In previous papers, one of the authors proposed a new technique of identifying nonlinear multi-degree-of-freedom systems, and showed that the technique produces accurate results when the dynamic data are of good quality. However, it has been found that the accuracy of the identified results becomes worse rapidly as the dynamic data are polluted more. In this paper, as an attempt to improve the accuracy under noisy measurements, the previous method is revised by introducing a statistical method, the Lagrange multiplier method. Some numerical simulations are conducted, and it is shown that the revised technique significantly improves accuracy.

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In a previous paper, the authors proposed a nonparametric Identification technique of nonlinear multi-degree-of-freedom systems. Theoretically, the technique can be applied to systems with any number of degrees of freedom, but it has been found that in practical cases the technique is difficult to apply to systems with larger degrees of freedom. The reason is that the unknown parameters for a system become vast as the degrees of freedom of the system become larger. In this paper, an improved technique is proposed which not only requires fewer unknown parameters, but also is more convenient for use in succeeding analysis. Numerical simulation is conducted, and applicability of the improved technique is shown. Furthermore, its advantage in succeeding analysis is demonstrated by applying the identification results to the incremental transfer matrix method.

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In this paper, a new approach to obtaining mode shapes is proposed. The method analyzes mode shapes from the variation of the natural frequencies of the structure when an additional concentrated mass is attached. Although the method is unable to acquire high accuracy, such as the experimental modal analysis method based on curve fitting, and its application is confined to flexible structure, the method is simply and quickly achieved by using the frequency data only.

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A repetitive control scheme which is applicable to a class of nonlinear systems with periodic reference signals is proposed. The nonlinear terms in the systems are assumed to be polynomially bounded. Sliding mode control is applied to an augmented system in which an integrator and a repetitive, controller are added in order to obtain a linear input-output relation. The stability condition for the repetitive control system realized by the proposed method is derived. It is shown that this system satisfies the internal model principle in some frequency bandwidth. The frequency bandwidth is given by the stability condition. An illustrative example is given.

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A new identification method for the loss factor and Young's modulus of viscoelastic three-layered beams was studied. The test beam, composed of two surface sheets with viscoelastic resin between them, was excited at its center sinusoidally. Vibration velocity ω and force F₀ were measured at the center, and frequency response curves of transfer function ω/F₀ were obtained using a two-channel fast Fourier transform analyzer. The complex Young's modulus E(1+jη) of the three-layered beam was determined as ω/F₀, whose measurement satisfies the beam equation of motion at every frequency. Good agreement was achieved for the complex Young's modulus measured by this method and by the conventional method. Shear modulus G'+jG" of viscoelastic resin was also calculated from the complex Young's modulus by means of the Ross-Kerwin-Ungar model. Good agreement was also obtained for the shear modulus. These agreements suggest that the new identification method presented is reliable enough to measure E(1+jη) of the three-layered beam and G'+jG" of viscoelastic resin in the middle layer.

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Loss factors for vibrating arches made of vibration damping steel sheets (VDSS), which are constructed in three layers with a constrained viscoelastic core layer, are predicted analytically. Thus derived vibration equations suggest that flexural motion couples with in-plane motion depending on the curvature of an arch and the vibration-damping effect caused by shear deformation of the viscoelastic core layer is influenced by the value of curvature. Numerical results for free vibration show several characteristics of the loss factor; i.e., the loss factor monotonously increases with the mode ratio which represents the ratio of the in-plane displacement to the flexural displacement. The mode ratio linearly increases with the square of the ratio of wave-length to the radius of curvature for simply supported arches. Meanwhile for arches fixed at both of their ends the mode ratio does not increase monotonously with the curvature. Experimental accelerance curves for VDSS arches with several arch heights are obtained and loss factors are estimated by half-value width. These results are compared with calculated results.

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This paper describes the static and dynamic characteristics of a new type of elastoplastic damper and seismic responses of a base isolated building using the elastoplastic dampers. The damper uses two pairs of V-shaped plates and its force-displacement curve is nonlinear with a hardening characteristic in the plastic range. The static force-displacement curve is obtained theoretically, and the dynamically equivalent model which takes into account elasticity, viscosity, plasticity, strain-rate sensitivity and geometry change of the damper is proposed. A seismic isolator consisting of rubber bearings and the elastopladtic dampers is also proposed, and the seismic responses of a 7-story building isolated by this isolator are calculated using a continuous system simulation language (CSSL).

