In this study, a base isolation device using pseudoelastic shape memory alloy (SMA) wires is developed. A base isolation device using softening spring restricts acceleration transmission from the source of vibration so that pseudoelastic SMAs, which have origin-oriented hysteretic restoring forces, are utilized as softening springs rather than damping materials. Two SMA wires are used as the spring arranged as they as buckled when the spring is subjected to a compressive load. Therefore, the spring's restoring force shows remarkable softening characteristic due to material and geometric nonlinearity. Furthermore, base isolation effect based on output acceleration is investigated experimentally and analytically.

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A new calculation technique is proposed for getting symmetric periodic solutions of the lumped mass discontinuous system to periodic excitation. This system is adopted as a typical piecewise linear oscillator having no stiffness. First, it is pointed out that the feedback super-position method which was formerly proposed by authors can not be directly applied to this zero-stiffness oscillator. In order to overcome this difficulty, an improved calculation method using Cesaro's summation technique for getting the physically meaning value of divergent series appering in pseudo-feedback responses is newly proposed. According to this method, even unconverged series of the periodic pseudo-feedback response become to be evaluated by the Cesàro's (C. 2) summation to viscous damped system and those (C. 3) summation to undamped system, respectively.

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An analytical approach is developed for determining the spacecraft attitude response for stick-slip induced disturbances of a large extended structure with tension control mechanism (TCM). In this method, attitude dynamics with flexible appendage is formulated as a general constrained mode model, and coupling with the stick-slip induced oscillations is formulated as the transition of equilibrium states of modal parameters. Numerical calculations are presented for the flexible solar array on the Advanced Earth Observing Satellite (ADEOS), which caused unexpected attitude oscillations due to the stick slip on the orbit.

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In this study, a simulation method of seismic wave propagation was constructed using the Cellular Automaton method. The ground, which is the analytical domain, was divided into cells and the local rules to update the state parameters between the cells were constructed as well as the local rules about the reflection and transmission between grounds, and the treatment of semi-infinite domain. The intermittent update method was also proposed to adjust the difference of propagation speed of wave. The validity of the method was checked by comparison of the simulation result with the measured one and the results agreed well. It was considered that the method constructed in this study was efficient for the actual application.

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In this study, a simulation method of seismic wave propagation was constructed using the Cellular Automaton method. A ground, which is an analytical domain, was divided into cells and the local rules to update state parameters between cells were constructed as well as the local rules about the reflection and transmission between grounds. The intermittent update method was also proposed to adjust the difference of propagation speed of wave. The validity of the method was checked by the comparison of the simulation result with the theoretical one and the measured one and the results agreed well. It was considered that the method constructed in this study was efficient for actual applications.

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This paper describes a roller type isolation device for individual showcases and individual works of art. The isolation device consists of two layers that form a XY-motion mechanism for two-dimensional horizontal motion; each layer consists of rails having a circular-linear-combined shape in the vertical cross-section to produce a restoring force, wheels, and fiction dampers comprising the wheels and the axles. Because the effective natural period of the device is independent of the mass, a long effective natural period can be achieved even for light equipment such as showcases. Shake table tests were carried out, showing good isolation performance of the device and confirming validity of the analytical model developed in this study.

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This paper proposes a structural topology optimization method for obtaining mechanical structures incorporating desired vibration characteristics for the design of mechanical resonators and vibromotors. First, a new type of homogenization design method is introduced, in which the continuous material distributions are assumed using a continuous interpolation function at each node, in order to overcome numerical instabilities such as checkerboard patterns. Next, three design requirements to implement specific vibration characteristics in the mechanical structures are clarified, namely eigen-frequency matching, eigen-mode control, and stiffness, and the corresponding objective functions are formulated. A new type of multi-objective function incorporating the three objective functions is proposed. The optimization problem is formulated using this multi-objective function, and an optimization algorithm is developed using Sequential Linear Programming (SLP). Finally, several examples are provided in order to confirm the usefulness of the generated optimal designs for vibrating mechanical structures.

