When a Fiber Reinforced Plastics(FRP) is used as a structure, it is necessary to design the dynamic property of FRP easily and accurately. In this paper, a natural frequency and loss factor of FRP is calculated by our equivalent mass-spring method. The FRP is expressed as equivalent homogeneous elements by the rule of mixture. The equivalent mass-spring model is expressed by shear springs of fiber and matrix resin which connect in series. The spring coefficients are identified by the sensitivity analysis. Then matrix resin is viscoelastic, the shear spring is presented by k_mj(1+η_mi). Therefore, the loss factor of FRP is calculated by dividing imaginary part of the total shear spring coefficient by real one. When the parameters or size of FRP are changed, the natural frequency and loss factor is calculated by corrected spring coefficients of fiber and resin. This method is sufficiently reliable and easy to predict the vibration characteristics of FRP.

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A smart structure was tested for active microvibration control of a 2-story steel frame building model of a 5×3×4^Hm outer size and a 2 500 kg total weight which was excited by ambient ground vibration. In the structure, piezoelectric actuators attached to the columns and the beams were used for the microvibration control by bending moment control of them. The controller was designed using the H ∞ control theory. The tests showed that the smart structure could effectively reduce the three-dimensional microvibration of the building model, and its applicability to floors and even entire buildings of semiconductor manufacturing factories having steel frame structures.

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Development of color printer, postal classification machine, automatic teller machine and so on requires higher moving performance of flat belt. Skew of the flat belt running between angular misaligned cylindrical rollers is investigate by experiment and FEM simulation. Characteristics of the skew phenomena are clarified to some degrees and the FEM simulation by MARC-MENTAT gives results corresponding to the experimental ones. The results show that the skew phenomena is composed of a transient skew and steady one. The skew rate in the steady skew increases in proportional to the angular misalignment. Both friction coefficient and belt initial tension have little effects on the skew rate. During the steady skew, the skew is composed of two components. The one is due to the difference in belt slope between the tension and loose sides of the belt. The other is due to the belt slip on the rollers.

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This paper presents formulations of FE analysis for viscoelastic structures based on polymeric materials such as silicone gel and rubber. Equations of motion and viscoelastic constitutive laws in three dimensions are manipulated. Development of the element relaxation matrices in three dimensional constitutive equations and of the element damping matrix in finite element equations is the main results of this paper. The resulting equations of motion of viscoelastic structures can be solved by a proposed numerical integration method. A simple problem is numerically calculated by the FE program developed by means of the presented theory. The formulation and the computational result show that the behavior of this kind of materials modeled by the fractional operators is different from that by well known integer differential operators.

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Evaluation method of vibrational characteristics of laminated FRP shells including damping is examined. Natural frequencies and loss factors of FRP circular cylindrical shells subjected to three kinds of prestresses are obtained on the ground of the first-order shear deformation shell theory by applying the modified Galerkin method. The results show that natural frequencies generally decrease, whereas loss factors increase for such the prestresses as external pressure, axial compression stress and torsional shear stress. Besides, it turned out through parametric studies that it is fairly difficult to find appropriate constructions of anisotropic laminated layers for which the both of natural frequency and loss factor become concurrently large. Considering the above, the following criterion optimizing vibrational characteristics of such structures as shells with the fairly large damping and the high frequency distribution density is proposed, i.e., that the least value of the product of frequency and loss factor for all vibrational modes should be maximized from the viewpoint of optimizing the free vibration reduction characteristics, in stead of the criterion to maximize the fundamental frequency which is one of the conventional concepts.

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Vibration characteristics of the horn and capillary system of an ultrasonic wire-bonder were studied experimentally under the condition that the capillary-tip was free. The wire-bonder used was a 65 kHz type, and a laser doppler vibrometer was used to measure the velocity of vibration. At first, variations of the resonance frequency due to the capillary length were measured, and two branches of the frequency were confirmed. Then, the mode of the horn and capillary system was measured at different resonance conditions, and vibration characteristics of the frequency branches were made clear. Finally, these results were considered by theoretical analysis based on a simplified model of the horn and capillary system.

