Railway drivers are trained the measures about various troubles faced during driving, and they can usually operate appropriately in the training. However, they can't meet an actual trouble calmly when they face it, so that they can take another mistake. As a part to examine support plan to prevent such an effect, we carried out a survey for all train drivers in our company, for example about their experiences and feelings in trouble caused by their own mistake or not, besides measures how they will manage an inexperienced trouble, and supports what they want to demand when they lost calmness.

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This paper demonstrates the possibility to detect suspension failures of railway vehicles using a multiple-model approach from on-board measurement data. The railway vehicle model used includes the lateral and yaw motions of the wheelsets and bogie, and the lateral motion of the vehicle body, with sensors measuring the lateral acceleration and yaw rate of the bogie, and lateral acceleration of the body. The detection algorithm is formulated based on the Interacting Multiple-Model (IMM) algorithm adding a method updating estimation model. The IMM method has been applied for detecting faults in vehicle suspension systems in a simulation study. The mode probabilities and states of vehicle suspension systems are estimated based on a Kalman Filter (KF). This algorithm is evaluated in simulation examples. Simulation results indicate that the algorithm effectively detects on-board faults of railway vehicle suspension systems in realistic situation.

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A control method of active suspension system, called Preview Control, applying road-surface profile measured in advance, is advocated. However, it is difficult to detect accurate road-surface profile for practical application, because no sensor can detect road-surface profile directly in general. This problem is unavoidable for a non-contact laser displacement sensor installed on the automobile active suspension system. This paper proposes a new method to estimate road-surface profile by the full-order observer, which uses body vertical acceleration, suspension stroke, lateral acceleration, longitudinal acceleration, actuator angle, and relative distance between road-surface and laser displacement sensor. Moreover, this method is applied to an electric active suspension system, and then improvement of comfortability in riding and decrease of energy consumption are verified.

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A permanent magnet DC brushless motor is the most suitable for high torque electric power steering (EPS). Unlike brush motors, these motors can be driven up to high revolution speeds by using the field weakening control that reduces the magnetic flux. However, a motor vibration is caused by this field weakening control. Therefore, we need to develop a low vibration motor at the field weakening control. The authors focused on this issue, and investigated a mechanism of the motor vibration caused by the field weakening control. As a result, the authors clarified the mechanism of the motor vibration caused by a magnetostriction of a stator core and developed a formula for calculating the motor vibration at the field weakening control. In addition, this mechanism and formula were verified by the experiment that used an actual motor. It was shown that the authors obtained a new finding by the process of this research.

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This paper describes a methodology regarding an intelligent cruise control (ICC) of circulating robots which is directly effective for solving congestion regardless of the presence of a bottleneck. For this purpose, we focus on an external interaction force between the robots. This force is generated with the use of a virtual damper. In this methodology, control models on the basis of the following two scenarios are presented: a damping force acts on a moving robot as the external interaction force, (I) only when its preceding robot(s) is/are stopping or being congested and (II) when a robot exists in front of the moving robot, in order not to become involved in the congestion. This paper deals with a circuit and a robotic material transport system. Through simulation experiments, it is shown that the proposed ICC successfully solves the congestion, and finally, improves the performance.

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Recently, the demand on an improvement of comfort in the automobiles has increased. When the car is considered as a room, the space planning of the seat arrangement influences the comfort greatly. In this research, the seat arrangement with rotating seat for improvement of passenger comfort is proposed. To rotate seat inside the room of the car can increase communication of passenger. To rotate seat outside the room of the car can produce private space. These effects improved the comfort in the room of the car. In this paper, the experiments of a sensory evaluation and a biomedical measurement are performed. These experiments use the driving simulator and the actual car. Therefore the effectiveness of seat arrangement with rotating seat for improvement of passenger's comfort has been confirmed.

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This paper deals with a method of tire modeling for vehicle dynamics analysis. In recent year, we are used the empirical model in the field of vehicle dynamics to perform more precise analysis. But it is very difficult to make the accurate tire model because it requires a large number of experimental data and the huge indoor test facility. In this paper, we develop a new tire model combined the analytical model and the experimental model to reduce the experimental data. The characteristics of lateral force with camber angle calculated by this method is very similar as those of experimental data.

