The exact solution to the forced vibration problem of a string whose length varies with time is presented. In this paper, it is assumed that the transverse driving force is uniformly distributed along a length of string, but its amplitude varies with time. The string supported at both ends is replaced by an infinite string, and one supporting point moving with time is replaced by a moving concentrated load whose amplitude is an unknown function of time. The wave equation of the infinite string is solved analytically, and the solution that satisfies the boundary conditions of the fimite string is obtained.

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The purpose of the study described in this paper is to analyze and predict the vibration response of an ICE (internal combustion engine). Firstly, all components of the ICE are modelled by the finite-element model, and their dynamic characteristics obtained by component mode synthesis or multiple component mode synthesis are checked by comparision with experimental results. Secondly, the dynamic characteristics of a FE model of the whole system synthesized by MCMS are compared with experimental results to verify the accuracy of the analyzed results. Thirdly, a computational prediction of the vibration characteristics, in the case that the supplementary parts are added to the original engine, is carried out and compared with an experimental result. In addition, the overall level of the force occurring at intake/outlet valve setting points is experimentally estimated for the purpose of application as a factor of excitation forces in the engine on operation. Then, by using the FE model and the estimated force at a valve setting point, a simulation of the forced vibration is carried out with MCMS, and it is shown that the results correspond well with experimentally obtained ones.

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In this report, the authors propose the addition of constraints between variable elements of spatial matrices on the experimental spatial matrix identification technique which they previously proposed, in order to enable the identification of physically meaningful spatial matrices by using a single-point excitation FRFs. Additional constraints are introduced by modelling an objective structure's dynamics, shape specifications, frequency ranges of interest, etc. After an explanation of the theory and its usefulness, an example is shown by using experimental FRFs of an actual beam structure on a free-free boundary condition. Three sets of physically meaningful spatial matrices of the specimen are obtained and studied by changing the modelling with respect to damping terms. In addition, two applicational simulations are carried out by using the identified spatial matrices

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A three-dimensional finite element technique is proposed for calculating the vibration of the stator of an ultrasonic motor by analyzing a sector corresponding to one polarized pair of the piezoelectric drivers. The validity of the computational technique is confirmed by comparison with the experiment conducted on a model stator. It is shown that the amplitude of the effective vibration in the circumferential direction is in proportion to the height of teeth cut out on the surface of the stator, while the displacement in axial direction remains almost constant.

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In this paper, we describe a construction method of global representaion of a general solution and Poincare mapping (or phase return mapping) from local exact solutions (or half return maps) for piecewise linear oscillators with discontinuous nonlinearity by using a pseudo-feedback approach. It is shown that for some piecewise linear systems, a general solution can be global represented by the form of superposition of linear system response and pseudo-feedback responses. Based on these global representations, we propose canonical forms of general solutions, steady states and poincare mapping. According to this formulation, phase return mapping can be expressed in a global analytical form depending on return time parameters. Finally, numerical simulations are performed, and the validity of the presented approach can be confirmed.

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A numerical and analytical study is presented here which suggests that jump phenomena and chaotic motion are possible from periodic excitation of nonlinear system of a single degree of freedom which includes the Duffing equation as a special case. Approximate analytical technilues (averaging method and Bogoliuboff-Mitropolsky method) are applied to obtain some of the resonance curves, and the chaotic motions are investigated by using the Poincare map, Li-Yorke's theorem, the Liapunov exponent, the invariant probability distribution and Mel'nikov's method.

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Accordind to the resonance phenomena with ground motion having a long period component, the displacement responses of base-isolated structures are expected to become quite large. Therefore, the base-isolated systems install Various types of devices to dissipate vibration energy. In this paper, to suppress such large displacement responses of the base-isolated structures, the characteristics of several types of nonlinear dampers to operate weakly in the range of small displacement and strongly against large dispacement are studied. In particular, the convenient equations for calculating the maximum responses are proposed by expanding the function consisting of the fundamental and third components into the Fourier series for the damping forces. Furthermore, the amount of the spike of acceleration is analyzed.

