Heartbeat interval in healthy subjects shows beat-to-beat fluctuation called heart rate variability (HRV). HRV is most prominent at rest and decreased with exercise and stress. Reduction of HRV in 24-hr ECG is an increased risk for death after acute myocardial infarction, in hemodialysis patients with end stage renal disease, and in general elderly populations. Respiratory sinus arrhythmia (RSA) is a major component of HRV and is also known as high-frequency component, an index of cardiac vagal function. RSA itself, however, is a phenomenon reflecting cardio-pulmonary interaction and seems to bare own physiological roles. Recent studies have shown that RSA improves pulmonary gas exchange efficiency through matching alveolar ventilation and perfusion within each breathing cycle. In resting animals and humans, RSA seems useful for saving circulatory and respiratory energy by suppressing unnecessary heartbeats during expiration and concentrating heartbeat effectively during inspiration. Indeed, the magnitude of RSA increases at rest, during slow-wave sleep, and with relaxation and it decreases with physical exercise and mental stress. Also, RSA decreases with advancing age and with severity of coronary artery stenosis and disappears in patients with severe heart failure. These suggest that RSA may be a resting function of cardiorespiratory system and its magnitude may reflect functional reserve of the cardiorespiratory system. Additionally, the association between RSA and cardiac vagal activity may be the indirect consequence of the fact that both of them change in the same direction at least against the physiological changes along the axis across resting and strain. RSA may be used as an index of physiological resting of cardiopulmonary system and may provide a useful marker for the effects of lifestyle modification and stress management in patients with cardiovascular diseases.

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When we evaluate the human-machine-environment systems, it is very important to consider not only the performance of the machine system but also the Mental Work Load (MWL) for the operator. Because human being have a high adaptability to their surroundings. It is difficult to measure the MWL directly. From this point of view, many researches on the vital reaction related MWL have been done in recent years. However, the evaluation method has not been established yet. In this study, we construct the MWL evaluation model using the Heart Rate Variability (HRV), because a strong relation exists between the MWL and the HRV. It is examined that the analytical method using this model can be to presume the facor of the MWL for drivers.

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This paper examines the feasibility of direct yaw moment control in the small-scale electric vehicle with two independent motors equipped at the rear axles. The direct yaw moment control system is designed with the application of model matching control theory. For realizing the proposed system in the actual electric vehicle, it is necessary to estimate the side slip angle instead of measuring it directly. The velocity-dependent observer is proposed in this paper. The experiments by using actual small-scale electric vehicle are carried out to verify the effectiveness of the proposed chassis control system on lateral stability.

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Electric Vehicles (EVs) have attractive advantages in motion control performance, such as 1) fast torque response, 2) accurate torque output, and 3) the possibility of distributed motor configuration. These advantages could be utilized for active safety issues. For example, fast feedback control techniques could be fully applied in EVs. If appropriate controller is applied, it can change the dynamics of each wheel and the wheel comes to be stable for slip phenomena. We assume that (1) such minor wheel controller can stabilize the unstable lateral motion, (2) thus it can be an effective minor loop in the vehicle stability control system or DYC (Direct Yaw Moment Control) system. Experimental results with "UOT March II", which is newly constructed, are also discussed.

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There have been serious problems of air pollution, energy consumption, traffic accident and congestion caused by automotive traffic. Electric vehicles, of cause, contribute to solving the problems of air pollution, energy consumption. To solve the rest problems, the vehicle should be more intelligent. This paper presents fruits of study on electric vehicles and intelligent vehicle. Automatic driving system, 8-wheeler electric vehicles named KAZ and 1m x 2m sized multipurpose electric vehicle are introduced.

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In the modern society, production system and physical distribution system are thought may be fusing. There are needs for an analysis of production system with manufacturing systems and the materials and handling system as a physical distribution in the local plant area In the meantime, there are needs for an analysis in between the plant area, on modeling of characteristics of each plants and productivity of window processing and so on. As the results by this situation, it is difficult that the clarification of the boundary of production system and physical distribution system, these systems are expanded to the logistics system. In this paper, the trend of such logistics system and the simulation for the evaluation of the system is explained. In addition, human and machine linkage modeling method is mentioned. Finally, as a case of the linkage simulation of this human-mechanical system, shown timber handling and carrying system in a port and snow removing work system in the city road are shown.

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Traffic safety is a very important society problem. In order to solve this problem, we can investigate the traffic accident from three sides of the car, the traffic environment and human. This paper addresses a new study approach of traffic safety from the viewpoint of man-machine system. The investigation of the human mechanism on visual and auditory interactive information processing is very important for safe uses of multimedia machines and driver. In this study, (1) human characteristics of the audio-visual information processing are investigated by functional magnetic resonance imaging (fMRI), (2) a virtual driver system and (3) a portable eyesight test system are proposed.

