposed homogenized NURBS. In the homogenized NURBS, the sum of the blending functions need not be unity and the fractional representation of the functions is replaced by the integral representation. By taking advantage of this characteristic and homogeneous curves, an extended finite difference method which efficiently and accurately computes points on a curve is presented. By using the homogenized NURBS, numerical instability vanishes, convex hull property holds strictly regardless of the signs of weights, and exact points on the curve can be computed very efficiently.

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