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Stochastic response of a random shear beam with viscous damping is theoretically investigated by the use of a spatially random differential equation. First, a partial differential equation describing the spatial-temporal variation of the shear response of the beam is randomized by taking into account the spatially random variation of its shear modulus, which is mathematically modeled as a homogeneous random field. Next, its stationary solution with boundary conditions is formulated by introducing a random differential equation for a transfer matrix. Further, an approximate solution is derived by the use of a perturbation technique. Finally, probabilistic properties associated with the maximum response are numerically examined. The numerical result shows that the variance of the maximum response near the resonance frequency is reduced owing to the effect of random mode coupling.

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This paper deals with the nonlinear coupled-vibrations of an elastic structure and liquid sloshing in an attached rectangular tank. The structure is vertically subjected to a sinusoidal excitation. The natural frequencies of the structure and the liquid sloshing are in the ratio of two to one, which is called a tuning condition. Influence of a deviation of the tuning condition on the resonance curves is focused on. In the theoretical analysis, the following results were obtained : (a) the small deviation of the tuning condition leads to causing an almost periodic oscillation and a chaotic oscillation, (b) these oscillations appear for a negative detuning in high liquid levels, and a positive deviation in low liquid levels, and (c) the coupled vibrations can occur separately in two regions of excitation frequency when the comparatively large deviation exists. In experiments, the experimental resonance curves were in agreement with the theoretical results, and almost periodic oscillations were observed.

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Vibrations of stay cables are often induced by wind because of their aerodynamic instability. They must be suppressed to prevent cable fatigue and to allay passenger fear. Although various countermeasures have been developed, totally effective one has not yet been established. In this paper, the authors propose a new method using a permanent magnet. A magnet installed near the end of the cable changes the vibration modes passively by repeating motions of constraining and releasing cables. With this method, growth of the unstable fundamental vibration mode is prevented by dissipating energy of higher stable modes. Comparing with other methods, it is expected to improve low temperature characteristics, maintenance and manufacturing cost. After decribing the principle, fundamental studies on energy transferring mechanism were carried out and it was verified that the lower modes energy is distributed to the higher modes when the cable is released from the magnet. The effectiveness of this method was confirmed by wind tunnel tests and numerical simulations.

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In order to improve passenger comfort in ultra high speed elevators, the authors investigated the reduction of lateral vibration transmitted to the cage from the guide rail irregularity. Following computer simulation carried out using optimally controlled Active Mass Damper (AMD), a full-scale test facility has been built in order to verify the control effects obtained by computer simulation. According to the experimental results, it is confirmed that (1) the developed full-scale facility can simulate the real dynamic performance, (2) the control effects of AMD on the lateral vibrations of the elevator cage can be clearly obtained.

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In this paper, a method for simultaneous optimum design of a structure and its control system is proposed. A beam is considered as an example, which is subjected to initial loads and a time-varying disturbance. Sliding mode control method is chosen because it is insensitive to disturbance and uncertainty if a matching condition is met, after giving a switching hyperplane. In this paper, an optimization method is used to design the switching hyperplane. The objective function of the optimum switching hyperplane is adopted as the objective function of the simultaneous design. The total weight of the structure is treated as a constraint condition, and the cross sectional areas of beam are all adoped as the design variables. This problem is a nonlinear programming problem. In this paper, the sequential linear programming method is adopted to solve it. In the example, after the optimum design the effect of attenuating vibrations has been improved obviously. Moreover, light design of the structure becomes possible by using the relationship between the structural weight and control objective function.

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A representation of thin object manipulation is proposed. First, the contact state between a thin object and an environmental surface in the two-dimensional space is represented qualitatively as 23 contact patterns. We can also represent the contact state of a thin object with multiple environmental surfaces by combining those patterns. Secondly, the contact pattern transition is defined. Thin object manipulation can represented as a network whose nodes mean contact patterns and whose arcs mean pattern transitions. Thirdly, the contactable region of the object for pattern transition is introduced. We can change the contact state if we make manipulators contact with that region. Finally, some examples show that our proposed method will be useful for the planning of the manipulation or the derivation of task strategies.

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A four-wheel flat belt chassis dynamometer with swiveling mechanisms had been developed mainly for indoor cornering tests. On the tester, a testing vehicle is restrained with wire ropes, and its longitudinal and lateral characteristics are well reproduced including body attitude. Because lateral response simulation in the set-up is consistent only in steady state in the strict sense, new techniques for lateral transient response are introduced in this paper. To reproduce the precise tire slip angles, the vehicle is equipped with Corrective Steering Systems for front and rear wheels. The CSSs are controlled in accordance with the real-time vehicle model which contains only the vehicle's mass property by making use of the vehicle restraint forces. The resultant testing system is proved to have sufficient preciseness in the overall running scenarios, and can be applied to various vehicle tests.

