Our previous report discussed a two-dimensional formulation of tethered dynamics with friction and impact : the dynamics between a captured target and a tether with load masses at the end of the tether. This paper conducts the numerical simulation on the dynamics, and clearly shows the following results : 1) the impacts cause motion state transitions, and the stick-slip motion of tether causes friction state transitions, 2) the tether tension can transfer from the angular momentum of target to that of wheel and weight, 3) relationships between the target angular momentum and the model parameters and conditions for winding the target are shown in terms of the initial conditions, and 4) the motion after winding is described in detail. These results shed light on the complicated motion of the tethered multibody.

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Recently the more complex properties have been required in the design of composite structures. In some cases, those requirements cannot be attained without joining of a composite structure to another. A single-lap joint structure is one of most popular joint structures, and its static poperties has been reported by many researchers. However the dynamic properties of this structure have not been significantly clarified. In our previous work, a new numerical modeling method of the CFRP single-lap joints structure was proposed, and the eigenvibration problem was simulated.In this modeling method, the heterogeneity of the single-lap structures could be considered in such a way that the adherend and adhesive layer were independently modeled by two types of finite elements. In the present report, the influences of fiber orientation angles in adherend and single-lap geometries on the vibration properties is discussed by using the proposed numerical modeling. The advantages and validity of the modeling method are shown in details.

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Study on the coupling phenomenon between transverse bending and in-plane stretching for antisymmetrically laminated plates or shells about the middle plane has been discussed. However, there is little theoretical and experimental studies to deal with the coupling effect of Filament-Wound(FW)formed shells on vibration characteristics. The purpose of this paper is to show the influence of coupling effect on natural frequencies of FW formed cylindrical shells simmply supported at both ends for parameters of material anisotropy, winding angle(α)and the number of layers(N). Firstly influencies of E₁₁/E₂₂ modulus ratio, shell geometry and lamination construction on the coupling effects for cross-ply laminated shells are studied. Secondly influencies of winding angle(α)and vibration mode(m, n)on coupling effects for angle-ply laminated shells are studied.

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This paper describes a study on an inverse analysis method to identify the crack parameters of Timoshenko cantilever beam by the simple genetic algorithm. The crack is simulated by an equivalent rotational spring model. By using this approximate model, a characteristic equation to calculate the natural frequencies of the system are derived employing the Timoshenko beam theory. In order to identify the crack location and the depth of the beam from frequency measurements, objective function that consists of the sum of square errors of frequencies is formed. The genetic algorithm is used to search the minimum value of the objective function. The proposed method is verified by numerical simulation of some sample problems.

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This research deals with the vibration of rotors containing liquid, such as rotors of washing machines with a fluid balancer, and is intended to predict the occurrence of self-excited vibration and to evaluate some other characteristics of these rotors by analysis. We developed an analytical method using the assumption of shallow-water sloshing to predict the motion of liquid contained in a whirling ring, and made some calculations for various whirling rates. These calculations confirmed the validity of the method, and yielded following results. (a)Not only major resonances, but also secondary resonances peculiar to nonlinear systems occur when multiples of the exciting frequency correspond to natural frequencies of sloshing. (b)There are some isolated waves(or solitons)near resonance points, and the number of solitons changes when whirling rates changes slightly.

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An asymmetrical shaft has been investigated for many years because unstable vibrations appear in this rotor system. However, when the natural frequencies hold simple integral relation exactly or approximately, an internal resonance may occur and the nonlinear phenomena change remarkably. In this study, the nonlinear oscillations and internal resonance phenomena of an asymmetrical shaft are investigated theoretically and experimentally in the vicinities of the major critical speed and critical speed of three times the major critical speed. Further, we clarified characteristics of nonlinear phenomena in the transition from the system with internal resonance to the system with no internal resonance.

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This paper describes an active vibration control system to effectively reduce the unbalanced vibration of rotating machinery with an overhung rotor. The overhung rotor is supported by a flexible bearing pedestal installed in four pairs of U-shaped electromagnets. The displacement signal measured at a flexible pedestal is fed back to the magnet. The pairs of upper and lower, and right and left electromagnets are independently controlled in the vertical and the horizontal directions. The PD control is performed in the system and the electromagnetic actuator can apply active control forces, that is, the equivalent spring force and the equivalent damping one in proportion to the PD feed back gain, to the flexible bearing pedestal to reduce the vibration of the overhung rotor indirectly. In the analysis, we confirm that there are the optimum values of the PD-controller gains to reduce the vibration of the overhung rotor. In order to make certain of our analytical results, we perform some experiments for the simply modeled test equipment with an overhung rotor. The suppression effect of the controllable flexible bearing in electromagnets is experimentally confirmed to unbalance vibrations of overhung rotor.

