A method for analyzing steady state vibration of a system with localized nonlinear springs by convolution integral is proposed. Scale of the nonlinear problem can be reduced by using localization of the nonlinear springs in the method. First, equation of motion with the convolution integral of nonlinear restoring force which is treated as an external force is made, second, a set of nonlinear algebraic equations on discrete-time history of unit period is derived and finally the nonlinear algebraic equations is solved with the harmonic balance method. Stable and unstable condition of the steady state vibration can be distinguished by the present method and the impulse response required can be also measured in the experiment because of the merit of the convolution integral. Two examples are shown and the validity of the method is discussed in comparison with Runge-Kutta-Gill method or the experiment.

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This paper describes experimental and analytical investigation on synchronized phenomena conducted with two metronomes on a base plate suspended by four wires. Two modes of synchronized phenomena, i.e., in-phase synchronization and out-of-phase synchronization, are experimentally observed. The synchronization mode and frequency in synchronization is strongly influenced by the natural frequency of the base plate. Calculated results based on a physical model of the experimental apparatus show good agreement with the experimental ones, not only qualitively but also quantitatively.

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In rotor systems, if the gyroscopic moment is small, the forward natural frequency and the backward natural frequency almost satisfy a condition of 1 : (-1)internal resonance. In such systems, the critical speed of a backward harmonic oscillation and that of a supercombination oscillation are near from the major critical speed. This study clarifies dynamical characteristics of nonlinear phenomena, including steady-state oscillations, almost periodic motions, bifurcate phenomena, and chaotic vibrations, due to the internal resonance at the major critical speed.

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This paper treats dynamic and static features of a sliding circular bearing with tapered grooves on its upper and lower sides. This bearing is called a tapered pressure-dam bearing in the present paper and designed in order to reduce lubricant pressure at high rotational speed. The preceding features of the bearing are analyzed by numerically solving the Reynolds equation and a heatconduction equation, considering the change of the ludricant temperature. The results show the designed bearing has a smaller value of cross-coupled stiffness coefficients when it is compared with a full circular bearing. Moreover, a Jeffcott rotor is used to investigate the stability characteristics of the bearing, and some design paremeters of the bearing are numerically determined to achieve good stability at high rotational speed. A comparison of the stability with a full circular bearing shows the proposed bearing possesses a better stability feature for a higher frequency region.

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Twin resonance tuning-fork type gyro that is one of Vibratory Rate Gyroscopes has a number of advantages. On the other hand, its output signal is very small on the structure of the vibratory body as a fault. Therefore, the rate gyro of this type is supported by an elastic mechanism and is required high gain in the resonance between the excitation system and the detection system by fine tuning⁽⁷⁾. However, the quick response and the stabilization of gyro vibration system worsen by high mechanical Q value. They are problems which do not coexist easily, and conflict. Then, it is necessary to give moderate damping to both of the twin resonance tuning-fork and the gyro support part for improvement of dynamic characteristics and stabilization. Therefore, this paper discribes an experimental study concerning the quick response and the stabilization of twin resonance tuning-fork type gyro made a high gain by the method of the first report, and reports on a method of obtaining moderate damping as the means.

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This paper investigates the mechanism of an electromagnetic acoustic transducer(EMAT). EMATs can generate and detect ultrasonic waves in a conductive specimen by noncontact electromagnetic coupling. This feature gives EMATs an advantage over conventional ultrasonic transducers : theoretical modeling and formulation based on elastodynamics and electromagnetics can be obtained. The process of detection by EMATs, however, has not been well studied theoretically so far. Thus, in this research, the process of detection by an EMAT as well as that of transmission has been analyzed numerically. Predicted signals of a receiver EMAT agree well with experimental results, which validates our numerical approach. Computed elasto-acoustic fields show us how ultrasonic waves propagate in the specimen, reflecting with mode conversion on the surface. Moreover, the mechanism of detection has been explained by using numerical results of electromagnetic field induced by ultrasonic waves. These results can be useful to establish a method of inverse flaw identification by EMATs in the field of nondestructive testing.