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We have numerically investigated the dynamics of a system represented by the Duffing equation with softening spring characteristics. In the principal resonant region of the system, there has existed the unsymmetric branch, corresponding to unsymmetrical solutions, in addition to the symmetric branch which corresponds to symmetrical solutions. The former branch has not been observed hitherto. It has been shown that the period-doubling bifurcation phenomena as well as chaotic phenomena occurred on both the symmetric branch and the unsymmetric one. Aperiodic vibrating phenomena have been concluded to be chaotic, based on the positive Lyapunov exponent. Further-more, the paper has illustrated Poincare maps and attractors, accompanied by the chaotic behaviors.

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The fast Fourier transform is very often used when time or spatial signals must be decomposed into their components. Zoom-FFT can be used if the resolving power of frequency should be increased to precisely determine the time or spatial frequencies and the phase angles of the components. However, the zoom-FFT requires many periods of the signals for that purpose. Nevertheless, there are many cases in which the resolving power of frequency must be increased even when only one period of the signals is on hand or can be obtained from the property of the measurement. This paper describes the equation and the calculation procedure of oversampling fast Fourier transform, which is useful in these cases, and confirms that the derived oversampling FFT is effective through applying it as an example to precisely determine the spatial frequencies and the phase angles of interference fringes in a speckle detected in an experiment on in-plane vibration measurement.

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This paper deals with the active control of structure-borne sound emitted from a vibrating plate. From the viewpoint of a feedforward control method, the suppression of the plate vibration is achieved. First, in order to control the vibration of a distributed parameter system such as a plate, a beam, etc, this paper proposes two kinds of vibration control methods: one is the progressive-wave type and the other the standing-wave type. Then, the characteristics of the sound radiated from the controlled plate are clarified. As a result, it is shown that there exist two types in radiation efficiency: one is a peak type and the other a notch type. Furthermore, a wave visualization system is constructed, making it possible to observe progressive waves propagating on the plate. By using this system, the validity of the control methods proposed in this paper is verified. Finally, the cancellation mechanism of the sound due to the existence of the negative acoustic intensity is discussed, and the reduction of the acoustic power because of that is investigated.

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In active vibration control technology, gust load alleviation and flutter suppression technologies are studied for aircraft. For this purpose, an aero-servoelastic analysis code was developed using the MSC/NASTRAN by MHI. Moreover, a control low-synthesis method was developed, being applied to LQG (linear quadratic Gaussian) method for reduced order control law design. To validate both the aeroservoelastic analysis and the control law synthesis code, the wind tunnel test of gust load alleviation was conducted in a 2m low-speed wind tunnel of Nagoya Aerospace Systems Works using an aeroelastic wind model equipped with an actively controlled trailing edge surface. Analysis results were compared with the results from tests and good agreement with test results was obtained for the wing acceleration. To estimate the effects of gust load alleviation and flutter suppression technologies, they were applied to a 150-passenger twin-engine commercial airplane. For gust load alleviation, a 46.9% wing bending moment reduction effect was presented and flutter suppression, 30.7% flutter speed augmentation effect was presented.

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A new air supply / exhaust control system was developed for pneumatic suspension of railway vehicle. This system which equalizes unbalanced inner pressure of air spring and horizontalizes the vehicle floor when the vehicle is slowed or stopped. It counters such defects experienced in the conventional leveling valve (LV) system as large unbalance of air spring inner pressure when stopping at distorted track of transient curve that might cause wheel unloading and decrease the derailment safety margin. The new control system is composed of solenoid valves, height and pressure sensors, clinometer and controller (CPU). Major control laws are (1) detect forced deflection of air spring caused by track distortion, (2) equalize the air spring height distortion when running, (3) horizontalize vehicle when slowed or stopped, and (4) equalize air spring pressure unbalance. These functions are implemented in a computer program.

