This paper presents the method of an optimal approach of the dynamic property of tennis rackets by combining the usage of the multivariate analysis and the neural network. Two approaches are used for the several data sampling about playing tennis. One is the evaluation of the dynamic characteristics of tennis rackets, and the other is the evaluation of sensibility of a player while impacting the ball which are obtained through the questionnaire. The several axes to explain the important factors are found by using SD method. Then, the physical properties are obtained by using correlation analysis. Based upon the results of correlation, the evaluate equations between the effective physical values and the sensory factors are established by using the multiple regression analysis. Furthermore the non-linear relation of sensibility is considered by using the neural network. Thus, the evaluate systems which is constructed by neural network, is closer the practical sensibility compared with the evaluate equations constructed by the multiple regression analysis. As the result, it can be said that the direction of an optimal approach of the dynamic property of tennis rackets is shown in the designing stage.

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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 under severe conditions of high loading. Therefore, for the purpose of increasing plant reliability, the blade with friction dampers has been used. This paper presents the analysis method to predict damping characteristics of the seal pin type damper blades by applying the substructure synthesis method and the harmonic balance method to the bladed disk. The model test is carried out and the experimental data are compared with the numerical results in order to verify the validity of the analytical method proposed here. Numerical results show good agreement with the experimental data and it is shown that the damping characteristics of seal pin type damper blades can be controlled by altering the weight of pin and the grooveangie.

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We have proposed a new type of ER hydraulic shock absorber, and a method of the optimum design for this ER shock absorber. This ER shock absorber is so constructed that it can return to a conventional hydraulic shock absorber when the electric current to the ER shock absorber has been blocked, so that the shock absorber can fulfill the intended function. We compared the present ER shock absorber proposed in this paper with an ER shock absorber which can not return to a conventional shock absorber under the above situation during the impact of a body (2250 kg) at 2. 875 m/s by simulation.

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The first paper described two important points concerning the reduction of engine idling vibration by theoretical approach. The first one was the lower resonance point of a rolling mode and the second one was to prevent a coupled vibration between a lateral and a rolling mode. This second paper shows the optimum design of a 6 mounting points engine model by FEM and the design of experiment, which is so called Taguchi methods. As the most important characteristic is tile lateral acceleration in C. O. G., which is the barometer of coupled vibration with rolling mode, the frequency response analysis is conducted to get it from 0 to 30Hz. As far as the optimization of 18 parameters is concerned, the 216 cases simulations are conducted by the allocation of L36 type orthogonal array. Even though the effect can be obtained by calculation, the bad test results are sometimes occurred by the errors. So, the error factors are also allocated to find out the useful parameters when errors are existing. Finally, nine effective parameters are found out. Among them, the mounting position changes to upward are the most effective. And moreover, by the reflection of the effective parameters, the engine mounting points can be reduced from six to four.

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The first paper described two important points concerning the reduction of engine vibration at idling rotation by a theoretical approach. The second one showed the optimization of engine mounting points and spring characteristics when the opposite phase vibration was added on the rail. This paper reports on the analysis of mechanisms concerning the engine exciting force and the rotational couple of forces. Because the new V 10 engine has the biggest power and displacement which is 441 kw and 30 litters respectively, its exciting force of 2.Sth and 5th orders are very large. On the other hand, as the V-bank angular is 80 degrees, the additional 1st order yawing vibration is also occurred by the generation of the rotational couple of forces. So, the optimum design is needed to reduce these vibrations by the frequency response analysis when these forces are added to the engine crank shaft. Finally, the vibration level could be reduced much lower than the lower-powered engine by the optimum design of engine mounting by using the FEM and the adoption of the new mechanism for the cancellation of a rotational couple of forceS.

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Structural intensity presents the energy transmission on structures. Statistical Energy Analysis which is based on the idea of energy transmission is an effective tool to analyze the structural vibration in middle and high frequency range. This paper discusses the structural vibration analysis using structural intensity measurement. The 5 points method using five sensors gives us the energy transmission path, and the wave decomposition method provides us with the position of excitation source and the mean intensity. In this paper, these methods are applied to some plate-like structures and a front door panel of a vehicle. As a result, it is shown that these methods are applicable and the results are effective to analyze the structural vibration.