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This paper presents the theoretical approach to predict the dynamic properties of a cylindrical shell transducer with finite length, Piezoelectric elements are embedded on the inner surface of the elastic shell at the constant pitch to generate the shell vibration in the specific circumferential eigen mode and to detect the incoming underwater sound through the shell vibration. Piezoelectrically excited vibration of cylindrical shell and its related sound radiation into water are discussed. Calculated frequency response function of the shell vibration, sound radiation efficiency and directivity pattern for the each eigen mode of the shell agreed well with the measured results. Shell vibration and associated electric output of the piezoelectric elements induced by the incident underwater sound wave are evaluated by the present method and these reisults are compared with the experimental data. Frequency response of the sum of the output voltage of the distributed piezoelectric elements induced by the incoming sound wave shows good agreement with measured results. Moreover, generated dynamic pressure distribution around the shell surface is measured and the comparison with the calculated results confirms the availability of the present theoretical method.

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To compose the human-machine interface of the speech for communication between human and machine system, it is necessary to develop a speech recognition method with high and stable accuracy. In this paper, a new method of speech recognition using cross wavelet analysis is presented. Furtherlly, recognition accuracy by using this method and cepstrum method is compared. Through the case study, it is concluded that higher and more stable recognition accuracy can be obtained for the speech recognition such as burst speech using the proposed method.

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In order to measure inclination angle of a rope-hopping robot when it jumps, we have developed a photo-sensor composed of double solar cells. Firstly, the principle of measuring an inclination angle using the sensor was discussed. Next, the characteristics of the sensors were investigated about output voltage, influence of noise and initial angle of cells, influence of lighting intensity and frequency response. It is confirmed experimentally that solar cell sensors developed in this study are very useful for measuring inclination angle and can be applicable to a rope-hopping robot.

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The marking mechanism were considered again, by pressing four kinds of fiber textures on two kinds of plates for automobile coating films. And the following results were obtained. 1. Fiber texture marks was the depression of the coating top layer. 2. The marks which resemble closely to those in traffic accidents could be formed on the following conditions. (1)Contacting time for fiber with the plate was 0.005∼0.01 sec. (2)Pressing vertical load for fiber to the films were 3.6∼9.1 MPa. (3)Friction coefficient between fiber and coating films was ca. 0.3∼0.5. (4)Sliding length for fiber on the films was ca. 0.018∼0.063 m. 3. The marks were influenced by the top layer of automobile coating films, fabric construction of cloth and another conditions. For example, metallic coating films which contains the top clear layer were printed more easily than the solid ones.

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This paper proposes a simple shock absorbing mechanism and stable capturing control law which makes no impulsive force responses in capture of a moving object. In order to reduce equivalent values of inertial force and damping force at colliding point of end effector, singular point of mechanism is utilized by stretching a wire between dual fingers. The passive shock absorbing performance is clarified by making comparison between the proposed mechanism and buffer materials. A desired active force which realizes stable positioning object at command position is calculated from estimated kinetic energy of the object. By inputting a desired value of tension transformed from the desired force to tension feedback control law, stable position control of the object is performed. On the other hand, for the sake of realizing accurate ejection velocity, a desired value of velocity control law is calculated from command velocity using a first lag system filter to reduce acceleration of the object at command velocity.

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In this paper, we discuss how to navigate a mobile robot along any paths in a certain environment. We realize it by supporting self-positioning ability of the robot using artificial landmarks. We propose a method to dispose artificial landmarks in the environment, and to navigate a mobile robot there. We dispose the landmarks so that the robot can observe at least one landmark at any positions in its working area. We consider the requirement for observing a landmark, and the robot plans the observation so that the requirement is fulfilled at all times. Through the navigation experiment using a real robot, the effectiveness of the proposed method is confirmed.