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This paper focusses on the stabilization of an electropneumatic valve positioner. When the pneumatic tube from controller to actuator exceeds a certain length, the actuator will generate hunting oscillation due to the time lag of the pressure signal through the tube. To prevent this hunting, a new stabilization method is proposed for such control systems with time lag and nonlinearity. First, the system's structure and compensating circuit are explained. Next, the stabilization method is described and the prevention of hunting is certified by the Nyquist diagram. Also, the dynamic behaviors are examined through simulation experiments. Third, the robust stability condition is derived based on Palmor's criterion. Moreover, the stability margins under the identified errors of time lag are evaluated.

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The paper describes an approach to estimating unsteady flow rate through a pipe in real time. In this method, the unsteady flow rate is estimated by using hydraulic pipeline dynamics, and measured pressures at two points (upstream and downstream section) distant by a finite length along the pipeline. By scheming the high-speed operations of convolutions between the weighting functions and measured pressure data, data processing in a microcomputer system is achieved in real time using exclusive precalculated maps. The weighting functions are obtained by the application of the inverse fast Fourier transform from the transfer functions which are derived from the transfer matrix. Under unsteady laminar oil flow, good agreement between the estimated and measured flow rate waveforms illustrates the validity of the method proposed here.

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A cochlea converts mechanical vibrations of the basilar membrane originally caused by eardrum movement into electrical signals and transmits these to the auditory nerves. This organ is considered not only to receive sounds passively, but also to produce acoustic energy actively and emit sounds revesely to the ear canal. These sounds are generally called otoacoustic emissions (OAE). OAE is expected to be a useful clinical tool for investigating the inner ear function which cannot be inspected objectively at present. However, there are many open questions and a comprehensive understanding of OAE is still lacking. Therefore, in our research, an attempt was made to investigate basic characteristics of OAE in normal-hearing subjects.

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This paper deals with an application study of 6-axis forces and moments such as two shearing forces (Fx, Fy), compression (Fz), two bending moments (Mx, My) and a torsional moment (Mz) that are acting on the stump of the thigh during walking. The goal of this study is invention of an evaluative method for alignment of the A/K socket with the above-mentioned 6-axis forces and moments. There are two types of alignments of A/K sockets. One is rotation. The toe of A/K prosthesis is set inside (toe-in) or outside (toe-out). The another is inclination. The socket is inclined backward. In this study, the 6-axis forces and moments are measured with these two settings. One A/K amputee walked while wearing his A/K prosthesis, which is equipped with the 6-axis force and moment sensor. As a result of the walking experiments, the differences between the adjusted alignment and the above-mentioned two settings were determined, and the following observations were made. In the case of the toe-in setting, it is difficult for the amputee to walk smoothly because the stability of the side direction decreases. On the other hand, in the case of the inclined-backward setting, the stability of the knee joint at heel contact decreases, so the amputee cannot walk smootly.

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A new accurate measurement of variation of cavity volume in the container has been investigated. It is difficult to obtain stable measurement with the air jet due to variable factors such as the compressed air pressure and pipe dimensions. This paper deals with a new resonance method using the radiated sound from a speaker. The sound frequency obtained by the experiment is compared with the calculation result of the frequency found by the theoretical analysis in which the cavity system is connected with two acoustic pipes. This method of measuring the volume is available to measure the volume of a solid, animal, etc.

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Granules conveyed by transportation equipment with screw blades, such as a screw conveyer, are discharged pulsatingly. Therefore, the accuracy of supply is usually represented by the quantity of granules discharged from the screw conveyer per unit hour. However, if the instantaneous flow rate can be detected and the control can be implemented on the basis of it, then we may be able to construct a better conveyer system. In this paper, the control of the outflow quantity from the screw conveyer is discussed. As a control algorithm, a generalized predictive control (GPC) method, which is useful to the nonminimum phase process and the process with variable dead-time, is applied to the screw conveyer process. As for the results, good response waves are obtained for a step reference input and a disturbance input by introducing a zero compensator and a filter polynomial into the control algorithm.

