Rhonrad is a gymnastic tool that is interesting in terms of dynamics and control. We presented an analytical model and governing basic equations of the Rhonrad mechanism controlled by a gymnast. Then, we numericaly analyzed Rhonrad motion caused by synchronized sinusoidal linear motion of a mass inside the Rhonrad. By numerical simulation, we clarified the effect of the amplitude and phase of the mass motion on 'Straight-line' and 'Spiral' motion of a Rhonrad.

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Magnetorheological (MR) fluid can vary the rheological characteristics according to applied magnetic field strength and has been applied to various kinds of devices such as dampers, clutches, etc. In the design of these devices, magnetic analysis is generally carried out to verify their performance. Though the permeability of MR fluid should be estimated beforehand in the analysis, it cannot be given uniquely because MR fluid is a particle-dispersed system and the particles form clusters under a magnetic field. In this study, the cluster formation of the particles was modeled and simulated by Cellular Automata. Cellular Automata is known as a class of discrete modeling techniques in which the whole phenomena of the system emerge through the local interaction among state variables defined on each cell. On the basis of the simulation results, magnetic analysis was carried out to obtain the equivalent permeability of MR fluid considering the cluster formation. It was shown that the permeability might be estimated from the iron content in MR fluid.

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This paper considers Active Boundary Control(ABC)of a flexible beam that enables the generation of any boundary condition at a designated position of the target beam. First, from a viewpoint of wave analysis, this paper begins by deriving an equation of motion of a flexible beam with arbitrary boundary conditions at both end of the beam. Then, the control law of ABC method using feedforward control is derived, thereby permitting one to produce any king of boundary condition at any designated position of a beam. Furthermore, as a result of applying the ABC onto an existing boundary condition of a beam, a methodology to create a completely vibration free state is proposed. lt is found that there exists a special case to generate a completely vibration free state by merely introducing ABC onto an arbitrary location of a targeted area of a beam. Finally, an experiment is conducted using a filtered-x LMS algorithm, demonstrating the validity of ABC.

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This paper describes about a concept of self-maintenance for self-sensing actuation system and how system identification and state estimation can be used to achieve self-maintenance. Currently, self-sensing systems that have concurrent actuation and sensing can be made by using a bridge circuit. However, hardware tuning is still needed due to the unstable nature of an imbalanced bridge circuit. This problem becomes serious in the space environment where human beings may not be available to perform the maintenance. A method of achieving self-sensing actuation without a bridge circuit is proposed in this study. Dynamics of this proposed system can be described as the state space expression with a direct transmission component. This means that the problem of balancing the bridge circuit is equivalent to the system identification and state estimation problem. The proposed method was verified with experimental results, demonstrating that smart structures can achieve self-maintenance.

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This paper describes the vibration suppression of torsional systems of finite degrees-of-freedom (DOF) by using the wave absorbing control method with online computation of a virtual wave propagating system that is similar to the real system to be controlled. This method makes up a wave-absorbing damper as the virtual system is always in wave propagating state. The basic concept of the control method was formerly presented for a multiple pendulum system to suppress free vibrations by one of the authors. In this paper forced vibrations are targeted. The presented method has shown to work well on the forced vibration as on the free vibrations. In order to obtain suitable parameters of the virtual wave propagating system, the theoretical analysis on wave propagation of a homogeneous spring-and-disc system has been conducted. And we got the fact that wave absorbing control can be conducted below the frequency of 2√(k/I), where k is spring constant and I is moment of inertia of disc. Experiments are conducted on 1-, 2- and 3-DOF systems.

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A self-sensing actuator constructed by four laminated piezoelectric films is developed toward the smart vibration control of two-dimensional structures. First, three kinds of mechanisms of self-sensing acutuators with two or four laminated piezoelectric films are proposed by examining the combinations of film construction and bridge circuits of analog electric controllers. And those self-sensing actuators are applied to the free vibration control of the first mode of a cantilever beam and it is ascertained that the vibration suppression effects are obtained by all the three mechanisms and the theories show good agreements with the experiments. Finally, the mechanism constructed by four laminated piezoelectric films is applied to the vibration control of a simply-supported rectangular plate as an example of two-dimensional structures and it is verified that the vibration control effect is actually obtained and the theory agrees well with the experiment.