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Cable-driven parallel architecture is a new robot mechanism which is suitable especially for high-speed transfer of lightweight objects. In this paper, the optimal cable configurations are derived within a class of mechanisms redundantly driven by 8 cables from the viewpoint of working space. The working space is determined by conditions that the traveling plate must be able to receive arbitrary force and moment and that the cables must not contact. Heuristics on cable configurations were obtained through optimizing and analyzing isotropic configurations of actuator units. Classification and comparison of various symmetric configurations derived the 2 optimal configurations : Rod-type and T-type. Simulation results proved the validity of these designs and showed their advantages and disadvantages.

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This paper describes a casting strategy for a tethered space robot. The robot is tethered to the end-point of a spacecraft mounted manipulator which performs the casting. The casting strategy comprises three phases : (I) initial momentum is generated for the tethered robot using the spacecraft mounted manipulator ; (II) the tethered robot takes off the spacecraft ; (III) the tethered robot translates to a destination point. The following two control objectives should be met. First, the mass center of the tethered robot should arrive at the destination point accurately (translation control objective). Second, the angular momentum of the tethered robot with respect to its mass center should be zero at the destination point (angular momentum control objective). The translation control objective can be easily achieved using the spacecraft mounted manipulator. The manipulator is able to adjust the translational trajectory by controlling tether tension. We show here that to achieve the angular momentum control objective, it would be sufficient to invoke position control of the tether attachment point, in a cooperative manner with tether tension control.

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Generally it is necessary to control a force in work of a trimming or a polishing by a robot. So we have already proposed the force control system making use of the stepping motors as the actuators of the robot, because this control system have the advantages that the rotary angle and the rotary angular velocity of the stepping motor can be controlled as a open-loop system and it is enough for this control system to be the only force sensor. However it is a problem that the proposed method cannot apply when the working object is positioned imprecisely. And then we propose the force control method that can be applied is case of the working object positioned imprecisely. Namely this proposed method is realized by switching over from the control system with the steady-state deviation to the control system with the over shoot during force control. Then it is shown that this proposed method is effective by the simulation and the experiment.

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At the wire mobile robot, when avoiding obstacle such as the insulator which exists on the wire, because the exchange movement in the running part such as the wheel becomes necessary, the securing of attitude stability is difficult. Therefore, either of these points for the wire mobile robot which was proposed so far had a difficulty. On the other hand, the robot composed 3-units which we are proposing can alwasys keep an attitude at stability. Also, as for this robot, it is possible to avoid and the obstacle which is large comparatively has the function which corresponds to the wind wire and the brance wire. In this paper, the structure and the obstacle avoidance method of this robot composed 3-units are described. Also, it examines the control method and the design method of the balancer which is the most important part at this robot.

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This paper deals with trajectory generation planning of a human friendly robot. The high intelligence of robots is required in walfare, dangerous area, and others. To realize human friendly robots, we propose a trajectoty planning method for robot manipulators based on human feeling. First, we build a fuzzy model of human feeling on the speed level and position of a robot manipulator. Next we apply an interactive genetic algorithm to generate a trajectory suitable to the state of human feeling. Finally, we discuss the effectiveness of the proposed method through experimental results.

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A soft actuator with an inherent flexibility has been required to build up a soft mechanical drive system such as a human collaboration robot. In this study, a rotary type soft actuator made of silicone rubber driven with a compressed air has been developed. This actuator can realize the desired rotary operation by using the fiber reinforcement and the partial difference of stiffness owing to the rubber thickness. In this paper, the structure and operation principle of the actuator is described, and fundamental properties of actuator are experimentally investigated. the experimental results show that the actuator has the sufficiently large operational angle and the dynamic characteristics of a damping the elasticity component. Its application to a soft robot finger and a robot hand are discussed. Owing to the flexibility of actuator, this hand can grasp unshaped or flexible objects without any complicated control algorithm. The availability of this actuator is confirmed through some experiments.

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A high-pressure common rail injection system with controllable injection rate has a high potential for reducing exhaust emissions. This system requires an injector which controls suitable injection rate for various engine load and speed. Conventional electric controllable injectors energized by on/off switching pilot valves, which are difficult to control the injection rate continuously. This paper has developed a new type electric controllable fuel injector to satisfy the requirement of such enhanced features. It consists of a main needle valve with a position feedback slot, and a 2-way pilot valve driven by a tandem-type giant-magnetostrictive linear actuator. In proportion to the pilot valve operation, this injector can control the transient characteristics of injection rate by the internal hydraulic position feedback mechanism insensitively to disturbances. In this paper, design strategies of the injector and giant-magnetostrictive actuator, and test results of variable injection rate control at the common rail pressure of 160 MPa are described.