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In the preceding papers, the authors proposed a method of the differential PWM for a hydraulic actuator operated by two 3-way high-speed solenoid valves. The actuator operated by this method shows good linear characteristics as a controller which achieves accurate positioning. However, when the actuator is connected to a load with large force over Coulomb friction, an oscillatory motion appears in the steady state. Therefore, the actuator control system becomes considerably inaccurate. To solve this problem, a new type of actuator, which has 4 check valves, is designed in this study. The dynamic characteristics of the actuator, which has a spring as a load, are investigated by simulations and experiments. Consequently, it is clarified that the actuator can be controlled with high accuracy, retaining a merit of the differential PWM method, and moreover, that the permanence of the proposed actuator can be improved by adopting a locking mechanism.

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We can recognize that both a model-following servo control system and 2-degree-of-freedom control system are constructed of the stable closed loop for the controlled object, the model, and the feedforward path from model to closed loop. In spite of the structural similarity, different names are attached to the individual control systems. Since the mathematical tools used for the formulation are the state equation and transfer function matrix, respectively, the approaches to solving the problem are different. However, it is inconvenient for us to potentially cause misunderstanding due to the entirely different control methods. Hence, clarifying the relationship between the model-following servo control system and 2-d. o. f, control system is a very significant matter in the case of application to a real plant. In this paper, the design methods of the model-following servo control system and 2-d. o. f. control system are each examined. Then, similar and different points are clarified. Next, the way of convergence of the control output into the model given by the designer is compared using the frequency response. In the model-following servo system, the dimensions of the model are not taken into consideration. However adequate convergence of the control output into the model is shown by using an example, if the dimensions of the model are restricted.

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This paper describes an investigation of the control methods for a scanner servomechanism used in a plain paper copier. Since wire and a spring are used in this servomechanism, it is not easy to obtain a step response without overshoot. Experiments with an actual scanner servomechanism used in a plain paper copier were performed, and good step responses without overshoot and with very small amounts of velocity fluctuations were successfully obtained through a design based on H_∞ control theory, and the use of learning control.

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This paper describes a control method for a baiting machine and presents its experimental results. The control law consists of proportional plus integral feedback. It then adds this feedback to a feedforward term in order to suppress the speed fluctuation resulting from the disturbance. The disturbance is mainly due to the cutting of bait. The feedforward term is introduced based on the observer theory that estimates armature current and disturbance torque by the discrete minimum-order observer. The baiting machine Control system is realized by the digital controller. The experimental results indicate that this control method shows robustness properties to the disturbance torque and is effective for control of the baiting machine.

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This paper discusses the regulator problem with the fixed terminal state for multi-input linear digital systems. First, for the general additive performance index, the fundamental structure of the regulator which drives the state to zero within a finite time is obtained. This problem is divided into three phases: the new free terminal state problem in the first phase, the new free terminal state problem for the time-variant system with the time-variant structure of the new input in the second phase, and the constant gain special deadbeat control in the third phase. That is, the new condition of optimality of the regulator problem with the fixed terminal state is expressed by the special deadbeat control and the induced regulator problem with the free new terminal state. The new solution of the deadbeat linear-quadratic optimal control problem is obtained to show the effectiveness of the new condition of optimality

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This paper deals with a new type of dynamically mobile robot modeling a gibbon, namely a long-armed ape, that moves branch to branch swinging his body like a pendulum. He does not use much force to move, because he makes use of gravity to swing. The manner of moving like a gibbon is called brachiation. In this paper we present the method to control the brachiation robot by showing the results of computer simulations using 2-link-model robot. The most difficult subject in this study is how to control it naturally and dynamically and with taking advantage of gravity force. First we introduce a heuristic approach to create driving force by exercising motions to move by the robot itself, then show that the interpolation of created forces in some situations makes new forces suitable to unknown ones. Finally we show that the proposed feedforward control system with a certain feedback loop gives a natural and dynamical motion of the brachiation robot.