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This paper deals with the quenching problem of self-excited vibrations by using a device composed of a Hula-Hoop and a generator. This device is also additionally able to generate electricity. The Runge-Kutta-Gill method is applied to the numerical analysis of a Rayleigh's type self-excited system with the device. The solutions obtained are divided into two main categories ; periodic solutions and chaos accompanied by Hula-Hoop's vibration and rotation. An optimum approach for quenching the self-excited vibration was discussed. As a result, it was clarified that for the optimum design of the device there existed a certain relation among the moment of inertia, the mass of Hula-Hoop and the capacity of generator, and the vibration at that time was chaos as in the impact damper which we analyzed before. The condition of maximum generation of electricity was not equal to that of minimum vibration amplitude of the self-excited system. An experiment was performed to quench vortex-induced vibration and to generate electricity by using the device. The experimental results agreed well qualitatively with those from the numerical computational analysis.

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This paper considers the minimization of a total acoustic power radiated from a vibrating distributed-parameter planar structure using a cluster control with smart sensors. It is the purpose of this paper to clarify the stability of the smart sensor-based cluster feedback control system. First, an acoustic power matrix comprising the total acoustic power is discussed, showing that the matrix is partitioned into four cluster matrices. Then, it is mathematically verified that each matrix is a "non-negative matrix", and hence the eigenvector associated with the maximum eigenvalue of each cluster matrix is found to be a "positive vector". It is also shown that the entries of the vector correspond to feedback gains of a smart sensor-based cluster control system, thereby guaranteeing the unconditional stability of the control system. Finally, an experiment is conducted, demonstrating the stability of the smart sensor-based cluster feedback control system.

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This paper deals with the modeling and vibration control of aerial vehicles for the live-line maintenance work. Since the mass of bucket is very heavy in comparison with the bending stiffness of the boom, bucket vibrations are caused by the quick change of the derricking angle or the rotation angle. First, the equation of motion for the aerial vehicle is derived for the simultaneous actions of derricking and rotation by using a sufficient number of variables. Then, a velocity feedback control scheme is derived based on the idea that the bucket vibration is suppresed by increasing the damping ratios of the 1st and 2nd vibration modes, where the bucket velocity is estimated using its acceleration signal, and actuators are small plangers attached to the derricking cylinder and the hydraulic motor. Simulation results illustrate the control performance and the closed-loop stability of the proposed scheme.

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The Interference between operation-side and drive-side roll gap control system arises in gaugemeter control on rolling mill. It appears as limit cycle with lower frequency. But, in the analysis with simplified model, the hunting had frequency of 34 Hz and increasing amplitude. So, we studied that limit cycle with the model which had inertia of roll and moving part of cylinder, oil-compresibility in cylinder and decrease of servo-valve dynamics at large opening. We found the conditions that such a limit cycle arose.

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A modeling method for the contact problem between a wheel with flanges and a rail is presented as one of the example of the analysis methodology for objects with complex configuration. The contact configuration between a wheel and a rail is identified by geometric relationships between contact judging markers on the wheel and the rail, then the contact force is calculated considering the variety of the stiffness, damping and frictional property of the contact surface. As applications of proposed method, a free fall simulation of a wheel, and a seismic response simulation for a flexible structure settled on the rail are conducted numerically and are discussed.

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Driver's behavior under steering assist systems is studied in this paper. Steering assist system is one of subsystems in ITS(Intelligent Transport Systems). Dual port element of electric circuit theory is proposed to analyze steering assist systems. By the use of dual port element, a(linear)steering assist system is described by 6 coefficients. In the latter part of this paper, weighted control of steering assist systems is proposed. Weighted control can be expanded to a variety of steering assist systems by changing the weighted function. Drivers' test of the system is done by a driving simulator. The results show that there is interference between the driver and system if weights of them are around halves.