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This paper establishes a new formulation strategy of the flexible beam with large rotation motion. The finite element based formulation, that is previously presented for the analysis of the 'Spaghetti Problem' by authors, is extended to realize the low order and high accuracy beam model using a kind of Component Mode Synthesis Method. The deformation of the flexible beam is modeled by the combination of static mode represented by the shape function and the analytically evaluated both end clamed dynamic mode with respect to the local coordinate system. Body attached local coordinate system satisfies that x-axis of it connects both-ends of the beam. To demonstrate the efficiency and the validity of the flexible beam model in Multibody Dynamics, a 2-link flexible robot arm is modeled as the flexible multibody system consists of some rigid bodies and two flexible beams. The validity can be indicated by good agreements between the numerical simulation and the experimental results.

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Analysis method of radiated sound from arbitray configuration solids shoked by an impulse is investigated mainly from the viewpoint of practical applicability. The analyses of vibrational response of solids and radiated sound from them are based on the Finite Element Method and the Boundary Element Method, respectively. And the both are formulated in the Laplace range and they are linked in such the meaning that the boundary conditions for BEM are directly given in this range by the Laplace transformed results of vibrational response of solids. The results of time domain of radiated sound and vibrational response are obtained by the numerical inverse Laplace transform using fast Fourier transform. As some examples of fundamental structure elements, straight and L-shaped beams, a circular plate and a ring are considered, and the theoretical results are compared with those of the experiments using the impulse hammer. It shows good agreement and it is proved that the proposed method is valid for practical use.

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In production and management of various plants, it is important to provide an effective human-machine interface for communication between human and machine system. Of all communication approaches human speech signal is the most natural and effective. To compose the human-machine interface of the speech, it is necessary to develop a method with high accuracy and high quality for identification and synthesis of the speech. In this paper, a new approach for speech identification and synthesis using multi-mother wavelet is presented. The optimum mother wavelet can be searched by using multi-mother wavelet method for the speech identification and synthesis. Through the case study, it is concluded that the efficient speech identification and synthesis can be realized by the proposed approach. In future the presented speech identification and synthesis technology is expected to be applied to various cases such as plant production process and control.

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Recently, Nishihara and Matsuhisa have proposed a new theory for attaining the H_∞ optimization of a dynamic vibration absorber(DVA)in the linear vibratory systems. This is a classical optimization problem, and already solved more than 50 years ago using the so-called fixed-points theory. However, this solution is only an approximate one for the H_∞ optimization of DVA. The new theory proposed them gives us the exact solution. Using this theory, they found the closed-form exact solution for a typical performance index, namely, compliance transfer function of the system. In this paper, we will apply this theory to another performance indexes : mobility and accelerance transfer functions for force excitation system, and the absolute and relative displacement responces to acceleration, velocity or displacement input to foundation for motion excitation system. As a result, we found the closed-form exact solutions for all performance indexes described above when the primary system has no damping. The results obtained here are compared with the approximate ones derived by the fixed-points theory.

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An analysis method of a head-positioning error due to rotational vibration of magnetic disk drive is proposed. The model takes into account the rotational vibration of the baseplate caused by the reaction force of the head-positioning actuator, the relationship between the rotational vibration and head-track offset, and the sensitivity function of the track-following feedback control. Simulation resilts obtained using the model coincide with experimental data. This model enabled us to predict the data transfer performance.

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The vibration and noise generated by the motion of the driven valve system are one of the highest levels in mechanical vibration and noise of the engine. As a result of investigations of the mechanism generating the vibration and noise in the valve system, it has been found that abnormal motions of the valve system called jump and bounce phenomena are the primary factor of vibration and noise sources and the collisions between each component of the system become an issue. On the basis of these investigations, the dynamic model of the valve system is maked and Mechanical System Simulation(MSS)is carried out. As the result, it has been found that the factor to reduce these motions is the cam profile and the optimum design of the valve system has been completed. From this study, it has been verified that reduction of the vibration and noise is possible by reduction of the abnormal motions in the valve system.

