The purpose of the present study is to develop a procedure for performing dynamic analyses of large deformations in a flexible-framed structure as it moves along an arbitrary trajectory. Equations of motion that describe the force of inertia on a flexible-framed structure as it moves along an arbitrary trajectory have been derived using a finite element method. These equations also account for the geometric nonlinearity that must be considered when the deformation is large. A finite rotational matrix was used to transfer vectors or matrices from one reference frame to another. A computer program that gives a time history response has been developed using the derived equations. The validity of the program and the formulation as they relate to geometric nonlinearity has been verified by comparing the results calculated by the program in predicting a time history response with our experimental results, the results calculated by the analysis method indicated in the previous paper, and results calculated and published by another researcher. Time history responses for models that moved along various trajectories were also calculated by the program in this study.

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For the design of tennis racket, finite element analysis using a realistic model is the most powerful tool. Total analysis system based on finite element method for the ball-racket impact without ball-spin has been developed. Improvement of the standard tennis racket in order to increase its coefficient of restitution is performed by using the developed system. Effects of changes of stiffiness, mass and string pattern for the racket are investigated. It is found that the optimal arrangement of frame mass is effective for the up of restitution performance of racket. Finally, an example of the improved racket is presented and its higher performance is verified. From present analysis, the applicability of the developed system to the optimal racket design is demonstrated.

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Natural vibration analysis methods proposed based on the boundary element method comprise the inner cell method and the dual reciprocity method, but these methods are not suitable for easily solving practical problems because of the large amount of labor required to produce data and the poor computation efficiency. In this paper, we propose an efficient 'equivalent mass method' that makes it possible to obtain natural frequencies without requiring inner cells, aiming at the practical application of the boundary element method to the natural vibration analysis of elastic bodies and sound fields. Regarding the natural vibration analysis of elastic bodies and sound fields, we propose formulation based on the equivalent mass method, the equivalent mass conditions, and the method for generating the equivalent mass that satisfies those conditions. And we prove the utility of this method with basic example and practical application.

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In this paper, an effective method for the nonlinear vibration analysis of rotor system is proposed by using the Component Mode Synthesis method and the Harmonic Balance Method. In that method, the system is divided into some components and the differential equations for each frequency for every components are derived. The equation of motion for the whole system, then, is obtained by using the Component Mode Synthesis method. The dynamic analysis of rotor system is carried out by using the Harmonic Balance Method. The distinguished feature of the proposed method is that the nonlinear restoring force term is represented by using modal coordinates in the convenient form. The order of the modal equation of motion and calculation time, therefore, can be reduced. In the numerical example, it is shown that the analysis method proposed in this paper is effective for the nonlinear vibration analysis of rotor system.

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Unstable vibrations appear around several critical speeds in asymmetrical rotor systems with nonlinear spring characteristics. However, when the natural frequencies satisfy an internal resonance relation exactly or approximately, these phenomena may change remarkably. In this paper, such internal resonance phenomena of an asymmetrical shaft-disk system are studied theoretically and experimentally. The changes in nonlinear phenomena during the transition from the system with internal resonance to the system with no internal resonance are also investigated.

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Vibration of a rotor in rotary magnetic field of a two poles induction motor has been investigated. The vibration is measured at any relative position of the stator and the rotor in various power supply frequencies in the experiment and is analyzed in consideration of structural factors of the rotor. The following conclusion is obtained through the experiment and the analysis, (1) 2ω vibration of two times of the power supply frequency ω occurs because of offset between the stator center and a gyration center of the rotor. (2) Two vibrations of ω(1-s) and ω(1+s) where s is slip ratio occur because of unbalance of the rotor or disagreement between the gyration center and the geometrical center of the rotor. (3) An unstable vibration is predicted in the analysis when the power supply frequency equals to a natural frequency of the rotor. But the unstable vibration did not occur in the experiment because of the damping.

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The authors put forward a new approach by which function and efficiency of the product can be expressed in model before its structure is designed, and proposed the concept of functional model. In this report, this approach is applied to various kinds of planetary gear trains, and their functional models are presented. The planetary gear trains are used broadly in many kinds of machines, but it was difficult to model them by the conventional modeling approaches. A transmission gearing and a differential gearing are modeled as application examples, and simulations are carried out. It is clarified that the proposed functional model is a general model that can be applied widely to the product development of machines in which various kinds of the planetary gear trains are used.