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Numerical analyses were carried about the bouncing vibrations of a two-degree-of-freedom (2-DOF) model of a tripad contact slider with air bearing pads over a harmonic wavy disk surface under 0.5 mN slider load. Its features were examined in regard to design parameters such as contact stiffness, contact damping, air bearing stiffness, rear to front air bearing stiffness ratio, and coefficient of friction. It was found that the effects of lower mode of the slider can be avoided if the front air bearing stiffness is not larger than the contact stiffness. It was also found that the contact sliding conditions can be predicted well by theoretically derived critical frequencies.

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On the trolly crane with a sensor of swing angle, a swing pendulum control with variable rope length was realized by adjusting trolly speed. This operation consisted of 3 periods, which is the hoisting up and acceleration speed period, the constant rope length and constant speed period, and the hoisting down and deceleration speed period. We reduced a swing at constant speed period by adding constant speed time for the hoisting up and acceleration speed period. And we controlled a swing at stop point, by feedback control for the constant rope length and constant speed period, and by feedfoward control for the hoisting down and deceleration speed period. According to above method, we could be satisfied with the practical accuracy (under 0.003 rad) swing at stop point, if initial condition of swing was large, too.

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In order to suppress an effect of disturbance in control system for flexible structures, we propose a new compensation method. The compensator is designed by use of inverse dynamics of the structure without any model of disturbance. And then it is able to be applied for control systems with nonlinear disturbance or random disturbance. The performance of the proposed control system is evaluated by numerical simulations with the model of the structures derived from FEM model.

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A method of active vibration control using regenerated vibration energy, i.e., the self-powered active vibration control is proposed. In this system, vibration energy is regenerated by an electric generator that is called energy regenerative damper, and is stored in a condenser. An actuator realizes active vibration control using the energy stored in the condenser. A variable-value resistance is used to control output force of the actuator. Since the damping coefficient of the energy regenerative damper is uncertain when it regenerates vibration energy, it is required for the controller to be robust to the parameter uncertainty; H_∞ control method is applied to the system. Through experiments, the self-powered active control system is shown to have stability robustness to the uncertainty of the damping coefficient of the energy regenerative damper and have better isolation performance than that of a semi-active and a passive control system.

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The self-sensing actuator (SSA) is a new concept for intelligent materials, where a single piezoelectric element simultaneously performs as both a sensor and an actuator. This concept is very advantageous in many aspects of control, and it makes it possible to reduce the size and weight of the structures. The bimorph piezoceramics are very useful to compose the soft-handling miniature gripper to control the minute grasping force. Our aim is to realize such a gripper making the most of the functions of SSA, that is to develop the method to detect the grasping force without a force sensor. The proposed method does not need the complete electric bridge circuit which is generally used to detect the strain information. Experimental result proved that the grasping force followed up some desired trajectories irrespective of the rigidity of grasping object.

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This paper presents a control method for the positioning of the flexible inverted pendulum and cart system. The distributed parameter model is derived in considering the elasticity of the pendulum. The frequency dependent optimal servo system is designed using the reduced order model, which is derived by eliminating the dynamics of flexible modes. The proposed design method enables not only to eliminate the spillover phenomenon caused by the residual elastic modes but to compensate the friction of the cart. Some experimental results show the effectiveness of the proposed control system.

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The simultaneous control problem between positioning and vibration in a flexible Pendulum system, which is constructed with a thin stainless beam (0.455 × 0.01 × 0.005 m³) hinged to a pivot mounted on a cart moving on horizontal rails, has been investigated based on the sliding mode scheme (free-hierarchical type) including a minimal order VSS observer, both from simulation and experimental aspects. The active damping effect on the vibrations induced during positioning is more expected in the sliding mode control system as compared with the LQ system, and the compatibility between the speed-up of the rigid mode positioning and the reduction in the vibration mode depends on the largeness of the switching input function. Furthermore, the robustness against such disturbance factors as the parameter variation and the spillover vibration mode is also more excellent in the composite sliding mode control system with the VSS observer.

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For a pendulum system whose pivot is vertically transferred, a stabilizing control law has been proposed using a Lyapunov-type function based on the mechanical energy. The stability condition is represented by the sign of the pivot acceleration. A design method of the servo system for the pivot is also developed that can control both the pivot position and the acceleration. A nonlinear observer is especially introduced for the estimation of the pendulum angular velocity from the large angle, while a linear observer based on the Gopinath method is adopted to estimate the pivot velocity. Similar to the VSS control system by Kawabe et al., satisfactory vibration-suppressing effects can be obtained with the results that in the simulation, the maximum damping capacity Q^-1_max≅0.15, while in the real system, Q^-1_max≅0.14.