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This paper deals with the analysis of the impact system, Which is composed of the ball and plane of high polymer materiales. An impact model considering both duration of impact and energy loss was proposed in a previaus paper. The impact system is modeled by both a nonlinear spring and a nonlinear dashopot using Hertz's contact theory. This model is applied to the impact system of high polymer materials. The validity of the model is shown from comparison between experiment and simulation without yielding of the materials. The experiment shows that characteristics of the impact change due to yielding of the material. An impact model in considering of yielding of the material is proposed. It is shown that the model can explain characteristics of the impact in the experiment.

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Accelerometers have been most widely used to determine the vibration characteristics and the behavior of a structure. It is, however, very difficult to measure the level of a vibrating surface of a panel because, however compact accelerometers are, the lowest resonant frequency is reduced by the masses of the accelerometers, and thus vibration modes are affected. In order to solve such a problem, non-contact type laser doppler velocity(LDV)meters have been recently used, which, however, are not only very expensive, but also susceptible to a shape and a reflection factor of a vibrating surface. In our study, handy type experiment equipment was made by using a microphone and acoustic tubes to pick up plane waves propagated from a vibrating panel, and thus to determine the volumetric velocity characteristics and the vibration modes of a vibrating surface. As a result, the volumetric velocity characteristics and the vibration modes determined by our method agreed well with those obtained by the LDV method.

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An analytical method is proposed to minimize sound level by choosing optimal pattern of porous materials in closed sound fields. Using the asymptotic method to the equations of acoustic motion, explicit expressions of modal loss factor are derived. The modal loss factor is calculated with the mode shape of standing wave. Finite element method enable to get the mode shape in various forms of acoustic space. These expressions evaluate contribution of acoustic damping in local area to that of whole space, clearly. Applying the proposed method to the sample problems both of an acoustic pipe and a rectangular room, fairly well optimization is achieved.

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To aim at agile reconfiguration of a robot system, the authors have been developing polishing robot control system as a member of Holonic manufacturing system consortium in "Intelligent manufacturing system", The authors developed impedance control algorithm of a macro/micro manipulator which is able to attach or detach the micro manipulator to meet a required specification of a given task. For agility of the reconfiguration of a macro/micro manipulator, the authors developed the impedance control algorithm which command format is same whether attachment or detachment of a micro manipulator. Motor algebra was applied to derive a impedance model with consideration of inertial force effected to sensed force. This control algorithm was implemented and experimented macro/micro manipulator consisting of a 2 DOF parallel manipulator mounted on a 6 DOF articulated robot arm.

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For the environmental issues on diesel exhaust emissions, this paper presents a new electrically controlled injector used for common rail fuel injection system. This injector consists of a high-speed switching pilot valve and a main needle valve with a position feedback slot. The needle valve is controlled in proportion to the pilot-valve operation by the internal hydraulic position feedback mechanism. It also has features of the quick response and the robustness against disturbances in the wide injection pressure range from 40 MPa to 160 MPa. The functions provide an advantage for reducing exhaust emissions by the variable injection control. As a result of the analysis using computational simulation and the measurement of the transient injection characteristics, it has been confirmed that the injector has flexible controllability to shape the optimal injection rates for various engine conditions.

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A new type of Selfbearing motor is proposed using Lorentz force. It is intended for a disc type PM motor to have two funcutions of rotary motor and radial magnetic bearing. The rotor has a flat disc with eight pole permanent magnets on its surface. The stator has two sets of six concentrated windings : one produces the rotating torque, while the other one gives the radial force. Since the flat disc type eight pole motor with six concentrated stator coils is widely used due to its high efficiency. First, the fundamental principle how to produce the motoring torque and the bearing forces is introduced. Then the theoretical background of separate control capability is derived. Finally, an experimental setup is made to confirm the principle and possibility of this selfbearing motor.