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This paper deals with a brake device attached to each wheel of small cars as a component of brake-by-wire system. The brake device consists of a disk brake, a piezoelectric pump, two accumulators and a three position solenoid valve. Mathematical model of the brake device, an approximation formula of the clamping force (CF), and a control scheme of the CF are presented. Simulation results show that (1) the CF large enough for small cars is generated by using a multilayerd piezoelectric element of 40 mm diameter, (2) the rise time of the CF is about 0.1 second including the time to contact the disk pad with the disk plate, (3) the formula gives close approximation to the simulated value of CF, and (4) the feedback control of the CF is achieved by using the disturbance observer.

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The poppet-type Brake Pressure Control valve (BPC valve) was proposed in the first report for use in hydraulic control systems for the friction brake of railway rolling stock. In this study, a simplified transfer function of the valve is determined to analyze the effects and choose the parameters for the valve. In order to shorten the trial-and-error process to determine the best valve parameters, mathematical simulations are performed. The validity of the mathematical model and effectiveness of actual orifices is studied experimentally. Simulations of pressure response and stability of the valve in the presence of disturbances are confirmed experimentally. The performance of the actual brake system is studied using a caliper brake device from the Shinkansen railway. The results show that the performance of brake pressure control can be improved by the hydraulic system with the developed BPC valve.

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This paper presents a design method to derive a closed-form control input expressed by a series of sinusoidal polynomial, namely a linear combination of sine functions each with a different frequency content, for any given control specification. Vibration system which is a crane system described by a pendulum model are discussed. In this paper, the several control specifications are given such as the robustness for parameter variations, the minimization of maximum swing angle, and so on. The proposed closed-form control input is given in a simple form of polynomial functions, and unknown parameters in a closed-form of solution can be calculated using the both of Genetic algorithm and analytical formula. Experimental results well agrees with simulation results, and then theoretical and simulation analysis discussed in this paper are validated.

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The purpose of this research is to establish the advanced filament-winding system by realtime sensing and control of the winding tension. In this paper, first, the design and the manufacture of the filament-winding machine is presented in order to be able to measure and control the winding tension in process, and the winding tension control method is proposed and implemented using PID, I-PD control and two-degree-of freedom PID control. Secondly, modeling of the Hoop-winding tension process (pattern) is studied in terms of a system identification technique, and the controller is designed by using Genetic Algorithm (GA). Finally, the effectiveness of the proposed approach is demonstrated via control experiments. Proposed tension control and its gain tuning methods respectively show good performance through the experimental results.

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A crane mounted on a tower-like flexible structure called the 'Tower crane' has a problem that a fast transfer of the load causes the sway of the load and the vibration of the flexible structure. Furthermore, if the length of the load rope varies, it is difficult to control by the fixed compensator, because the natural frequency of the load rope and gain of the plant to control input vary also. This paper discusses the control design considering operator command with varying load-rope length. A two degree-of-freedom control system is designed, which is consists of the feedforward controller by using a command-shape filter and the gain-scheduled controller considering varying load-rope length. From the results of the experiment, it is shown that the work efficiency is increased by using our proposed control system.

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In crawler-type construction machines, flexible suspension system like bogie mechanism type suspension is used for the running equipment particularly to improve the comfortability in riding. However, in the running equipment with bogie mechanism, there are many unclear points in the dynamic behavior and loads due to the complicacy. In this paper, first, a modeling method of crawler-type running equipment with K-type bogie mechanism as a multibody system is shown. By using the model, in traveling on a firm ground with a rectangular bump, a simulation to analyze the dynamic behavior is conducted and the bouncing acceleration and the dynamic suspension loads are calculated. The simulation results are compared with experimental results, and the validity and the applicability of the simulation method is verified. After that, in passing over a bump with several heights, effects of the type of bogie mechanism including K-type bogie on the dynamic behavior of construction machine, such as the bouncing behavior and the dynamic suspension loads are shown and discussed. This kind of simulation could be useful for designing and deciding the optimum running system under given environmental, economic and operational constraints.

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Recently, in the viewpoint of environment problems, the improvement of the efficiency of the construction machinery such as excavator or crane is demanded. For this purpose, it is investigated that the hybrid system used in the automobile is adapted into the construction machinery. The one of the problems in this development is that the operating property of the system needs to be close to the present hydraulic construction machinery. Therefore this study focused on the swing system of the hybrid construction machinery and proposed the control method to derive the operating property that is close to the present hydraulic construction machinery. The effect of this control method is confirmed by experiment.