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The purpose of this study is to develop and propose an efficient interaction model and an analytical method of a tire and the soft ground which can be applied to the multibody dynamics for off-road vehicles. The model presented in this paper describes the deformable behavior of the elastic tire and the behavior with large displacement of the soft ground. We adopt a distributed lumped mass-spring model as the tire, Discrete Element (DE) model as the upper soft ground and a mass-spring model with Bekker's theory as the lower soft ground. A tire model with the lug considering contact geometry with the soft ground is also developed on the basis of the original tire model. Numerical simulations of the tire behavior on the soft ground under several conditions using the proposed model have been conducted. The numerical results showed that the proposed model and analytical method would be validated for the vehicle dynamics simulation compared with the results of a lot of previous experiments from some references. They also indicated that the tire with low stiffness and with the small angle lug could be effective in improving the tractive performance of the tire on the soft ground.

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The result of a study on a faster numerical method for Kalker's "EXACT THEORY" is presented in this paper. For solving contact problems between wheel and rail, Kalker's "EXACT THEORY" is a precise method based on the three dimensional theory of elasticity of Boussinesq and Cerruti, however it has not been used widely because of its calculation cost. It is explained in this paper that with the use of the primal-dual interior point method one can improve the exact theory in calculation speed, and therefore one can solve contact problems more effectively. In this paper, first, the formulation of contact problems and original Kalker's numerical algorithm are stated. Secondly, the numerical algorithm based on the primal-dual interior point method is stated, and then, both the algorithms are compared and lastly it is shown that by applying the primal-dual interior point method one might solve contact problems 1.5〜10 times faster than by applying Kalker's original algorithm.

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In this paper, we present the result of a study made on an effective numerical method for evaluating the area, which has to be analyzed to find a contact area precisely. The contact area is found as an area where normal contact pressure is plus in the analyzed area when one solves a normal contact problem applying Kalker's "EXACT THEORY". Therefore, it is inferable that one can find a contact area and contact pressure finely within a limited amount of analyzed points if the analyzed area can be set slightly larger than the true contact area. It is allegeable in this paper that applying our proposed method one can find a better analyzing area minifying the former analyzed area in the process of an optimal calculation and can find a precise contact area, pressure distribution, etc. in the end of the calculation. First, the algorithm of reducing the analyzed area is stated and applied to the normal contact problem of two balls. Then, it is applied to contact problems of wheel and rail. The algorithm works satisfactorily, and the results revealed a good coincidence with the results calculated by the Kalker's original algorithm. The iteration counts of our method where the analyzed area is set approximately 10 to 100 times as large as the true contact area is less than two times that of Kalker's where the analyzed area is purposely set slightly larger than the true contact area.

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Carter's theory is famous adhesion model in railway braking technology. However, the range the adhesion force characteristic cannot express over 0.2% range. Recently, the studies about adhesion model using automobile tire. The author had proposed the beam model for adhesion force model which can express adhesion force in all slip ratios for railway vehicles at braking. However, it has a problem that the contact pressure distribution is different from Hertz theory. Kalker reported wheel-rail contact theories based on Hertz contact pressure, however those were not considered dynamic friction coefficient in slipping area. Moreover, This paper will present the simulation results about adhesion force model considered dynamic friction coefficient in all slip ratios based on three-dimensional contact theory. Proposed adhesion model is described only longitudinal direction not considered spin creep for wheel slip prevention of brake dynamics for railway systems. Calculation method of proposed adhesion model based on three-dimensional Hertz contact is finite element method.

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It is very important to secure running safety of railway vehicles even when vehicles get derailed. In 2004, a Shinkansen train was derailed by a huge earthquake and its derailed wheels ran on concrete slabs. Taking account of this kind of accidents, a number of vehicle-guidance devices have been developed. Some of these devices are designed so as to lead derailed wheels onto a runway made of concrete slabs. In order to simulate the derailed cars running behavior on a runway of concrete slabs, it is necessary to make clear creep force characteristics and friction coefficients between wheels and concrete slabs, which are essential elements in determining vehicle dynamics. However, there is scarcely a study of rolling contact between steel wheels and concrete slabs; therefore the authors have executed an experimental investigation to evaluate creep force characteristics and friction coefficients between a steel testing wheel and a concrete slab.

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At Mid Niigata Earthquake in October 2004, a Japanese high speed train was derailed under commercial operation at the speed of 200km/h. Investigations of the case concluded that the horizontal ground motion by the earthquake was the major cause of the derailment, which implies that railway vehicles could be derailed solely by the ground motions of earthquakes with no fatal damages of vehicles or tracks. Based on the reports and facts, we believe that we should study both the derailment mechanism and function of guard rail, to pursue to minimize the risk of railway system against large earthquakes. In this paper, we developed a simulation program to study the basic mechanism of the function of guard rail to prevent derailment due to large eathquakes. Then through numerical analysis based on the simulation program, we obtained the following results. Firstly, anti-derailing guard rail is effective to prevent derailment due to large track excitations. Secondly vertical ground motions, light weight body and curve running on canted track have relatively smaller influence on the derailment mechanism.