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It is considered that locomotion robots are aggressive under the circumstances where human hardly work, for example, in the nuclear power plant, in the bottom of the sea and on a planet. The injury and the fault of the robot might occur frequently under those circumstances. It is very important problem that the robot can realize the walking with the fault. This is very difficult problem for biped and quadruped robot to realize a stable walking in the case that actuator or sensor is broken. And, in walking of mammal, gait pattern is generated by neural oscillator existing in the spinal cord. In the case that a lower neural system is injured, mammal realize a walking by a higher neural system. Thus, mammal has a self renovation function. In this study, in order to realize the stable walking of the quadruped robot with fault, we discuss the control method with self renovation function for the fault of the decentralized controller and the angular sensor. First, we design the centralized controller of one leg by sliding mode control for the fault of decentralized controller. Second, Sky Hook Suspension Control is applied for the fault of the angular sensor. The proposed methods are verified by 3D simulations by CAD and experiments.

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In this report, the rotation control system of the flexible robot arm is constructed with both the desired signal planning algorithm of the joint angle and the tracking controller. The tracking controller consists of the PD controller and the disturbance observer. Then, the experiments of the rotation control of the flexible robot arm have been carried out. As the results, it is seen that the residual vibrations of the flexible robot arm can be remarkably reduced. Therefore, the usefulness of the present rotation control system of the flexible robot arm using the desired signal planning method of the joint angle and the disturbance observer is confirmed experimentally.

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A control scheme of cooperative object transportation on a 2-D plane with two parallel biwheel vehicles(PBVs), whose wheels are driven with stepping motors individually, is described. The posture of each PBV is stabilized with a discrete time sliding mode regime and the reaction force from the transporting object is regulated with a fuzzy logic controller to hold the object between PBVs. As the forward side PBV runs along a reference pass, the backward side PBV is controlled so as to follow the forward one with an appropriate velocity and curvature which are estimated from the reaction force deviation and difference. With a smooth "S"-bent reference pass of 1.2m in pass length and of 2.5m^-1 in maximum curvature, the PBVs can transport a block of 50g in weight successfully with the proposed control scheme. The steering characteristics of the PBV are also discussed, where an open loop control method shows excellent steering performance for both spin and pivot turns. These results are brought from the inherent control characteristic of the stepping motor.

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Observe same phenomena K times, then one obtain K sample paths x₁(·), x₂(·), …, x_K(·)of the time series. The graphs of these K sample paths are similar, but they do not same exactly. Although the state x₁(t₁)at time t₁ of the 1 st sample path and the state x₂(t₂) at time t₂ of the 2 nd sample path mean same events, t₁≐̸t₂ and x₁(t₁)≐̸x₂(t₂)in general. Time normalization between two sample paths x₁(·)and x₂(·)is the process of finding the time t₁ of the 1 st sample and the time t₂ of the 2 nd sample path, such that x₁(t₁) and x₂(t₂)show same events. Consider graphs of two sample paths. If the local form of the graph of the sample x₁ at time t₁ is similar to the one of the sample x₂ at time t₂, we can think that x₁(t₁)and x₂(t₂)mean same events. In order to evaluate the similarity of the local forms of the graphs, the wavelet coefficients of the sample paths are used. If one know x₁(t₁), x₂(t₂), …, x_K(t_K)mean same events, one can normalize these time fluctuations and obtain new average time series (x^^-)(t^^-) where (t^^-)=(t₁+…+t_K)/K and (x^^-)(t^^-)=(x₁(t₁)+…+x_K(t_K))/K. This time normalization method is applied to action time series of a Bunraku puppet, for generation of humanoid robots' actions with fertile emotions.

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Experiment for teleoperation of a truss structure on Engineering test satellite-VII (ETS-VII) is performed as a part of space robotics missions. Truss is effective for a space structure because of its lightness and compactness. Recently, a space robot operated from the ground is expected to construct a space structure. This paper reports the results of space experiment for truss operation tasks by ETS-VII robot arm using force accommodation control. Since the robot arm applies the commanded force and torque against to the object, the force accommodation control has merits in teleoperation with time delay, such that no trajectory information is required, and excessive force and torque cannot be caused. It is especially effective in deployable truss operation.

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This study considered the development of the gripper mechanism for a micro-manipulator. In the development, it was aimed at the formation which consists of the mechanism as simple as possible, especially as for the mechanism of displacement magnification by applying the buckling phenomenon of long column. For this purpose, a phosphor bronze plate for springs like a strip of paper was bent to shape into the form of a character M, which central bottom part with the form of a character V is pulled to drive by screw mechanism. As a result, a prototype of gripper mechanism has been fabricated by which mechanism closing amount of the finger tip to a stroke of pull is easily magnified approximately 15 times. Thus, this gripper mechanism does not need the special mechanism for the magnification of displacement, it will be able to progress the further miniaturization in the near future.