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This report deals with the seismic response behavior of piping systems in industrial facilities such as petro-chemical, oil refinery and nuclear power plants. Piping is generally put on the supporting structures. Therefore, frictional vibration occurs between piping and supporting system during seismic excitation. Special attention is focused on this nonlinear frictional dynamic responses of piping systems due to frictional vibration appearing among piping and supporting devices. Mock-up piping structure model is excited by large scale shaking table. FEM model is made from the mock-up piping of shaking test, and model parameters of linear system are calculated. Equivalent damping ratio is estimated from friction response spectra. The maximum responses calculated by linear analysis using equivalent damping ratio are compared with the maximum responses obtained by experiment.

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In this paper, the dynamics of tethered systems with friction between the tethers and the bodies, as well as impact between the bodies, is investigated. This type of problem occurs during tethered capturing maneuvers such as those previously proposed by the authors to capture and remove the many damaged satellites floating in orbit. The capturing process involves the motion of the capturing device, as well as the ejection, deployment, and wrapping of the tether. Thus, a coupled tether, friction, and impact analysis is required. This paper presents a two-dimensional formulation of the dynamics between a captured target and a tether with load masses at the end of the tether. The tether mass is neglected but the slack in the tether is considered. Furthermore, the impacts between the tether load masses through the tether, as well as between the load mass and the target, are treated using the Lagrange impulse method. During the wrapping process, the dynamic and static friction between the target and the tether are considered.

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The contact wire corrugation occurred in Shinkansen Lines adversely affects the performance of current collection. It is important, therefore, to clarify its generating mechanism and establish effective countermeasures against this phenomenon. The author proposes a simple model in which a contact wire is represented as an infinite tensioned beam and a pantograph as several point masses. The growing rate of corrugation amplitude is calculated as a function of train velocity and wave length by using the contact forces generated by given sinusoidal irregularities. The analysis shows that there are high growing rates in some velocity-wave length regions and they essentially agree with conditions to generate real line corrugation. It is considered that in a contact wire excited at two point the deformation wave is represented as a sum of those from the two points and under some conditions the wave is completely canceled in the outside of exciting points. As the intrinsic mechanism, it is considered that the contact force and the irregularities become in phase with each other due to the interference between the waves.

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The 1st report discuseed the formulation, using stress wave propagation theory, of dynamic analysis of flexible manipulator under impact. In this paper, using this theory we conduct numerical simulations for the impact of flexible manipulator systems. For the numerical simulation model, two dimensional 2 link manipulator system is chosen. From the result of numerical simulation, properties of wave propagation theory is investigated. The difference between stress wave propagation theory and Newton method which is a commonly used approach is also discussed. Then, we show that the coefficient of restitution is strongly depend on the dimension, but not so on configuration and etc. The reason why the coefficient of restitution is different by the material is depend on the damping coefficient is also discussed. For the characteristics of the wave propagation theory, we can obtain the impact stress history at the impacting point as well as the influence on the joint.

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This paper is concerned with the design of an active suspension system of quarter car models using the theory of sliding mode control. The model is described by a nonlinear system with two degrees of freedom excited by an unknown input from road surface. In the previous report, the proposed control for the active suspension was constructed as a sum of LQ control and nonlinear switching control based on a reduced linear system with one degree of freedom, and the improved performance by the proposed method was experimentally shown in a small-scaled model. The present report proposes an active suspension system based on the original nonlinear system using a minimum-order observer for estimating the unknown input from a road profile. The experimental results indicate that the proposed method is much improved in the suspension performance.

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This paper deals with the inverse analysis method for estimation of the locations of noise sources. The noise sources located in three dimensional field are considered in this study. The sound intensity measurement method which takes account of the intensity and the direction of sound is used to find noise sources. The proposed procedure is formulated as an optimum problem to minimize the square sum of the residuals between the measured reference and trial sound intensities. The trial sound intensities are calculated by using boundary element method. The genetic algorithm is employed in this optimization and the proposed lattice investigation is subsequently applied to reduce computational efforts. Numerical calculations are carried out to demonstrate the effectiveness of the procedure. Furthermore, the identification of sound source locations can be performed in experiment.