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In the Laplace transform boundary element analysis for unsteady elastodynamic problems, the inverse transform must be performed numerically. Computational accuracy and efficiency of the results are influenced by the computational conditions such as the sampling number and the number of boundary elements. This paper proposes a new procedure to determine the computational conditions for accurate and efficient analysis of the unsteady elastodynamic problems. The proposed procedure employs two techniques of the numerical inverse Laplace transform, that is, Hosono's technique for obtaining the reference results and Durbin's technique for main use in numerical analysis. Numerical computation is carried out for several two-dimensional problems to demonstrate the usefulness of the proposed procedure.

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In this paper, the relationship between two methods of checking safety against derailment for rail vehicles has been clarified. One is the method used to constrain the ratio of wheel load and lateral force, which is used for conventional railways in general and is expressed by the so called Nadal equation. The other is expressed by the ratio of loss of wheel load and static load, which is used for rack railways in Switzerland. The later method is more sufficiently on the safer side than is the Nadal criterion. A new evaluation method for safety against derailment is proposed, taking account of the merit of the Swiss method.

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Moving-bed heat exchangers have extensively been used for waste-heat recovery from hot particles in many industries. However, if the particle diameters are large, the heat-conduction effect within the particles has to be taken into account. In this paper, a model of the heat exchangers, taking into account the heat conduction within the particles, is proposed. In addition, three dimensionless parameters (Cr, NTU and Biot number), governing the characteristics of the heat exchangers are described. The proposed model has subsequently been employed for calculating the transient response of the temperature of the outlet gas, subject to step changes of the moving-bed speed. It has been found that the dynamic characteristic of the heat exchangers is dependent not only upon the heat conduction, but also upon Cr and NTU. The heat conduction has a more significant effect on the static behavior than does the dynamic characteristic of the heat exchangers. Furthermore, the experimental data have also been presented to confirm the validity of the proposed model.

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A mesh-generation technique which generates a three-dimensional computational mechanics model is hereby proposed for mechanical design work. The technique is based upon the extended oct-tree representation method for a geometric model, and utilizes attributes known as features of the design model to generate a well-graded mesh. The features describe the meaning of geometry and the intention of analysis. In mesh generation, the octant detects the features and the mesh density is controlled by handling the depth of the oct-tree, in order to generate a well-graded mesh for either FEM, BEM, or FDM. The technique realizes both shell- and solid-type mesh generations. The solid meshes are yielded by utilizing the shell-mesh-generation process to improve the robustness. The robust shell-mesh generation is realized by interpreting the features and relocating the nodes of the octants. The technique is also useful for an h-version of the remeshing process.

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The massive algebraic calculation is usually required to carry out the higher order analysis by perturbation method. In this paper, the method of multiple scales is automated on Computer algebra (REDUCE 3.3) by introducing a new operator, so that the higher order analysis, which is unthinkable by hand calculation, can be accomplished. By applying this algorithm, the 6th order analysis of the typical nonlinear dynamical system, as well as expressed by a nonlinear differential equation with a periodic coefficient and a nonhomogeneous term, is quickly and accurately performed. Furthermore, by comparing the above approximate solution with the numerical one, it is shown that the 6th order approximation is effective.

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This paper deals with an automatic culture monitoring system of the plant cell "protoplast". The conventional monitoring system mainly has two problems : [i] no method of recognizing the life or death of a cell without using chemicals, [ii] the hard and laborious work for biologists to monitor cells and to find the best culture condition for them. In this paper, a new method using image processing and the neural network is proposed to solve these problems. The image processing can provide a method of measuring of the shape and the colors of a cell. The neural network can recognize the life and death of a cell from image measurements. This method gives correct answering at an accuracy rate of 85 percent. Because this accuracy is considered about equal to human performance, this system will provide an alternative method to monitoring cells.

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A sequential point method was proposed by Tozawa et al. to measure workpiece straightness on machine tools. The apparatus is very simple, but its error is not always small in comparison with standard techniques. Therefore, some improving techniques to correct the error were reported. However these techniques are not always effective in improving the measuting accuracy because the relationship; between the error and its factors were not clarified. This paper thowed the mathematical function based on gradual functions and the solutions to describe the sequential point methods and its error. The functions clarify the error easily. According to the analytical results, the error caused by calibration error of sensor position is much larger then the error caused by the random measuring error of the measuring point.