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The purpose of this study is to develop a procedure for carrying out analysis on torsional vibration of a mechanical system including piston-crank systems such as a reciprocating compressor. In the present study, we adopted the mechanical system consisting of a motor, a fly wheel and multiple piston-crank systems. We have derived equations of motion considering both variable moment of inertia of a piston-crank system through revolution of the crank and the boundary conditions that both ends of the crankshaft are free. The computer program for eigenvalue analysis and the one for time history responses have been developed using the derived equations of motion. The dynamic characteristics of a model system were investigated comparing the calculated results of eigenvalue analysis with the experimental results. The time history responses on torsion of the crankshafts of the model system were also calculated.

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A study is made on the effect of delamination on the natural vibration characteristics of laminated beams. Free vibration of the simply supported beam with a delamination of arbitrary size and location is analyzed on the basis of the Euler beam theory. Axial forces induced by bending in the parts of the beam above and below the delamination are determined by regarding the cracked part as two lapped beams hinged at both ends. Numerical results for natural frequencies, mode shapes and normal contact pressure between the delaminated layers are presented for the first four modes. Experiments are also conducted. It is shown that the analytical solutions for natural frequencies agree well with experimental results.

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This paper investigates moving characteristics of a particle which has the slant leg with rotational spring at the joint. The device travels on the sinusoidally excited floor due to the difference in friction force between forward and backward direction during stick-slip motion. Numerical simulation and experiment show that the moving direction and velocity are controlled by the exciting frequency. Furthermore, the effects of the angle of the slant leg and the sliding coefficient of friction on those characteristics are investigated.

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This paper describes self-excited mechanism of in-line oscillation of a circular cylinder excited by vortex shedding. First, the stability criterion of the oscillation and the flow pattern around the circular cylinder are obtained. Next, the pressure fluctuation around the cylinder surface and the oscillation displacement are measured and the phase angle between the pressure and the oscillation displacement are calculated. As a result, it was shown that the exciting force in oscillation was nearly equal to the damping force. The fact means that the oscillation of the circular cylinder is caused by the self-exciting mechanism.

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A new simulation method for obtaining the transient response of composite fluid line systems, such as city gas transport networks, air brake systems, pressure instrument lines and fluid control systems, has been presented. This method is based on the wave diagram of traveling waves in the system, Brown's approximate step response of semi-infinite lines, and the reflection and transmission coefficients at all joins and ends in the system. It is shown that the output pressure at any point of the fluid line system to a transient input can be expressed as the sum of the pressure of the infinite wave series traveling through the output point. Each term of the series is made up the product of "the pressure of simple wave" and "the function of reflection and transmission coefficients at the joins and ends in the system". The pressure of simple wave, the function of reflection and transmission coefficients, and the arrival time of each wave to the output point are computed by the wave diagram simulation of the fluid line system, and the output pressure is obtained by these quantities.

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In the first report of this subject, a new simulation method for obtaining the transient response of composite fluid line systems, such as gas transport networks, air brake systems, pressure instrument lines and pneumatic control systems, has been presented. This simulation is based on the wave diagram of the fluid line system and Brown's approximate step response of semi-infinite line. In this report, two kinds of the reduction technique of the waves are introduced for the effective computation of the transient response. One is the unification of the equivalent and similar waves at any join of lines from the different traveling routes. The other is the elimination of the small waves attenuated by the partial reflection and the long distance propagation. In addition, the step responses of composite fluid line systems (a loop line system and multiline branching systems) are also presented.

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This paper describes the identification of the time-varying transfer function from a pair of single realization of the input and output processes. We propose an identification method based on the nonstationary spectrum estimator with time-frequency smoothing kernel and derive the optimal kernel to minimize a mean square error measure. Then we show how to construct the optimal estimator approximately using the given data. Simple examples are examined to illustrate the performance of the proposed method.