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This paper proposes a 3D laser motion measurement system. This system consistes of a laser scanner mounted on a vehicle and retro-reflections(corner cube)placed in the environment as landmarks. The laser scanner rotates a fan-shaped laser beam to detect the retro-reflections and measures their relative directions. Using the information of the directions, we can get three dimensional position and posture of the vehicle in real time.

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A New Automatic Coil Recognition System has been devrloped for the purpose of full automated crane operation in the steel coil transportation fields where great demand for automation can be expected. The sensed information including the coil position and the dimensions from the Automatic Coil Recognition System are sent to the crane operating controller and these information will enable the crane to operate with full automatic mode from the transportation work of the coils on the trailer truck which has been forced to work manually. This report describes the summary of the Automatic Coil Recognition System, in case coil orientation is perpendicular or parallel to trailer, its algorithm and the result of performance test.

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A novel method for measuring the velocity-dependent adhesion force exerting on the magnetic disk has been developed using a micro-probe for Scanning Probe Microscope(SPM). The deformation of the cantilever having a diamond tip was measured based on the Michelson laser interferometry wherein an interference fringe pattern was formed over the cantilever. The fringe images were captured by an ultra high speed CCD camera, and then the deformation of the cantilever was accurately obtained through the image processing for extracting ridgelines. The high speed camera enabled one to observe the fringe image variation while the tip was being separated from a target surface accompanied by transient vibration. To circumvent the difficulties in identifying the separation point, the position and the deflection of the cantilever just at the separation were obtained as the initial values of the transient response, which was identified by means of the least squares method. Finally, the present method was applied to the measurements of the separation force exerting on the glass disk having a moleculary thin lubricant film. As a result, the separation force was found to be approximately in proportion to the square root of the retractive velocity.

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A new type of combined motor-bearing is proposed. It is intended for a rotor to have two functions of rotary motor and radial magnetic bearing. In the previous works, P±2 pole algorithm has been proposed to realize combined motor-bearing function. But the construction and the control system was complicated. In this paper, hybird active magnetic bearing(HB AMB)type combined motor-bearing is proposed with used DC magnetic flux to control radial force. The structure is the combination of hybrid type magnetic bearing and PM type AC motor. First, the fundamental operation of the proposed hybrid AMB type combined motor-bearing is explained. Then the minimum pole number that realizes the independent control of levitation and rotation is derived theoretically. Finally, the experimental setup is made to confirm the capability of the proposed motor. The results show high stability and strong rotating torque of the proposed motor-bearing.

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A design scheme of a direct neuro control using σ-modification method for a pneumatic servo system is presented. In this design scheme, sigmoid function is used for the output of the network to eliminate the effect of non-linear factors such as compressibility of air, friction between cylinder and piston in the pneumatic servo system. Furthermore, σ-modification method, which is famous for the rule of the robust parameter adjustment in the Model Reference Adaptive Control, is applied as the learning rule of the weights to progress the control performance of the system. The effectiveness of the proposed method is confirmed using the existent pneumatic servo system.

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We have developed a robot that inspects the air volume from square air diffusers that are called "anemo" on the ceiling at office buildings. The robot moves automatically, relocating its self-position by recognizing the anemo as the landmark with CCD cameras. However, self-position of the robot cannot be calculated, when the robot fails in recognizing the landmark. Then the robot stops working. Therefore, we have proposed the behaviors of error recovery. In this paper, we propose "Hierarchical Adaptive and Learning Architecture System(HALAS)" that makes the robot to be adapted to the environment by learning so that the robot can continue to work.

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Path planning algorithm in unknown environments by multiple mobile robots is proposed in this paper. The algorithm is based on the combination of Learned Visibility Graph and Learning Real Time A^*. It aims to find the shortest path that connects two known points efficiently. To avoid collisions between robots, we proposed "handing" method. Effectiveness of the proposed method is shown by simulations and experiments.