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A method of calculating the increment of the joint angle velocity vector at the impact, Δq, which is substantial to the forward dynamics is proposed using Newton-Euler equations. First, assuming that (1) a landing leg does not bounce, (2) the force and the torque vectors from the ground are delta functions of time t, and (3) the joint torque vector is piecewise continuous in t, we obtain the increment of the joint angle velocity of the joint i, Δq_i, and the increments of the linear and angular velocities of the frame attached to the link i, Δv_i and Δw_i, as homogeneous linear equations with respect to the increments of the linear and angular velocities of the frame attached to the foot link 0, Δv₀ and Δw₀, and the impulse force and torque from the ground to the foot link, δ_f and δ_n. Next, 14 homogeneous linear equations in (Δw^s₀, Δv^s₀, δ^s_f, δ^s_n)_{s=r, l} (r : right, l : left) are derived recursively using the above equations from the foot link to the trunk link. Then, imposing the feet conditions to the linear system, we obtain all the unknowns including Δq. A numerical experiment of the method applied to a 4-degree-of-freedom (dof) biped walking machine with stilt foot links shows (1) all the unknowns including Δq are obtained, and (2) the 14×12 system of linear equations to be solved in the method is of full rank in almost all the cases.

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The authors have previously announced the development of a new design concept for flying head slider mechanisms to be used for information storage. These mechanisms operate under completely noncontact start stop mode conditions with magnetic disk media based on negative pressure slider self-loading. The reliability of this system's dynamic self-loading depends on the self-loading velocity, which is defined as the velocity when the slider approaches toward the disk surface under control of suction force provided at the slider air bearing surface hydrodynamically. Therefore, the critical governing factors in its self-loading dynamics were studied in detail in order to achieve high head/disk interface reliability. The disk surface velocity and the initial slider pitch orientation are confirmed to be the most critical parameters for reliable self-loading. The optimum self-loading criteria for the proposed self-loading flying head slider mechanisms have been successfully derived.

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This paper presents a control scheme for redundancy resolution through local optimization in impedance control of redundant manipulators. The proposed control scheme achieves the desired target impedance while utilizing the redundancy to optimize any kinematic objective function. The scheme is also implemented for real-time control of a 3-DOF planar redundant manipulator by utilizing a multiprocessor controller, and experimental results are presented. The experimental results validate the proposed control scheme and demonstrate its capabilities for optimizing various objective functions. Furthermore, the experimental results also show that both free motions and contact tasks can be controlled successfully using the proposed control scheme.

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In the space environment, due to recent active development, there are an increasing number of cases where it is necessary to move objects quickly with a large moment of inertia. Hence, it would be desirable to develop more powerful actuators. An actuator developed for hydraulic control in space is called a flexible hydraulic actuator (FHA). The actuator consists of a rubber core tube and string cords to cover it. The main feature of the FHA is no need for lubrication. The precise mathematical model in static and dynamic motion is derived and compared with experiments. The actuator with loads is investigated through experiments. It is also ascertained that the FHA responds quickly.

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This paper deals with a new concept of an optical servo system and an experimental analysis on photostrictive ceramics for use as an optical actuator in the servo system. The optical servo system proposed here may be characterized by the introduction of an opto-hydraulic control valve into the system. The opto-hydraulic control valve can be operated by an optical actuator which is directly dirven by light irradiation. The photostrictive effect in PLZT ceramics, which is produced from the superposition of the photovoltaic effect due to light irradiation and the piezoelectric effect, is evaluated experimentally from the viewpoint of the applicability to a servo actuator. Experimental results show that the PLZT (3/52/48) ceramics produce a strain as large as conventional PZT ceramics, but that they have a very slow dynamic response of about 100 sec. The slow dynamic response is due to the time lag in the photovoltaic effect.

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This paper presents a practical construction of a minimum-energy positioning control using an optimal regulator. The positioning control system with various positioning times can be realized with only one basic time-varying feedback coefficient vector, that is calculated for the maximum positioning distance X_max. Calculation results show that the proposed control method can position an optical head with consistent accuracy and power consumption per unit time for various positioning times, when the positioning time T is determined in proportion to the square root of the positioning distance X, that is, T ∝ √(X). An optical head positioner with an air slider is examined. The motion straightness is verified to be sufficient for precise positioning of optical heads. Experimental positioning results demonstrate the effectiveness of the proposed control method and the positioning mechanism for high-speed positioning.