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This research deals with the development of a load-sensitive continuously variable transmission designed for use as a linear actuator. This mechanism, named X-screw, has several unique features not found in other transmission systems that make it especially suitable for use as a robotic actuator. X-screw has a transmission ratio that automatically changes in response to the load. This novel loadsensitive variable transmission makes it possible to combine relatively high speed motion under low loads with a large maximum load capacity in a much smaller space and with less complexity than traditional transmission systems. X-screw also has built-in overload protection since it will stop advancing if the load exceeds a certain value although the motor is able to continue to rotate. Furthermore, X-screw can produce arbitrarily slow linear motion from a high-speed input, elimination the need for bulky gear reductions.

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This paper proposes of flexible transfer system (FTS) as one of the self-organizing manufacturing systems. The FTS is composed of autonomous robotic modules, which transfer a palette carrying an object. Through the self-organization of a multi-layered strategic vector field corresponding to a task, the FTS can generate quasi-optimal transfer path in fully distributed way. We apply the learning automata for path generation algorithm. Simulation is conducted to evaluate the basic performance of the system and the results show the feasibility of application. Also, the developed hardware is explained.

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For the purpose of establishing the mathematical beckground of a kinematic analysis of a multiple body system, the Lie aglebra of a motion group has been studied, and the algebraic experessions for kinematic analysis which is applicable any motion group is determined. Firstly it is shown that the equations for determining relative velocities and accelerations among rigid bodies can be expressed by the Lie algebra of addition and commutator product representing a Lie algebra of a motion group. Next, it is also clarified that the velocity and the acceleration of the point on a rigid body in a motion can be computed by multiplying an function of elements of the Lie algebra to the vector indicating the point from the left side. There exist eight groups of the rigid body motion, and the characteristics of the motin groups can be described by the theory of Lie algebra.

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Currently, the seismic design method of a container crane is adopted the 'seismic coefficient method'(pseudo static method). In case of extremely high intensity input seismic motion such as Level 2, the dynamic behavior of a container crane is expressed in terms of lift off of the legs from the rails and locking motion. The current design method can not treat the behaviors mentioned above. To evaluate and develop the design method for the Level 2 input motion, 1/15 scale model shake tsets, simple mass-spring numerical analyses and 3-D dynamic FEM analyses were conducted. From the model shake test results, a threshold acceleration level of the lift off of the legs from the rails showed good agreement with a pseudo static horizontal acceleration of lift off the legs predicted in the design method. Proposed 3-D FEM model of container crane can simulate the dynamic behavior of a crane model during a shake table test even when the legs lifted off from the rails. The simple mass-spring model is also a useful numerical method for the case of smaller acceleration level when the legs do not lift off.

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A new method on the detailed examination about vertical buckling phenomenon of railway train sets is studied in this paper. One cause of this phenomenon is an excessive coupler force that acts on a decelerating vehicle, which is being supported by soft bellows. The coupler force has already been analyzed dynamically using the model composed of a draft gear and a mass equivalent to the vehicle and coupler. The buckling phenomenon, on the other hand, has been analyzed statically and the upper limit of stationary compressive coupler force has only be made clear. The present study is technological importance on relief of Shinkansen electric-car which has been broken down. Especially, some kind of car and train set form is diversifying. Thus, it is important to examine the relief method which can be applied to various accidental situations.

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Reductions of meshing and bearing clearances are requisite in design and production of small backlash planetary gears. In this case, however, there is a risk of losing proper load distribution to each planet gears, which has risk of occurrence of non-working flank load. The state of non-working flank load increases unnecessarily working flank load and gives some undesirable influences on reliability of planetary gears. To solve this problem, this paper aims to analyze quantitatively about relations between the load distribution and position deviations of planet gears. These deviations are considered to be most influential to the problem in reality. About one type of the device with 4 planet gears, 20 kinds of combination pattern of the position deviations are selected out, and the influences of backlash, reduction ratio and gear module to the above relations are clarified. Consequently, allowable position deviations to avoid the state of non-working flank load are found out for various conditions and useful materials for design are obtained.