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In positioning control problem, generally, the influence of uncertainty in a controlled object model increases at the period of stoppage. That is, it possesses a nonstationary characteristic. For such a problem, this study presents a nonstationary robust control method (NRCM) taking account of nonstationary influence of uncertainty. In this method, we define a frequency-shaped weight and a time-varying coefficient on unstructured uncertainty. Moreover, we introduce the generalized plant including them. The nonstationary controller is derived from the combination of the following two criteria. The first one is a time-varying game-type criterion function. The second one is the criterion function on the error between the responses of the nominal system and the uncertain system with the controller derived from the first one. Therefore, NRCM corresponds to the optimization problem based upon the coupled criteria. From its application to a positioning control problem of a flexible structure, the usefulness of the method is verified numerically and experimentally.

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A design scheme for an adaptive compensator to cancel the effects of unkonwn disturbances on outputs in linear, time-invariant, multi-input multi-output control systems is given. The design scheme is derived by coprime factorization approach. The adaptive compensator proposed in this paper cancels the effects of disturbances by identifying the disturbance model. The scheme is applied to an inverted pendulum control system, which has one input and two outputs.

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An approach for feedback active noise control of a one dimensional duct with multiple control sources based on modal analysis is presented in this paper. Based on experimental modal analysis, the modal parameters of an acoustical system are derived from measured multiple frequency response functions. The state equation of the duct is described by the identified modal parameters. Considering eigenvectors of the acoustical system calculated by finite element method, control sources are located to the duct. A feedback active noise controller is designed based on mixed H₂/H_∞ problem in addition to H_∞ problem, preventing the increase in dimensions of the controllers. Simulations are carried out using the designed controllers. Moreover experiments are carried out using identified controllers based on modal analysis to reduce dimensions of the controllers. The desired performances are obtained by the presented approach.

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The overall aim of this research is to establish an optimum design method to obtain quiet structures by modifying their shapes. For this purpose, the quantity to evaluate radiation loss factor was first led from approximate calculation, and then the relationship between mode shapes and radiation loss factors were investigated by using the evaluation quantity, because radiation loss factor is one of the important parameters required to estimate sound radiation power and has the strongest relation with sound radiation power among the parameters. As the result, the followings were found; (1) the evaluation quantity is the sound intensity with respect to the largest displacement point of vibration, (2) the mode shapes with minimum radiation loss factor have plural nodal lines and / or circles, and (3) radiation loss factor, namely sound radiation power, is more reduced when the number of nodal circles increases than when the number of nodal lines increases.

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Vibration and sound radiation of visco-elastically damped rectangular plates which were held between a pair of frames and clamped at the edges were evaluated analytically. The modal properties and modal damping loss factors of the plates were calculated by the FEM analysis and the modal strain energy method. The loss factors of the applied damping material were obtained from the reduced-temperature homogram based on the Oberst beam measurements. A practical consideration for the modal strain energy method to use the materials with frequency-dependent properties was illustrated. The modal frequencies and loss factors of the test plates were measured by the experimental modal analysis method and the half-power bandwidth method in a thermostatic chamber. The comparisons between the analytical and measured results showed good agreement for various plate modes. The vibration responses of the point--exited plates were estimated using the obtained modal properties. The predicted transfer functions between the applied forces and the vibration responses were compared with the experimental results. Finally, the radiated sound field was evaluated by the BEM analysis using the vibration responses of the plates.

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Simplified dynamic damper design expression based on minimization of mechanical energy is proposed in order to reduce the computational complexity of the simultaneous optimum design of rotor shaft configuration and damper parameters. Assuming that the dynamic interaction among multiple dynamic dampers is neglected, each dynamic damper can be designed independently. Under the above assumption, the ratio of the natural frequency and the damping ratio of the dynamic damper for each torsional vibration mode are given by simple expressions of the function of mass ratio. The expressions are derived under the stationary condition of the mechanical energy of each torsional vibration mode. Vector objective function for the simultaneous optimum design is constructed from several measures of the optimality of rotor shaft design and dynamic damper design. Mini-max method are used for converting the vector objective function into the scalar objective function. The effect of the proposed design expression will be shown by the numerical simulation results. Not only rotor shaft configuration but also parameters of multiple dynamic dampers are successfully optimized.