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Three-phase induction motor causes an unstable vibration because of electromagnetic force. In this paper, a criterion for unstable vibration was introduced. To confirm this criterion, numerical integration was carried out and the results showed a good agreement with the unstable region obtained by the criterion. This criterion gives us the complete story about the stability for the case when the parameters e.g., phase current, air gap length etc. are changed. It was cleared that the natural frequency changes owing to the variation of the phase current, and that the unstable vibration occurs when the frequency of power supply and the natural frequency (changed by current) are nearly the same. And it was also showed that the parameters can be classified into the categories whether they have influences on the stability or not.

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Graft attachment location is one of the important factors which affect the results of ligament reconstruction of the posterolateral structures of the knee. The reconstructive procedure is usually performed without the detailed information of ligamentous isometricity. In this cadaveric study, length changes between the possible graft attachment sites were calculated in a reconstructive procedure for the posterolateral structure of the knee. The three dimensional knee motion during active knee extension was recorded and the bony surface was digitized using CT images. The ligamentous isometry map for the lateral femoral condyle from the tibial attachment site was constructed. The length change pattern of the graft during knee motion was found to vary depending upon the femoral attachment site. The most isometric area was found to be located at a few millimeters anterior-distal to the lateral femoral epicondyle. The attachment sites of the supportive yet nonrestrictive graft were shown to be located at the lateral femoral epicondyle and head of the fibula.

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The acoustic radiation from baffled finite plates with free visco-lastic damping layers excited by a random point force have been studied in order to evaluate damping treatment performances under the condition of neglecting fluid loading due to the back reaction of the radiated acoustic pressure. The plates are rectangular and clamped at the boundaries. The vibration responses of plates with damping layers are obtained by the finite element method. Modal damping ratios are estimated from undamped normal mode results by means of the modal strain energy method.The expressions for the surface acoustic intensity and the radiated sound power are derived in the transform formulation and evaluated numerically from the discrete Fourier transform of the vibration velocity responses of the plates in the spatial co-ordinates. An experimental study is carried out to measure the surface intensity distributions and to compare them with the analytical results.

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In order to analyze the tire noise emission during vehicle acceleration running, noise source detecting method with acoustical holography was applied to vehicle acceleration running condition, which was developed to constant speed running. This paper describes the effectiveness of this method by simulated calculation and the analysis results of the tire noise sources during acceleration running for the electrical vehicle with the test tires.

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In this study, we propose a complex multi resolution analysis (CMRA) with RI-Spline wavelet and dual-tree algorithm corresponding to CMRA in order to carry out discrete wavelet transform, and apply it to remove pulse noise from music. The main results obtained can be summarized as follows: 1) Poor shift invariance which occurred by the discrete wavelet transform in the case of using real mother wavelet has been improved by using CMRA was conformed. 2)The discrete wavelet transform corresponding to CMRA has been applied to removal of the pulse noise in record music, and the usefulness of our approach was demonstrated.

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An on-line identification problem is investigated, as one of the inverse problems, for estimating unknown model parameters which should be determined to establish a valid mathematical model. The system considered in this paper is the linear dynamical system which is subjected to random disturbance. The on-line identification is realized by splitting the procedure into state estimation and parameter identification. The former is curried out by the Kalman filter, and the latter is accomplished by modifying the conventional Gauss-Newton-based algorithm. The basic idea of the identification is to introduce the principle of contraction mappings in order to guarantee the stability of the algorithm. The resulting algorithm consists of the two procedures which are processed on-line alternately. In order to show the efficacy of the proposed algorithm, simulation studies and experiments are shown by applying the theory to an inverse problem of determining physical parameters of the cantilevered beam model.

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In this research, we investigated the characteristics (i.e. frequcency response, stability) of EDM control system which has two stage positioning system using a high speed actuator in detail. EDM system must be dealt with as a non-linear system because the gap voltage of that system has nonlinear characteristics. Therefore, the gap voltage was approximated as a saturation element in analytical model for the EDM system. The limitation of control gain for the EDM system was clarified by using the describing function analysis. Then, we examined an EDM cutting test, and it was confirmed that the stability condition is in a good agreement with the experimental result. Finally, it was confirmed that the speed of small hole EDM could be improved by the high speed actuator.