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A motion planning problem of cooperative multiple manipulator system carrying on the wall tracing task in the inner space of the concave object is considered. One manipulator holds the concave object rigidly and the other holds the tool and works in the inner space of the concave object. We only specify the tool task on the object's inner wall, so the object and manipulators can move arbitrary paths in the world coordinates frame. Using these degrees of freedom, we propose an algorithm to generate joint paths for cooperative grasp-work type manipulator system to accomplish the specified task effectively.

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This paper describes the characteristics of torque transmission in a magnetic fluid coupling when a magnetic field is controlled under the PWM (pulse width modulation) and the fuzzy controller. Whenever a magnetic field is applied to a fluid coupling, the magnetic fluid shifts to the outer area of the rotating disk, and a torque is transmitted through the viscous friction of the magnetic fluid between the disk and the case. The output torque is changed by the PWM controller that determines an amount of electric current to the coil at a high velocity of the rotating disk. Since the relation between the duty ratio of the applied voltage to the coil and the output torque is nonlinear, fuzzy controller is used to get a desired torque. It is confirmed experimentally that the output torque can be controlled under the PWM and the fuzzy controller. This system is also valid for the disturbance of temperature.

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Servo motors are widely used as actuators to drive many automatic machines. A manufactured servo driver (amplifier) is usually selected to drive and control each motor at high performance. Motion of the motor driven by such servo drivers has very complicated dynamic characteristics in fact. These characteristics cannot be explained by considering the driver as a linear system. In this study, it is analysed what control is done in the manufactured servo driver and clarified its non-linear dynamic characteristics of motor motion.

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Severe osteoarthrosis of the knee joint often requires total knee arthroplasty to yield adequate knee function. Ideally, the knee joint with total knee arthroplasy is expected to restore the characteristics of the normal joint kinematics, however, this is not necessarily true in the clinical cases. In this study, the motion of the intact knee joint and the knee joint after total knee arthroplasty (TKA) was investigated numerically using computer simulation. With the analysis of active knee extension from 90 degrees of flexion to full extension, the intact knee joint exhibited anterior tibial translation near the full extension and it showed only rotation at other flexion angle. Physiologic external rotation of the tibia near full extension known as screw home movement was also noted in the analytical model. Analysis with three different shapes of the tibial insert (flat type, semicurved type, curved type) demonstrated characteristic rotational and sliding motion as well as different contact forces.

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In the case of severely destroyed knee joint, TKA (Total Knee Arthroplasty) is indicated as surgical treatment. An ideal design of a prosthesis will provide (1) good initial and permanent fixation, (2) improvement of range of motion, and (3) excellentsurvivorship. The purpose of this study was to analyze the influence of viscoelastic property of the bone on micromotion with different tibial prostheses in TKA. The interface of the bone and a prosthesis was considered as debonded and relative displacement between prosthesis and bone was regarded as micromotion. Viscoelaastic property of the bone showed significant influence on the analysis of micromotion. The tibial prosthesis with a central stem of 60 mm length was found to exhibit less micromotion with differnt conditions. It was found to cause prosthetic loosening with less incidence.

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This paper presents a simple, cheap and effective sheet exchanger composed of four rolling cylinders because it is a troublesome task to change a bed sheet for a bedridden person. To change a bed sheet, while a cylinder wind the used sheet, the new sheet wound around another cylinder is spread under the body with advance of the device. The system composed of the exchanger, a person lying on the bed and an operator was investigated. It is found that the energy for driving dissipates immediately during operation. According to the result, necessary torque to drive the device is less than 4 Nm. Therefore, it can be driven easily by hands or by a small electric motor.

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In this paper, we focus on the problem of safety and operability which is involved in a teleoperation system (master slave system) for medical application, and propose a new control strategy to improve performance of safety and operability by two force display methods. One is a multiple sensor information display method which display several force information that are measured by several force sensors on one master device. The another one is a variable impedance characterization of master device which changes the impedance parameter of the master device according to the situation of the medical operation. We also apply this method to the neurosurgical telemedicine system, and perform an experiment to evaluate our method.