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When a robot is used for doing work such as laser processing or water-jet processing, not only the trajectory of the end-effector but also its velocity is very important from the viewpoint of the processing accuracy. On the other hand, several curve-interpolation methods have been suggested, but it is cannot be said with certainty that the correct velocity control of the trajectory is possible. In this study, in order to solve this problem, a method using the clothoidal curve is introduced, and this method enables the velocity control with high accuracy for any trajectory.

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This paper discusses the new optimal digital filter for the single-output linear time-invariant discrete-time system without the prior stochastic information about the initial state. The Kalman filter is obtained on the assumption that the prior information about the initial state is known. Since this assumption is not satisfied practically, the new optimal digital filter which is named the deadbeat Kalman filter is derived. The deadbeat Kalman filter is independent of the prior information about the initial state, and is unbiased and optimal after the minimal finite step. Finally, the duality between the deadbeat Kalman filter and the deadbeat LQ optimal control is shown.

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In this study, the simulator of a gasoline engine is built, and the fuzzy theory is applied to the air/fuel ratio controller. The gasoline engine simulator is made of simple mathematical equations and torque map. The simulator consists of three parts : intake, combustion and mechanical load. The intake part had a first-order lag. The combustion part is mapped from the data based on the engine torque test. The mechanical load part is described by a differential equation. The fuzzy controller is designed to keep the air/fuel ratio constant. The controller has two fuzzy rule tables made by considering the nonlinear characteristics of the oxygen sensor. Experimental results show that the engine system with fuzzy controller has good responses from the viewpoints of engine speed and torque control.

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The results of experimental study on ultraprecision orthogonal microdiamond cutting of single-crystal copper are presented. The orthogonal cutting tests were carried out on an ultraprecision fly-cutting machine under various nominal depths of cut from 3.0 μm down to 0.01 μm (10 nm ). The machinability in microcutting and the influences of crystal orientation on the microcutting process are discussed from the standpoints of chip formation, cutting forces and surface integrity. It is confirmed that the continuous chips are formed under the whole cutting conditions examined. The magnitude of the cutting force and the shear angle are substantially influenced by the crystal orientation at depths of cut of 1 μm or more, while they are not notably influenced with a decrease in the depth of cut below 1 μm.

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This paper deals with the machining tests regarding the oxygen-free copper (OFC) as one of the suitable materials for diamond turning. The machining tests were carried out to study the proper cutting condition for OFC, the selection of suitable high-purity OFC material for mirrors and the mirror-finishing properties of the suitable OFC material over long cutting distances. The test results show the following : (1) The proper cutting conditions are 9-17 μm/rev in the feed rate and 15-20μm in the depth of cut. (2) The raw material produced by the processes of hot roll, cold roll and heat treatment is most suitable in the aspect of the surface integrity. (3) The surface roughness is stable in the range of 500km of cutting distances. As for the tool wear, the crater wear is especially ramarkably large, while on other hand, flank wear is negligibly small.

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The study deals with the development of an ultraprecision lathe consisting of such elements as an air bearing spindle, a tool-moving device and a feed mechanism. The spindle-attaching workpiece is driven by an AC servomotor. The diamond tool is mounted to the tool-moving device driven by a piezoelectric actuator. The tool-moving device is mounted on the feed mechanism composed of the combination of the air slider and the friction drive. These elements, set on the concrete bed supported by air dampers, are placed in a clean booth. The lathe is enabled to produce a workpiece of aluminum alloy with the accuracy of 0.24 μm in surface flatness and R_max 94nm in surface roughness. In addition, the movement error of the feed mechanism and the spindle rotation error are measured to improve the machining accuracy. The tool-position control on the basis of measured errors leads to the improvement of surface flatness.

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Urethane vacuum chucks which are in use for diamond turning to aluminum discs because of their high friction coefficient and the high damping ratio have problems such that the swelling by a coolant and nonuniformity of the supporting rigidity due to the chucking grooves make the form accuracies of workpieces deteriorate. Thus, a sintered porous chuck made of fluororesin has been developed. The investigation on the mechanical features of the chuck indicated that the chuck made a small deformation against vacuum suction and loading and that it had an adequate friction coefficient and adequate bonding strength onto the chuck body for diamond turning. Then, diamond turning of aluminum discs was carried out using a hard aluminum chuck, a urethane soft chuck and two types of fluororesin porous chucks. Consequently, the cutting using a fluororesin chuck achieved better straightness and smaller acceleration of a turned surface than that using a urethane chuck and an aluminum chuck.