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This paper presents the estimation of depth based on the cylindrical re-projection of images captured by a stereo setup of ODV (OmniDirectional Vision). In general, images obtained by such a device have relatively low spatial resolution and have some aberration in comparison to standard camera images and thus, considerable range estimation errors are caused. We propose a stereo setup of ODV, which features two mirrors with the original curvature to minimize blurring influence. We also propose an edge-based intensity interpolation method to improve the spatial resolution of the developed image. The bidirectional subpixel matching procedure and the discontinuity compensation algorithm are also presented to improve the quality of the range estimation. The experimental result reveals that the proposed ODSV (OmniDirectional Stereo Vision system) can successfully contribute to reduce disparity error and has subpixel range estimation accuracy even in the cluttered outdoor environment.

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A torque reference control scheme for stepping motor is proposed in conjunction with the soft actuation where passive softness due to step failure and inherent position/velocity controllability can be achieved selectively. It is easily expected that the motor torque will be adjusted by the motor current, when the torque angle, the rotor angle with respect to load free stable position, is well stabilized by the innermost control loop of the soft actuation. In regular full step operation, however, the step angle is somewhat bigger to provide sufficient resolution in the torque angle. To improve torque angle controllability, a micro-step driving method is introduced into the soft actuation scheme. Performances of proposed torque reference operation regime is demonstrated by contact force measurements and constant torque indicial responses with a direct drive manipulator.

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The safety requirements of a radar sensor, one type of presence-sensing device, are presented, and one method is proposed for constructing the radar sensor that meets the safety requirements. An ultrasonic radar sensor and a scanning optical radar sensor for safety monitoring are described as concrete application examples of the proposed construction method. The safety requirements that concern the sensing function of the radar sensor are that the energy transmission process should be free from transmission failure and increased delay and that the specified area should be monitored. The radar sensor that meets the safety requirements can be realized by proving the radar sensor with the check function to confirm the safety requirements. More specifically, a reference object is installed in the energy transmission path, and a hazardous event is periodically produced. The check function confirms that the radar sensor can detect the hazardous event as hazard within the specified response time.

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This paper proposes a seamless tracking system that is a real time visual surveillance system for detecting and tracking people and monitoring their activities in a wide area environment with multiple overhead cameras. This system is composed of multiple vision systems with overhead cameras and a database server. AIl vision systems are connected with a database server through a computer network in order to upload and download some information of a detected human such as hair color, cloth color, and human location. A vision system can identifies people previously detected by a vision system, checking corresponding features and position stored in the database. AIl people are therefore tracked in a wide area environment. We propose the seamless tracking system and the ways to detect and to identify those people and then show their performance using our developed system.

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This paper describes the new design method for force feedback micromanipulator capable of controlling both grasping and non-grasping conditions. Micromanipulator is now actively applied in the medical field such as a brain surgery operation, a cancer test, etc. However, the problem of this application is the stability of the system itself. Thus the proposed method mainly focuses on the stability of the bilateral servo system used in the design of micromanipulator. For this aim, a mathematical manipulator model is proposed which can apply both in grasping and non-grasping conditions. The displacement transmission ratio and the rigidity transmission performance, which are key factors in this proposal, are actually measured in the hardware design with one degree freedom. Further a simulator is also proposed to analyze the manipulator operation, in particular, the abnormal self-exciting oscillation in the operation. As the result, the performance anticipated by the design is obtained by the machine and the simulator.

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The load capacity of a manipulator depends on a load capacity of a low output joint or load capacities of some low output joints of the manipulator. Even if a manipulator could not handle an object because of its load capacity, some of its joints still have enough capabilities for handling of the object. In this paper, we propose a method to handle an object using available joints of the manipulator by introducing virtually unactuated joints. The virtually unactuated joints are controlled so that no load will be applied to the joints. Experiments illustrate the validity of the method proposed in this paper.

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In this paper, we propose a new control algorithm for an electrically-power-assisted cvcle. The algorithm estimates a drag force for riding the cycle and adjusts it based on rider's conditions using a disturbance observer. By this system, the rider could pedal the cycle as if he/she is on the horizontal road, even if he/she pedal it on uphill road or downhill road. With this system, people could ride the cycle with less pedaling force. In addition, this system requires only a torque sensor and a speed sensor, which are built in conventional electrical cycle. The proposed control algorithm is experimentally applied to a tricycle and experimental results illustrate the validity of the proposed control algorithm.

