Corrugation is a phenomenon in which periodical undulation is formed on a railway track by wheels running on it. One of the principal causes is the contact force fluctuation at the contact point between the wheel and railway track, which is generated by coupled vibration. In this study, contact forces between wheels and railway track are calculated using a model in which two masses move on an elastically supported beam and Hertz's contact elasticity between wheels and railway track is taken into account. As a result, it is shown that the ratio of the contact force of the trailing wheel to that of the leading wheel can be smaller or larger than unity and is uniquely determined by the relative contact position index introduced by us.

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This paper presents analytical results of nondimensional frequency parameters and mode shapes of vibrations for curved and twisted cantilevered cylindrical panels. The method is based on the three-dimensional elasticity theory with consideration of rotating inertia and shear deformation. Numerical results for curved and twisted cylindrical cantilever panels having typical geometries are compared with those available in the literature. The effects of twisting, aspect ratio of panels and central angles of the cylinder on the results are also discussed.

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The paper deals with a theoretical instability analysis of a rotating flexible disk subjected to swirling fluid flow, resulting in the generation of a strong coupling between the flexible disk vibration and swirling fluid flow around it, and a possible mechanism governing unstable vibration. In the instability analysis, the basic equations of swirling fluid flow around the rotating disk are based on Navier-Stokes equations integrated over the gap width between the rotating disk wall and the shroud wall. The structural vibration equation of the rotating flexible disk is based on the Kirchhoff plate model. The equations of coupled fluid-structure motion take into account the moving boundary conditions with respect to both the rotating disk and the fluid flow. These equations were linearized for small deflection of the disk near the equilibrium state, and the solution of these equations is obtained using the multimodal expansion approximation and applying the Garlerkin method. Instability is defined as the negative imaginary part of complex eigenvalues for the characteristics equation. The unstable vibration mode shapes and the frequencies are in good qualitative agreement with the experimental results.

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Polymeric viscoelastic material has been developed as an important industrial material for use in shock and vibration devices. Proper use of the material requires a deep understanding of the characteristics for describing an appropriate mathematical model. This paper describes the fractional differential approach to model the polymeric viscoelastic material. The definition and the theory of the fractional differentials for describing the fractional differential equation of motion of a single degree of freedom viscoelastic oscillator are given. The fractional differential equation is solved and the characteristics of an oscillatory system with the material are discussed.

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The present study deals with vibration in the case of a high-speed rotary machine that is subjected to earthquake with vertical shock. We derived the equations of motion in the case of a rigid rotor that was supported by squeeze film dampers and subjected to vertical base excitation, and developed programs that can carry out dynamic analyses. It is assumed that damper journals do not collide with damper bearings even if the rotor is oscillated by basic excitation and unbalance of the rotor. Dynamic characteristics of a model rotor were investigated by eigenvalue analysis. Time history responses in the case of the model rotor subjected to a vertical sine wave were calculated. Validities of the equations and the programs developed here were confirmed by comparing calculated results with those for an elastic rotating shaft system shown in the previous reports.

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In this report, we developed programs for calculations of time history response in the case of a flexible rotor system that is subjected to base excitation such as earthquake with vertical shock. A finite element method was used in the equations of a flexible rotating shaft. As an analytical model of a SFD, the same one as that in the 1st report was used. A program was also developed for calculating time history responses even if damper journals collide with damper bearings due to vibration caused by a large base excitation. We calculated the natural frequencies and modes of vibration for the rotor system modeled in the dimensions near those of an existing turbine, and investigated the dynamic characteristics of the rotor system. Furthermore, we calculated the time history response in the case of the rotor system that was oscillated by a vertical seismic wave that was observed in Kobe City when the Great Hanshin Earthquake occurred.