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This paper deals with the change in shape of the front surface of vacuum chuck employed for ultra precision machining due to the centrifugal force generated by the rotation of the spindle. Displacement, change in shape of the front surface and the diametrical expansion of the chuck made of aluminum are analysed experimentally under several contact conditions. Deformation analyses of the chuck by FEM based on several models for the ordinary contact condition are also carried out to compare with the experimental result. It is clarified that the axial and radial deformations of the aluminum chuck agree well between the experiment and the FEM analysis based on a model with fixed contacts at the interface between the chuck and the spindle. Deformation of another type of chuck consisting of a combination of steel and aluminum parts is also analysed.

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In order to develop an ultraprecision machine tool or coordinate measuring machine, it is the most important to understand the characteristics of the connecting mechanism between the table and its driving system. The conventional connecting mechanisms so far used are considered to be inadequate to meet the current needs of ultraprecision machines. An advanced connecting mechanism should provide high rigidity only in the feed direction, i.e., direction-oriented rigidity, simultaneously having high flexibility in other directions to isolate unfavourable vibrations and disturbances. In contrast, such a connecting mechanism does not allow any heat transfer from the driving system. In this paper, therefore, to establish a precision feed table system, the two connecting mechanisms based on a new concept were proposed, and their performances were proved using a precision feed table system.

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The characteristic comparison of three kinds of leadscrews (a precision sliding screw, a precision ball screw and a rolled ball screw) is described on the one-dimensional ultraprecision positioning apparatus with a position feedback system in the PTP method. The followings are clarified ; (1) Since the damping factor of the ball screw is ten times smaller than that of the sliding screw, the table response using the ball screw is sharper and shows a larger vibration, (2) when three kinds of leadscrews have the same friction torque at low speed, the relationship between the variation of the friction torque and the positioning error is clarified from the quantified point of view by a step response using the proportional control. (3) The relationship between the electric current of the DC servomotor and the table displacement in the step response under sub-micronmeter stroke is of stick-slipping characteristic for the sliding screw and of elastic characteristic for the ball screw.

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The sequential two-point method is a new method of straightness measurement with a simple algorithm which does not need a specific base line. Advantages of the method such as measurement of both the accuracy of tool movement and cut surface by the single path of data acquisition, good accuracy for the repeated measurement, and stable measurement even for dynamic conditions have been pointed out. In this paper, in addition to these, it is proposed that the accuracy can be improved by making use of the data which are interpolated by feeding the sensor device with shorter steps than the distance of the two sensors. The effectiveness of the method is proved by measuring the profile of aluminum thin film pasted on an aluminum disc cut by a diamond tool. It is also made obvious that the measured straightness can be corrected by adopting a series of the interpolated data whose distance is just equal to that of the sensors.

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A precision steel ball mounted at the center of the spindle end and an electronic capacitance type transducer installed on the tool slide with three dimensional sliding stage. Relative displacement in axial direction between the ball and the transducer is detected during spindle rotation. Detecting method of the central position is based on the fact that undulation component synchronized with rotational speed of the spindle in the displacement signal comes into minimum value at the central position of rotation. The results of preliminary experiments may be summarized as follows: (1) The new method is capable to detect the central position better than ±0.1 μm measuring resolution. (2)In case of the spindle with hydrodynamic bearings, central position of the spindle rotation very differs in different rotational speeds.

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Measurement method of surface profile by using scanning electron microscope (SEM) was applied to plastic materials, which have needed other method than the conventional ones such as optical method, needle trace method and others. The method by SEM has advantage in accurate and non-destructive measurement. Metal coat on surface is required for plastics in SEM environment. SEM using four detectors which was developed for the measurement of surface profile was used. Standard specimen of sphere made from polystyrene whose diameter was 0.03 mm was adopted. It was made obvious that sufficient time for coat such as 10 min is required for stable output intensity to derive the profile. Correlation between emission voltage of electron beam and the output intensity for the profile in terms of coating time indicates that adequate emission voltage which effectively represents the profile can be taken depending on thickness of coat. Accurate measurement is shown possible for the profile of cut surface of acryl and for the sphere of small ruby ball.