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In this study, an interactive scientific visualization environment was constructed by directly connecting the five-screen immersive projection display CABIN with an IBM SP2 parallel super-computer through the FDDI network. In this environment, numerical simulation can be executed interactively according to the user's motion and the result of the calculation can be visualized in real-time. In particular, a parallel redundand prediction method using the parallel computer was developed to realize a real-time numerical simulation. This method was applied to the deformation analysis of the rubber using the non-linear finite element method, and the interactive visualization according to the user's "push" action was performed. By using this visualization, the performances of accuracy and calculation time were experimentally evaluated.

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This paper deals with an operational assistance system of a rough terrain crane. The rough terrain crane is one of the frequent used machines in construction sites. We forcus on the straight-line transfer operation of the crane. It is difficult operation because an operator must use two or three levers at once. Thus we propose the operational assistance for the straight-line transfer operation. A control rule for the straigh-line transfer is proposed. Some kinds of operational assistance information are provided based on the rule. We present some experiments on a crane simulator, and show the effectiveness of the proposed operational assistance system.

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As a base for the prediction of deterioration of hypoid gear performance due to tooth flank wear, a method of data processing of measured tooth flank form deviation is proposed, that is used for the input data of performance simulation of hypoid gears with manufacturing and alignment error. Simulated contact patterns of tooth flanks as function of different kinds of measured and then processed tooth flank form deviation are compared with observed contact patterns of new and worn gears to find a proper data processing method. This method reflects and compensates the weak points of today's measuring method for tooth flank form deviation of hypoid gears, because the region of measurement on tooth flank cannot cover whole the region of contact zone of tooth flank under load transmission. The influence of uncertainty with obscure value of shaft alignment error in actual gear box is also considered for the performance simulation.

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A well known empirical relation for abrasive wear as functions of sliding velocity, contact pressure and sliding distance is applied to silulate the tooth flank wear of hypoid gears. The simulation for stress state of hypoid gears has incorporated to obtain the state of tooth flank wear, and using this state of worn tooth flank form, the change of gear performance with progress of tooth flank wear was investigated. The simulated results for the deterioration of tooth contact pattern correspond well to the observed state of tooth flank contact pattern of actual automotive hypoid gears. This simulation also reveals some characteristics of the tooth flank wear of hypoid gears, for instance, the root of pinion tooth flank is prone to severe wear. The characterisitcs of gear performance change due to tooth flank wear is also shown, and it is clarified that the no-load contact pattern of worn hypoid gears tend to be line like at root of wheel tooth.

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The influence of the difference in initial tooth flank form of hypoid gears on the progress of tooth flank wear and its influence on gear performance is discussed. The tooth flank forms of two new gears from the same production line as that of wear tested gears were employed as the initial state. The wear simulation developed by this investigation has revealed that the tooth of pinion is prone to considerable wear, and when the tooth flank wear develops itself enough, the composite error surface of worn gears tends to have a resemble 3D figure. The change of the gear performance with progress of tooth flank wear is although somewhat different as function of the difference in the initial composite error form of individual gears. The difference in the change of vibrational excitation with progress of tooth flank wear is especially large. The maximum value of static stresses generally decrease in some extent with progress of tooth flank wear so long as wear is not severe enough.

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This paper describes the analytical method for calculating contact stresses in spur and helical gears using the boundary element method. Since in many old studies the effect of load distribution is not analyticaly taken into account, attention must be given to some essential and fundamental method for computing the influence of contact stresses into the analysis. The main advantage of applying the boundary element method to the contact problem of gears is to give the proper expressions for load distribution and contact width along the line of contact.

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This paper presents a study on the effect of sintering process and rolling on the surface durability of sintered metal gears. Test gears made of partially prealloyed steel powders, which were compacted and sintered under various processes, were hobbed and then case-hardened. Some gears were rolled under various amount of rolling before case-hardening. The contact fatigue tests were carried out for these gears using the power-circurating-type gear testing machine. The effects of sintering processes and rolling on the surface durability and wear of sintered metal gears were determined to a considerable extent. Furthermore, the surface durability of the sintered metal gears were compared with those of the wrought steel gears.