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The purpose of this study is to clear the derailment mechanism and effect of anti-derailing guard rail on large earthquakes because the Shinkansen train was derailed by the Mid Niigata Prefecture Earthquake in October 2004. At first, in 2005, we have designed the 1/5 scale vehicle-track model and excitation device and have introduced these devices in Komaki of JR-Central and until now we have conducted the 5000 cases of excitation experiments in order to complement the result of the full-scale bogie excitation test. As a result, we conclude that the derailment occurred in the excitation frequency range of 0.5-2.0Hz (full-scale corresponding value) is the rocking derailment and that the anti-derailing guard is effective for the rocking derailment.

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Considering anti earthquake measures for vehicles, preventing vehicles from derailment is the most important issue. To minimize the risk of fatal accidents, it is also essential to consider preventing derailed vehicles from veering off the track as a secondary measure. Central Japan Railway Company has developed anti-derailing guard rails as the primary measure and post derailment stopper as the secondary. For the development of the stopper, we conducted running tests in the condition of derailment using real bogies and tracks. Through the series of running tests, we observed the stopper prevented the derailed vehicle from veering off the track and verified the effectiveness of the stopper.

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Field measurement and model shooting experiments are conducted to study the compression wave generated when a bluff-nose train enters a single-track tunnel and to devise countermeasures for reducing the amplitude and pressure gradient of the wave. Field measurement is carried out for five different types of real trains traveling at about 120km/h on a meter-gauge railway line, and model experiments for three varieties of rounded corners of the fronts of circular cylindrical trains entering a circular tube. It is shown that the maximun values of pressure gradients of the compression waves generated by the bluff-nose trains decrease with increasing the degree of roundness of the front ends of the trains and that an 8-meter tunnel entrance hood can reduce the maximum values of the pressure gradients by approximately 70 percent.

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Wind tunnel and running experiments are conducted to study the compression wave generated by a bluff-nose train and to devise countermeasures for not only reducing the waves but also aerodynamic drag by preventing the flow separation. Effects of rounded corners of the front end of bluff-nose trains and aerodynamic attachments are investigated. It is demonstrated that an attachment of fins to the front end-edges of a two-car test train traveling at 120km/h can reduce the maximum values of pressure gradients of the compression waves by approximately 40 percent and its running resistance in the open enviroment (non-tunnel) by approximately 20 percent, respectively.

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To decrease a present number of Labor's injuries, it is necessary to execute not only the educational initiation for workers' safety but also the essential safety protection measures of the machine and the device of the production line at the life cycle by the risk assessment etc. However, being able to prove the investment effect to be effective enough as Enterprise Management for the safety protection measures become a motivation to move forward for the manager's execution. Therefore, evaluation index of the investment effect related to the safety protection measures would be necessary. This paper proposes Key Performance Indicator (evaluation index) for the investment effect concerning safety from the aspect of the total cost of the machine and the manufacturing system.

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A vehicle for the individual usage called a personal mobility vehicle (PMV) is investigated in terms of its affinity with pedestrians. A PMV sometimes share the space with pedestrians. Therefore, it is very important to ensure the safety and comfort of pedestrians and PMVs in the space. In this investigation, we evaluate the affinity between pedestrians and PMVs using the personal space. The personal space is the space which causes the psychological strain by the approach of others. By using the personal space, the psychological strains of the pedestrians and the PMVs are measured by physical distances. It is shown that the personal space of the two-wheeled dynamically stabilized vehicle has higher affinity with pedestrians than that of the bicycle, which has 2,0 to 2.3 times larger personal spaces for the front, back and side. It is also found that for a pedestrian, the approach of the dynamically stabilized vehicle for the front does not have high impact; however the passing of the vehicle side to the pedestrian causes more discomfort and fear. Finally, the experiments using multiple pedestrian were carried out and the discomfort and fear level of the pedestrians were confirmed.