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Sound radiation characteristics of vertically vibrating rail are investigated to clarify the nature of rolling noise of high-speed railway, since the contribution of wheel movements to rolling noise is verified to be very small. The slab track is considered and steady-state vibration responses of an infinite-length rail excited by a concentrated harmonic force is first obtained for various frequencies on the ground of the Bernolli-Euler beam theory and by applying the Fourier transform. Then, by using the Boundary Element Method based on the Helmholtz equation, the generated sound pressure is calculated under the boundary conditions of rail surface movements and rigid ground, and the sound radiation characteristics are examined especially from the view-point of directivity. Besides, the influence of restoring and damping effects of the foundation of rail on the sound pressure level is studied. Finally, the theoretical results of sound pressure distribution are compared with the existing experimental results, and it shows fairly good agreement.

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This paper describes a variable-damping dynamic damper applying Electrorheological (ER) fluid to the damping element of a conventional-type dynamic damper. A prototype of variable-damping dynamic damper was constructed and its performance was verified with a three-story structural model. The special ability of the present dynamic damper is to reduce the vibration amplitude at several frequencies by a single dynamic damper. ER fluid is functional fluid whose yield shear stress can be changed by the applied electric field strength. Because of its peculiar property, ER fluid has been applied to various mechanical components such as shock absorbers and engine mounts for vehicles, clutches, valves, etc. One of the practical ways in applying ER fluid to mechanical components may be to expand the performance of conventional mechanical components by combining ER fluid effectively with them. In this sense, this paper shows a successful application of ER fluid to a conventional-type dynamic absorber. An adaptive neural network control system composed of a forward model network for system identification and a controller network was introduced to control the variable-damping element of the dynamic damper. The numerical simulations show good agreements with the experimental results.

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This paper deals with the vibrational suppression/servo control for a standard mechanical system with 1-input 2-outputs. In order to achieve such multiobjective control system, the mixed-norm optimization based on Q-parameter approach is often used. In this control design the main goal is to obtain a servo system which keeps insensitive to the exogenous input and the vibration suppression under some constrained conditions on transient response. We finally design the L₁/H_∞ mixed-norm optimization controller with low order Q parameters by quasi-optimum solusions in the ellipsoid algorithm.

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The stability and follow-ability of articulated vehicles has been studied for many years. These studies have brought about progress in analytical techniques as simulations based on the equations of motion, root locus approach for stability judgment, and analysis of jackknife behaviors. Recently, the trailer's wheel steering is also being theoretically and experimentally implemented for improving directional stability and track follow-ability. In this paper, the author applies both nonlinear control theory and optimal servo to the trailer's wheel steering control. Under this trailer's wheel steering control, tractor's and trailer's center of gravity are on the same locus. This steering control method is also evaluated through a series of simulations in terms of off-tracking characteristics at low speed and steering responses at high speed. The results have indicated that the steering control method is highly effective for both the directional stability and reduction of off-tracking.

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Sensorless control is a method to realize the motion or vibration control without using displacement sensors or acceleration sensors which are generally used in the control of mechanical systems. The advantages of applying sensorless control to mechanical systems are cost reduction, prevention of instability of the control system by collocation, downsizing and lightening of the apparatus. In this study, a sensorless control to magnetic bearing system was investigated. Sensorless magnetic bearing control has been already realized by using an observer which is estimating the state of the system using the measured current in the electromagnet. However it is difficult to realize a sensorless control of magnetic bearing system using an observer for such a system with eddy current loss because the modeling of an eddy current loss is so complicated and has not been clarified yet. So, a model of magnetic bearing with the effect of eddy current was identified by curve fit based on least square method, and an output feedback type sensorless control system was designed based on H_∞ control theory. It is clarified through the experiment that the proposed control strategy in this paper is a very useful approach to realize a sensorless control.

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A mass measurement system with an active dynamic vibration absorber is developed. The purpose of the development is to lighten the mechanical setup, and to lower its resonant frequency for performing measurement at lower rotational speeds. In the developed system, a mass to be measured is fixed on a rotating table for introducing some unbalance to the table; it causes the structure to vibrate during rotation. This vibration is eliminated by the absorber, which also works as a measuring device because the mass is estimated from the vibration amplitude of the absorber mass when the structure does not vibrate. For eliminating vibration, a disturbance cancellation control using signals synchronized with the disturbance is applied; it succeeds in eliminating the vibration at any rotational frequencty. The measurement results demonstrate that linearity between the actual and estimated masses is good in the developed measurement system.