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In this paper, the motion of a tethered system with large deformation and large displacement is discussed experimentally. A tethered subsatellite in space is well known as an example of this system. However, even fundamental experiments about the motion of the tethered system have not been done. Also in a viewpoint of flexible mulutibody dynamics, it is expected that simple experiments for a motion of very flexible body are completed in order to verify the validity of the proposed approach. In this study, a system consisting of a very flexible body and a rigid body is regarded as the tethered system. First, we conducted an experiment about fundamental motion of a very flexible body with a attached mass in gravity space. We select steel and rubber as the tether material. In these experimental results, the characteristics of the complex motion of a very flexible body are obtained. Second a experiment in micro gravity space was done. The coupled motion between the very flexible body and rigid body is investigated. It is verified that the motion of the system with large deformation excited in micro gravity space and the interaction between the deflection of the very flexible body and the rotation of the rigid body.

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This paper describes vibration analysis using finite element method for a viscoelastic block supported by a nonlinear concentrated sping. The restoring force of the spring has cubic nonlinearity and linear hysterisis damping. Finite element for the nonlinear spring is expressed and is connected to the viscoelastic block modeled by linear solid finite elements in consideration with complex modulus of elasticity. Further, the discretized equations in physical coordinate are transformed into the nonlinear ordinary coupled equations using normal coordinate corresponding to linear natural modes. This transformation yields computation efficiency. Influences of share of dissipated energy on nonlinear frequency responses for the viscoelastic block are clarified.

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This paper presents active cluster control of a distributed-parameter beam for the purpose of generating a completely vibration-free state on a designated area of the beam. First, theoretical development of cluster control consisting of both cluster filtering and cluster actuation is shown. Cluster filtering falls into a category of model filtering that may extract information necessary for control. Therefore the output of the cluster filtering per se is the desired control signal. Based upon the principle of reciprocity, cluster actuation is introduced, thereby exciting a particular cluster filtering output without causing any spillover problem. With a view to generating a completely vibration-free state on a beam ; there are neither progressive waves nor reflected waves, state variables governing the vibration of a beam are extracted as a cluster filtering output. As such, the suppression of the state variables leads to the generation of a completely vibration-free state of a beam. Numerical simulation as well as an experiment is conducted, elucidating the validity of the proposed cluster filtering and cluster actuation. Further experiment is undertaken, demonstrating the capability of active cluster control for generating a completely vibration-free state on a designated area of a beam.

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In this paper treated is the impedance-matching wave absorption control of rope system near fixed end. The rope system is approximated by finite difference method and the end element is controlled to absorb the vibration energy of the whole rope system. The imaginary system in a controller that is constructed by the same elements as those of the controlled system and has the impedance matching condition at the end is virtually connected to the end element by the control force. The simulation has confirmed that the finite difference approximated system based control has enough effect to the distributed rope system and that the superior damping effect of wave absorption than that of the normal velocity-proportional damping near fixed end. The results have also verified by the experiment.

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The effect of the wave absorbing filter for torsional vibration system consisted of solid discs and torsional bars has been investigated both theoretically and experimentally. Two wave absorbing filters are developed based on the impedance matching condition, one is by introducing a 1-degrees-of-freedom imaginary system which has the impedance matching condition at an end (imaginary type), and the other is by changing the boundary condition to apply the impedance matching condition directly at the boundary (boundary type). The irrational transfer function of the impedance matching condition is numerically approximated as 6-order polynomials by using a curve-fitting technique. As the result of experiment both filters have shown to work very well compared to the authors' former wave control strategy⁽⁴⁾ using a large degrees-of-freedom imaginary system and its initialization. The experiments of 2-and 3-degrees-of-freedom controlled system show the wave propagating state as the phase shift between adjoining elements, which correspond to the theoretical result. By comparing the effects of both filters, the boundary type is better than the imaginary type in the case without small sampling period, 4 ms in our experimental apparatus.