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This study examines the braking assistance system for train drivers when stopping at a station to prevent the drivers from overrunning. The braking assistance system informs the driver visually of a predicted stopping position based on present vehicle velocity and deceleration. If the predicted stopping position is in front of (over) the desired position, it is presented in green (red) color. It makes the driver aware not only the predicted stopping position, but also the appropriate braking operation. Train-driving simulator experiments are examined with several subjects who are required train driving with the mental calculation which assumes the mental workload. Subjects with the braking assistance system can operate the brake handle smoothly as well as the usual driving without the mental calculation, while subjects without the braking assistance system repeat the modified braking operations. These differences are observed in the standard deviation of the brake handle change by the drivers. The braking assistance system decreases the standard deviation of the handle change value with a significant difference.

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Vehicle stability is decreased with crosswind disturbances and lane following situations during high speed driving. Thus, steering control systems are developed in order to improve the vehicle stability. However, the performance as man-machine system is not always improved by the control. Therefore, it is necessary to design the system in consideration of the driver characteristics. In this research, we designed steering assist control by using a closed loop system simulation, and evaluated the effect using the driving simulator with lateral motion.

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Recently, many amateure pico satelites named "CubeSat" were launched and are under developing in the world. Kagawa University developed a robotic pico satellite named "STARS". STARS was developed for technical verification and evaluation of a tethered space robot proposed in 1995. This paper especially focuses on the daughter satellite, whish is a tethered space robot. The downsizing robotic system, which has a defferential gear joint mechanism for two degrees of freedom, was designed for STARS, and the robotic control system available for a pico satellite was installed. STARS was launched by the H-IIA rocket from Tanegashima, Japan on January 23, 2009. After confirming the condition from the housekeeping telemetry that robotic motion was possible on orbit, the arm link motion by the developed small joint mechanism, and the robotic control based on the feedback information of the gyro sensors, were performed. Although attitude control of a tethered space robot could not be performed because tether was not extended enough, the main functions for the robotic pico satellite were verified and evaluated.

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The compound gear has a gear on one side and a cam profile on the other side. It is used in a seat belt system for an automobile. The compound gear has been produced through multiple forging processes and cutting processes. From the requirement for the lower costs of production and labor saving, it is very important to reduce the number of forging processes. So, the compound gear forming by the forward-backward extrusion in the cold forging was attempted. But it is very difficult to obtain the product without the defect, and the damage of the die sometimes occurs. In this study, to obtain the suitable slug shape for improving formability of the slug and preventing the damage of the die, 3D finite element simulations for the forward-backward extrution process using several types of slugs with the different shapes in cross section and the same volume were carried out, and the relationship between the slug shape and its formability and the influence of the slug shape on the stress of the die in the extrusion process were examined in detail. On basis of the obtained results, the suitable slug shape which was able to be formed into near net shape of the product and which could be formed in the lower extrusion load were proposed. The effects of the proposed slug shape on the forward-backward extrusion in the cold forging were also confirmed by the finite element simulation and the experiment.

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We propose a design method of an active front wheel steering controller that guarantees closed-loop stability under the rear tire side forces saturation. The proposed controller utilizes the information on the rear tire side forces to counteract the destabilizing effects caused by the rear tire side force saturation. The controller can suppress the magnitude of the slip angle while the rear tire side forces are saturated. The effectiveness of the proposed method is shown through numerical simulations.

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A wave absorbing control of beam near boundary by finite difference (FD) approach is presented. The FD equation of motion of the boundary node under the influence of the boundary condition is compensated to be the same as that of the inner node free from the boundary condition by using the characteristic solutions. The control strategy consists of a real-time convolution integral of the measured boundary node displacement and the time domain transfer function between adjacent nodes (characteristic solution). The real transfer function has two arbitrary constants. Control for beams has been investigated for these arbitrary constants considering the causality. Some suitable combinations of the arbitrary constants can realize both wave control and the fixed boundary node displacement smaller than the static one. Comparison between the FD approach and the impedance matching control for cantilevered beam shows that they have equivalent performance. We also confirmed the effectiveness of the wave controller by the time domain simulation.

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In this paper fundamental sound absorption characteristics of expanded polystyrene beads with several geometries are reported when they are packed in some thick layers with and without back air space. The normal incidence sound absorption coefficients, which were obtained by the experiments using two-microphone impedance tube, were evaluated comparing to theoretical estimations. Experimental data were also compared to the similar conditions but hard material particles like glass beads whose acoustic property was investigated by Sakamoto et. al. in a preceding study. Then following results were obtained; packed layer with expanded polystyrene beads has almost equal sound absorption coefficient to the similar layer with hard and solid material: numerical estimation of sound absorption coefficient is valid enough except for the case having large back air space: lowering peak frequency of sound absorption coefficient is available by overfilling and compressing particles. The authors also consider that applying soft, light, and low cost material to the sound absorbing structures is very meaningful. Because human damage caused by falling of wall and ceiling panel of buildings is avoidable particularly under an earthquake attack.