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The silicon ingot must be cut to yield wafers with fiat and smooth surface. However, the flatness and the smoothness are easily affected by the cutting condition of the inner-diameter saw blade. In this paper we present an experimental study on real time monitoring of the ID blade slicer cutting the silicon ingot. The vibration and acoustic signals generated during slicing ingot are measured by a piezoelectric 3-axis sensor fixed onto the supporter of the ingot. The collected data are analyzed by wavelet analysis, and indexes for evaluation of the ID blade slicing state are proposed and discussed in detail. The results show that the condition of the blade could be predicted and monitored by the slicing signals with add of the wavelet analysis.

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This paper deals with function generality and inner-structural characteristics of morphology/intelligence in autonomous mechanical (robotic) system which is generated using evolutionary design method. In the realistic virtual world including physics such as gravity, collision and friction, the robotic systems generated are found to have various morphologic feature and intelligence. In performing a given task, they show a various morphologies together with the corresponding interesting strategy. At first, the effect of noise addition to the initial condition on the task performance is discussed, and then we analyze the complexity of the robotic morphology and "dimension consistency" in the intelligence described by the decision tree expressing the inner-structures of the robotic system. It has found that 1) a small noise addition has improved markedly the task-performance rate, and also the robustness of the robotic system, and 2) the physical-dimension-consistency can explain the inner-structural character of the robotic intelligence that realized the better task performance.

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A hydraulic servo system which has quick-response characteristic, high positioning accuracy and high power by itself is often used in an air plane, a construction machinery and the center of a vibratory testing machine. Several papers for application of Neural Network to servo systems have been reported. Most of them were for systems which have slow speed response characteristic such as pneumatic servo systems. Recently applications to improve the characteristic of a hydraulic servo system, a vibratory waveform control system and so forth are studied. In this study, we applied Neural Network to the hydraulic servomechanism directly and discussed about the basic characteristic such as convergent problem of output waveform for reference input signal and stability problem of the system. The result were as follows: (1) When the Neural Network is applied to the hydraulic servomechanism and learns with the plural number of times in one sampling interval, the theoretical convergent conditional equation could be obtained and confirmed by the simulation and the experiment. (2) In this control system, there are convergent and divergent domains. And we found that the stable and unstable areas existed in the convergent domain.

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An effective method for designing neural network to classify patterns in the multidimensional feature space is introduced. Voronoi diagram is constructed over points in feature space which represents input teachers in order to realize the desired classification. In order to reduce the size of neural network and to make the learning process efficiently, clustering procedure which enables to manage a number of teachers in a lump is implemented. Two examples demonstrate that the present method gives stable result and a calculation time is smaller than that of back propagation method.

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In this paper, a new method of Guidance Control System for the Moving Robot is described. As a method of layout Planning to navigate the robot, Trajectory Design using B-spline curve is proposed. It has at continuous curvature, and passes near to the given points on a 2D space by adding appropriate new points. The Velocity Data is calculated from B-spline curve in order to navigate the PWS robot, and authors suggest Servo Mechanism which make robot track the trajectory accurately. The results of simulation and experiment show the effectiveness of this method.

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In this paper, we propose an operation method to easily control multiple mobile robot groups by a single human user and build a system in which the human user and the robots achieve tasks cooperatively. We do research on command and monitoring. Regarding command, we divide the orders from the user into levels and consider the relationship between orders and necessary autonomy of the robots. As for monitoring, we give information on at display, which shows the image of the work area. The user can monitor a remote environment and simultaneously obtain information needed for operation. By designing this methodology, our system has a flexible command structure, adaptable to robots of varied capabilities. That is the main advantage of our method. We verified the efficiency of our system by means of experiments.