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In this paper, it is performed to suppress the transverse vibrations of elevator-ropes on high-rise building caused by the resonance between building and rope sway. The elevator-rope has the characteristics due to its flexibility and the variation of its length and the constraints for the active vibration control. Hence, for compensating the influence of time-varying characteristics and spill-over, the nonstationary robust controller which has the robustness for the uncertainties categorized by the unstructured and the scaled structured is used for the active vibration reduction of elevator-rope. The suppression and robust performances of the controller are demonstrated through the numerical calculations for the case that a building is subjected to the ground disturbance like an earthquake and the tension of elevator-rope varies. Thereupon, the control input system actuated by ac motor is located below the traction sheave and then it moves the elevator-rope directly with the existence of gap between the rope and the actuator. Consequently, the nonstationary robust controller shows the advantage for the robustness on the uncertainties and the performance in comparison with the optimal one, and it adequately suppresses the transverse vibrations of the elevator-rope.

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This paper proposes the new steering bogie for very tight curved track. The bogie consists of independently rotating wheel controlled by power steering yaw-dampers. Independently rotating wheel with EEF bogie naturally has self steering ability making use of gravity restoring force aroused by nonlinear tread gradient, but has vibration nature in yaw mode of wheel. The proposed power steering yaw-damper enable the wheel vibration to decrease while controlling the steering motion on transition curve. The authors combined the self steering ability of the bogie and power steering yaw-damper to get the compatibility between excellent steering behavior and enough high speed running stability. Experimental results with scaled model vehicle show the effectiveness of active control and bogie mechanism.

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In the present paper, a newly developed ultrasonic brake is proposed. The ultrasonic brake can solve problems of conventional passive elements, such as time delay, instability, and large size, by using unique characteristics of ultrasonic motor, as fast response, silent motion, and non-magnetic feature. It can also be desiged to be smaller than conventional elements due to is simple structure. The brake locks or releases the rotor by use of ultrasonic levitation phenomenon. First, we have designed the structure of the ultrasonic brake using an equation of ultrasonic levitation phenomenon, results from structural analysis and finite element (FE) analysis of piezoelectric material of the vibrator. Then we have manufactured the ultrasonic brake and have conducted a driving experiment. Finally, we have demonstrated that the maximum levitation force is around 40 N and the friction torque of the ultrasonic brake is up to 0.38 N·m. Moreover, we have confirmed that both response time and torque/inertia ratio of the ultrasonic brake are much more superior to the conventional ones.

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In this paper, we propose vehicle front environment recognition method using stereovision system. In the vehicle, which we developed, two cameras are installed in front of rearview mirror and a disparity image is obtained by analyzing grabbed stereo-image. The road plane is extracted by simple geometrical projection of disparity image with an assumption that the stereo camera is installed in parallel with road plane. Then, obstacles are recongnized by computing the ratio of the object that exists in the fixed height from a road surface. As a result of implementing on general-purpose PC and performing an examination on a highway, it was confirmed that real-time computation is possible for the proposed technique, and it has very high robustness.

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We have already proposed a 2-Dimensional Complex Multiresolution Analysis (2-D CMRA), which can provide 2-dimensional shift invariance approximately. In this study, we improve a 2-D Directional Selection using the 2-D CMRA and applied it to image processing. The main results obtained can be summarized as follows : 1) The poor 2-D Dimensional Selection of the 2-Dimensional MultirResolution Analysis has been improved by using 2-D CMRA. 2) The 2-D Dimensional Selection has been applied to image processing, and encouraging results were obtained.

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This paper describes a new exploration and modeling method for an unknown continuous state space environment. The purpose of our study is to divide a continuous state space and to construct a discrete Semi-Markov Decision Processes (SMDPs) model so that the agent can perform the task well. In our method, a hierarchical Fuzzy-ART (Adaptive Resonance Theory) network structure enables to construct the optimal discrete state space for the task by using SMDPs model information about state values and probabilities of state transition. If there are great differences between values of the next states and the highest probability of state transition is very low value about a state-action pair, the state is divided into several smaller states. The SMDPs model is constructed by using kcertainty exploration method efficiently. The result of mobile robot simulation showed that our system could construct useful SMDPs model to perform the task well.