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We previously proposed the motional-mode decoupling control scheme for a micro-moving stage with three-degrees-of-freedom. In this control scheme, the acceleration feedback as a minor loop against the position loop was implemented and this minor loop had a role of damping. Since the displacement loop based on the motional-mode was constructed, the same loop structure was also adopted for the acceleration loop. However, there is not much meaning in the structure of motional-mode based damping loop, because the acceleration feedback is implemented to compensate for lack of mechanical damping. Then, it is preferable to adjust the damping for each vibration-mode rather than for each motional-mode. In this paper, we propose a modified decoupling control scheme in which the motional-mode is applied to the position loop and the vibration-mode is applied to the acceleration loop.

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The present study deals with an adaptive truss having a number of wire members as its actuators. Compared to conventional rigid length-adjustable actuators of a telescopic mechanism, wire members have advantages such as large stroke and light weight. An important point to which we must pay attention is the lack of rigidity of a wire member against any compressive force ; that is, such an adaptive truss must have a statically indeterminate topology. An iterative analysis procedure for statics problem of such a mechanical system is proposed and the stability analysis based on the procedure is given. Possible designs of truss unit are investigated based on the stability analysis. We also discuss the formulation of inverse and forward kinematic problems taking account of the statical indeterminacy. Illustrative simulation studies are conducted and the feasibility of this kind of adaptive truss and an interesting mechanical property coming from the wire member characteristics are demonstrated.

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Obstacle avoidance motion planning for a three-axis planar manipulator with a passive revolute third joint from one zero velocity state to another is investigated. This kind of manipulator is small-time locally controllable on its zero velocity states and can follow any arbitrarily path in zero velocity states almost exactly. We constructed positioning trajectory by connecting rotational and translational motion segments which are preferred motion of the manipulator considering its dynamics and can be executed at higher speeds. The way of constructing trajectories makes six-dimensional trajectory planning be reduced computationally as simpler three-dimensional path planning and time-scaling on the specified paths. The algorithm for obstacle avoidance motion planning is presented. The experimental result shows that the manipulator can reach the desired configuration according to the planned trajectory.

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Motion planning for coupled rigid bodies in a horizontal plane is investigated. The rigid bodies are serially connected by passive revolute joints. The dynamic constraints on the system are second-order nonholonomic constraints. We attempted to control those n coupled rigid bodies by the translational acceleration inputs at the first joint. If each rigid body is hinged at the center of percussion, it is possible to compose a positioning trajectory by connecting rotational and translational trajectories. Each rigid body can be rotated about its center of percussion by turns. When all rigid bodies are aligned on a straight line, they can be translated. The algorithm for positioning is presented. Simulation shows that the coupled planar rigid bodies can reach the desired configuration by the constructed inputs.

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This paper describes continuous motion control experiments of swing-up and handstand of a two-link horizontal bar gymnastics robot. The model robot has an inertia rotor to generate hand grip torque. The feedback acceleration of robot joint angles using resolved acceleration control are obtained from the dynamic equation of the free joint which means the coupling characteristics and integrated to use motor velocity commands. Digital gains are obtained using regulator control with unstable poles assigned for swing-up motion and, after the swinging motion, using sliding mode control for handstand state. Two posture modes of straight and bow of the handstand state are experimented. The experimental results show that continuous motion of swing-up and handstand is possible using above proposed control system.

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Under micro-displacement, pre-rolling friction at the head actuator bearings of magnetic disk drives has spring and damper characteristics. To compensate this friction, a force observer designed on the basis of a friction model of spring and damper characteristics has been developed. This observer enables precise estimation of the friction force at head actuator bearings and eliminates the influence of pre-rolling friction. Hence the dynamic property of the head actuator recovers its pure inertia property, which is represented by 1/s² in the frequency region below 100Hz. To compensate the friction force and recover its pure inertia property is important to apply a feed-forward control because it is designed on the basis of the model of the head actuator. By simulation and experiment, it is confirmed that this control method enables the head actuator to recover the inertia property in the low-frequency region.