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We have previously developed a navigation system for autonomous mobile robots. It can find landmarks on the ceiling to move and work. However it is impossible to recognize landmark in case that the size of landmark is different from the size of template. In such cases, the robot cannot continue to work. Therefor we proposed Variable Template Matching (VTM) which makes it possible to recognize landmarks of different sizes. We realize VTM by using the optimization method called Evolution Strategy (ES). The robot can recognize the landmark faster by binary density projection to infer landmark parameters. Minus Fuzzy Template is useful for the robot to avoid misidentifying.

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This paper describes distributed controls for an ultra multilink bending propulsion mechanism in water. Functions in neural oscillator of an organism were programmed to each unit that consists of controller and actuator. The bending movement was generated by coordination of each unit. As an experiment of the robustness, we supposed the case of a joint is locked (no rotation). The bending movement was recovered by other joints' cooperation. We discussed influence of movement of the mechanism on thrust force.

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In this paper, we propose a concept of an information-sharing-type teaching for robot task programming. In this teaching, wide, nonverbal and bi-directionaI communication channels are provided for an operator and robot to share information about the task field. This makes it easy for an operator to recognize robot state and to express explicitly his implicit intentions using human common ability of perception and knowledge of taskS. Based on the concept, the multimedia communication pendant (MC pendant) is designed and implemented for a tool manipulation task. Experimental results show that the MC pendant improves operational accuracy and greatly reduces the time needed for teaching, compared with a conventional pendant.

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This study discusses the communication between autonomous robots and humans through the development of a robot which has an emotion model. The model refers to the internal secretion system of humans and it has four kinds of the hormone parameters to use to adjust various internal conditions such as motor output, cooling' fan output and sensor gain. We surveyed 126 visitors at '97 International Robot Exhibition held in Tokyo (Oct. 1997) in order to exaluate psychological impressions of the robot. As the result, the human friendliness of the robot was confirmed and some factors concerning with the human robot emotional communication were discovered.

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This study develops a flexible artificial hand system with slip sensors. The artificial hand is composed of four flexible actuators. Two pairs of two opposite actuators are driven by the independent air pressure sources each. In each pair, one of opposite pair of actuators is equipped with a slip sensor. The slip sensor is composed of a photo reflector and a conductive rubber sensitive to load force. The contact of the hand to an object is detected by the change of resistance of the conductive rubber. After the detection of touch, the slip velocity is measured by ca]culating the cross-correlation function of the output voltage waveforms of two photo transistors in the photo reflector. The grasping force of the hand is increased according to the measured slip velocity. The calculation of the crosscorrelation function and the generation of control signals are made in a host personal computer. From the experimental results of holding several objects, the hand system is proved to grasp suitably the object whose weight is previously unknown.

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In this paper, we examine a fast method for computing the continuous wavelet transform (Fast Wavelet Transform). We propose some methods to improve accuracy and to compute phase information which arises when attempting to use the fast algorithm in the frequency domain. In order to improve accuracy, we show that it is effective to use mother wavelets whose frequencies are lower by 2 octaves than the Nyquist frequency. This technique doesn't have an influence on the computation speed. Furthermore, in order to get a high degree of accuracy in the high frequency area, we show that it is effective to use up sampling by using a L-Spline interpolation. In addition, the effectiveness of our method for phase information was confirmed using a model signal. As an application, the electroencephalogram (EEG) was analyzed by the fast wavelet transform and several knowledges were obtained.

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In order to examine the effect of loading rate on the holding force and the diameter of cylindrical object at maximal holding force, the subject was requested to grasp the cylindrical object at various loading rateS. The loading rate produced a large difference in holding force among cylinders. The force to hold the cylinder with a diameter of 20-25 m was influenced considerably by the loading rate. In the loading rate ranging from 5 to 600 N/min, the maximal holding force increased logarithmically with the loading rate. The relationship between the diameter of cylinder at maximal holding force (Dmax) and the loading rate (dF/dt) within range from 10 (or 20 N/min) to 600 N/min can be expressed using the following equation: D max=a dF/dt ^-b These results in the present study proposed the necessity to introduce the loading rate against the operating hand to the design of the operating parts of machines or tools.