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This paper addresses the development of at three-fingered anthropomorphic hand and discusses a strategy for grasping unknown objects by groping. In the former part of the paper, the design of the developed robot hand is presented. The robot hand has a thumb, an index finger and a middle finger with a total of nine degrees-of-freedom. The location of thumb is designed considering the opposability seen in a human hand. Eighty-seven touch sensors are distributed over the palm and fingers of this hand. In the latter part of this paper, a strategy for grasping unknown objects by groping, using the devoloped hand, is discussed. Groping is a kind of "active sensing". When the system does not have any models available for the objects to be grasped, active sensing becomes inevitable. The aim of the groping is to find at grasping configuration for the unknown objects. A ball, a can, a cone, at rectangular cube, and cube are chosen as the unknown objects in the experiments. Experimental results demonstrate the capability of the strategy for grasping unknown objects. This strategy needs neither models of the objects nor any complicated computations, and therefore, is useful especially for tasks in the real world.

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A 6 degrees of freedom parallel mechanism actuated by vertically fixed linear actuators was developed for heavy material handling and machining. The mechanism allows easy trajectory generation, since the vertical arrangement of the linear actuators simplifies the calculation of its inverse kinematics. This paper presents inverse kinematics and jacobian matrix solutions. Ways to avoid component interference, which is divided into three types, are proposed. The combination of design parameters is decided by comparing the characteristics of area of movement, resolution and velocity. The working space is then shown. The singularity is analyzed by evaluating determinants of the jacobian matrix. Lengthening the connecting rods and limiting the range of the end-effector rotational angles are effective in avoiding the singular configurations as well as interference. Finally, the developed prototype mechanism is introduced, and its application to tool positioning and machining described.

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In this paper, we develop a new method of simultaneous optimization of trajectory and shape for flexible manipulators utilizing the B-spline function and a mathematical programming method. We adopt approximate flexible manipulator model which consists of rigid bar elements and spring elements. To determine trajectory, we approximate the joint angles by 4th degree B-spline function so that they can be 2-times continuously differentiable with respect to time. For shape optimization, we determine cross-sectional size of each link. The used total performance index basically consists of 2 performance indices. The first is the driving energy, and the second is the trajectory deviation which is caused by the modeling for the flexible manipulator. By searching optimum positions of the control points for B-spline approximation and optimum sizes of links which minimize the performance index i.e. to minimize both energy and deviation, we design optimal trajectory and optimal shape of flexible manipulators. Furthermore, consider work time which is one of the primary factors for cost, we optimize work time, trajectory and shape simultaneously. Some examinations through numerical examples show the effectiveness of the method.

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Precise positioning and fast access, which increase the areal storage density and improve the data access performance, are required in the head positioning servo system of magnetic disk drives. The analysis of the settling response in one of the most important themes to meet these demands. In this paper, the settling response is decomposed into its contributing modes using an enhanced prony method wcich is one of the experimental modal analysis methods. Mode characteristics, which are damped natural frequency, undamped natural frequency, decay rate, damping ratio, initial amplitude and initial phase, are identified. These modes are divided into servo modes and mechanical vibration modes based on the damping ratio in order to recompose a servo response and a mechanical vibration response. Finally, each mechanical vibration mode is evaluated according to its initial amplitude and its decay rate.

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In this paper, we attend to propose the new method based on the Wavelet analysis to estimate the clearance between the cam and the valve spring in the automobile engine. At first, we measure the acceleration of the engine valve and the sound emitted from the engine to check the dynamic characteristics of the engine valve. Next, the new data processing technique based on the Wavelet anlysis is applied to estimate the deviation of the valve clearance from the desired value. Finally, our experimental results show the proposed technique can evaluate the excess of the valve clearance quantitatively.

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Large self-aligning roller bearings are assembled with human hands because it is not mass production, although small ones are assembled by special machines. This task is expected to be done automatically. Main part of the task is insertion of a roller into a hole. It is classified into two parts; one is handling the roller to the hole, and another is pushing it in. This paper presents a new handling method of the roller by a manipulator for bearing assembly task. Our system can estimate the direction and the distance for the compensation of the roller position when the roller touches parts among a hole. The estimation is realized by monitoring the pseudo contact point position calculated from F/T sensor data. Finally, the experimental results show the effectiveness of our method.