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The authors have developed a parallel bicycle-type mobile robot which has a double controlling arm suspended from the upper end of its body and an articulated joint at the center of the body. This robot can change 1ts configuration by folding the body: therefore, it can be driven in the form of a bicycle or a four-wheeled vehicle. In the former. stability of the bicycle is attained by using the controlling arms. and in the latter. the controlling arms also touch the floor as well as the vehicle. In the previous paper. we reported the methods and experimental results on stability control together with ascending and descending stairs using arms and body cooperatively. In this paper, the control methods of driving with two wheels and experimental results on driving straight and turning are described. It is confirmed that the robot can be driven along an arbitrary path and stability control using the controlling arms is useful in driving control.

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This paper deals with the mechanism and the control method of the man-robot cooperation work type of manipulator with four degrees of freedom aiming at the application to the construction field. Because of the coming labor shortage of the aging society in the near future, robots will be used in the Construction fields more and more. To support robot operation, this study aims to develop a cooperation work type of robot to be controled easily by the direct teaching. The robot has the following features: (1) It has 4 D. O. F. and a parallel link mechanism. (2) It has a control sensor and a force sensor to cooperate with the operator and to control contact force between the robot and payloads or wall, etc. (3) The end effector of this robot has a vacuum system to carry payloads. (4) To make the operations of position control easy, the first arm is made fixable and also it has the bending vibration control system. With these features, this robot system makes it possible to carry heavy payloads easily and this system can be used for various kinds of work.

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Collision phenomena are very fast and nonlinear making it difficult to control the manipulator with collision phenomena. Therefore, in the past, manipulators moved slowly in order to avoid a collision. However, the necessity for high. speed tasks has been growing; thus, it is indispensable to control the manipulator with collision phenomena. In such fast phenomena, it is effective to use learning control in the forward manner. In this paper, we propose a learning control method to optimize the weighted least-squares criterion of learning errors. This method is applied to obtain a unique control gain by the Riccati equation which has the state dimension equal to the sampling number. It is shown that the convergence of learning error can be readily assured because the present learning rule consists of a steady-state Kalman filter. Using this learning control method, we report the results of the experiment on force control with a collision phenomena.

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In conventional optimum design process, symbolic formulation of mathematical optimization problem usually must be done by the designers before numerical computation. And these pre-process tasks are sometimes tremendously hard and time consuming for the designers. In this paper, we will show a simplification of these pre-process tasks with an aid of symbolic manjpulation systems which have been studied in the field of Artificial Intelligence. In almost existent symbolic manipulation systems, their main purposes being stressed on verifying the expression, the computer programs in the systems could not obtain any information directly from the operator during the excuting of the program. In this study, to reduce this disadvantage we use menu system as interactive computer system to define and decide the objective function and constraints freely. And, we applied a symbolic manupulation system to a formulation of the objective function and the constraints as well as to structural analysis by Energy method. Consideration have been given to the obtained optimum designs and the effectiveness was confirmed.

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Recently, in order to improve power plant thermal efficiency, the turbine blade, which is the most important element of the power plant, has been used in a severe condition where the high loading works. Therefore, for the purpose of increasing plant reliability, we must establish a precise calculation method and optimal design procedure of the blade, taking its specific characteristics into consideration. In this paper, an effective autotuning technique of the blade's natural frequencies is presented by combining sensitivity analysis with nonlinear programming, and its application is shown. In the blade design, many natural frequencies must be tuned between engine order frequencies, satisfying various constrained conditions which come from the requirement of thermal efficiency, manufacturing and so on. The new optimal technique in this paper is very useful in such blade design because the blade profile having the required natural frequencies can be obtained automatically.

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The characteristics of spiral grooved thrust air bearings, i. e., stiffness, load capacity, power loss and the fraction of critical damping, are analyzed. The finite element method and the computer simulation method are applied to obtain the numerical solution of the Reynolds equation. Based on the computed results, the effects of various specific design parameters of the bearing on the load-carrying performance and the damping characteristics are discussed. The principles for the optimization of the bearing design are proposed.