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The Goal of this work is to provide a more in depth understanding of the navigation in the autonomous robot using stable visual points derived from the repeated experimentation by the stereo vision in a natural featured environment. In order to identify the position of the robot as well as to establish the 3 D obstacle map under the unknown environment, we discuss the simultaneous stereo type localization and map building (SLAM) problem. The design of the planning algorithm for a vision guided mobile robot depends upon the two main characteristics of visual environmental recognition i.e. Uncertainty and Efficiency. The uncertainty is reduced by the Extended Kalman Filter algorithm based on the process and observation model of the mobile robot. Regarding the efficiency, the optimal path planning algorithm which uses the dynamical localized Voronoi division is a new concept in our proposal. This method has the ability to make the path for mobile robot with only suitable number of natural features.

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This paper proposes a new system for omnidirectional vehicles or robots, in which the arrangement of actuators is designed according to the intended application. In other words, the number of actuators and the disposition there of are determined based on the specific application. The system consists of two controllers, a feedforward controller using an inverse-kinematics model and a feedback controller that reduces the effects of disturbances due to eccentric loading or imbalanced driving force. In order to illustrate the proposed system, we conducted experiments using a Horizontal Wheel Driving Mechanism as an actuator. The performance of the system was verified experimentally for various actuator arrangements. As an operative example, the system was applied to provide a steel office desk with omnidirectional movement. The proposed system will expand the applicability of omnidirectional vehicles or robots.

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This paper presents a tactile sensor based on electromagnetic induction method. The proposed sensor has simple mechanical structure and its signal circuit is simple. Because of this structure, this sensor can be realized as a small size and can be integrated in small space like robot fingers. In this sensor, an flat elastic material is inserted between a primary excitation coil board and a secondary induction coil board. By measuring output voltage of secondary induction coils, it is possible to estimate displacement of the elastic material and three-axis forces. Numerical simulation of integral element method and experimental results clarify the characteristics of the proposed sensor. Experimental results show that three dimensional forces can be measured using the proposed electromagnetic tactile sensor.

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This research presents experiments of stability evaluation using criteria based on reaction and stabilization motion for the dynamic motion control of a mobile manipulator. Previous research have not discussed tipover motion dynamically. Then, we proposed the model of the dynamic mobile manipulator which can express a stable state and an unstable transient state during tipping over. In this paper we constructed experiment equipments to classify the validity of the proposed model and confirmed that the real mobile manipulator can return from an unstable state to a stable state by performing a stabilization motion. First, the experiment equipments of the mobile manipulator are constructed. Second, a model of the manipulator including characteristics of the constructed hardware system is formulated. Third, it is clarified that the formulated model can express the motion of the hardware by performing experiments and simulations. Finally, it is shown that the real mobile manipulator can return from an unstable transient state to a stable state by performing a stabilization motion.

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In attitude control of spacecraft using more than three reaction wheels, the distribution of the attitude control torque to the wheels is not unique because of the redundancy. Usually, the wheel torque distribution is given by multiplying a constant matrix to the control torque, but more efficient distribution method using the redundancy is desired for more effective control. The wheel torque distribution problem is formulated as a simple minimax problem, but it is not practical to solve the problem directly on spacecraft onboard computers because of the computational cost. In this paper, the wheel torque distribution problem (minimax problem) is transformed to a linear programming problem, and then by using some geometrical characteristics of the problem, an effective algorithm is derived. In the proposed algorithm, only simple algebraic calculations are needed and the optimality is guaranteed theoretically.

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The inner skeletal humanoid robot needs the actuator with the high performance such as a natural muscle. In this study, we aim to realize the actuator that is comparable with a natural muscle from the viewpoint of flexibility, power and response. We constructed a Shape Memory Alloy (SMA) actuator protected by “Rolled film tube” made of polyimide film with high heat resistance. The SMA actuator proposed in this study is driven by Pulse Frequency Modulation (PFM) found in the bio-motion. As the fundamental characteristic of the actuator, the output force and output displacement against input pulse frequency are investigated in the experiment. Consequently, it is found that the SMA actuator proposed can be employed in place of a natural muscle.