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This paper describes an optimizing algorithm for a global optimization problem, which has multi-local optimum solutions. 0n structural optimizations, some problems cannot be solved by using nonlinear programming method for convex optimization problem, because those are non-convex problem by complexity of constraint or objective function itself. Therefore, the global optimizing system that makes use of local optimizing procedure is needed for more effective searching in some design problems. The proposed method is to be characterized by using clustering procedure for convex subspaces, which are formed in a local optimizing procedure, and by using Lebesque measurement to evaluate a termination criterion. In order to evaluate the effectiveness of the algorithm, some numerical examples are illustrated

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The present paper describes the simultaneous design method of location and cross-sectional shape of a frame structure. On the design to optimize some kinds of variables, the suitable design procedures will be different according to a kind of variables or other detail design condition. An entire design problem is solved by the proposal method, which separates the entire design problem to subproblems, such as location and cross-sectional shape design problems and solves the problem with consideration about correlations of each sub-problem. In the proposal method, the correlation of each sub-problem is expressed by the inclination allocation of resources for design calculated by the first-order-sensitivity analysis. As a numerical example, the proposal method is applied to thelocation and cross-sectional shape design of a frame structure. From the numerical results, effectiveness of the proposal method is shown.

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Knowledge acquisition on AGV collision avoidance with other AGV has been investigated for realizing AGV autonomous driving by use of Q-learning. A proposed method adopts an indirect approach to solve collision avoidance problem. Namely, the knowledge acquisition method on AGV collision with other AGV is proposed by using Q-learning. Q-value in Q-learning plays a role in representing knowledge and it is obtained by trial and error. The obtained Q-value for collision is inversed and applied to collision avoidance. Through numerical experiments, it is verified that Q- value realizing collision knowledge is obtained and collision avoidance is realized by using inversed Q-value. At the same time, additional learning on Q-learning is also examined by comparing with simultaneous learning. As a result, it is found out that additional learning is as effective as simultaneous learning.

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In this investigation, the slip-phenomenon that occurs in the paper feeding system and deteriorates the accuracy of printing is studied. The system presented in this paper is such that the printing paper is pinched with two rollers. The driving roller has protrusions on their surface and the driven roller is coated with rubber. The slip value that is calculated by the velocities of the driving roller and the paper is used to represent the amount of slip-phenomenon in this paper. In the experimental study, characteristics and contribution ratios of various factors with respect to the slip value are found. In theoretical study, mathematical model of the paper feeding system based on elastic theory is developed to calculate the slip value. Consequentially, the slip value is calculated with these results. The analytical results show good agreement with the experimental ones.

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This study uses experimental and computational analysis to investigate the dynamic behavior of a fly line. Fly-casting is one of the most significant issues in fly-fishing, In order to cast a lightweight fly, the weight of a fly line is utilized. Fling speed, the casting process and the loop shape of the line while in flight are important for the proper presentation of flies. Moreover, the shape of a fly line is also important for a long cast or controlled cast. In this paper, the fly-casting process is investigated experimentally. In addition, the system of a fly line and a rod is modeled and calculated.

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The twisting somersault is such a complicated motion by gymnasts and other atheletes, that many people can't grasp its dynamics. The mathematical equations of the constraints of aerial human multi-linkage systems are highly nonlinear. Firstly, approximating the equations into linear form and analyzing them, we derive the induction mechanism of the motion. Next, recording the real performance by a trampoline jumper, we calculate his orientation variations and joint movements, and compare them to the studied mechanism. We show that he unconsciously applied the mechanism to his performance efficiently. Finally, we consider the guideline for stable landing and orientation control by opening both arms. This research will be practically useful to physical education as well as robotics.

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The purpose of this study is to investigate the influence of lower saddle height on the knee joint. Five healthy male pedal at 60 rpm against the work load of 100 and 200 W. Three saddle heights of 80, 90 and 100% of trochanteric leg height are selected in this study. During each trial, the position data of the right lower limb's joints by the video camera and the force data of the right pedal by the force sensor are measured. Using these data, the inverse dynamics analysis is done, and the following results are obtained. The peak link force acting on the knee joint and the peak knee extension moment do not indicate any change over the three saddle heights, however, the angles at their peak values shift to the knee flexion as the lower saddle height. These results indicate that the lower saddle would overload at the knee joint.

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This paper describes the power loss of bevel gear drives. We measured the friction loss and the churning loss of a straight bevel gear and a spiral bevel gear using a power circulating-type bevel gear testing machine, with the oil immersion method which is based on the oil temperature rise caused by the power loss in the gear drives. It was found that the friction loss of the straight bevel gear is larger than that of the spiral bevel gear, and the gear friction loss ratio of the bevel gears decreases with the increase in the gear torque. Furthermore, we calculated the gear friction loss and the churning loss of the bevel gear drives. The calculated value agreed approximately with the experimental data.