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The pressure between a disk and a pad become un-uniform when the pad inclines due to the moment of frictional force applied when braking. The pad stiffness also becomes un-uniform because the stiffness depends on the pressure. The influence of the un-uniformity of the stiffness between the disk and the pad on squeal generation is examined by using a surface-contact-analysis model. To facilitate the stability analysis, the model consisted of a minimum element that can reproduce the squeal vibration. Specifically, the model was composed of a disk with one degree of freedom (out-of-plane direction) and a pad-caliper with two degrees of freedom (rotational and translational). The disk and the pad-caliper are connected by a distributed spring. The analytical result clarified that the coupled vibration of the disk and the pad-caliper became unstable when the pad stiffness was un-uniform, and the self-excited vibration (squeal) was then generated. Additionally, the influence of the un-uniformity of the pressure between the disk and the pad on squeal generation was examined by executing squeal tests. The moment of the frictional force could be counterbalanced by enlarging the load added to the trailing side edge of the pad, which resulted in uniform pressure between the disk and the pad. The results of the squeal test clarified that squeal was not generated when the pressure between the disk and the pad was adjusted to become uniform.

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This paper presents the analytical method to evaluate the impact force induced by piston slap considering the dynamic effect of motion and vibration of piston, connecting rod, crank shaft and engine block. The inertia force of connecting rod in vertical, horizontal and rotational direction are taken into consideration and the effects of these inertia forces on the piston impact force and main bearing impact force of crank shaft are discussed comparing with the conventional simulation method in which the inertia force of connecting rod is idealized as the added mass to the piston and crank pin. The difference of the wave form of piston slap force is recognized between the present method and the conventional method. Moreover, influences of motion and vibration of piston and connecting rod upon the crank shaft vibration and main bearing impact force are examined. The effect of the coupled vibration is seen in the wave form of the torsional vibration of the crank shaft and main bearing impact force in the horizontal direction.

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This paper presents a new motor current control strategy to reduce current fluctuation. Such current fluctuation may cause undesirable torque ripple and acoustic noise for tactile torque control system such as EPS. Using a DC-motor, current fluctuation associated with change in the battery voltage, etc., may occur. We have developed a new current control strategy which effectively alleviates current fluctuations of the motor without using higher performance microprocessors. The new controller is based on the newly proposed disturbance observer with phase compensator to estimate the disturbance voltage and compensation for it. We have analyzed the sensitivity to the disturbance, that is to say, the transfer function from disturbance to electric current and show that by using high pass filter, the transfer function has the notch filter characteristics against disturbance without causing change in transfer function from reference current to actual current. We have bench-tested the performance of this control strategy and confirmed that current fluctuation is reduced to coincide with the analytical result.

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The purpose of this paper is to optimize the throughput of step-and-scan lithography equipments. For this purpose, we propose a method for MSOP (Movement Sequence Optimization Problem) which is a problem of visiting all shots on a wafer in the minimum time. It is well-known that, as a traveling salesman problem, MSOP on stepper lithography equipments can be formulated. In step-and-scan lithography equipments, the scanning directions of all shots must be determined in addition with the sequence of shots. For this reason, the traveling salesman problem formulation could not be applied to MSOP on step-and-scan lithography equipments. We overcame this problem on step-and-scan lithography equipments by introducing dummy vertices to express scanning directions in the traveling salesman problem formulation. By this method, the exactly optimized sequence with scanning direction of shots became available for MSOPs given. As a result of numerical experiment, our proposed method could exactly solve difficult MSOP with over 232 shots on a wafer. In addition with this, our results showed 0.25%〜4.66% improvement on the productivity of step-and-scan lithography equipment.

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This paper introduces a monocular stereo system that can switch its viewpoint 1000 times or more in a second by using a high-speed viewpoint switching iris mechanism. To measure three dimensional shapes of moving objects correctly, the temporal displacement in capturing two different viewpoint images was designed as a short inverval within 1/1000s in our developed system. Actually several experiments were performed for moving objects, and the effectiveness of our monocular stereo system was verified by measuring their three dimensional shapes at a high-speed frame rate.

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This paper presents an acceleration visualization marker which can display moire fringe that correspond to a magnitude of acceleration without the use of electronic elements, such as amplifiers, strain gauges and wires. To obtain moire fringe, the marker consists of two plate printed with a line gratings. Numerical value of the acceleration can be obtained from an image of this marker. We propose an image processing method and have experimentally verified the utility of the proposed marker by taking images with a high-speed camera.