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The detail in geometrical shape of each tooth flank of mass-production gears is usually not the same. Even a slight deviation of tooth flank form of several micrometers has a big influence on the running vibration/noise of the transmisstion gear box. The influence of the scattering in tooth flank form on the vibrational characteristics of gears must therefore be taken into consideration at the design stage to achieve low vibration gears. In this report, the influence of typical types of scattering, i.e.inpressure angle deviation and helix angle deviation, on the vibrational excitation is clarified in terms of the relationship between vibrational excitation and actual contact ratio. Those types of scattering decrease the actual contact ratio of a gear pair from that value of the tooth flank form designed on a draft. Gears with scattering in tooth flank form can run silenter, when some less amount of tooth flank form modification than the optimum one for gears without the scattering is given. The design algorithm for optimum modification of tooth flank form with scattering is proposed.

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An analysis method to predict the 3-dimensional vibration behavior of a multistage helical gear system is proposed. The method considers 6-degrees of freedom for each gear and introduces variables indicating the tooth deflection and the torsional angle between drive mechanism elements, i.e., couplings and a motor. The calculated and measured results for the helical gears and the torsional vibration of drive mechanism elements were compared. The calculated eigen frequiencies and vibration responses agreed well with the experimental results. The usefulness of this method was shown.

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Spherical gear is a new type of gear invented by one of the authors. The spherical gears can transmit a rotational motion between two intersecting shafts with variable shaft angles. Thus, they have the possibility to become new machine elements which will develop a new frontier of motion transmitting systems. Some hobbing methods have been tried to make the spherical gear, but the correct spherical gear could not be made until today. The autors' aim is the practical application of the spherical gear, and for this purpose they developed a new hobbing method for producing the correct spherical gear. First it is proven that the gear cut by the conventional hobbing method is not the correct spherical gear. Second, a new hobbig method is presented. Finaly, four test gears are cut and measured, and it is proven that the new hobbing method can produce the correct spherical gear with the possibility of practical utility.

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A precies analysis has been made for the relationship between resharpening of the screw rotor hob and the profile error of the cutting edge. Firstly, in case that the profile of a relief grinding wheel is given as a series of dispersive points, theoretical equations are derived to represent the profile of the cutting edge after resharpening the hob. Secondly, a numerical analysis method is proposed to obtain the profile error of the cutting edge by using these equations. Thirdly, the theories in this analysis are verified by applying the numerical analysis method to the dimensions of screw rotor hobs and relief grinding wheels. Finaly, the calculation is made for the profile of the screw rotor which is cut by using the resharpened hob. Then, it is clarified that the relationship between the resharpening amount of the hob and the profile error of the screw rotor.

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Following to a study on tribological properties of a duplex surface treatment of tool steel, which comprises nitriding of a substrate and coating of a titanium nitride(TiN)layer, effects of tempering of the substrate sre studied by sliding experiments against aluminum alloy without lubrication. Experiments are carried out under a high-load, low-speed condition, where wear takes place predominatly. Results show that the tempering prolongs the film life more than twice. This is caused by increased fracture toughness of the substrate and improved adherence at the coating-substrate interface by formation of a high-titanium layer, both suppressing wear of the TiN layer by scratching.

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In the case of large-size marine diesel engines, it is advantageous to measure lubricating condition between piston rings and cylinder liner to prevent scuffing and abnormal wear. The authors have developed the oil film condition monitoring system using electro-conductivity sensor on cylinder liner running surface. This sensor could recognize the condition of oil film formation easily. It was found that when the sensors were attached in 10% stroke area from top dead center, where the lubricating condition is severe, the difference of lubricating condition could be evaluated well. The lubricating condition between piston rings and cylinder liner was strongly influenced by the change of running surface roughness, bot by the change of oil feed ratio in the range of 0.8∼1.5g/PS·hr.

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A two-dimensional lubrication equation of finite length journal bearings lubricated with ferrofluid considering both magnetic force and the effect of the angular momentum of particles in ferrofluid is developed. The numerical calculation results show that the latter, which was ignored by former researchers, is almost in the same order as the former and should not be neglected. The characteristics of the finite length journal bearing lubricated with ferrofluid involving the cavitation region of the bearing are investigated and discussed.