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A series of experiments is carried out using a strip-ironing type tribometer to investigate the possibility of the volatile lubricants as the lubricant for the bulk metal forming process. The tool material is the die steel alloy SKD 11, and the workpiece material is the mild steel SPCE, the stainless steeI SUS 304 and the aluminum alloy A 3004. Experiments show that the volatile lubricants have the same lubricity as the generally used mineral oil with low-viscosity judging from the value of friction coefficient, the surface appearance of ironed workpiece and the surface damage of the die. The volatile lubricants can be applied to the ironing process with 40% reduction in thickness when the workpiece surface texture and the compatibility between the die and workpiece are properly considered.

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The turning test was carried out under the dry cutting condition to evaluate the machinability of aluminum alloys (Al-5.6mass%Cu-4.0mass%Si) which aged up to several stages, as a candidate of the free-cutting aluminum alloy without lead. The chip breaking during turning were low in the under-aged alloys, but that were increased in the over-aged alloys. The chip breaking of the most over-aged alloys was equal to that of the free-cutting aluminum alloy with lead. The changing of the chip breaking by aging treatment for the alloys was closely related to generation of the adhesion on the cutting tool. Although the increase of the adhesion caused increasing the chip breaking, that also caused roughing of machined surface.

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The increasing demand for quiet gear systems has created the need for precise analysis of gear-drive vibration. Furthermore, these days, noise should be predicted during product design. In response to these needs, the authors have developed a new method for predicting the vibration and noise of a total gear system, including not only multi-stage gear pairs but also shafts, pedestals, and a gearbox. The method consists of three separate analyses : three-dimensional gear-vibration analysis, FEA (finite element analysis) of gearbox vibration, and BEA (boundary element analysis) of the sound field. To verify the effectiveness of the method, sound-pressure levels at two points in the horizontal and the vertical directions from the experimental apparatus's gearbox were measured. These measurements agreed well with the corresponding calculated levels by developed analysis method. It can thus be concluded that the method can accurately predict vibration and noise and sufficiently assess the noise radiated and propasated through air. It can therefore be utilized for designing a low-noise gearbox by determining the area from which the noise is radiated intensively.

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Swing pad journal bearings consist of several segmented pads supported by curved laminates of rubber and metal. The pads swing and tilt because of the radial and circumferential deformation of rubber layer due to the hydrodynamic pressure in the oil film and also the frictional force. The swing pad journal bearing to study is assumed to have a single layer rubber. This simple design, different from the conventional one, leads to the reduction of production cost. The dynamic performance of multi-pad swing pad journal bearing, such as the stiffness and the damping of the oil film, the oil whip stability and the unbalance response characteristics have been studied. Compared to a 4 lobed bearing of the same size under the same operating conditions, the multi-pad swing pad journal bearing is found to have lower cross-coupling stiffness terms, leading to higher oil whip stability.

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A dynamic explicit thermo-elastic plastic FEM simulation is established in order to clarify ultra high-speed metal cutting mechanism in detail. Geometrical and thermal penalty methods are applied to the chip-tool contact problems. The node separation technique is used for the chip generation. When cutting speed exceeds the speeds of plastic waves, the shock waves are developed ahead but close to the rake face. Especially when the cutting speed is much higher than the speeds of plastic waves, the shock waves can be seen clearly. Since the shock waves induce the high levels of hydrostatic stress, the cutting force increases rapidly with cutting speed, resulting in very high levels of normal stress on the rake face though the shear angle rises up to 40 degrees.

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In centerless grinding of large dimensioned workpiece, two serious problems to be solved are, firstly, chatter vibrations originated in dynamic stiffness of grinding system, and secondly, copying accuracy of generator profile between master cam and workpiece. A new centerless grinding machine is designed and built recently based on new design concept. That is the combination of load compensated positioning mechanism and plain bearing guideways for high stiffness and accuracy in feed direction. Another one is application of stationary spindle structure for both wheels which assures high dynamic stiffness. The results obtained are summerized as follows : Copying accuracy of master cam to workpiece is around 0.2 μm/200 mm. 50 mmdia×200 mm length workpiece is ground without chatter, achieving roundness of 0.2∼0.3 μm. Chatter analysis assures the new machine of absolute stability under usual grinding condotions, and simplified criterion for absolute chatter free grinding is shown.