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In a field of railroad operation, various kinds of checking and nondestructive testing are executed periodically in order to maintain thorough safety. In this report recent techniques are reviewed for important three parts such as axle, wheel, and rail. Then, three new techniques developed by us are introduced. The first is ultrasonic nondestructive technique using SH-waves to evaluate fretting fatigue cracks on axle of Shinkansen vehicle. Second is acoustoelasticity measurement of residual stresses in wheel rim, and the third is nondestructive measurement of axial stress in long rail.

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Conventional control algorithms for ABS (Anti-lock Braking System) uses the slip ratio calculated from the difference of vehicle speed and wheel speed for control of the braking force between road surface and tires. However, measuring vehicle speed used for calculation of the slip ratio is difficult. Recently, research on the "Smart Tire" which measures forces between road surface and tires on real time is actively conducted. In this paper, the ABS control that measures the forces acting between road surface and tires without necessity of the slip ratio is analyzed by computer simulation.

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This study deals with construction of estimation algorithm for road conditions in order to predict tire-road friction ahead. Road condition sensing system consists of alebeo value, road image processing and laser rader units. Firstly, field test drives have been carried out to verify the performance of these sensors. From the result, these sensors could decide the difference of the road condition. If the road condition is complication, it is difficult to distinguish by one sensor. Next, in order to deal with these measurement results comprehensively, this estimation algorithm was constructed using a learning system with these values. Finally, it is found possibility that the proposed algorithm could estimate the difference of the road conditions efficiently.

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In the present study, following efforts have been made, relating to the unsteady straight running stability of a passenger car. To build a model, on-road vehicle experiment is performed and the straight running stability of a vehicle is verified. Also, to investigate a driving index, sensory test and evaluations of heart rate variability by a driver are performed. To investigate the relationships between vehicle dynamics and tire characteristics, a model for the straight running stability has been built. A 3-degree-of-freedom vehicle model together with a general drivers model are utilized for the analysis. Next, the proposed human-vehicle-model is investigated and the index to quantify straight running stability is determined. Also, by identifying the tire characteristics that improves straight running stability, the effectiveness of the proposed human-vehicle-model is demonstrated. Lastly, tire test is performed against the same operational conditions used for the on-road vehicle test, to verify the validity of the developed human-vehicle-model.

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This study deals with development of a traffic simulator as an evaluation tool for traffic flow. In the simulator, dynamic behavior of vehicles, control algorithm of drivers, and traffic environment are described in order to analyze the effects of the ITS and exhaust emission, and so on. In this study, it is shown that a fundamental design for a flow-chart of total traffic simulator especially for the calculation algorithm. And, longitudinal and lateral behavior of the vehicles including driver's control behavior is calculated as an example of the simulator output. Finally, it is found that the models are described real traffic condition qualitatively.

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In age of 6 degree-of-freedom parallel link mechanism driving simulator, conventional algorithm for simulating acceleration is used to separates total physical sense acceleration into transitional acceleration and continuous acceleration and reproduce them simultaneously. But this algorithm cannot avoid the error between target acceleration and simulating acceleration. In this paper, the new algorithm of simulating acceleration for the purpose of improvement acceleration simulation in the driving simulator is proposed. Acceleration simulation created from the new algorithm of acceleration simulation is examined which used at driver's head. The new algorithm for acceleration simulation uses angle-of-inclination in order to compensate the error between target acceleration and transitional acceleration when longitudinal acceleration is reproduced.

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This paper proposes a simple system to assist a driver in parking manoeuvre. The system consists of an obstacle sensor, a resisitance controller of steering wheel and a computer system. The obstacle sensor uses the light section method with a CCD camera and a laser scanner. The on-board-computer calculates optimum steering angles and control signals for the controller. The controller makes some resistnace force if the driver rotates the wheel not to the desired direction. This paper presents the composition of the system and and some experimental results of the sensor.

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This paper presents road tests of electromagnetic damper for automobiles. The authors propose electromagnetic damper system for automobiles for improved ride comfort and compatibility between stability and isolation. The electromagnetic damper (EMD) uses DC motor as generator, so it can electronically control damping force. Former trial EMD had linear characteristics of damping force, but the authors developed power electronics circuit for EMD to have nonlinear damping force, and proved that the EMD system has suitable ability for automobile damper from experiments using new damper system. This time, we equipped electromagnetic dampers with an automobile, and did the road tests to make sure of its nonlinearization of damping force.

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Large vehicles such as trucks and buses are known to have high and varying center-of-gravity heights. This fact causes large vehicles to have pronounced roll motions, which consequently affect the planar motions and stability of the vehicles, especially at high speeds. In this paper, lane-change experiments are conducted using a vehicle with and without a load to consider the effects of the varying c. g. height and vehicle velocity on the dynamic characteristics of a truck. Results are analyzed to determine how the velocity and amount of the load affect the peak values of the steering input and vehicle output and the output's delay with respect to the input.