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The authors tried to apply traction drive to a constant velocity servomechanism for NC machines. The 1st report described basic characteristics of the traction drive servomechanism. This 2nd report describes a method to achieve high-accuracy rotation. The high-precision servomechanism requires a high-resolution encoder to detect rotary position, whereas conventional high-resolution encoders can not rotate at high speed. Therefore, the authors tried to solve the problem of resolution and maximum rotary speed by using non-sinusoidal-wave two-phase type PLL (Phase Locked Loop). By using this non-sinusoidal-wave two-phase type PLL for interpolating tracking error, a very high resolution detection of rotary angle at a high speed rotation was achieved even using low-cost encoders of which output is non-sinusoidal wave. Traction drive damps torque ripple of high frequency, but transmits torque ripple of low frequency. Most part of torque ripple of low frequency is due to eccentricity of toilers. As the rotary speed of rollers gets high, the torque ripple has a frequency at which it can be eliminated neither by traction drive nor by feedback control. Because the mechanism of torque ripple is very complicated, it is difficult to conpemsate by detecting of rollers' eccentricity. Therefore, the authors used repetitive control to reduce the position error associated with roller rotation, and obtained high-accuracy rotation in the experiments. This paper presents the interpolation method of tracking error using non-sinusoidal-wave two-phase type PLL and the reduction method of tracking error using repetitive control.

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Vibration control of a flexible beam with piezoelectric film sonsors/actuators is investigated. Triangular-shaped piezoelectric films are bonded on the both surfaces of a flexible beam, and are treated as collocated sensor/actuator pairs. Equations of motions of the beam and sensor output are derived for two boundary conditions: 1) fixed-free, 2) both ends simply supported. Direct velocity feedback (DVFB) control law is employed, and closed-loop stability is analytically checked using Lyapunov's direct method. Forced vibration responses of the beams are calucutated under the condition that the system is harmonically excited. Analytical results show that first several bending modes can be controlled with reasonable feedback gains. In the simply supported case, anti-symmet-rical modes (even modes) are also efficiently controlled, and thus it is shown that the proposed control scheme is valid for multi-mode vibration control' of flexible beams.

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When using computer for pattern recognition, excellent featrue parameters are necessary, by which patterns can be precisely distinguished. Currently, there is not acceptable method for extracting optimum feature parameter. For overcoming this difficulty, this paper proposes a new method called "self-reorganization of feature parameters" in frequency domain by genetic programing. When patterns cannot be precisely recognized by using conventional feature parameters which are also called "primitive feature parameters" in this paper, the primitive feature parameters can be automatically reorganized into a new one by using genetic programming. The new feature parameter can be used to distinguish the patterns sensitively. For raising the accuracy of the recognitions, the noise contained in the pattern signal can be canceled by the method called "standard spectrum ratio" proposed in this paper. The distinction index has been defined by statistical theory to evaluate the goodness of a feature parameter, and it can also be used for the fitness in the genetic programing operations. By using the method to many practices, the optimum feature parameter can be quickly discovered, and the distinction rate of the optimum feature parameter is raised much higher than that of any primitive feature parameter. Examples of failure diagnosis for a gear equipment are shown to verify the efficiency of this method.

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This paper focuses on the lateral motion of the automobile considering roll dynamics at high speed. The equation of motion of the vehicle response to steering input considering coupling motion between roll and lateral direction is theoretically solved by means of replacing roll motion by tire equivalent lateral deformation. The result shows that the effect of the coupling motion reduces yawing damping ratio, keeps the yawing natural frequency, and delays yawing response to steering input. Moreover, good agreement is found between the theoretical and experimental frequency response to steering input.

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This paper discusses the identification method of automobile response to steering input using "normalized cornering stiffness", which is equivalent cornering stiffness divided by normal load and represents both vehicle response and axle property. Thus we can determine suspension, tire and steering system property to satisfy target response using normalized cornering stiffness. Firstly, this paper proposes the measurement method of normalized cornering stiffness using critical speed at which the vehicle attitude angle equals zero. This method features high accuracy because it is independent of the error of speed sensor. Next, the measurement result about over twenty vehicles is shown. This result points out that the variance of rear normalized cornering stiffness is quite large.

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The purpose of this paper is to show basic structure of a driver model that simulate driver's behaviors in emergency situations. The features of this model are that the parameters are systematically set up without trial and error by using predictive control method and a driver's internal model is introduced and a minimum lateral jerk line is applied as target course. The results of experiments to decide the structure, the internal model and predictive time, are shown. The model was applied to simulate driver's behaviors in lane change maneuver. It follows from the results that the driver model adequately simulate general and expert driver's behavior in experiment.