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This study aims to construct a design method of human friendly machines, which enables human to use their full potential. We especially focus on skill based implicit support by adjustment of machine characteristics. Skill support based on such information is expected to raise the performance of novice operators as well as psychological impressions. From such viewpoint, this paper focuses on operational and biological rhythms. As the first step, relationships of such rhythms in experienced operators engaged in machine tool operation are examined. Under the assumption that experienced operators feel friendliness to the system as well as having the ability of achieving high performance, a support system was designed for novices to enable generation of rhythms similar to experienced operators. Experiments were carried out to evaluate the support system, which adjusts its interface characteristics according to respiration rhythms. Results show the support system increases performance by means of work accuracy as well as psychological impressions.

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In recent years, an articulate-type steering vehicle, which makes a turn in smaller area compared to an Ackerman-type steering vehicle, is developed and practically used on agriculture and construction sites. Since the articulated vehicles are generally equipped with tire wheels, it could be possibly stuck on soft ground due to the high ground pressure under the wheels. In this paper, we consider an articulated vehicle with four track units instead of the tire wheels, which we expect more trafficability on soft ground. In order to clarify the basic characteristics of turning motion of the vehicle, numerical analyses have been conducted on various running conditions solving the equations of motion constructed for the vehicle. For the validity of the mathematical model, the numerical results were compared with the experimental data of a scale model.

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Nowadays, R&D of intelligent transport system(ITS)is actively performed, and the aid system of driving operation is becoming important. The aid system of driving operation has to be designed with consideration of characteristics of car drivers. The system designed without such consideration gives strange feeling to drivers and conflicts with drivers. In this paper, a nonlinear steering controller is designed so that it has a similar structure to that of car drivers. At usual situation, the characteristics of car motion are regarded to be almost linear, and the drivers' operation and the control structure are simple enough. On the other hand, at a quick motion situation, the characteristics of car motion become nonlinear, and the drivers' operation and the control structure should be treated to be nonlinear. Therefore, a neural network(NN)steering controller that consists of 3 NNs is applied to such a problem. This structure has a similar function and structure to that of car drivers. These NNs are learned by using the genetic algorithm with numerical simulation for the case of passing through some simple curved roads. The effectiveness and the feasibility of this controller are verified by numerical simulation.

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For the shortening of journey time on railway, many kinds of steering truck have been developed to improve the curving performance and some of them are in practical use at present. However, in the previous report, it was shown that the truck with forced steering mechanism can not reduce the lateral wheel force on sharp curves. This paper deals with a study of a forced steering truck with three axles that has an asymmetric steering lever. In the steering mechanism, the 1st axle in each truck, front and rear, has a larger leverage ratio than the 3rd one, because the lateral force of the leading wheelset is greater than the ones of the other wheelsets on the sharp curve. In the analysis, it is shown that the asymmetric steering mechanism is effective for the reduction of the lateral force of the leading wheelsets in both trucks on the curve sections of radius down to a certain value. For sharp curves of radius less than that, it is confirmed that the addition of self-steering ability to the forced steering truck can make the curving performance better, and it is made clear that the existence of slack affects much to the self-steering ability.

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In order to reduce the lateral force between wheel and rail during curve negotiation, the possibility of railway trucks with actively steered wheelset has been investigated. This paper deals with a basic study about the active steering trucks, which employs force control that is proportional to bogie angle. Three different types of steering control are compared under the condition of expected operation speeds of +45km/h over the regulation, and the control type that steers only leading axles in each truck is recognized to be appropriate. Here, tilting trains with the tilt angle of 7 degrees are premised. The wheel lateral forces are compared with those of usual tilting trains without steering mechanism running at speed of +25km/h. Simulation results show that the wheel lateral force of the leading axle in the active steering truck is smaller than that of other trucks. The active steering truck shows also its superiority over the conventional trucks on the axle lateral force under the practical curving condition with truck irregularities.

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This paper deals with analytical results of steady state curving performance of a railway vehicle with three bogies like a driving car. First, the effects of uncertainty of input data such as the friction factors between rail and wheel, the friction moment M acting on truck and body, on the lateral force is discussed. Next the effect of the spring stiffness on the lateral force and flange force is discussed. As a result, it is clarified that 10% deviation from standard values of all uncertainty factors gives about 10% error to the analytical results and one or two order change of the spring stiffness is necessary in order to change the lateral force.