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Characteristics of axial vibration of an optical disk-spindle-bearing system are experimentally and partially theoretically investigated using a focusing error signal. The measured error signal is separated into two components, averaged component (RRO) and variable component (NRRO). The main frequency of RRO is six times of spindle rotational speed due to an irregularity of the six motor driving coils, while those of NRRO are rotational speeds of the inner, outer race and retainer of ball bearings. The error signal increases when these excitation frequencies approach natural frequencies of the disk bending vibration and the axial vibration of the spindle. Furthermore, methods for estimating both the disk bending natural frequenchies and axial stiffness of the ball bearings are proposed. The stiffness is strongly dependent on a preloading process and is affected by preload, additional axial force due to the motor rotor magnet, and bearing clearance.

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The three-dimensional vibrations of a crankshat system were calculated using the dynamic stiffness matrix method taking into account gyroscopic effects. The dynamic bending stresses at fillets of the No.1 crank journal and the No.1 crank pin were measured. From the experimental and calculated results we found that: (1) the maximum bending stresses are caused by bending vibrations coupled with torsional vibrations, and the second largest bending stresses are induced by bending vibrations caused by the mass-elastic system of the torsional damper about the axis orthogonal to the No.1 crank throw plane and by gyroscopic vibrations of the inertia ring of the torsional damper; (2) forward whirl and reverse whirl of the crankshaft are induced in a crankshaft system with gyroscopic vibrations. With forward whirl, the center of the crankshaft front end traces an elliptical locus in the same direction as that of crankshaft rotation, whereas the direction is reversed with reverse whirl.

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This paper shows experimental results of a method determining what kind of chaotic bifurcations occur. The method is an application of statistical mechanics. In the previous paper, in order to apply the statistical mechnics to time series analysis in practical situations, we proposed a method of calculating statistical mechanical quantities without system equations. The results showed that the method is effective for characterization of unknown systems whose equations are not known. The next step is to investigate whether the method is also effective for experimental chaos. For this purpose, we analyze chaotic motions in an experiment on a parametrically forced pendulum by our method. The results are in good agreement with our previous numerical results. This means that the method will be useful to identify physical chaos near burst bifurcation.

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The purpose of this work is to identify the characteristics of a nonlinear vibration system subjected to a random input. In general, a statistical technique of a higher-order spectrum could be used for non-Gaussian data analysis. The dependencies between two frequency components are expressed. And the authors tried to understand the characteristics of a nonlinear system through bispectra. In this identification method, smoothing with a bispectral window is needed. The design of this bispectral window is dealed with an optimization problem here. Statistical characteristics for the design of bispectral window are bias and variance. The factor of the bias for this window is equal to that of the squared variance. Here, a numerical simulation was executed for an asymmetrical nonlinear vibration system. Moreover, the results of an experiment for one degree of freedom models with a cell sponge are examined and discussed.

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The self-sensing actuator is a new concept for intelligent material, where a single piezoelectric element simultaneously functions as both a sensor and an actuator. This idea should be advantageous in many aspects of control, especially for vibration control of flexible structures. The key component of this device is an electric bridge circuit that includes a piezo element. This circuit could provide significant information about strain in the element if it were well-balanced. Our aim is to use μ-synthesis to design a controller which guarantees that the performance of a self-sensing actuator is robust against perturbation of the bridge balance and to confirm the advantages of this technique from the viewpoint of control. Experimental results show that the self-sensing actuator driven by the designed controller exhibits excellent performance in suppressing the vibration of a cantilever and is robust compared with the conventional control scheme.

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We presents an active control of cantilevered pipes conveying fluid with constraint on input energy. The controller used in this study is designed with constraints on input energy variances. LQG control law is used to obtain the feedback controller. This controller design method takes the performance of the actuator into consideration. The control object which consists of a pipe system and an actuator is modeled mathematically by the Galerkin method. The experimental setup consists of the pipe system, a laser sensor, an A/D converter, a personal computer, a D/A converter, and a DC servomotor which produces a transverse force for active control of the pipe. The experimental results show that the effectiveness of the controller in stabilizing unstable phenomena of cantilevered pipes conveying fluid varies according to the conditions of input variance constraints.