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Human facil color can be applied to the display of virtual face image, emotional evaluation, individual identification, and remote health care. We already developed a method for emphasizing the individual characteristics in facial color based on a virtual face image using the HSV (hue, saturation, value) color space. To make virtual face images more natural and richer, the clarification of the relation between facial color and emotion would be expected. In this paper, we propose a synthetic method for the virtual face image based on the analysis of facial color in emotional change. First, the facial colors under the emotion of joy or anger are determined quantitatively by using the HSV color space. Secondly, we examined the relation between the facial color and the physiological index of facial skin temperature, which indicates the change of blood flux, in drinking for the emotion of joy. Also, we examined the relation between the change of facial color and that of skin temperature under the joy in laughing. Finally, on the basis of these results, we synthesized seven enhanced facial color images based on an average facial color image from 68 females, and evaluated the effectiveness of these images through sensory evaluation by paired comparison.

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This paper proposes a system, which manages both efficiency and flexiblity ill the AGV (Auto Guided Vehicle) transportation system. Generally, It has been considered that a distributed autonomous system is superior to a centralized system in terms of fail-proof, expansion, load dispersion, flexibility, and the possibility of the evolution. Especially, the most effective characteristic of an autonomous distributed system is a restoration behavior for the system performance. In this paper, to realize the behavior so as to restore the system performance on managing efficiency and flexibility, we propose the method, where each AGV organizes the whole number of the AGV in the system by self-organizing behavior through interaction in the local domain under the change of environment, and evaluate the efficiency which is defined as amount of transportation per an AGV. It is shown that the system exhibits autonomous restoration of the system performance and higher efficiency compared with the centralized system by introducing self-organizing in the dynamical environment.

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Sheet-handling machines often use two rollers that contact each other in order to transport sheets of different sizes. One of these rollers is driven, and the other is simply a follower (i.e., not driven). However, when at thick sheet goes into the nip of these transporting rollers, the sheet sometimes stalls or jams. This paper gives the characteristics of the feeding force and the feeding limit of the sheet transporting rollers. First, an analytical model of the transporting rollers is presented. Then, by using this model, the characteristics of the feeding force and feeding limit of the rollers are determined. From this study, it is concluded that the sheet may stall or jam if its thickness is over a limit that is determined by the radius of the rollers and the frictional coefficient of the driven roller.

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The integrated control of suspensions and steering systems in cornering on uneven roads is analyzed by means of LQR control theory, assuming that cornering forces depend on normal tire loads in addition to tire slip angles. The effectiveness of parametric design for the integrated control is discussed in the vehicle stability on curvy road. By simulations of this control system under a preview driver control, it is furthermore confirmed that maneuverability is much improved for safer cornering along a desired curve on uneven roads, and it is necessary to design the integrated control with saturation condition of individual control systems.

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This paper is concerned with the sway control system for rotary cranes during boom hoisting operation. In the previous reports, the sway control system in lever operation was performed by developing a sway angle sensor and a sway controller, and the load sway was regulated by a feedback control due to the regulator theory. However, the feedback control for the regulator theory needs an expert knowledge for a setup of parameters. In this report, the control system setups parameters according to each operator's taste by using fuzzy set theory. It is confirmed by the experimental results that the proposed sway system shows excellent performance and gives easy operation.

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In the research work on dynamics of railway vehicles it is efficient in time and cost to employ scale models on a test stand. However, the similarity of creep forces between the wheel and the rail can not be satisfied in a scaled wheelset if it is made of steel, though steel is the material same as practical wheelsets. This paper deals with the effects due to the fault in the similarity of the creep force on the rolling behavior of scaled steel wheelsets. Then, referring to the idea developed by L. M. Sweet et al., a method is proposed for the experiments that utilize the scaled wheelsets. The method can keep the similarity on creep force by adding extra sprung load acting steady. The method is confirmed to be valid through the numerical simulation, but it requires the scaled wheelset to roll at the same speeds with the prototype and to be added large extra load. The apparatus that allow those demands has to be studied more before the method is realized in the practical experiment.