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This paper proposes a new method for detecting rail corrugation using wavelet analysis of acceleration of axle box. Here a track inspector is used to record the data of vertical acceleration value of the axle box. According to the wavelet analysis of the vertical acceleration data, the exact position and frequency range of corrugation can be detected. Modeling is also discussed to find out the relationship between amplitude of acceleration value and height of corrugation. The detecting results were compared to the actual measurement of corrugation profiles to prove the validity of the proposed detecting method as well.

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This paper deals with a theoretical analysis and a numerical simulation of the residual vibration on the indexing cam mechanism. Higher speed operation of cam mechanism causes a larger transient and residual vibration, thus deteriorates the positioning accuracy and results the lower settling time. It requires longer time and much manpower to design an optimal motion curve for every applications and analyze the dynamic behavior, which is largely determined by specifications of cam mechanism including motion curve. For this reason, motion curves have been selected by evaluating the characteristic values(i.e.the maximum acceleration or velocity of a motion curve)or by past experiences. This paper generalizes parametrically defined trigonometric and polynomial universal motion curves for vibration simulations, this enables to select optimal motion curves fitting the given specifications in a shorter time. From the results of the simulation, a better motion curve which is differ from the curve which is thought as best was selected, thus this theory and simulation system was verifies as effective.

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Some kinds of dielectric fluids such as dibutyl decanedioate generate jet flow between electrodes. One of authors names the fluids ECFs(Electro-conjugate Fluids), which are considered as smart fluids. In this study, a micro motor by making use of ECF is proposed. On the proposed motor, some pairs of electrodes are located inside of a cylindrical tube(stator)filled with ECF. In the stator, rotational flow is induced by ECF jets. By taking out the rotational flow power with a rotor, micro motors are easily realized. In this paper, fabrication of micro ECF motors having I.D.φ3mm, I.D.φ4mm, I.D.φ8mm is described. Basic characteristics such as rotational velocity, load characteristics, output power, efficiency are experimentally examined. Also, mathematical models of the ECF motor are proposed and verified with experimental data. Finally, miniaturization characteristics are examined through the fabricated ECF motors.

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Noise levels of motor vehicles are becoming an important subject of environment regulation. Recently, a reduction in the noise and vibration of planetary gear drives to be used for an automatic transmission of passenger cars has become an important project. The authors designed and made a planetary gear testing machine which can test the component planetary gear trains in an automatic transmission of the cars. The phase difference in gear tooth meshing is given to the planet gears which make contact with the sun and internal gears. As component gears, shaved and hardened helical gears with and without grinding were used and the rotational speed and the tooth load were changed. The experimental results clearly showed that a reduction in running noise and vibration was surely obtained when the phase difference in tooth meshing was introduced.

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Friction of spur gears was studied and evaluated under the conditions of high loads and low speeds. In this study the lowest circumferential velocity of any test gear was about 0.03 m/s. In order to obtain these test conditions, a power circulating test equipment, of which center distance was a=48mm, was used. The test results show that the coefficient of friction μ on the tooth surface at an extremely low speed is about 0.10 lubricated with oils having no EP additives. It was also shown that EP additives decrease the coefficient of friction about 25%. But this effect was obtained at a high temperature. The lower the oil temperature, the lower the effect and also the higher the circumferential velocity, the lower the effect. In the case of low speed and lubricated with hand lubrication at room temperature, the kind of oil used does not affect the friction loss.

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In this paper, we experimentally analyzed the influence of lubrication for Non Repeatable Runout(NRRO)of a ball bearing, and proposed the best design for a ball bearing used in HDD spindle motors with regard to NRRO and acoustic endurance. The results are summarized as follows : (1)In grease lubrication, NRRO fluctuated in accordance with torque fluctuation caused by grease splush. On the other hand, NRRO fluctuation was not observed in oil lubrication. (2)When ceramic balls were used, the acoustic increase was very small even when bearing was lubricated with minute amount of oil. (3)It was thought that the best design for a ball bearing used in HDD spindle motors was that the number of balls was 12, the material of balls was ceramic and the lubrication was minute amount of oil.