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An active vibration damper and an isolator are capable of reducing vibration remarkably and adaptively. One of their disadvantages is that they require a large amount of energy. Since vibration is a type of energy, a question arises as to how we can utilize this energy. In this paper an energy regenerative type suspension is presented, wherein an electrodynamic actuator is used and electric power is regenerated during the high-speed motion of the actuator. For low-speed motion, an active control algorithm is applied to the same actuator to achieve good damping performance. In order to reduce energy loss in the control amplifier, active relay control is applied instead of linear control. The system is simulated on a computer and a simple experiment is performed, The results show that the system has better performance than a passive suspension system and can regenerate vibration energy.

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Recently, sound or noise radiated from vibrating structures has become a problem of importance in society. Most of the sound radiated from vibrating structures is known to be structure-borne sound. The purpose of this study is to investigate the sound generating mechanism from the viewpoint of both sound energy and vibrational energy. To evaluate the transformation from structural vibration to radiated sound, the sound radiation efficiency is generally used. However, the sound radiation efficiency does not directly express the relationship between structural vibration energy and sound energy. In this study, we propose a definition of energy transformation efficiency which expresses the relationship between structural vibration energy and radiated sound energy. The energy transformation efficiency of a rectangular plate from vibration to sound is calculated from the eigenfrequency, eigenmode and size of the vibrating rectangular plate. As a result, these parameters of the vibrating rectangular plate, which influence radiated sound energy, are clarified by using the proposed energy transformation efficiency.

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An analysis method and equations are established for calculation of the frequency spectrum and over all value of the sound pressure emitted from a multi-modally vibrating beam, which is excited by the slit of a motor's commutator, by investigating both the forced transient vibration and the free vibration of the beam, and by taking the Fourier transform calculation analytically. We note that in addition to the conventional wave cancellation occurring on the beam surface, a cancellation mechanism exists also in the calculation of the amplitude of the surface velocity because the integral function involved yields both positive and negative values. Hence, it is suggested that by making use of this concept of cancellation of amplitude of velocity, reduction of the volumed surface velocity and emitted sound pressure can be achieved by altering the shape parameters of the structure. Results of experimental studies confirmed the results of the theoretical analysis presented.

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Based on the investigation of the generation mechanism of the unusual noise of nearly pure sound generated from axial flow fans, it has been clarified that the harmonic torque of the induction motor which drives the fan is resonant with the torsional vibration of the rotary system, and since the vibration frequency lies in the audible range, it is a source of noise. To prevent the generation of this unusual noise, in this work, the following two methods are investigated and executed to evaluate their effects, namely, a method of mechanically avoiding resonance by setting of torsional rigidity in the rotation axis, and a method of reducing generation of harmonic torque of the induction motor. Both methods are found to be effective, and it is confirmed that the generation of this unusual noise is completely prevented. The cause and the countermeasure described in this paper are expected to be used in practice for troubleshooting and design of axial flow fans.

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This paper describes the study of active noise control schemes using two-degree-of-freedom control based on model matching for a one-dimensional exhaust duct. In this study, the controller is designed using a model identified based on frequency-domain test data. Simulations and experiments are carried out using the designed controller. The experimental results show a good agreement with the simulation results, and noise reduction of more than 15dB is obtained over the frequency range from 100Hz to 500Hz at the microphone location.

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This paper deals with a control technique for eliminating speed or torque variations, which are locally generated inside a gear reducer and excite a driven machine system, in the lower-frequency domain. This technique is based on a self-compensating control applied to the gear reducer. In the self-compensating control loop proposed previously, band-pass filters with fixed center frequencies were employed to suppress such variations at constant speeds of the driving motor. To enhance the performance of this method, band-pass filters whose center frequencies track changes in the motor speed are integrated into the loop. This proposed variable self-compensating control loop is used to reduce the exciting components of the harmonic drive gear upon increase and/or reduction of the motor speed. The stability conditions of this control system are clarified by the loci of the system eigenvalues. Furthermore, this control technique is used to suppress the vibration level at passing-through-resonance. Simulations and experiments show satisfactory control results.