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This paper presents a convenient analysis method for the plane cams. This method is based on the principle of the offset curve of a plane curve and has the feature that the concept is clear and the computing process becomes simple. Almost the same manners can be used for the calculation of both the cam profile and the tool coordinates in manufacturing and for the influence analysis of the errors which occur in the manufacturing and assembling of cams, because the cam contour, the pitch curve and the path of tool center are the offset curve each other. Its validity is certified with some examples. This method can be effectively applied for CAD/CAM of the plane cam mechanisms.

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In this paper, the method of tooth contact analysis (TCA) is applied to hourglass worm gearing generateded by a conical surface, to analyze the influence of machining and assembling errors on tooth contact. Various errors in machining and assembling are introduced from the viewpoint of actual production. Software for calculating TCA and for mapping the contact pattern is developed. Different contact patterns are presented as examples to show the changes of the contact area with different errors, such as errors of the center distance, errors of the position in axial direction and errors of the axis angle. It is shown that the influences of machining errors and assembling errors on tooth contact can be eliminated under certain conditions. The results are expected to be useful as a reference for improving machining and assembling accuracy in production.

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In recent years, many new kinds of industrial materials have been extensively developed and applied. Some new ones have also been used as materials of worm gears. However, the applicability of new materials for worm gears must be further studied. In this paper, the authors investigated the practical possibility of a new combination of a super-hardness material, cermet and ion nitriding steel which are used as the materials of worm and wheel, respectively, in the case of heavy loads. First, the characteristics of velocity and load of this combination were clarified by using the disccylinder test machine. Then, the applicability was examined on actual worm gears.

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The bending fatigue strength of gears is quite sensitive to the qualities of the tooth root surface, such as roughness, heat treatment procedure and the properties of the gear materials. Howaver, in the conventional evaluation method for bending fatigue strength of gears, the influence of these qualities is not considered clerly. In this research, a method to evaluate the strength of carburized spur gear teeth is presented based on fracture mechanics. Under the assumption that the procedure of tooth fatigue breaking is that of crack growth the initial crack length, the length before the tooth was loaded, is calculated from the results of tooth bending fatigue experiments. Although the initial crack length is longer under a lower load used in the experiments, there is a limit on the initial crack length depending on the qualities of the tooth root surface. The bending fatigue strength can be determined by comparing the limit of initial crack length with the threshold crack length, which can be treated as a function of hardness for the carburized gear.

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Using hardened and tempered SCM440 alloy steel rollers with a hardness of about 450Hυ, the authors examined the effect of roughness combination of mating two surfaces on the occurrence of pitting under nearly pure rolling or rolling with sliding conditions. The present results showed a similar manner to the previous results obtained using thefmal refined S45C carbon steel rollers of about 320Hυ, but the roughness effects appeared more distinctly owing to the higher hardness and a decline in the running-in ability of the material. Namely, it was shown clearly that pitting is apt to occur on the smoother surface but is restrained on the mating rougher surface when two rollers with a large difference in the roughness are combined. Consequently the pitting life became very short when the faster side roller was rough and the slower side roller was smooth, while the life was extremely long when the roughness combination was reversed in rolling with sliding conditions. And it was supposed that such a distinctive feature in the occurrence of pitting is attributed to the difference in the plastic deformation due to the asperity interactions in the process of running-in.

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It has become very important to improve hydraulic motor efficiency, especially in the low-speed ranges, for finer operation. From this point of view, this report aims to prbvide technical data to help improve swashplate-type axial piston motor performance, particularly concerning the leakage and oil film thickness fluctuation between the valve plate and cylinder. The factors on their fluctuation were experimentally examined, and improvement by using the pistons with forced lubrication holes and a crowning shaft was attempted. The results show that the fluctuation of the tilt angle of the cylinder and the azimuth of minimum oil film thickness depend mainly on change of the high-pressure -side piston's numbers, and that the leakage flow rate fluctuation is mainly caused by the accuracy of the motor shaft.