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Roller-burnishing is one of the post-machining methods employed to finish the machined surface. The increase of fatigue life, hardness and reliability of a machined surface are achieved easily by the method. This paper discusses with the affect of burnishing conditions on the pre-machined surface and the influence on subsequent roller-burnishing process. The finishing experiments was conducted on internal surface of small diametral cylinder of SUS 304 with various burnishing conditions. The experimental results are described and the optimal burnishing conditions are discussesed. The finishing surface roughness less than 0.5 μmRy could be obtained easily by the roller-burnishing method in optimal burnishing condition.

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The Machining-producibility Evaluation Method(MEM)for cutting and grinding was developed to assess design quality for easier processing of parts and products, thus for productivity improvement and manufacturing cost reduction. It features the followings : 1.Quantitative evaluation using easy to understand 100 point scale and accurate processing cost estimation. 2.Method is easy to both learn and use, using 12 basic evaluation element symbols. 3.Concurrent calculation of processing cost for workshop with indices. This paper describes the basic theory of the method.

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This paper discusses a new concept of the rapid manufacturing system that produces steel products automatically from CAD data. This paper proposes a sheet steel laminating method as one of typical rapid manufacturing systems, and develops a prototype machine of the method. A steel sheet coated with U-alloy is also developed as a special material for the machine, which enables us to solder steels by a hot press easily. This prototype machine is examined by manufacturing some machinery elements. This paper discusses performances and problems of the rapid manufacturing system, and possibility of sheet steel laminating method.

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Mechanism synthesis problem is discussed with an example of configuration design of chain-type mechanisms. Mechanisms are system elements of various products which are composed of mechanical pairs. In the design process, the functional structure of mechanisms, i.e., sequential chains of pairs and the spatial configuration of them, i.e., arrangement and geometry are determined simulataneously. In this paper, we propose a method for simultaneously considering both issues for designing a certain level of practical mechanisms. The concepts of marker sequences and cell-based planar representation are introduced to manipulate a design through generating marker sequences, mapping between markers and cells, refining both of them, and embodying configuration and arrangement of mechanisms. Finally, an experimental computer system is applied to several design examples. This study leads the necessity of imaginary media for representing and computing the conceptual and configurational phases of design process.

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The generation of ozone in a stable regime of DC corona discharge at a pin electrode is modeled to provide data that can be utilized for the evaluation of charging and transferring devices of electrophotography with respect to reducing the ozone emission. The results of a theoretical investigation show the following : (1)The ozone generation rates of the 50 μm radius pin electrode are 0.085 ppm/μA and 0.010 ppm/μA under 5 liter/min air flow rate in case of negative corona and positive corona, respectively. The generation rate increases in accordance with the increase of the pin radius. Although the rate of ozone emission is nonlinear with respect to the discharge current, it can be assumed to be approximately linear within the usual design and operation conditions of electrophography chargers. In case of the positive corona, ozone is formed just at the surface of the discharge electrode, but on the contrary, in case of the negative corona, ozone is formed at about 0.1 mm apart from the tip of the electrode. (2)The ozone generation rate of the charger with saw-tooth electrodes is reduced to about one third of that with a biased charger roller and it is only 1/140 of that with a corotron. The saw-tooth charger has a potential to realize virtually ozone-free charger.

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In this paper, the flexible material handling operation model on container yard is presented based on the analysis approach of flexible operation which was put forward in the first report of this research. In this model, the optimum operation scheduling plan has been carried out to realize the multi-objective optimization on operational criteria such as minimum ship waiting time and minimum operation time of transfer cranes. Meanwhile, the container information is recorded individually as the basis for operation commands from the yard production management system. Moreover, in order to enhance productivity in rehandling operation, the stack height of container block for unloaded containers is modified dynamically with fuzzy neural network according to the status and prediction of yard system. Finally, the optimal operation plan is determined by means of genetic algorithm combined with simulation analysis. The study has shown that this model can yield satisfactory operational scheduling plan for container yard by an actual case analysis.

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