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Displacement method(DM)is based on a very simple principle for straightness measurement, but there are few experimental examples. It requires three operations to measure straightness. Two of these are operations to scan the measuring piece like a reversal method, and the other is to displace the measuring piece in scanning direction. However, such a displacement becomes serious problems in practical application because of operability and accuracy. In order to solve these problems, authors propose an improved displacement method(IDM). In this method, three displacement sensors are mounted on a stage in the pattern of triangle. Instead of the displacement of measuring piece, the stage is turned through half a revolution between two scanning operations. In this paper the effectiveness of IDM was discussed theoretically and experimentally as compared with DM. According to the experimental results, both methods are about the same in measuring accuracy, and the measuring operability of IDM is much better than DM. IDM can be applied on machine tool.

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Cyclic braking tests at extreme conditions were carried out using large one-piece brake disks having some small holes in their flange. When the number of braking cycles was beyond 300, some tiny cracks occurring around holes were found. They grew in the radial direction of brake disks. In order to examine whether braking torque is a driving force for crack initiation or not, the time interval was altered 10 times longer than the previous braking decreased when the braking interval was extended. The crack length also decreased. An alternative test at the same braking torque condition was also conducted while the disk surface temperature was always kept lower than 40°C. In this case, no cracks were observed after 300 cycles of braking. This results indicates that the braking torque itself does have little direct effect on crack initiation.

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A series of experiments have been conducted using a rolling-type tribometer to investigate the mechanism and lubricating effects of the outflow behavior of lubricant trapped in a pit. Experiments using aluminum and mild steel sheets with regularly arranged pits showed that lubricant flows out along the friction stress direction and moves larger distance with increasing sliding ratio. The outflow trace becomes deeper with increasing the forming velocity or oil viscosity. Based on these facts, it was concluded that lubricant trapped in a pit flows out by MPHL(Micro Plasto-Hydrodynamic Lubrication mechanism. With an increase of sliding ratio, the friction coefficient of both the pit region and blank region increses when the blank surface is smooth, but decreases when the blank surface is rough. The lubricating improvement effects of pits are largely dependent on the lubricating regime in the blank region and disappear rapidly with the shift of the lubricating regime in the blank region from the boudary lubrication to the hydrodynamic lubrication.

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In deep drilling, a series of our study is going ahead with the plan for improvement of accuracy. As the result, the control system for axial deviation of holes was developed. This paper deals with a new measuring method for axial deviation of holes, which was useful not only measurements of machined parts but also in-process sensing. The deviation can be evaluated from the path length and the pulse amplitude of the ultrasonic flaw detector in this new measuring system. In comparison with the optical measuring system using laser and coner cube prism, this tool can be simply constructed, because was not in need of a measuring pipe in tool shank and a prism holder in tool head. For this result, tool head of small diameter can be produced. In conclusion, the guide for practical use was presented on the control system for axial deviation of holes.

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It is well known that cutting oils are used in hobbing with high-speed steel(HSS)hob. Recently, however, hobbing without cutting oils(dry hobbing)with HSS hob has become a center of attraction, because of prevention of environmental pollution and safety for the operator, as well as reduction of costs for cutting oil and its waste disposal. This paper deals with crater wear mechanism, in addition, flank wear and finished surface roughness in dry hobbing, in order to develop hob material and coating for dry hobbing. Experiments were carried out using a fly tool. As a result obtained, it was found that hob material of corresponding to SKH 55 coated with(Al, Ti)N is suitable for dry hobbing in terms of decreasing the crater wear and the flank wear, and in improving surface finish. It was suggested that it is possible to be hobbed in dry by selecting the hob material and coating.

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To examine the effects of local hot turning on the machinability of Stellite self-fluxing alloy spray deposit, YAG laser beam of 1.2mm in diameter was irradiated at the position of 1mm ahead of the cutting region. The laser beam absorptance of the work material was as small as 0.074. Experiments were carried out for three kinds of tools. Polycrystal synthetic diamond tool was the only one able to cut the work material. The flank wear was classified into two types depending on the laser power Q ; one was the chipping of the major flank at Q=0W and Q=100W ; the other was the abrasive wear of the minor flank at Q=160W. At Q=160W, the work material could be cut at cutting speeds up to 200m/min ; the tool life was 7 times to 20 times longer than that without the irradiation ; the plane analyses of the flank with EDS demonstrated that the irradiation acts effectively to prevent the adhesion of the work material to the major flank, which increased the tool life.