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A measuring method and a test equipment for the softness and the viscoelasticity property have not yet been established. The testing method which could measure the surface texture of measured object for processed food such as jelly and agar and perishable foodstuff such as pig roast and bird liver is established and the development of the functional equipment is desired. In this study, the dents was made to arise using air jet on the surface of measured object. The shape of the dents is measured in the two-dimensional laser beam. The measuring method of the softness was proposed by the measurement of diameter and depth of the dents which arose to the measured object. And the method for examining the viscoelasticity property by time course of the dents depth was proposed. The functional testing equipment based on them was manufactured and the flexible thing was measured. As a result, it was possible to show the softness at the surface area per unit load. Creep and creep recovery for the depth of the dents were clearly also obtained. Therefore, the measurement of soft measured object was possible for this measuring method, and it was possible to confirm the performance and the advantage.

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A micro pump is one of the most essential components in μTAS. However, conventional pumping systems have some difficulties to be miniaturized because it requires a power source. In this paper, we propose a novel micro screw pump driven by electrostatic force. Since the electrostatic force becomes dominant in micro region, it may be an effective driving source for micro pump. We propose an electrostatic drive principle of a screw pump using three-phase AC input. The micro screw pump is composed of a stator having flexible printed dircuits and a screw covered with a PET sheet. The drive experiments confirmed the effectiveness of the proposed driving principle and successful pumping with the developed micro screw pump at a flow rate of 111.4μl/s.

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In this study, five kinds of state variables characterizing the eye blinking behaviour for detecting low wakefulness level of car drivers were investigated. This investigation was carried out in a driving simulator for clarifying what kind of state variables are useful for designing the algorithm of awaking alarm, in terms of minimizing the missing alarm in low wakefulness condition and the excess alarm in awaking condition simultaneously. In applying the ratio regarding opening/closing time of eyelid and the variation of this ratio for designing the algorithm, the time frequency of the missing alarm was approximately 1.5% and extremely lower than the conditions when the algorithm was based on the other state variables like the total time for eye closing or the opening rate of eyelid. The time frequency of excess alarms in applying this algorithm is also not so high. An effectiveness of awaking alarm based on this algorithm was also evaluated and clarified that the awaking effects by the acoustic alarm evaluated in terms of the fluctuation of RRI (ECG) was not sufficient, and the methodology for awaking the driver should be studied.

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This study describes an equipment to evaluate potential of fall of human in seated position. The equipment can make a subject fall safely by supporting the upper body with a wire parallel mechanism. Therefore, the equipment can measure behavior of a subject at fall moment and obtain evaluation data of fall behavior. The wire parallel mechanism consists of four wires connecting the base chair to the output link and can generate spatial 3DOF motion. The output link is attached to the thorax of a subject so as to support and control 3DOF motion of the upper body. Each wire has strain-gages to detect its tension. Furthermore, a force-plate is set on base chair to measure the center of pressure (COP) for comparison. The equipment uses measured wiretension, posture of the wire parallel mechanism and COP as evaluation of fall. The wire-tensions change sharply at fall moment and the posture of the mechanism show the tendencies of potential of fall of a subject clearly. Further human body can be supported by the wire parallel mechanism after falling. Thus, it has been confirmed that the proposed equipment can measure potential of fall of human safely.

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This paper proposes a patient robot system for nursing students to practice injection training and describes verifications of the training effects. A prototype of a patient robot has been designed and developed with the functions of letting the students inject to its vein and expressing countenances and emotional behaviors to make the robot system be seen similar to actual human. Challenging how to achieve the objective of providing the student trainees with the feeling as if they are nursing actual human, we propose to utilize chaotic transitions generated by non-linear dynamics to avoid repeating actions. The motion of the patient robot is generated according to the internal state, which represents trainee's nursing behaviors recognized through the robot's eye-camera and chaos mimicking human's time-varying emotional transitions. The effects to the injection trainings of the patient robot have been evaluated by vital sign such as students' heart beating rate and questionnaire after practical injection trainings.