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A method of time historical response analysis for large-scale structures is presented. This method is derived from a combination of the transfer influence coefficient method and the Newmark-β or Wilson-θ method, and it improves the computational efficiency and accuracy of the transient response analysis remarkably by means of several advantages of the transfer influence coefficient method. The present method is free of the numerical instabilities which often occur in using the Newmark-β or Wilson-θ method combined with the transfer matrix method or the Runge-Kutta-Gill method. An algorithm for the transient response is formulated for the three-dimensional three structure which is mainly found in pipeline systems. We regard the tree structure as a lumped mass system here. The validity of the present method compared with other methods for transient analysis is demonstrated through various numerical computations.

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The effect of variation of impacting masses on the maximum acceleration and maximum displacement of the masses and the maximum resisting force of a hydraulic shock absorber is analyzed using an optimization method proposed in this papar. The maximum value of the maximum accelerations of nondimensional ten masses is set as an objective function for the optimum design of a hydraulic shock absorber, and is minimized. Furthermore, the above optimization results are compared with optimization results obtained under the condition that the objective function to be minimized is the maximum acceleration of the maximum mass only. The maximum acceleration of the masses and the maximum resisting force of the shock absorber obtained by the former optimization are less than the those obtained by the latter optimization at impacts of masses in the range of 55-90% of the maximum mass.

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An omnidirectional vehicle (ODV), which can move in any direction without changing its body direction, was investigated. The principal driving motion involves four wheels equipped with rollers on their circumference. These rollers rotate along the axle direction of the wheels. The wheels are installed on all four sides of the vehicle. Moving properties of this vehicle were investigated through computer simulations and experiments. The simulation tests confirmed that the ODV can move to arbitrary places in arbitrary directions. Spinning motions and turning motions are also possible in addition to the omnidirectional motion. A variety of movements were examined in the ODV experiments. To analyze these results, an omnidirectional robot (ODR) called "calligraphy robot" was constructed, which drew a cursive style Chinese character with a writing brush on a sheet of Japanese writing paper. Movements and control of the ODR were evaluated, and satisfactory movement and control performances were confirmed.

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A magnetic bearing has merits of no friction and no energy loss because it can support a rotor without physical contact. However, there are some problems such as poor system robustness and vibration caused by rotor imbalance. In this paper, we introduce two control methods to resolve these problems; disturbance cancellation control and repetitive control. First, the disturbing torque is estimated by the observer and fed back to the plant along with the position and velocity signals. This technique also cancels the difference between the actual control plant and its nominal model. As a result, the control system has accurate positioning and robustness from parameter variations. Repetitive control is a kind of servo control that follows a constant periodic command. Hence it is applied to a real magnetic bearing in order to remove the imbalance vibration which has the same period as the rotor speed. However, the rotor does not always rotate at a constant speed. Therefore, angular domain repetitive control is derived and applied to the magnetic bearing. The stability problem of the system is solved by an optimal regulator theorem. An experimental setup is made using rotational interruption, and the proposed method is tested.

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A method has been developed for constructing a neural control system that can be used to control the machines used for tunneling underground conduits for telecommunication optical-fiber cables. The neural control system is based on a feedback controller whose gains are tuned adaptively using neural networks. The tunneling machine's displacement, which is used as a feedback signal, is estimated using a direct neural identifier. To avoid an undesirable local minimum problem within the learning process of the neural identifier, a learning algorithm is proposed that combines both genetic algorithm and back propagation. Simulation using a nonlinear system confirmed the algorithm's characteristics; identification results using the experimental data of a tunneling machine showed its usefulness for a practical system. Numerical simulation of the proposed neural control system confirmed its feasibility and showed that the direction of the tunneling machine can be controlled for various construction trajectories and soil types using the neural network's learning ability.

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In the field of roundness measurements, the 3-point method is very useful. We used this method for precise column estimation in the range of 0.01 micron p-p including high-order harmonic components up to the 254th. The high-order calculation is critical for setting angles among three sensors. We determined the invalid setting angles and showed it on a chart, and we show a method for obtaining suitable accurate angles among these sensors. We are testing the relative accuracy on the testing model. Absolute accuracy has not been confirmed yet, but we consider that these results show me a reasonable roundness.