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In design problems, design variables are roughly divided into three types; integer, discrete and continuous. And in practical design, they are composed by mixed variables of these three types of design variables. And these types of the problems are hard to optimize, because there exist no particular method to treat these kinds of problems. Although genetic algorithms have been said to be the powerful tools for mixed optimization, it cannot treat continuous variables by its nature and most of the cases they cannot search global solution right away. In order to overcome these situation, we have been developed the adaptive range genetic algorithms, which will change the searching range adaptively from the information obtained in the previous generation and showed its effectiveness to mixed optimization. However, there are some lack in certainty in finding global optimum and also the accuracy will change in each trial. In this study, we will propose some new operators to raise certainty to obtain global optimum and also to reduce the number of function call. We demonstrate the proposed method to two type of bench mark test and show the effectiveness of the proposed method.

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A novel decomposition method for solving large scale mixed-integer linear programming (MILP) problems with the block angular structure is proposed to efficiently conduct the operational planning of energy supply systems with thermal storage units. The method is composed of solving two types of problems repeatedly: One is a large-scale MILP master problem with the values of part of integer variables fixed from the results of the other; The latter is a small-scale MILP subproblem with the values of simplex multipliers obtained from the results of the former. The method is applied to the operational planning of a heat supply system with cold and hot water tanks. The validity and effectiveness of the method is evaluated in terms of solution optimality and computation time. As a result, it turns out that the method is superior to conventional branch and bound methods with the depth-first and best-bound searches.

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A control system of a biped walking machine with consideration of compensation of external disturbance has been proposed which utilizes the concept of reflex control of animal. A walking machine has been modeled as a sequential machine, and the motions of the walking machine are composed of a series of single reflex motions. A hierarchical control system with three level controllers has been constructed. As disturbances, two types of external forces have been considered, which are "impulsive" force with large magnitude and short action time and "continuous" force with small magnitude and long action time. State variables of a walking machine for rapid and reliable sensing of each disturbance have been investigated and the thresholds of their values used as the triggers for changing the gaits from periodic gait to disturbance compensation gait have been clarified. Concepts of compensation and algorithms of determining reflex motions for disturbance compensation have been presented. A control system for an experimental biped walking machine whose mass is 18 kg, total height is 0.66 m, step length is 0.25 m and walking cycle is 133 steps/min has been constructed and tested. The walking machine has successfully realized avoidance of tumbling and/or returning to periodic gait by means of the proposed control system.

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Conical involute gears used for marine transmissions are mostly helical conical involute gears. Besides these gears are not intersecting axis gears but also nonintersecting-nonparallel axis gears. The contact between tooth surfaces of a pair of gears is the point contact. Hence the tooth surface durability is generally small. In order to overcome this weak point, one of the authors invented a new type of conical gear, which is called "Concave conical gear". Concave conical gear has higher tooth durability than the conventional conical involute gear. In this research, a new method to generate the helical Concave conical gear is presented. First the principle of generating method is introduced. Theoretical tooth surface is analyzed. Secondly test gears are ground. Tooth surfaces of the test gears are measured and compared with theoretical ones. Two tooth surfaces are in good agreement.

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It is necessary for design of a link mechanism to grasp the input torque property, but it is difficult to calculate it theoretically because of the existence of resistance at the pairs. In this study, we propose a method that can be used to identify the resistance at the pairs experimentally. For this purpose, it is supposed that the resistance at the pairs is proportional to the relative velocity of pairs. Based on this assumption, the equation of motion of the link mechanism with the resistance at the pairs is derived. Then, the resistance coefficients of the equation are identified by using experimental data. As an example, we apply the proposed method to a simple slider-clank mechanism, and confirm its validity.

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Abnormal vibration of a ball bearing lubricated with grease was studied. The test bearing was lubricated with three types of grease such as Li soap/silicone oil grease, Na soap/mineral oil grease and Li soap/mineral oil grease. In the experiment, the axial-loaded ball bearing was operated at a constant rotational speed, and the vibration and the temperature of the test bearing were measured. In addition, the shear stress and shear rate of the grease was measured by using a rheometer. Experimental results showed that the abnormal vibration is observed on the test bearing lubricated with all three types of grease that were used in the experiment. On the basis of the experimental results, the generating mechanism of the abnormal vibration was discussed. From the discussion, it seems reasonable to conclude: (1) Li soap/silicone oil grease and Na soap/mineral oil grease have a negative damping moment characteristic. The abnormal vibration of the ball bearing lubricated with these greases is generated by the negative damping moment. (2) The abnormal vibration of the ball bearing lubricated with Li soap/mineral oil grease is generated by decreasing the positive damping moment of grease due to the rise in temperature.