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In the conventional torque control method, clamping force scatters widely in each bolt tightening due to the scatter of coefficients of friction between screw surfaces and between bearing surfaces. It has been a common knowledge that the coefficients of friction are generally influenced by roughness of the mating surfaces and lubricated conditions. However, it must be noted that the configuration error such as burr on edge of bearing surfaces is also an important influencing factor. In this study, variations of coefficient of friction between bearing surfaces against bolt head types with different conic angles of bearing surfaces and with configuration error such as burr on the edge of bearing surfaces have been investigated. The conic angles of bearing surfaces in the each bolt head types are 0°, +1° and -1° to bolt head and to outside. As the result, in case of using bolt head type with +1° to bolt head and to outside, the variations of the coefficient of friction is relatively small. In cases of using other bolt head types, the coefficients of friction vary remarkably. Accordingly, the bolt head type with +1° to bolt head and to outside is considered the optimum type for bolt tightening. The optimum bolt head type is also effective for increasing reliability of the new torque control method which simultaneously loads with torque and compressive force to a bolt.

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The ultrasonic wire bonding is widely used in making many kinds of semiconductor devices. With growing demand of down sizing, semiconductor chips become smaller and sraller, which brings about an increment of bonding miss problem which is likely to occur on the sides parallel to the vibrating direction of the ultrasonic wave. As far as a fixing method is concerned for a chip during bonding, the vacuum suction force is generally employed. In order to find a way to settle the problem this investigation was carried out particularly focusing on the strength of the fixing force of a vacuum suction method and vibrating condition of a silicon chip. Some equations were derived to calculate the suction force and a friction moment under an assumed pressure distribution. Furthermore the rate of velocity components between rotation and translation was calculated. A close agreement was confirmed between the experiments and the theoretical results.

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Pb-8%Sn coated steel sheets are used for the fuel tanks of motor vehicles. Lead-free steel sheets are used to prevent pollution. Aluminum-coated steel sheets are used for vehicle, but the short life of electrodes used for spot welding of the steel sheets is a serious problem. Three kinds of copper alloy electrodes were manufactured and used for the investigation. They are Cu-Cr, Cu-Cr-Zr and alumina dispersed copper alloys. Both sides of aluminum-plated steel sheets 0.8 min in thickness were used for the study. The upper electrodes showed a convex shape and an penetration of aluminum and iron was observed. The lower electrodes showed a concave shape by reverse pick-up. Furthermore, the penetration of aluminum in depth was shorter than that of the upper electrodes and no iron was observed. The results obtained in continuous spot welding with 11 kA shows that the life of alumina dispersed copper alloy electrodes was 800 spots which is two times that of Cu-Cr alloy electrodes.

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Increasing requirements on coating properties results in trends to develop new system, the most important of which is a multilayer coating. Multilayer coating can solve simultaneously very different requirements that the coating can meet at both the substrate/coating interface and the upper functional layer of the coating. Ti/TiN multilayer coatings were deposited on a silicon (100) by rf magnetron sputtering, using multi S-guns. Under the condition in which the total thickness kept 150 nm, the numbers of layers were changed from 4 to 40. Mechanical properties of a film were improved by straining and preferable crystalline orientation. Energy evolved in the coating during its growth can dissipate, and this may decrease internal stresses in the coating, improve its resistance to mechanical loadings, and prevent breaking of the coating. A mechanism of improving mechanical properties with increase of a layer number was discussed based on various analyses and measurements-that is, auger electron spectroscopy, x ray diffraction, nano-indenting test, scratch test and atomic force microscopy. Suppose that the overall energy W_hkl of multilayer film with constant overall thickness is the sum of the surface or interface energy S_hkl and strain energy U_hkl (W_hkl=S_hkl+nU_hkl where n is layer number), the preferred orientation of the film grown by physical vapor deposition is decided by the lowest conditions W_hkl resulting from a critical competition between S_hkl and U_hkl. Therefore a film should exhibit preferred orientation of the lowest U_hkl at small n but exhibit that of the lowest S_hkl at large n. The preferred orientation is predicted to change from (111) to (100) with increase of layer number because S(100)<S(111) and U(100)>U(111). XRD gives expected result. Relative strengths σ/τ along [100] and [111] can be estimated for the slip system of TiN, {100}<110> by using Schmid's law.