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According with the advancement of aged society, the further improvement in function of the welfare apparatus for an aged person is required. Although various medical equipments, such as a mat to prevent bedsore begin to be used commercially, the function of prevention of bedsore seems not enough. Moreover, it is require for such a nursing equipment to have the flexibility and safety since it contacts with human directly. In the highly advanced aged society, the nursing people is also aged one and it is necessary to decrease their physical burden. In this study, we have developed a mat which has a function to prevent bedsore. In order to distribute the pressure applied to the body, we have proposed a body pressure distribution strategy by using 24 mats driven independently. And the effectiveness of the proposed method is confirmed through some experiments. In this paper, first of all, the structure of the proposed medical care mat is shown. After-wards, its effectiveness is confirmed through experiments.

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Elastic impact and contact of spheres are frequently encountered in the field of engineering and science. It is usually treated by the Hertz theory of impact. There are also other theories proposed by Y. Tatara and P. Villaggio. In the present paper, elastic impacts of sphere are analyzed by using the Finite Element Method (F. E. M.). At first, the results from F. E. M. and those from the theories mentioned above are compared. The dependency of the force-compression relation on the impact velocity is examined. Then, the dynamic elastic contact force-displacement relation of sphere is presented. It is thought that this equation can give the accurate force-compression relation for the impacting spheres. It will also give valuable relation for the evaluation of dynamic contact force between particles in the numerical analyses such as DEM.

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The effect of the shaft length on the head speed in golf swing is investigated in order to obtain a longer distance of driving shot. Seven driving clubs, which have almost the same specifications except the shaft length, were manufactured for the experiments. Using these clubs, the head speed at the impact was measured during the swing by fifteen experienced golfers of both sexes in comparison with that by a golf robot. Results showed that the increase in the length of the club shaft created an increase in the head speed at the impact on all the subjects. The rate of the speed increase on the professional golfer was almost the same as that of the robot, and those on the male golfers were larger than the robot. On the other hand, it was smaller on the female golfers. By the consideration on the relation between the head speed and the ball speed at the impact, the total effect on the increase of driving distance is expected by the increase in the head speed using a longer shaft in spite of the reduction of the head weight.

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In order to make clear the effect of aging on postural controlling ability in standing, we developed an evaluation system using a force plate and CRT monitor. In the present experiment, 14 young male (age 21-24), 7 middle-aged male (age 30-36), 5 middle-aged male (age 40-45), 16 elderly male (age 59-70), 17 elderly female (age 57-70) subjects participated. The subject stood on the force plate in front of CRT monitor, and controlled center of gravity following a target dot which traveled on the CRT monitor. Both the postural sway of the subject and the target dot were displayed simultaneously. The length of postural sway and time course were respectively recorded during the experiment. The current results indicated that 1) the postural controlling ability decreased by aging, 2) all of the subjects showed higher postural controlling ability in forward than in backward, 3) the postural controlling ability in horizontal was the lowest in the elderly subjects, 4) the postural controlling area decreased by aging.

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As for this research, the driver risk (subjective dangerous feeling) at the time of the pylon slalom and the drift turning was evaluated by the perspiration amount measurement. It has been understood that the result (multiplication of the amount of the maximum perspiration and the perspiration amount area at the unit running time) corresponds to the subjective rating of dangerous feeling. Moreover, it was understood that there was a peculiar phenomenon which is that fear which is that the spin might be done was large, and the amount of perspiration grew very much at the time of the drift cornering.

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The integrated design of structure/control systems for high-speed positioning control of a head gimbal assembly (HGA) in spin stands is considered in this paper. A diamond shape structure, which is axisymmetrical to two orthogonal axes, is adopted for the displacement amplifier of a HGA. Two PZT linear actuators are built in the structure to control the position of the HGA. If the generated forces of the two actuators are acted symmetrically to the two axes and there is no disturbance force acting on the structure, non-symmetrical vibration modes to the two orthogonal axes will not be activated in the structure; moreover, only one symmetrical mode will come out. Since the natural frequency of the mode which can be excited by the symetrical operation of the two actuators is very high, there is a possibility to achieve a much higher bandwidth of the HGA positioning control system in comparison with conventional structures of displacement amplifiers. The simultaneous optimization on these parameters of the structure and the controller has been conducted, and then the effectiveness of the design result has been verified in the frequency responses. Moreover, the robustness properties against the worked accuracy on the structure and the imbalances in the generated forces of the actuators and/or the masses of suspended loads have been tested to ensure the performance.