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A new type of knee prosthesis capable of making deep knee flexion has been long awaited for Asian and Muslim people. Our research group has developed a prosthesis for deep flexion and designated it as CFK (Complete Flexion Knee). In order to assess the performance of CFK, we have set up various kinds of simulation/experimental projects, such as a cadaveric study, a mathematical model analysis, a photoelastic analysis and FEM analysis. For carrying out the above-mentioned projects, we faced the most fundamental problem; the information about the muscles' forces and the forces acting on the joints is limited for the activities with low and middle flexion of knee angle such as waking, but not for deep flexion such as squatting or sedentary sitting. The objective of this study is to introduce the muscle and the joint forces at deep knee flexion by using a 2D mathematical model. Double leg ascending and single leg ascending from deep squatting were studied for 10 healthy male subjects. The results demonstrated that the knee joint force was largest for the legs during double leg ascending, followed the dominant leg during single leg ascending and it was smallest for the supporting leg. The critical state for the prosthesis for deep flexion was found as the maximum joint force with F_<nmax>=4.6±0.6 (4.3〜5.2) times Body Weight at knee flexion angle of β=142±8 (134〜147)°. Ascending speeds did not affect the values of the muscle and joint forces as long as the motion was not strenuous like jumping.

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There has been no question that some strings do provide a better grip than others, but that did not guarantee that the ball will produce more spin. Furthermore, experiments with hand-held rackets has been needed to solve the vexed question of how players can tell the difference between different strings when laboratory tests indicate that they should play the same. The previous paper of the authors made clear the mechanism of top spin performance in actual tennis and its improvement by lubrication of notched nylon strings according to the high speed video analysis on the court for the first time. It succeeded in an experiment showing that as the main strings stretch and slide side ways more, the ball is given more spin due to restoring force parallel to the string face when the main strings spring back and the ball is released from the strings. Since the notches of strings decrease spin rate, the lubricant materials are effective to the notched strings. Furthermore, it showed that the more spin results in the reduction of shock vibrations of the wrist joint during impact. This paper showed that the ball is given less spin rate (40% decrease) with the notched used strings compared to that with the new strings in the case of the nylon in this experiment, which has remained to be seen which gives more spin between new strings and the lubricated used strings, and it showed that the ball is given more extra spin (30% increase) by oil lubrication at the string intersections compared to that with the notched used nylon strings. Furthermore, it also showed that the used natural gut with notches decrease 70% of spin rate compared to the new natural gut without notches in the another experiment, which has remained to be seen whether the same results will be obtained. It also showed the difference of the topspin behavior when a pro and an amateur hits a ball.

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Impedance control of a 3D4M parallel link mechanism (PLM), a 3 degree of freedom (xyθ) planar parallel link mechanism with redundant 4 actuators, is proposed. The impedance control requires the forward kinematics, which gives position and orientation of the end plate of parallel link mechanism. The notable link arrangement of the 3D4M PLM makes it easy to derive the forward kinematics, which have been difficult to derive the conventional parallel links. By using the forward kinematics, formulas of the impedance control of the 3D4M PLM were derived. Based on the previous report about the design of decoupled dynamics, experimental system of the 3D4M PLM was developed. A parallel link mechanism was constructed on linear motors in which 4 moving parts were individually driven on one stator part. Workspace impedance control achieved by force commands were implemented in the experimental system using a DSP based real time controller. Experimental responses of free vibrations to impedance control were compared with corresponding theoretical responses.

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In this paper, we propose a small and simple slider-crank mechanism using flexible links that realizes both a wide flapping angle and lead-lag motion toward the development of a small flapping robot modeled on insects. Butterfly-style flight is attractive because of its low flapping frequency and fewer DOFs, unlike flies and dragonflies. However, since a butterfly flaps the wings over 150 deg and claps both left and right wings, a conventional slider-crank mechanism cannot generate sufficient torque for flapping at the top dead point that the driver and follower are parallel. Furthermore, an additional actuator for lead-lag motion makes the mechanism heavy and complex. To overcome these problems, we developed a new slider-crank mechanism that can flap the wings widely by bending of the flexible links and that realizes the lead-lag motion by twisting them. The flight performance of the butterfly robot with this mechanism was comparable to that of a butterfly, unless a butterfly kicks ground at takeoff.

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In this paper, we propose a new robotic manipulation: planar caging manipulation by robots and walls. Caging is a method to make an object inescapable from a closed region by rigid bodies. Previous studies use only robots for caging, while we use walls as well. First, we formulate planar caging with the environment such as walls. Next, we derive the caging manipulability condition. The manipulability problem is trivial in robot-only caging, but crucial in our cases. Finally, we present a method to plan planar caging manipulation of a circular object by circular robots and rectilinear walls.