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Improvement of the efficiency of hydraulic motors in a very important issue, especially in the starting and low-speed range, for finer hydraulic operation. From this point of view, this report aims to provide technical data to help improve the swashplate-type axial piston motor performance, particularly in terms of friction, leakage characteristics and oil film thickness between the slipper and swashplate. The effects on thede characteristics are examined with regard to rotational speed, phase angle and static force balance. The following results are obtained: (1) friction torque between the slipper and swashplate is negligible; (2) the leakage flow rate is affected by rotational speed and static force balance; (3) the slipper rotates and its speed is affected by rotational speed and phase angle.

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An indirect assessing method of wear progress on a magnetic disk surface was developed. The applicable amount of worn volume is limited to the order of roughness amplitude in 2-dimensions which can be measured by a stylus instrument with light load. Having established the physical measuring conditions and statistical sampling ones, several kinds of topographic parameters based mainly on asperity tip geomrtry were proposed such as radius of asperity tip, slope of the peak. tip segment area and mean gap between two adjoining peaks. Furthermore, a distinctive method for selecting higher peaks which are related to the contact with a head was developed. The values of these parameters were obtained on the Contact Start/Stop experiments and they were Verified to be effectual to distinguish the surface textures and assess the wear progress in a more quantitative way.

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The cost of casting products consists of material cost and molding cost. Up to this time, the inconsistency has been pointed out that the pricing of casting products is based on the weight of casting products. If the weight of casting products which use cores equals that which does not use cores, the shape of casting products which use the core is more complicated than that which does not use cores. In the case of an automatic molding machine, timely supply of appropriate core to the machine side is requireds. It is supposed that the core making time depends on the complicated degrees and numbers of cores. This paper analysed the relations between the data from the drawing and the data of core making time, and discussed the cost estimation methods for casting industries.

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One of the difficult-to-machine materials, austempered bainitic spheroidal graphite cast iron (ADI), has been machined so far only by grinding. In this paper, the effect of tool life on sintered elements of CBN tools was investigated. Cutting of ADI was attempted with the different CBN tools of sintered, elements which consist of c-BN grain size, binding material and content rate in both the c-BN grain and binding phase. The CBN tools containing small-sized c-BN grains exhibited excellent wear resistance and surface roughness compared to that containing large-sized c-BN grains. The cutting performance of CBN tools is due to the influences on cracking in the c-BN grain by stress concentration and bonding strength in both the c-BN grain and binding phase. The content rate shows that the optimum combination of both the c-BN grain and binding phase is about 40c-BN grain/60 binding phase in which the thickness of the binding phase is 3μm. The optimum cutting condition is 1.67m/s from the standpoint of wear resistance and surface roughness.

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Single-side straight cutting of an aluminum sheets is performed to investigate the effect of lower tool surface friction and workpiece constraint on lateral force in shearing of inclined sheet metals, in comparison with the results of conventional shearing. Tensile lateral force decreases with a decrease in the tool surface friction, resulting in an increase of the deflection of the sheet and deteriorating the ease in cutting the material. Compressive lateral force acts throughout the process even when the cutting-off length is comparatively large in conventional shearing of the loose workpiece constraint and the low tool surface friction.

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A new spray gun for laser spraying has been developed. The gun consists of a center outlet for a wire as a spraying material and two coaxial ring nozzles (inner and outer one) for assist gases. The wire was fed into a carbon dioxide laser beam with a high energy density and melted. The assist gas made the molten wire into fine particles and carried them to a substrate, where they formed a coating as a sprayed layer. In this report, a pure titanium wire was melted and blown in the form of titanium particles by argon, or titanium nitride ones by nitrogen. It has been found that gas flows are important in bringing about stable spraying and a small divergence of the particles, and influence the spraying efficiency and surface roughness.

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This paper presents the effects of heat fluxes from environment on the temperature distribution. A heating test was carried out on a wheel head stock of cylindrical grinding machine, which was placed on a steel base and enclosed with aluminum plates. A radiant heat flux from surrounding walls is calculated by using the measured temperature of walls and configuration factor. The effects of heat fluxes from environment of the temperature of a wheel head stock is discussed by comparing the practical experimental data and the theoretical finite element analysis (FEA) ones. The following result was obtained: Wheel head stock temperature was affected greatly by radiant heat flux due to temperature difference between the wheel head stock and surrounding walls, and also affected by convection heat flux.