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Multi-wire sawing with loose abrasives is widely employed for slicing brittle materials, but the process has problems in the viewpoint of inefficiency and bad working environment. Therefore, fixed-abrasive wire sawing processes have been introduced by using a resinoid diamond wire tool or an electroplated diamond wire tool to overcome these problems. Electroplated diamond wire tools have higher wear resistance, but the production cost is very high because the time required for electroplating in the manufacturing process is too long. As a result, the tools cannot be put to practical use. In this study, ultra high-speed electroplating using felt brush is proposed to adopt for manufacturing the tools in order to reduce the production cost. A series of experiment revealed that a production speed of a newly developed method is 30 times higher than that of conventional manufacturing method and a developed wire tool has a high wear resistance as compared with commercial wire tool.

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Vapor grown carbon fiber (VGCF) is a kind of carbon nanotube, which has outstanding properties such as high mechanical strength and high electrical conductivity. In this study, injection molding properties of polystyrene (PS) filled with VGCF and evaluation of mechanical and electrical properties are discussed in comparison with composites in which conventional carbon fillers were filled. As a result, volume resistivity of VGCF/PS composites dropped significantly between VGCF concentration of 3 and 4 vol.%. Resistivity of the composites filled with VGCF was 1.2×10² Ω·cm when VGCF concentration was 11.6 vol.%. The resistivity was significantly lower than that of composites which were filled with conventional carbon fillers. The conductivity change due to volume fraction of VGCF was discussed using the thermodynamic percolation model. The elastic modulus slightly increases with increasing VGCF concentration, whereas the tensile strength slightly decreases in the VGCF concentration in the range from 0 to 12 vol.%.

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Virtual Enterprise (VE) is a temporary alliance of enterprises that come together to share skills, core competencies or resources in order to better respond to cope with demand of customers. It is very important activity to select appropriate business partners in VE, because each enterprise considers not only pursuing its profit but also sharing the risk. In this study, we focus on the negotiation process in VE, and try to apply multi-agent paradigm with game theoretic approach as its decision making mechanism. We develop a VE simulation model to analyse the forming dynamism of VE amongst several potential members in the negotiation domain, and finally clarify to realize the flexible partnering by the proposed approach.

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In this paper we investigate the effects of part machining and measuring errors on the production efficiency of a high quality relay produdion system applied a 'Matching method'. In this method assembly errors occurred by part machining errors are adjusted by reprocessing parts using tools selected according to the assembly errors. At first, we build the part's flow model and analyze the effects of part machining and measuring accuracies on the production efficiency. Next, we analyze the effects of other system parameters on the efficiency and propose a method to increase the efficiency. Results show that the improvement of measuring accuracy and the enlargement of assembly error range within which each tool can reprocess are useful to increase the efficiency. But the improvement of machining accuracy and the increase of number of tools are not useful. The proposed method using additional tools is useful to increase the efficiency and there are optimal assembly error ranges for the additional tools to reprocess.

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This paper proposes a new Petri-nets description method for factory automation system software development. As factory automation systems are becoming larger and more complex, sometimes we encounter difficulties ; for instance, inadequate expression methods, and not yet established analyzing techniques for control mechanism. For the flexibility and expandability of the factory automation system software, programming paradigms modeled by network, such as Petri-net, are useful. As shown in the previous researches, the description capability of Petri-net is high ; nevertheless, sometimes the network model becomes complicated lacking comprehension. The complicated system specifications can be broke down by analyzing them from several different standpoints. That is to say, the control logic and hardware configurations are defined from each respective standpoint, and then the total system is reconstructed by integrating the planes. In this paper, we propose the conversion algorithm from the specified data to a Petri-net. The validity of the method was confirmed through an experimental application example.

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It has been clarified experimentally that newly developed torsional damper can effectively reduce the torsional vibration of crankshaft system by adjusting the weight of balls of the experimental damper. The purpose of this study is to quantify the damping mechanism as the basis for its optimum design. First, the modeling and the computer simulation on the torsional vibration of testing crankshaft system with the damper are carried out. Then, by examining their results in comparison with the experimental results, it is made clear its primary damping mechanism is constituted by not only the friction torque between crowds of solid balls and damper mass but also the fluctuation of the natural frequency caused by alternating between angular displacement and coupling of damper mass to damper case every period of torsional vibration.

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