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We are developing a human-symbiotic robot "EMIEW", which supports people in their daily lives. To move nimbly and safely among people, EMIEW has an inverted pendulum mobile system and a collision avoidance system. Moreover, the high compliance of the position servo control is very important for the safe robot operation. We present compensation control methods of a precisely moving control for three type motions; a moving with an upper-body motion, a moving on a slope environment, and a trajectory tracking motion. Precisely trajectory tracking is important for the collision avoidance and other moving application such as multi robots cross running. Therefore, we proposed a new moving motion planning method by focusing on a "immovable point" which is a unique character of the inverted pendulum mobile system. With using this moving motion planning method, we could generate a trajectory that EMIEW can trace with a small error, and that conforms to specified constraints of maximum speed, maximum acceleration, and motion distance.

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This paper proposes a method for simultaneously planning the whole-body-motion and the foot-place for a humanoid robot dynamically walking on the flat ground. As constraint conditions imposed on the planner, we consider the differential equation of the robot's motion. To solve this constraint, we use the real-time walking pattern generator. We randomly sample the configuration space to search for the path connecting the start and the goal configurations. When sampling the configuration space, a few milestones are sequentially connected to the parent milestone. To show the effectiveness of the proposed method, we show an experimental result where the humanoid robot HRP-2 avoids the obstacle dynamically walking on the ground.

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While engineering a power plant layout, objective functions and constraints of the power plant frequently conflict each other in terms of factors such as safety, economic costs, maintainability, and construction term of works. This paper proposes a multi-objective layout optimization system for a power plant through effective interaction between the designer and the computer; this system is developed by applying an interactive Satisficing Trade-Off Method (STOM) for multiple-criteria decision-making. In order to obtain the layout candidates for decision-making, the authors present a suitable genetic algorithm (GA) approach to arrange the plot plan for the layout of buildings and equipment in a site. In this GA approach, the coding method and evolution operation method used for obtaining a diverse optimal layout solution are employed with a low computational load and simple design information. Finally, the validity and usefulness of this proposed system is demonstrated by solving a layout design problem for an actual gas-turbine combined-cycle power plant.

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The tribological performance of the titanium nitride (TiN) duplex coating has been studied as a potential surface modification for tools and machine parts for an aluminum alloy. Unlubricated sliding experiments on the duplex treated alloy tool steel blocks against an aluminum alloy ring were conducted under the oxidation-limited condition simulating the tool and machine surface where a transfer of aluminum alloy occurs. In the sliding experiments a transfer of aluminum alloy was predominating and little wear of the TiN coating film took place. After sliding for a certain distance, however, under the transferred layers a shell-like chipping appeared on the TiN film surface, and which grew downstream to cause a macroscopic spalling of the film. The film life defined by the occurrence of the spallation larger than 50 to 100μm is markedly prolonged by the tempering of the substrate nitrided layer. Possible mechanisms of the life improvement are discussed.

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A cerebral aneurysm is the dilation, bulging, or ballooning out of part of the wall of a vein or artery in the brain. If the cerebral aneurysm ruptures, it will become serious life-threatening condition. An aneurysm clip is a medical instrumentation that is used in operation of the cerebral aneurysm to clip the ruptured aneurysm and to reduce the risk of rebleeding. In order to prevent the aneurysm clips from slipping out of the blood vessels, a number of pyramidal depressions are formed on their clamp surfaces. Generally friction forces are determined by the normal load applied on the frictional surface and friction coefficient of the mating surfaces. In this study, load-displacement characteristics of the aneurysm clips were theoretically obtained based on the curved beam theory. The existing pyramidal depressions of the aneurysm clips increased the friction coefficient on the clamp surfaces. However, it is not verified whether the form of pyramidal depression is optimum or not. We used a THG laser process machine to produce the clamp surface with circular depressions or grooves. Frictional characteristic of each clamp surface was examined.

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This paper proposes a practical approach to estimating the path errors produced by the NC acceleration/deceleration motions around connection points between every two segments for a linear interpolation cutter path of a machining center. The approach consists of two parts. The first is an experimental method to identify the value of each related parameter in NC appareture to the acceleration/deceleration motion control, in which only an operation is needed to measure a few simple motion trajectories with two linear segments with the machining center. The other part is a concise and efficient simulation algorithm based on the identification results for a cutter path composed of a number of short linear segments. A comparison result of the simulated cutter path trajectories with the measured ones and contours of machined work pieces sufficiently demonstrates the effectiveness and reliability of the proposed approach. Therefore, as a useful tool, the approach is applicable to beforehand estimating the influence of the NC acceleration/deceleration motions on cutter path accuracy or judging the cutting conditions for the machining purpose without performing an actual machining test with the machining center.

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