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Scoring is sometimes found on the surface of a toothed wheel that is rotating under high-speed and high-load conditions. Scoring is said to be strongly influenced by the surface temperature of the toothed wheel. However, it is very difficult to measure surface temperature. We proposed a new concept of thermography which can measure the surface temperature of a toothed wheel with high-speed revolution. We applied thermography to measure the surface temperature of a rotating toothed wheel, and described the results briefly.

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The purpose of this study is to analyse on human eyes. Some of the autonomic nervous system effects analysis systems developed in this study are expected to be useful for obtaining much data regarding the pupil light reflex and convergence reflex. In observations of the pupil litht reflex using the aforementioned systems, we found small pupil diameter variation due to parasympathetic nervous activity from the velocity phenomenon of pupil contraction and dilation. We also observed pupil focusing with alternate movements of contraction and dilation at about 0.5Hz in analysis of the pupil convergence reflex.

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We developed a musculoskeletal model consisting of thirteen rigid links and thirty-one muscles in order to analyze whole body motion such as rowing. Nine experiments were carried out for different rowing forms and pitches. The motion and external forces while rowing were measured for five skilled men who belong to a university boat team and five nonskilled men. Energy consumption and muscular tensions were calculated from the measured data and the musculoskeletal model. Both energy consumption and muscle fatigue became minimum in the case of the ordinary rowing style of skilled subjects. Therefore, whole body motion such as rowing seems to be performed so as to decrease both entire loads due to motion and partial loads due to muscle activities.

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Our aim is to develop a microactuator to be used for endoscopic surgery. The purpose of this study was to construct cylinder-piston-type microactuators that are actuated by thermal expansion of paraffin. We use a paraffin as the material for expansion because paraffin has a large coefficient of expansion in the temperature range of 35 to 45 degrees of centigrade. For smooth actuation of the piston, we must prevent the paraffin from sticking on to the inside surface of the cylinder. Thus the paraffin is enclosed in a silastic tube. The cavity between the cylinder and the tube is filled with silicone oil for lubrication and prevention of expansion loss. The outer diameter of the actuator is 2.5mm and its length is 130mm. The actuator can generate a stroke of 8mm against a load of 1kg.

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Micro manipulation is required for assembly and maintenance of micro machines and their parts. If the objects to be handled are miniaturized, interactive forces between micro particles and grip surface become dominant. We proposed a handling strategy of micro objects based on physical phenomena in the micro world. In this paper, we propose the adhesion-type micro endeffector. This endeffector is designed to pick up a micro object by adsorption force. In order to pick up the micro object, the endeffector temperature is increased to exceed room temperature before touching the object. After contact with the object, its temperature is decreased and positive pressure is generated inside the micro hole. To release this pressure, the endeffector temperature is increased again. This system realizes quick response due to its scale advantage as long at it is miniaturized in micro order. We made a prototype endeffector by Si surface micromachining. We analyzed the performance of this endeffector and conducted experiments. Finally, the effectiveness of the proposed method is shown.

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A multigrid method has been introduced as a fast alternative to conventional relaxation methods for obtaining a solution to the Reynolds equation for self-acting gas-lubricated bearings. This paper verifies the procedure applied to both static and time-dependent dynamic analyses of plain-cylindrical journal bearings. The method gives successful results with less computational effort compared with single grid-oriented iterative methods. In addition, the new approach does not require a trial and error process to optimize the overrelaxation parameter unlike a successive overrelaxation method. The nonlinear orbit method which is an accurate but time-consuming transient analysis is expected to be reduced to a handy design tool for a complicated bearing system on incorporating the multigrid technique.

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In this paper, a duplex spread-blade method for cutting hypoid gears with modified tooth surfaces is proposed. The duplex spread-blade method is a rapid and economical gear manufacturing method because both the ring gear and pinion are cut by a widely spread-blade cutter, that is, both sides of a tooth space are finished simultaneously by a cutter. In the proposed method, the nongenerated ring gear is cut by a cutter in which each cutting edge is altered from the usual straight line to a circular arc with a large radius of curvature and the pinion is generated by a cutter with straight cutting edges. The circular arc cutting edges enable application of the duplex spread-blade method theoretically and produce a tooth surface modification. The main procedure of this method is the determination of cutter specifications and machine settings which satisfy the duplex spread-blade conditions taking account of the position of tooth bearing. The validity of the proposed method was confirmed by the actual gear cutting.