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The cooling lubricants are still widely used for machining operation today to extend the tool life and to improve the quality of the machined surface. However, due to increasingly strict regulation aiming at controlling environmental pollution, the costs of using cooling lubricants are rising. It is, therefore, necessary to reduce the amount of cooling lubricant used in production lines. The logical step which can be taken to avoid the environmental problem is dry machining. But sometimes dry machining is not possible due to manufacturing process aspects, such as extensive tool wear and insufficient surface quality. To solve those problems, this study proposes cutting with minimal quantity lubrication(MQL), which is able to achieve the function of the cooling and lubrication with an extremely low consumption of lubricants and great amount of air flow. In this paper, the mechanism of the MQL system is introduced and by using this system, milling provess on carbon steel and aluminum alloys is tested to see the effectiveness of the MQL method.

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In the present study, a method is proposed which generates process planning of sheet metal bending by robot. In bending process, the handling operation of sheet metal parts has been performed by human experts. In case of human worker, the main purpose of process planning is to determine the bending sequence and tools used. If handling operations are replaced to robot, the grasping position and reposition of sheet metal parts must be indicated in detail as well as bending sequence and tools. In this paper, the problem of constraints for bending sequence is solved by using a connectivity graph which consists of bend lines and faces. And the graph is made for each grasping position. The bending sequence which contains some geometrical bending features are determined on basis of channel feature. As a result, searching space of bending sequences is reduced and feasible bending sequences can be obtained by taking the grasping positions into consideration. A computer simulation was performed based on the proposed method, and bending sequences with grasping positions and reposition are determined and sorted in order of the number of repositions. Illustrative examples and results of various simulation models are given and the effectiveness of this method is discussed.

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In order to establish a new product development methodology for machine tools, it is necessary to analyze thinking pattern of mature designers and also to systematize the actual product planning procedure of machine tools. However, the decision making methodology for product planning has not been investigated yet. In this study, therefore, a description method and a characteristic analysis of product specifications for product planning of machine tools have been proposed. Furthermore, it has been verified that the proposed methods have high potential to analyze and determine the optimal product specifications of machine tools through some case studies.

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Purpose of this study is attenuation of sound radiated from ventilation apertures and holes setting up on all apparatus by using circular slit resonator. The circular slit resonator composed of thin air layer that is radial expansion with very short axial length was set up machinery wall. The circular thin air layer acts as an acoustic resiatance, inertance and capacitance. The noise was reduced greatly at a natural frequency of the circular thin air layer that shows symmetrical circular mode of standing wave. In this paper insertion loss, IL, of the circular slit resonator designing to reduce discreat frequency noise(DFN)radiated from axial flow fan was clarified on both experimental and theoretical studies. The insertion loss, IL, of the circular slit resonator was measured by using sound intensity method. IL indicates narrow peak at resonant frequency and it strongly depends on the slit depth and slit width. IL level increases with the slit width, thickness of resonator panel and separator. The prediction of IL by the calculation model is approximately accurate.

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This paper describes a method of solid modelling using the three-dimensional polyharmonic function of volume distribution. This method requires the arbitary points or lines on the free-form surface of solid model. The free-form surface is defined using algebra sum. The free-form surfaces of solid model are searched, after solving the simultaneous linear algebric equation. In this paper, the polyharmonic functions of volume distribution and their related functions are deduced. These functions effectively smooth the obtained surface, even if functions of low order are used. In order to investigate the efficiency of this method, several examples are given.

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Motion transform mechanisms are designed for driving the wrist joint of a manipulator whose power sources(motors)are installed on the base in order to reduce masses and moments of inertia of arms. The wrist joint is composed of a spherical five-link mechanism of 2 DOF(degrees of freedom)and two linear-rotational motion transforms of Stephenson six-link mechanisms. Rotational motions of motors are transformed to linear motions by means of ball screw mechanisms, and then these motions become inputs of linear-rotational motion transformers which are driving the spherical five-link mechanism. Kinematic constants of the linear-rotational motion transformer are determined by means of a random search of the Stephenson six-link mechanism of its structural errors and forces acting on pairing elements. It is shown experimentally that the linear-rotational motion transformer is useful for the mechanism to drive the wrist joint.

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