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In this paper, we propose a new anti-windup method with clear procedure of initialization to avoid overshoot in spite of saturation of control input. This method is based on a 2 degree of freedom model matching control system and by using a switch, instead of a control input and a reference output those are not affected by an input saturation, a saturated control input and an output are respectively used for updating a reference output and a feedforward input. By this means, when the input come to unsaturated, the Model Matching works correctly because the memorized values of the reference output utilized for updating reference output correspond with the past values of the output. Furthermore, a procedure to initialize the reference model with which the overshoots do not occur even if the control input is saturated is given. This method is suitable for systems in which overshoots are taboo such as tool machines and temperature controls. The proposed method is verified the effectiveness by numerical simulations and experiments.

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In the present paper, we give the parametrization of all stabilizing modified repetitive controllers for non-minimum phase systems. The basic idea to obtain the parametrization of all modified repetitive controllers for non-minimum phase systems is very simple. If the repetitive controller stabilizes the plant, then the repetitive controller must be included in the class of all stabilizing controllers for the plant. The parametrization of all stabilizing controllers for the plant, which is not necessarily repetitive controllers, are obtained by Youla et al. and Vidyasagar. The parametrization of all stabilizing controllers includes a free parameter, which is stable. That is, stabilizing repetitive controllers for non-minimum phase systems can be designed using the free parameterin the parametrization by Youla et al. and Vidyasagar. Using this idea, we obtain the parametrization of all stabilizing modified repetitive controllers for non-minimum phase systems. Next, a numerical example is illustrated to show the effectiveness of the proposed parametrization.

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At the solder ball mounting process on the CSP (chip size package) package, must have inspection of excess solder on the inhaling tool. This study is how to detect excess solder during inhaling tool moving when using laser through-beam sensor. First, in order to remove the influence of the sensor output value by the normal solder ball and to extract only the sensor output value by the excess solder ball, the gobo was attached to the inhaling tool and the effect was checked. Next, create a slit on the laser receiver that increasing sensitivity of laser through-beam sensor and confirmed the improvement. The slit is created to increase sensor output value that compares result of excess solder on the inhaling tool with or without excess solder ball. Furthermore, we supposition production line study the inhaling tool movement error. Therefore then inhaling tool movement error is occur then measure sensor output value. Then we attempt to use difference value. It turns out that the detection method developed by this research can apply to manufacture line, because the excess solder ball of φ 0.30 mm, φ 0.25 mm and φ.0.18 mm can be detected certainly, without being influenced of the movement error of inhaling tool.

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This paper describes the method of determining the sampling distance using electric capacitance type of displacement sensor for areal surface form measurement. Amplitude transmission characteristic of the sensor was disclosed and analytical simulation was carried out. Its inconvenient sensor output signal was functionally compensated with Spline low pass filter. From the sampling condition for the Spline filtration, the necessary minimum sampling distance was determined while the maximum sampling distance was introduced from auto-correlation curve of filtered profile. Macroscopically similar surface profiles were obtained at the sampling distances determined by the two methods.

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On-board measurement system that can simultaneously obtain such information as road infrastructure, traffic conditions, driver's operations, vehicle running conditions and exhaust mass emissions, was installed in a light duty freight with EGR system and in one box vehicle without EGR system. In order to analyze mechanism of roadside pollution caused by vehicles, road tests were carried out in real traffic conditions. The vehicle with EGR system showed intensive NO_x pollution to roadside in vehicle start, in which EGR rate was low, but it was effective to reduce NO_x mass emissions at low speed running in traffic jams where EGR rate was rather high. In case of the vehicle without EGR system, intensive NO_x pollution was observed in low speed running such as in traffic jams. The reduction of NO_x during vehicle start is important for vehicles with EGR system to reduce intensive NO_x pollution at roadside. EGR system is effective to reduce intensive NO_x pollution for vehicles without EGR system during low speed running like in traffic jams.