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High concentration of active grains and low bonding strength are important features for the increase of the removal rate and the reduction of the subsurface damage in lapping of brittle materials. Thus, high-concentration lapping discs with low bonding strength have been developed. First, the finishing characteristics using the lapping discs were investigated, varying the concentration of bonding agents and thereby determining that a high removal rate could be obtained at a small concentration. Next, soft abrasives which might have a mechanochemical reaction with workpiece materials were adopted as the abrasive material of the lapping discs, and colloidal silica which might have a mechanochemical reaction with workpiece materials was applied as a coolant in finishing. A mirror-surface finish of less than 10 nmRa was obtained for various brittle materials, and a smooth -surface finish with no dropping-out of grains was achieved for aluminum-nitride substrates.

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It is very important to decrease the amount of chipping in the dicing process of brittle materials for the reduction of material loss and the improvement of surface integrity in the production of optical and electrical components. The use of ultrafine abrasives reduces the grain depth of cut, which results in the minimization of subsurface damage. Thus, a new dicing technology has been developed by applying electrophoretic deposition of ultrafine abrasives. During the process, the abrasives cohered around the thin conductive blade used as the anode in an electric field and polished the side surfaces of grooves. Consequently, chipping-free dicing was accomplished and an optically smooth surface was obtained on the side surfaces of the groove.

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The purpose of this study is to develop a geat-cutting method for hypoid gears to obtain good tooth bearing and to attain good performance for practical use. In this report, the authors propose a new cutting method of the parallel-depth hypoid gears which mesh with each other at one point at a constant angular velocity ratio. The most important point that the authors want to claim is that not only is the conjugate contacting granted, but also the designer can control the trace of the point contact mark on the tooth surface as he desires. Finally, the authors show an example of the design in which the trace of the point contact mark coincides with the tooth trace.

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Changes in head geometry caused by head-to-tape contact are investigated analytically. In this paper, an original algorithm of numerical analysis for wear progress of a head is proposed, and transient changes in the head-to-tape contact condition and head contour induced by wear on the head are analyzed. Numerical analysis on the amount of head wear was carried out under the concept that the head is divided into finite the elements and these elements wear cut selectively at the high-contact-pressure region during the wear process. The validity of the algorithm was examined by comparing the estimated wear amount and head geometry with the measured ones. From these investigations, the following points were clarified. The process of head wear can be calculated by the proposed algorithm whereby finite elements are scraped selectively by the contact force acting on the head. The sized of time steps and finite elements should be determined based on the surface roughness and the stability of nordal load, respectively. When the head starts to slide on the tape, an imbalance in contact pressure causes a rapid increase in contact pressure immediately due to redistribution of contact pressure, and it becomes maximum. The sooner the head comes into contact with the tape, the larger this maximum value becomes. However, in accordance with an increase in the contact region, contact pressure does not have maximum value and increases gradually. As the result, the head wears uniformly.

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An electric connector is produced by press working with a progressive die. The surface of the workpiece is roughened by the compression process, which is harmful to the subsequent gold plating. The behaviour of the surface roughening of Cu-Ni-Sn alloy with 0.645 mm thickness was examined through the changes in the oil viscosity, the velocity and the grain size of the workpiece with a drop tester and conventional presses. The roughening was caused by the squeeze effect of trapped oil between the surfaces. The roughness increased with increases in the reduction rate of the thickness, the velocity and the grain size. After having the minimum value at 30 cSt, the roughness generally increased with the oil viscosity. The roughening behaviour by the drop tester was almost the same as that on the free surface appeared by the tensile test.

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Impedance of the piezoelectric ceramics indicates a peculiar frequency characteristic, when the alternating current is supplied to the ceramics. The frequency characteristic around a resonant frequency changes greatly due to distortion of the ceramics. Using this property which is caused by the pressure difference between the two sides of the ceramics, the pressure sensor is divised. In this study, it is shown that the sensor is effective in measuring pressure. The fundamental properties of the sensor, especially the sensitivity to pressure and the dependence on temperature, are examined.

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This paper will investigate the use of a new sensor device for detection of acoustic emission through fluid for a drilling machine and for the machine center. Within the industry there has always been the need for a practical application of the sensor of AE through fluid to detect the cutting-process-related signals from the tool side. Amounting device which enables the sensor to be fixed close to the rotating multipoint cutting tool has been developed to meet this need. Thus, there is now a more practical method for detecting the tool fracture and tool wear of twist drills. Judgment of tool life by use of a method for quantifying by the ratio of the event count and oscillation count per unit time allowed to the judgment of tool life was carried out very accurately from the above transaction, and the evaluation method for quantifying tool life by the ratio of the event count and oscillation count was found effective.