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We have developed a roller-type sideslip tester. The developed tester is examined under the conditions that are considered in an industrial application. We have investigated the influence of toe angle, camber angle, size of tire, pressure of tire, coefficient of friction between tire and roller, pressing power of tire, revolution velocity of roller, axle load and so On. The validity of the developed tester is confirmed under these conditions. It was found that it could be used in practical USe. Some measurement results are presented in the form of parametric plots and tables. And we have also compared the measurement data of the roller-type with those of the fiat type using several automobiles.

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An inflatable tube is used for separation of two satellites which artificially generate variable gravity environment by rotating each other. This tube is deployed by nitrogen gas and it gets sufficient rigidity finally. Behavior at deployment of the inflatable tube which had been stowed in a test apparatus at first was monitored under microgravity using the world longest dropshaft. The satellite model was successfully deployed, even though it encountered a catastrophic break Up. It verified that inflatable tube had excellent characteristics of recovering from a break up by increasing inner gas pressure. Typical break up condition of tube was analyzed by numerical simulation. Experimental data was successfully explained by the analysis.

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A high speed half-toroidal continuously variable power transmission, CVT, has been developed. The transmission consists of the CVT with a ratio range from 2.0 to 0.5 and of a final reduction gear-set of 4.78. Some design features of the CVT are minimum spin on the traction contact, application of ceramic materials to thrust ball bearings and loading-cam rollers, and 21 MPa electro hydraulic speed control servomechanism for keeping the output-shaft rotational speed at 3000 rpm against input rotational speed changes from 10000 to 20500 rpm and load torque from 0 to 175 Nm. The CVT works at a speed transmission efficiency of 98% and a torque transmission efficiency of 85% in whole input speed ranges. This paper describes that the experimental micro-slip can be predicted by the theoretical spin analysis.

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In the design of planar link mechanisms, moving links are arranged in parallel offset planes in order to avoid their mutual interferences. Therefore, not only the input moment, the transmitted force and the output moment but also bending and torsional moments in planes containing moving links (motion planes) act on each links. Moving links and pairing elements of the revolute pair are deformed and the links deviate from their theoretical hi_orion planes, so the performance of the link mechanism remarkably decreases. In this paper, a new method is presented for a three dimensional static analysis of planar offset four-link mechanisms and the torsional rigidity about the revolute axis of the driving link is calculated by this method. Consequently, it is possible to evaluate deviations of driving, coupler and driven links perpendicular to their theoretical motion planes.

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Flexible couplings are required both torsional rigidity and shearing or bending flexibility to maintain constant velocity between the drive and driven shafts subject to one or more killds of misalignment. In the previous paper, the transmission errors between the drive and driven shafts connected by a flexible coupling are measured. Higher torsional rigidity in flexible couplings can contribute to better transfer characteristics of servo mechanism, but it would lead to an increase in lateral load on the shafts. The present paper is concerned with the lateral load generated between the drive and driven shafts connected by a coupling with flexible resilient or kinematic flexibility. Conclusions drawn from the present research are summarized in the following. (1) Lateral loads generated between drive and driven shafts, which is connected by a coupling with resilient parts (such as helical beams, diaphragms, metallic bellows, etc.), are made up of the component proportional to parallel offset misalignment and the alternative component almost independent of misalignment. (2) The former component depends on the shearing flexibility of the flexible coupling and the later component depends on some machining error of the shaft connecting hole and initial deflection of the flexible coupling. (3) Oldham's coupling generates less lateral load than the couplings with resilient parts, but it irregularly changes by friction forces generated between the contact surfaces of the slider and hub.

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The increasing demand for quiet gears has created an increasing demand for precise analysis of gear drive vibration. There has been a lot of research on gear vibration analysis; most of which was dealt with a single gear pair. This report shows a new method for building a vibration model for an actual gear drive system. Each gear has six degrees of freedom; three translational motions and three swing motions. Stiffness matrixes for each gear shaft and for tooth meshing were made and overlapped into a stiffness matrix for the total system. This enabled easy modelling of the complex gear drive systems; such as multistage gears and branched gears. The results are in good agreement with experimental results with respect to the major resonance frequencies and vibration modes.