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Eleven modified surfaces including thermochemically treated surfaces, hard coatings and electroplatings were evaluated in terms of fretting damage resistance on fretting test. The damage mechanism of the modified surfaces, especially fretting fatigue crack was also examined in comparison with soft and hard uncoated surfaces. Tested condition is dry at room temperature in air fretted against a bearing steel sphere as a function of normal force, tangential force and repeated cycles. As the results, the chemically modified soft surfaces by salt-bath nitriding and oxy-nitriding showed the best damage resistance without the fatigue crack and corrosion. The fretting fatigue crack of the modified surfaces is deeply related to the contact condition which belongs to elastic or plastic region, and this result is in common with the uncoated surfaces. The factors such as the substrate hardness, hardness ratio of the coating film to the substrate and thickness of the film greatly influence the fretting damage.

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The behavior of elastohydrodynamic lubrication (EHL) films is directly observed with all oil having rather high pressure-viscosity coefficient under conditions of rolling or sliding reciprocating motion using the optical interferometry technique. The EHL conjunction is formed by an oscillating glass disk and a steel ball having a transversely oriented long bump and a groove. Under pure rolling conditions, the effects of the surface irregularity is localized to a region around it. Under pure sliding conditions, each bump and groove which stays at the entrance of the EHL conjunction causes a reduction ill film thickness. Its reduction rate is larger for the bump than for the groove. It has however been found that under pure sliding reciprocation with a short length of stroke, the collapse of the oil film and consequently the surface damage easily occur when the groove exists in the inlet of the contact.

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In the new method of calculating elliptical Hertz contact pressure described here, an elliptic integral is not necessary. Even the simplest numerical integration yields a Hertz contact pressure within 0.005% of the theoretical spherical contact pressure. Dimensionless parameters calculated using this method agreed well with the values given in the references. Elliptical Hertz contact pressure can thus now be calculated using a spreadsheet program for personal computers.

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Fundamental and informative data of axi-symmetric stretch-drawing of several sheet metals with thicknesses of 0.7-1.0 mm are presented both for single and double operations. Very small radius is applied to the die profile (or-shoulder) in all operations to induce wall-thinning by the effect of bending-under-tension, from which the name 'stretch-drawing' comes. It is clearly demonstrated that deeper cups could be formed by single and double stretch-drawings from smaller circular blanks due to such wall-thinning action than in the usual deep-drawing of larger blanks. From this fact, it is emphasized that the deep-drawability of a sheet metal is not evaluated simply by the conventional L. D. R (limiting drawing ratio), but the depth of the drawn cup should also be taken into account. Many experimental data about various metals and thicknesses given in this paper offer a valuable information in this process for more general use which recommends to replace the conventional deep-drawing process by the stretch-drawing process both for single and double operations. In the single stretch-drawing, it is also confirmed that a deeper cup can be produced by raising the blanks-holding force at later stage of operation.

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One of the authors invented a unique SiC whisker wheel in which the whiskers were aligned normally to the grinding wheel surface. In this paper, grindabilities of the SiC whisker wheel are investigated and compared with those of other wheels of SiC grains, Al₂O₃ grains, as well as Al₂O₃ long and short fibers which were also aligned normally to the grinding wheel surface, respectively. The main research contents grinding characteristics of a directionally aligned SiC whisker wheel such as material-removal rates, wheel-wear rates, integrity of the ground surfaces, grinding ratios and grinding efficiency. Furthermore, grinding wheels of whiskers and fibers have a common disadvantage : they tend to load easily. The authors introduced a simple method of loading-free grinding to overcome this propensity and investigate some related grinding characteristics under loading-free grinding conditions.

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This paper reveals the cause of the machining error of free form the surface when providing the NC command by continuous short blocks. This paper proposes a method to decide a limit value of the distribution to realize the machining error within allowable tolerance, and also a method of acceleration and deceleration of the motion that machines faster as possible as under those limitations. The proposed methods can be installed not only into NC. equipment but also into personal computer that process CAM data out of NC., and are able to increase twice the productivity of existing machine tool by small additional costs.

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