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This paper describes two methods concerning vague knowledge in multiobjective evaluation reasoning. Multiobjective evaluation reasoning has a two-stage reasoning process which can assist the design process of production line design. Vague knowledge and factual knowledge are simultaneously expressed by frame knowledge representation combined with four other types of knowledge. In frame knowledge representation, vague knowledge is constructed by the structural tree arrangement which is expressed by vague descriptions of knowledge and attached procedure demons. Because of frame knowledge representation, vague knowledge is systematically expressed. The interview performed by a pairwise comparison, based on the hierarchical relationship constructed by the interdependence relationship of a whole and a part, makes it possible for an inexperienced user, who possesses only vague knowledge, to answer the system questions concerning a scaling constant.

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This paper aims to design a flexible GT cellular layout and discusses its methodology. The method integrates production planning and GT cellular layout during a long-run planning horizon. The integrated planning model is formulated as a mixed-integer program (MIP), which contains two types of integer programming problems : determining (1) the production quantity and (2) the timing of the adjustment for the GT cellular layout in a finite planning horizon with a dynamic demand situation. This decision problem is solved so as to minimize the sum of inventory holding costs, group setup costs, material handling costs and layout adjusting costs subject to the capacity constraint and the demand requirement. The Benders decomposition is used to solve the MIP. The obtained dual problem is solved by linear programming using large-scale programming techniques. The decision rule determining the decision variables in the dynamic demand situation is proposed by examining the properties of the optimal solution obtained. And a method is also presented to cope with the uncertainty by adjusting individual production rates from their initially planned levels on the rolling horizon of T periods. Finally, a numerical example is demonstrated to explain the analytical results.

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This paper deals with a machine tool design system based on a mathematical model of the shape generation process, aimed at establishing a systematic design methodology for new machine tools taking consideration of machining accuracy. In particular, emphasis is given to analysis of geometric errors on product surfaces due to kinematic errors of shape generating motions between tools and workpieces. The main topics are as follows: (1) the establishment of a mathematical model of shape generating motions of machine tools with kinematic errors; and (2) the estimation of geometric errors on product surfaces due to the kinematic errors in shape generating motions.

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Decreasing the friction loss of gears and its quantitative estimation have become very important problems, because these problems relate to economizing energy and improving the load carrying capacity of gears. However, past research concerning the friction loss of spur gears is not sufficient for estimating the friction loss. Therefore, we have carried out experiments to study the influences of tooth form, chemical structure and viscosity of lubricating oils, sliding velocity, and load on the friction loss of spur gears. Many new tendencies of friction loss of spur gears were brought out, and finally, empirical formulas for calculating the friction loss of spur gears are established.

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This paper describes the step response of a hydrostatic thrust bearing which can have a very high static stiffness by using a new type of self-controlled restrictor. Many design parameters affect the step-response characteristics of this type of bearing. Here, the influences of each parameter on the step response are theoretically investigated, and the theoretical results are compared with experimental ones in order to confirm the validity of the theoretical predictions. It is found that the hydrostatic thrust bearing with the self-controlled restricotor consitently shows a stable step response.

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This paper proposes a new method for modeling flexible structures with distributed parameters into a reduced-order model with ramped parameters, taking into consideration both the prevention of spillover and physical correspondence at modeling points. To control the vibration of a flexible structure using modern control theory, it is necessary to make a reduced-order model of the structure, due to restrictions on control system design. The order reduction may invite the problem of unstable vibration control, called spillover, by the effect of an ignored higher-order mode. In this method, nodes of the higher-order vibration modes are selected as the modeling points to prevent spillover, because of the phenomenon of uncontrollability and unobservability. The effectiveness of this method is demonstrated by applying the vibration control to a flexible tower structure.

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This research work deals with the development of a simple and practical manufacturing technique for metallic micro structural parts in the order of 0.01-1mm in size. In this technique, an ultra-violet laser beam is irradiated into a liquid photopolymer material through a mask. The irradiated pattern is then developed to obtain the solid mold. The metallic part is then made by electroforming process. This paper deals with the first process that is making a photopolymer mold. At first the accuracy of the mold is estimated by applying diffraction and absorption theories of light. Next the accuracy is examined experimentally. The results show an accuracy of ±1μm can be obtained when the distance between mask and photopolymer layer is 10μm. By using the stacking of thin films, precise mold with deep straight Walls are made.

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