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This paper considers an assembly scheduling problem for a flexible manufacturing cell (FMC), which consists of m dedicated machines and an assembly machine. There are n jobs to be processed in the FMC. Each of the dedicated machines produces a component of a job. In addition to m components, each job requires some other components purchased from outside. The assembly machine cannot start processing the job until both of all components produced in-house and those purchased from oustide are available. The objective is to find a schedule of the n jobs that minimizes the maximum completion time (i.e., the makespan). It has been known that the scheduling problem is strongly NP-hard even when m = 2. This paper proposes a greedy heuristic algorithm to the problem, and shows that it delivers a 2-approximation solution in O (mn²) time. The heuristic is also examined by means of numerical experiments, and the results are reported.

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This paper describes the development of a XML system, which is not only able to display the required information, such as the metallic mold manufacturing area, but also to remotely control, such as the NC machining tool, by using the web browser through the Internet technology. In this XML system, collection and display of information required for on-site management of a factory can be performed using the machine surveillance feature, the monitoring feature using video camera, the schedule management feature of a machine, and the data analysis feature for a machine. This XML system links various systems which exist inside and outside a company flexibly and quickly and therefore, enables information to be exchanged. This research is being progressed concurrently with MOII (Manufacturing Operation Information Interface) standard that is promoted by JOP (Japan Open System Promotion Group).

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This paper presents a scheduling method using the mixture of a genetic algorithm and a priority rule to make effective schedules in a dynamic job shop scheduling environment. Dynamic scheduling problems are assumed to be a series of static problems and scheduled on a rolling basis. Each static problem is solved by a genetic algorithm in which genes are used for the priorities for next job selection. In the genetic algorithm, an effective priority rule is embedded to solve the static problems efficiently in a limited calculation time. The priorities for next job selection are calculated by multiplying two values for each operation of waiting jobs : the value of gene assigned for the operation and the value of priority calculated using the priority rule. It is possible to search schedules efficiently according to the scale of problems by tuning the weight between the genes of the genetic algorithm and the priorities calculated using the priority rule. Numerical experiments show the effectiveness of the proposed method.

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Scence Transition Net (STN) is a discrete/continuous hybrid system model which has been developed by one of the authors. In this paper, we attempt to develop a new simulation method of STNs in a distributed environment. For the purpose, we extend the definition of STN and propose the concept of a distributed net. The distributed nets communicate with each other in order to notify them of information about firing transitions. Furthermore, we point out that excessive communication overhead is required when multiple distributed nets decide if a transition fires. We show that restructuring these distributed nets avoid such situation. As an example of distributed STN simulation, we illustrate an integrated simulation of a manufacturing system which consists of 2 processing lines and transfer system in a distributed environment.

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Leading design is a concept to support designing a highly advanced artifact for which necessary technical seeds are not sufficiently developed. Leading design allows a designer to complete a design process by using virtual technical seeds to avoid the deadlock caused by the shortage of required technical seeds. As the result, the designer should obtain an overall view on what are actually required to what extent to achieve the goal. Introducing virtual technical seeds, however, causes problems such as explosion and uncertainty of design solutions in an extremely broad design space. This paper proposes a method of solving those problems and embodying the “leading design” concept as a practicable design method. By defining a development “hardness” of virtual technical seeds and using it as an objective function for an optimization, leading design solution can be converged to a virtual but least-difficult one. Also, probability distribution is introduced to give a leading design solution probability estimation. The embodied method is applied to a leading design of a micro factory component.