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The sound of rail-type rolling guides with recirculating balls was studied. The test rolling guides were operated at a constant linear velocity and the sound of a rolling guide itself was measured. In addition, an experimental modal analysis was performed on the bearing block of a rolling guide at a constant linear velocity. Experimental results showed that the rolling guide has a sound property between line sound source and point sound source. Moreover, the sound level increases with a linear velocity and the frequency of the main peak in the sound spectra is not affected significantly by the linear velocity. Analysis indicates that the main peak is caused by the vertical, rigid-body natural vibration of the bearing block.

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The sensitivities of the general spatial 7-link, 7R mechanism, namely, the ratios of the small changes in angular displacements of the links to the deviations of the kinematic constants, are estimated as the solutions to the simultaneous equations obtained from partially differentiating the necessary and sufficient equations for the purpose of displacement analysis. The partial differential coefficients that comprise the elements in the simultaneous equations are given in a recurrence formula. By using this procedure, the sensitivities of a constant-velocity joint as a special case of the general spatial 7-link, 7R mechanism are analyzed, and they are divided into four classes. Moreover, by using the noninfluencing or mutually compensating characteristic of sensitivities, asymmetric constant-velocity joints of the 7R linkage type are derived.

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The aim of the present study is to represent a probability to design of step shape noncontact mechanical seals under high-speed and high-pressure conditions for water pumps. Existing contact-type mechanical seals under these conditions show unstable seal performances. For a noncontact mechanical seal, we estimate the leak rate and obtain the conditions for stability and reliability. We derive equations for calculation of the leak rate, taking into consideration the influence of fluid inertia force by defining S, an inertia coefficient. Since the leak rate is influenced by fluid inertia force, it decreases as speed increases. We found that seal face stiffness is important in calculating seal dimensions and developed a diagram for seal design which takes into account fluid inertia force.

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In this paper, we describe an experimental study of the fundamental characteristics of bouncing vibration of a contact slider for future high-density hard disk storage. For the experiment, we made four different types of contact slider, composed of similar stainless steel beams and glass or lead balls. Vibration of the slider is measured using a laser Doppler vibrometer. The measured data are analyzed by an FFT analyzer. From the experiment, it is found that the bouncing vibration is always low when the slider load is high, the coefficient of restitution is low and the slider beam damping is high. In the lead contact sliders, the bouncing vibration is smaller for smaller mass. However, in the case of some glass sliders, a large mass can reduce the bouncing vibration because of the increase in the inertia effect. Almost all experimental results qualitatively agree with the theoretical ones. However, we also observed new resonance phenomena in the low-frequency range.

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Frictional behavior in sliding pairs of pig articular cartilage and glass plate has been studied to elucidate the tribological role of constituents in a synovial fluid and a surface layer of the articular cartilage. Pig synovial fluid and water solution of hyaluronic acid were used as lubricants. The synovial fluid had a significantly superior lubricating ability to a sodium hyaluronate solution of equivalent viscosity under physiologically high load condition. The superiority of the synovial fluid seems to be responsible for the boundary lubricating ability of constituents other than hyaluronic acid. Langmuir-Blodgett films of phospholipid (Lα-dipalmitoyl phosphatidylcholine, Lα-DPPC) on the glass plate maintained low and stable friction, depending on the number of film layers. In conditions of mixed films containing γ-globulin and Lα-DPPC, the frictional behavior was improved by increasing the quantity of γ-globulin. A model of the boundary lubricating mechanism is proposed in which the effective adsorbed film is composed of proteins, phospholipids and other conjugated constituents on the articular surfaces, and controlled by hydrophobic groups in those amphiphiles.