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The Vacuum pump composed of the variable lead screw is noticed as a potential one that has high power efficiency. In case of the variable lead screw, the grinding wheel has only a point contact with the screw surface. One of the authors tried the grinding by the method that has easy way of calculating the contact point of the mating surfaces. The try resulted in the interference of the grinding wheel and the screw. Accordingly, this paper proposes another way of positioning of grinding wheel and analyzing the contact point. This paper discusses the interference in the axial plane of grinding wheel for the convenience of the wheel design. Then, size and pose of grinding wheel that could avoid the interference are examined numerically. The proposed setting method is clarified to be effective for the interference avoidance. The limitation of pose change of grinding wheel is showed in the relation with the interfered position of surfaces.

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Finish machining used to be carried out in grinding, but it is being replaced by cutting with very small undeformed chip thickness. In super precision process, the effect of the cutting conditions and complicated factors on the machined surface integrity is a serious problem. In this research, work hardened surface layer was dealt with as an evaluation of machined surface integrity and the effect of the mechanical factors on work hardening was investigated experimentally in orthogonal cutting. As a result, it is better to deal with a shear angle and shear zone separately as a factor affecting a work hardened surface layer. Furthermore, it was found that not only the shear angle with variation of the cutting conditions but also the thickness of plastic deformation zone have effect on the depth of the work hardened surface layer below the machined surface after orthogonal cutting.

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The Extended Machining-producibility Evaluation Method (MEM) was developed to assess design quality for easier processing of parts and products. It has been extended, from the MEM for cutting & grinding, to the one covering metal working, welding, molding, diecasting, and casting. It is featuring in 1) quantitative evaluation by means of easy to understand 100 point scale and processing cost estimation within ±15% error, and 2) method is easy to both learn and use, using approximately 20 basic symbols and 5 supplementary elements. This paper describes the theory of the extended MEM for various processing methods.

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An error for positioning the spindle head or at the workpiece mounted on the fixture in NC machine tools, has 6 degree of freedom, in which pitching, rolling and yawing errors and included together with axial errors in x, y, and z directions. Among them, later three errors can easily be compensated, but others are difficult to compensate. This paper proposes a new method to compensate all the errors in 6 degree of freedom, which is characterized by the co-ordinate conversion without reproducing NC command data. Moreover, the proposed compensation method can decrease the stock of removal and the working time for mounting workpiece, shorten the production time and simplify production sequence in FMS.

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As higher precision machining is required, reducing thermal deformation of a machine tool becomes more important. Today, there are much study about the thermal deformation of machine tool ; a compulsory cooling of main spindle or some ball screws, a feed back control of thermal expansion, an isolation of heat source and etc. In case of the compulsory cooling of main spindle, however, it is difficult to decide the most suitable temperature of cooling in order to reduce thermal deformation of machine tool, because there are many non-linear factors in the thermal deformation of machine tool ; these are an irregular ambient temperature fluctuation, a property of temperature dependence on a material, change of pre-stress on a spindle bearing and etc. Therefore, in this report, a new method for estimating the most suitable temperature of cooling oil on a spindle was established. Inverse analysis using neural network was used for calculating the most suitable temperature, because neural network is suitable for controlling non-linear phenomenon. At first, in the experiment, a bench lathe was used, some structural temperatures and cooling oil temperature of a spindle were measured by T-type thermocouples for study data of the neural network, and thermal behavior of the bench lathe was also measured by a dial gauge for study data of the neural network. Next, the neural network was used to learn the relationship between the measured temperatures and thermal deformation on the bench lathe. Then, the most suitable temperature of cooling oil on a spindle was calculated by inverse analysis using pervious neural network. At last, in the experiment of the bench lathe, this method was evaluated about the various experiment conditions. It is concluded from the results that the proposed method was able to estimate the most suitable temperature of cooling oil on a spindle and effective in order to reduce thermal deformation.

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A new information exchange method named recursive propagation is proposed in order to solve job shop scheduling problems in decentralized manufacturing system. Each machine has only to notify the change of its plan to other machines which are directly influenced by the change. The effect of the change in the plan is directly fed back to the machine which notified the change. The change in the plan is notified to all the machines concerned by simple one to one communication among the machines, and the influence caused by its action can be reported to the initiator through the same communication path. The proposed method is applied to a 20×10 job shop scheduling problem, and the feasibility of this approach is verified by simulations.

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