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BMC (Bulk Molding Compound) is composed of glass fiber, UP (unsaturated polyester) resin and filler. Bagasse is the waste obtained after squeezing sugar cane. Our purpose is use bagasse fiber as a reinforcement and filler of BMC, and fabricate product by injection molding and injection compression molding. The mechanical properties of product were improved after adding bagasse fiber. Viewing the fracture surface on tensile test specimen through SEM, we could observe the glass fibers were penetrated into the bagasse fibers longitudinally. Along with the UP resin solidifying, the glass fibers were firmly fixed into the bagasse fibers and finally united with them. This effect indicated the glass fiber length was prolonged so that the adhesion interface with UP resin became larger, and leaded to increase the mechanical properties. Otherwise, it was observed the UP resin was sufficiently permeated through the bagasse fibers and solidified. These phenomena also contributed to enhance the mechanical properties drastically.

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A motor driven by pressurized fluid flow, such as flow of water, hydraulic oil, or air, is presented. The motor structure is simple, which enables easy motor fabrication. The motor can be designed such that it can be applied to the spindle rotation of an ultra-precision machine tool. An advantage of the motor is that the pressurized fluid flow in flow channels, which are made in the spindle body, can generate torque for rotating spindle. This paper introduces theoretical equations of the motor. It is shown that the theoretical results are agreed with experimental results. As a result, based on the theoretical equations, software for designing a motor, which can introduce optimum parameters for obtaining highest efficiency, is developed. Performances of the motor are investigated through theoretical and experimental studies.

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We proposed a new estimating method of a high-speed and high accurate tooth contact by using thermography. This method has aimed to short the measurement time, and to know an accurate tooth contact area and the strength of the surface pressure by measuring the heat generated at the time of meshing gear teeth without contact. First, the radiation performance on the gear tooth surface was investigated as a basic experiment, and the effect of lubricantion was examined. Moreover, experimental conditions were researched. Next, the reliability of the present method for measuring the surface temperature distribution was evaluated by comparing with the result obtained by paints. The surface pressure on the tooth surface was estimated based on obtained temparature distribution on the gear tooth surface. Finally, we made an attempt to predict the gear meshing force based on the proposed estimating method.

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A new type of a mechanical variable transmission, which consists of a 2 K-H type differential gear and a HST unit is devised. The pattern of this transmission is replaced with a combined planetary gear train system. Through a theoretical analysis of the system, it is confirmed that the power circulation is occurring in the system. And it is made possible to realize a new type highly efficient transmission only by controlling the quantity of the power flow.

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Several types of metal doped DLC films were developed in order to improve the adhesion property and the lubricity. This paper discussed lubrication mechanism of Ti doped DLC films (Ti-DLC) with the results of sliding test and surface analysis by using TOF-SIMS. Large amount of sulfur and molybdenum was detected on wear track of Ti-DLC with ZnDTP+MoDTC additives. On the other hand, there were few amount of sulfur and molybdenum on the CVD-DLC. These analytical results indicate that MoS₂ was generated by tribochemical reaction of ZnDTP and MoDTC on the Ti-DLC, and formation of MoS₂ caused the low friction property.

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The crosshead bearing in large two-stroke diesel engines operates under severe lubrication conditions, because the bearing oscillates within a small angle at a low speed and is always subject to a high downward load. The recent trend towards more compact engines with increased output raises the bearing specific load, thereby causing the lubrication severity to increase significantly. Thus it is very important to improve the load carrying capacity of the crosshead bearing. In the present study, experiments using a dynamically loaded bearing seizure test apparatus were carried out to clarify the influences of the clearance ratio and the oil-groove geometry on the load carrying capacity. The electrical resistance of the oil film was also measured to evaluate the extent of the oil film formation. The major results are : (1) A decrease in the clearance ratio is effective in enhancing squeeze action on the entirety of the bearing pads, thereby improving the load carrying capacity. When the clearance ratio becomes too low, however, the ability to form an adequate wedge film is degraded, causing the load carrying capacity to decrease, (2) Because incorporating the taper geometry on both sides of the oil-groove promotes a thicker oil film, a significant improvement in the load carrying capacity can be expected ; and (3) The maximum load carrying capacity is achieved by the taper geometry of a subtended length of 5 degrees and a taper angle of 0.1 degree.

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