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We propose a method for achieving a topological tooth profile using a conventional grinding machine. The first step defines the coordinate systems for the grinding wheel and shaving cutter and specifies their coordinated interactive relationship. The shaving cutter coordinate system includes a pitch block with offset and the pitch band. The second step specifies the grinding wheel profile in a generic way using an nth-order polynomial such that it can be used in any grinding analysis. The third step analyzes the interaction between the grinding wheel and shaving cutter based on the conjugate principle and characteristies related to the symmetry of the grinding wheel profile. The last step determines the combined motions of the grinding wheel and shaving cutter and the equations for the ground profile are formulated. Using these steps, the finished shaving cutter profile can be calculated by defining the grinding wheel profile and machine setting conditions.

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Cutting fluid are essential in metal cutting to increase the tool life and reduce the finished surface roughness. Due to increasingly strict legislation aimed at controlling environmental pollution, however, the cost of using cutting fluid is rising. Therefore, it is necessary to reduce the amounts of cutting fluid used. In this study, we propose a method in which cooling and lubrication are achieved using extremely small amounts of cutting fluid. The effect of the proposed method is investigated through experiment.

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To accomplish high-precision machining, it is essential to minimize the tracking error of machine tool servosystems. A controller for the servosystems should compensate the tracking error due to servosystem dynamics and reduce the influence of parameter change on the controlled system. In this regard, we designed and implemented an adaptive feedforward controller and a dead band compensator on the CNC machine tool developed in our previous report. The feedforward controller consists of an on-line parameter adjustment device coupled with a discrete time inverse transfer function. Experiments including cutting tests proved that the dead band compensator always effectively reduces the tracking error. The inverse transfer function greatly improves the tracking accuracy when the on-line parameter adjustment device is working, although a disturbing signal or load is applied on the system. Without the parameter adjustment device, however, the implemented inverse transfer function can increase the tracking error.

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The wear of a polycrystalline diamond tool in the cutting of a SiC grain-reinforced plastic composite is investigated. The effects of grain sizes of SiC in the composite and the diamond of the tool were concerned. The cutting experiments showed that higher wear of the tool occurs in cutting of the composite with larger SiC grains; the coarse-grained tool exhibits a higher wear resistance than the corresponding fine-grained one for all composites. Moreover, tool wear is increased drastically when the SiC grains are larger than the tool grains. On the other hand, a wear model, called the "tear-off model", was proposed to explain the wear mechanism of polycrystalline diamond tools in cutting the SiC-plastic composite. The model illustrated that the greater wear of the tool with the larger SiC grains call be attributed to the iscrease in debonding force of a SiC grain. Finally, an empirical relation, introduced as a fatigue-like curve, between the maximum stress on the tool grains and the number of stress cycles was established to describe the generalized relationship between the SiC grain size in the composite and the flank wear of the tool, taking into consideration the SiC volume ratio, SiC size and tool grain size.

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In a manufacturing system, the dynamic characteristics of machine tools exert a profound influence on the machining accuracy of components. In particular, the performance of the interface between machine tool and workpiece has significant effects on the machining accuracy and efficiency. Nevertheless, the importance of these interface devices, remains unknown since there has been insufficient research on these devices. In this study, in order to improve the characteristics of a chucking system, we clarify and evaluate its damping mechanism. In particular, the relationship between machining accuracy and the dynamic characteristics of a chucking system in a machine tool is investigated with a damper of elector rheological (ER) fluid. The results are as follows. (1) The damping characteristics of the ER damper in a chucking system of a machine tool can be controlled and improved without influencing stiffness. (2) The damping characteristics are proportional to the yield stress of the ER effect. (3) It is necessary to investigate not only the numerical value but also the fluctuating rate of dynamic characteristics in order to evaluate the dynamic performance. (4) An accurate evaluation method is proposed for damping characteristics.

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We present a statistical model for analyzing the reliability of multistage machining systems, and a statistical procedure for designing high-reliability multistage machining systems. The disadvantage of a multistage machining system is that if one of the k tools fails during cutting, the workpiece inprocess becomes defective and interruption of cutting occurs. A replacement procedure is formulated from a statisical point of view. In this work: (1) a statistical model to analyze the reliability of multistage machining systems is developed and (2) a statistical procedure for the design of high-reliability multistage machining systems is presented.

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