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This paper proposes an iterative approximation method for minimizing the maximum lateness for a jobshop in which n jobs with ready times and due dates are processed on m machines in different orders. The proposed method consists of two phases I and II. Phase I sequences m machines one by one successively to obtain a feasible schedule of the m-machine shop, repeats this procedure m times by changing the first machine to be sequenced, and selects the best one. Phase II locally reoptimizes each machine based on sequences of the remaining (m-1) machines that have been the best ones obtained thus far. This procedure is repented until no improvement is possible. Computer simulations show that the proposed method can give schedules comparable to the SBI method by Adams et al., and better ones than representative dispaching rules.

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In this paper, we propose a numerical representation method of color by using a color image processor. We develop an HSV chart to show the color characteristics graphically from the relative frequency and relative cumulative distribution of HSV parameters, which have been applied widely in the field of computer graphics. The difference of color among scenes is shown by the Euclidian distance calculated from the parameters of the HSV chart. It is made clear from the analyses of some factory models that the HSV parameters of beautiful color are quite different from those of notice-able color.

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When and how machine dynamics emerged from practical engineering issues is historically studied. The ever-increasing speed and power of steam engines in the mid-19th century energized the engineers to develop new techniques of balancing wheels, particularly those of steam locomotives, to obtain running stability at high speed. Vibration of slender shaftings placed along the ceiling of factories was another urgent problem to be solved. The concept of flexural critical speed of a rotating shaft was thereby introduced, resulting in the birth of a new disciplinary field known as "machine dynamics".

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Development of any new product is similar to solving multiple simultaneous equations with so many variables that yield an infinite number of solutions. The course of development from the initial concept to the final product is a spiral that goes up to higher levels by repeating plan-do-see cycles. Selection of direction at every crossroad by a trial-and-error method is necessary to reduce the initially too many possibilities down to zero to reach the product. Contradiction of cost and safety must be solved in each decision-making process to build safety in the product. Recent rapid growth of the productive power of industry is bringing into play the principle of strict liability in tort.

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It is expected that four-wheel-steering (4WS) vehicles will enable higher performance than the conventional front-wheel-steering vehicles. Many kinds of 4WS systems have been proposed and studied. Most of them deal with tire characteristics as linear. However, a cornering force many be nonlinear depending on road conditions or vehicle state. In this paper, an adative control of a 4WS system taking into consideration the nonlinear characteristics of cornering force is developed based on the model following the control method and the neural network theory. The computational analysis demonstrated the effectiveness of using this type of control.

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This paper is the third report in our series of studies concerning the seismic design of tall structures such as reactor tower pressure vessels in chemical engineering plants and oil refinery complexes. Particular attention is paid to anchor-bolt yielding during earthquake excitations whose dynamic behaviour has been fairly precisely observed by shaking tests as described in the former report. In this specific work, we have proposed two types of simplified mechanical models (the single-degree-of-freedom slip-type model and the two-degree-of freedom rocking-type model) where-by inelastic energy-absorbing characteristics of the anchor bolt are simulated by referring to the experimental results. With the aid of these simplified models, numerical response analysis using the Runge-Kutta-Gill method is carried out under the similar conditions for shaking tests. As far as the structural response waveforms, inelastic loads and dynamic strains for the anchor bolts and energy-absorbing hysteresis curves are concerned, satisfactorily good agreement can be achieved between the testing results and the numerical simulation results.

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The monitoring of cutting conditions is one of the most important techniques in the machining process. In this paper, we monitor the cutting condition from the start of the cutting process and classify the cutting condition into normal, chatter, built-up edge and tool fracture. This paper consists of the following: (1) modeling of abnormal cutting processes; (2) choice of characteristic parameters to classify the cutting condition; (3) experiment and consideration for confirmation of our proposed method. Finally, we show that the monitoring based on cutting models has a good ability to detect abnormal cutting conditions.

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