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For planetary gears in factory-automation use, compact size, high torque capacity, high precision rotation, and small backlash become required conditions. These requirements bring difficulties to reasonable estimations of influences of geometrical errors to important characteristics; load distribution, transmission error, and sun gear radial displacement. This is considered to be the unsolved subject in the accuracy precision design in this field. This paper deals with static modeling, simulations with a composed model and relating experiments to clarify the subject mentioned above. The model is formulated by regarding eccentricities of axes, cumulative pitch errors of gears, positional deviations of planet gears' axes, stiffness in gearing contacts and loading torque as parameterS. The simulations, under practical conditions, are carried out with regard to load distribution, transmission error, and sun gear radial displacement. Good agreements are obtained between the experiments and the simulated data.

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In this paper, the load carrying capacity, in particular, the surface durability of gear pairs with a combination of Austempered Ductile Iron (ADI) gear and hardened steel one is investigated using a power-circulating type gear testing machine. The surface durability of cermet-hobbed ADI gears approaches to that of hardened steels if an adequate tooth profile modification is made. The surface durability of shot-peened ADI gears is lower than that of cermet-hobbed ADI ones. This difference is caused by the difference in surface roughness. Furthermore, the impact strength of ADI is investigated with a impact testing machine for gears. It is found that the impact strength of ADI for the gears is as same as that of steel with almost the same hardness as ADI.

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This paper introduces some results of grinding test for decreasing grinding time in gear grinding. A prototype developed by the authors and an electroplated CBN worm of double threads were used for the test. To know whether high speed grinding impairs gear accuracy or not, some grinding experiments were carried out with changing rotary speed of a grinding spindle. And to know whether grinding with deep radial feed and rapid axial feed impairs gear accuracy or not, some experiments were also carried out with changing above conditions. In this case, the gears were ground into the root of the gear tooth for evaluating a performance of a servo controller of the prototype under heavy load. After experiments, it was confirmed that profile errors and pitch errors of the gears ground are very small at 7000 min^-1 within a rated torque of the wheel spindle because angular positioning errors of grinding' spindle and workspindle of the prototype are always small enough. Moreover we examined a power consumption of the grinding spindle and cleared that it is in proportion to a removal stock rate of the gear tooth.

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To clarify the friction and wear characteristics of surface modified rollers in vacuum, two cylinder test was carried out under non-lubricating condition in high vacuum less than 2 × 10^-3 Pa. Thermal diffusion after Sn plating (Sn), electroless Ni-P plating (Ni-P) and sulfurizing were employed here. Friction coefScient of the surface modified rollers was smaller than that of non-coated rollers. The initial friction coefficient of Sn plated rollers increased under low contact pressure, where wear particles were transferred onto the frictional surface, while the friction coefficient decreased when surface modified layer worn uniformly. The sulfurizing contributed to the reduction of the initial friction. The friction behavior of Ni-P plated rollers indicated the most stable in all test rollers. In addition, the relation between the test results in the two cylinder tests and the previous gear tests in high vacuum using the same surface modification treatment as employed in these two cylinder tests was evaluated. The initial friction in the two cylinder test was greater than that in the gear test in the cases of non coat, Sn and Ni-P. However, where sliding distance was large enough, the friction behavior in the gear test was similar to that in the two cylinder test.

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C-N thin films were prepared with evaporation of C by electron beam and simultaneous bombardment of N ion beam. TiN films with the (111) and the (200) preferred orientations and the Si (100) wafer were used for substrates. The microstructures of C-N flms on TiN substrates were columnar structures similar to the microstructures of C-N films on Si substrate. The N/C content ratio of C-N film was determined to be up to 0.44. The friction coefficients against SiC and steel balls were 0.2-0.3 irrespective of substrate materials in both laboratory air and vacuum of 1.3 × 10^-4 Pa. The films prepared with transport ratio of N/C=1 on the TiN (200) substrate showed good wear resistance in comparison with that on a Si substrate. The wear rate of this sample is 1/4 times less than that of DLC films. The difference in this wear behavior was attributed to higher adhesive strength due to the chemical bonding between the film and the TiN substrate.

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Transparent conducting thin fillns made of Indium oxide (In₂O₃) have been prepared by a mechanical process conposed of rolling' and oxidizing stages without vacuum procesSeS. The In ingot was rolled to approximately 5μm in thich first, and then the In sheet was pretreated by corona discharge in the air. Finally, the sheet was annealed in a furnace in the temperature range from 300°C to 700°C. The corona discharge pretreatment was found to have an important role to oxidize the In sheets due to the introduction of the oxygen species through micro pits formed by electron and ion bombardments. The transmission coefficient of the In₂O₃ film prepared by this process was 40%, when the corona discharge time was 3 h and heat treatment temperature was 700°C. The resistivity of this ITO film was 8.0 × l0 ^-5Ω·m according to the conventional four-probe measurement.

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This study was carried out to investigate the contact condition, between impacting hammer and oiled anvil. To estimate the contact condition during impact, the anvil sputtered with gold film was used. Oil film break down was evaluated by a electric resistance method. It was found that the pattern of impact prints left on a sputtered Au film were roughly divided into three kinds, a circle pattern, concentric circles pattern and random pattern. The ratio of diameter of impact print that seemed white to that of Hertzian contact circle was fairly small as compared with the dry contact condition. The squeeze film prevents from metallic contact according to the oil property. Most oils showed perfect separation due to the existence of squeeze film. As far as the relation between oil film breakdown and the kind of pattern is concerned, oil film breakdown is likely to occur when a circle pattern was recognized.

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Experimental investigation of the illstability in the fluid film of thrust bearings are presented. Flow between a stational and a rotational disk of 180 mm and 80 mm diameter are used as a model of fluid film of thrust bearingS. The gaps between two disks are varied from 0.15 mm to 4.0 mm. Water is used as a working fluid. In order to visualize the flow, two types of fine particles are used. One is the powder of barium sutfate and the other is aluminum powder. Under appropriate lighting, the flows are observed and taken a photo. Photographs show that the three types of instability patterns are observed. The first one is the spiral vortex generating in high Reynold's number region and the voltex lines are nearly concentric. The second one is a series of wave like pattern generating in middle Reynold's number region. This pattern seems to be the one called viscous instability or type II instability. The third one is cross pattern. This is observed only in narrow gaps and low Reynold's number region. These three types of instability are summarized by the relationship between the Reynold's number and Ekman number respectively.

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Not quite a few extruded aluminum alloys are used for parts of building materials today. We develop an expert system for blanking process planning for such three dimensional materials by feature elimination. We think that blanking is the procedure adding' features to a raw material and process planning is the procedure eliminating features from a product. We attempt to implement this feature eliminating procedure on computers. A shape model of a product consists of two parts; a basic-extruded-material and features. A basic extruded material model represents shape of a raw material. It is a plain surface model by polygonal faces. Feature models are surface models, too. But, they describe negative volume representing blanked parts of the product. The expert system attempts to eliminate features by eliminating faces of features on each face of basic material model. At first, the system chooses one face of basic material model, and collects features' faces on it. Then, it searches database, we call 'feature eliminating case base, ' at each feature, and finds the blanking procedure which can eliminate, or make it. Repeating the above from the product to its raw material, the system gets process plans of blanking for the product.

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Amorphous alloys with the wide supercooled liquid region are called metallic glasseS. In the supercooled liquid state, the metallic glasses exhibit superplasticity, which suggests the possibilities of forming the metallic glasses into various intricate shapes. In this paper, formability of two types of Zr based metallic glass; Zr₇₅Cu₁₉Al₆ and Zr₅₅Cu₃₀Al₁₀Ni₅ (atomic%) are examined in the supercooled liquid state. The example metallic glasses showed superplasticity under compressire stress and high thermal stability in the supercooled liquid state. Furthermore, forming accuracy of the example metallic glasses was better than one micrometer. As the application of such precise forming, a concave mirror with a l0 mm diameter was formed. The profile error of the mirror was 0.5 μm and the surface roughness (Rmax), 90 nm. This superplastic forming of the Zr based metallic glasses is expected to be used for the production of various components of high precision and intricate shape.

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An arrangement of cooling channels in a mold should be designed properly to improve productivity and formability for a molded product in injection molding, because temperature distribution on the mold is dependent on the arrangement and has some influence on molded defects. The purpose of this study is to develop a methodology for automatically designing arrangement of cooling channels so as to obtain the suitable temperature distribution to reduce molded defects and to realize high productivity. A cooling channel is modeled by a set of autonomous elements which is arranged as a line and has performance for extracting heat in the mold. The arrangement of cooling channels are automatically obtained by autonomous action of these elements, according to information sent from sources which are located on the mold cavity surface and evaluate temperature on its location. For estimating the temperature distribution, a steady-state heat conduction is assumed for heattransfer in the mold and calculated by numerical analysis. Several numerical experiments have been conducted for estimating the proposed method, and the effectiveness and feasibility have beeit confirmed for automatic design of cooling channels.

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