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In this study, we deal with the autonomous run by the integrated control of a bicycle. Integrated control means the control by the steering angle, the movement of the rider and the driving forces. It is considered that the effect of the driving force control is big especially under low speed operation. Our final goal is to evaluate the stability and controllability of the various types of bicycles, with the feedback gains under autonomous run. In this report, as the first step, the experiments results of autonomous run only by the steering angle control are shown. The autonomous runs of about 9 seconds were achieved.

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We study about the autonomous run by the integrated control of a bicycle. Integrated control means the control by the steering angle, the movement of the rider and the driving forces. To decide the control algorithm, the information how a rider controls such control variable are very important. In this report, developed measurement equipment of control variables of various bicycles and the results obtained by this equipment are shown.

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This paper presents the study on the stability of compact bicycle. Recently the bicycles become being focused on transportation tool to solve environmental problem and traffic congestions in cities. In particularly the role of compact bicycles and folding bikes becomes important so that inter modal connection between bicycles and other public transportations for convenient and flexible traffic. However the compact bicycles are less stable than normal bicycles. In this study, the equations of motion of bicycle are led from Newton-Euler law and bicycle dynamics has been simulated using obtained equations

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This study analyzes how structural flexibility affects the motorcycle weave mode using the energy flow method. As a result of examining the change of the effect mechanism by vehicle velocity, the effect mechanism is changed when the term that depends on vehicle velocity like gyroscopic torque affects the weave mode stability. On the other hand, the effect mechanism is not changed when the term that does not depend on vehicle velocity like the tire camber angle affects the stability.

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In this study, we construct autonomous two wheeled vehicle (the Rider Robot) which uses for evaluation of two wheeled vehicle dynamics. The Rider Robot consists of electromechanical device and is operated by the control algorithm without a human rider. We consider the control algorithm which is separated into two parts, directional and standing control. The algorithm of standing stability is constructed for the model using the data based on maneuver of the rider using multiple regression analysis. The desired roll angle is adopted for the directional control by using of image processing and second order prediction model.

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In order to improve the characteristics of guidance for Maglev vehicles, an electromagnetic guidance control system is proposed, to add a current 90 degrees different in phase to the propulsion system. It enables Maglev vehicles to run at higher stability of guidance. We calculated the properties of Maglev vehicle dynamics in the levitated and wheel-supported running modes and found some advantages in the new guidance control system.

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Magnetically levitated vehicle, so-called Maglev vehicle, is noticed as the next generation high-speed public transportation system. For the practical use, it is important to improve the ride comfort at high-speed operation. Maglev vehicle is composed of lightweight car bodies and bogies mounted on super-conducting magnets (abbreviated as SCMs) and on-board refrigerating systems. It is rather difficult to design the secondary suspension as a vibration isolation system between the car body and bogie, because the ratio of sprung to un-sprung mass is small and the damping between SCMs and ground coils is very small. In this paper, the modal analysis by using the vehicle model, and the theoretical analysis of the vibration characteristic of the car body and bogie are inspected. Position of damper that is suitable for vibration mode, is evaluated in order to reduce the vibration. Moreover, the vibration control system for the ride comfort improvement is examined and effectiveness is confirmed.

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In this study, the influence of the undersurface flow of a high speed move object on dynamics are studied. The concrete problems concerning this study are anticipated unstable vibration caused by undersurface flow of a racing car and a high speed surface transportation vehicle with the speed improvement. The opened literature though that they imagined that the concrete examination has been made on the racing car in the manufacturer, that it is very few. In this report, we simplified the problem as much as possible, and the relation between flow and dynamics are examined. Flow around wedged shape move object are calculated with CFD and these results are introduced to dynamic simulation program. Some simulation results are shown.

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Airships are expected to provide new business because of small influence upon the environment and are basically stable in their motion. Pitching oscillation motion with a long period is however easily induced on airships and it is hard to be reduced when their motion is in acceleration by thruster. Such motion is undesirable when airships are used for transporting passengers, and used as the platform for observing low atmosphere and the Earth surface. The pitching motion of airships in acceleration is studied and the problem is formulated mathematically yielding a numerical simulator to study the control problems concerning to the pitching motion of airships.

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The container crane received large damage in the 1995 Hyogoken-Nanbu earthquake. In order to confirm the behavior of the container crane, the shaking table tests were carried out by using 1/15 scale model. Two kinds of states of the crane were examined. One was the state of the boom down (working) and another one was the state of the boom up (resting). The rocking with uplifting of legs of container cranes was observed in the state of the boom down, and was not in the state of boom up. Therefore, the bending moment at the damaged member in the state of the boom down was 1.25 times the bending moment in the state of the boom up. The numerical analysis simulation result showed the experiment result and a good agreement including the residual stress.

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This paper is describes the anti-skew control system suitable for container crane used in container yards. We developed the new type anti-skew control system performed to damp oscillatory skew movements automatically for improvement of the container handling efficiency. This system controls the skew cylinder device as the skew vibration detected by the sway sensor. The result shows the anti-skew control system performs well in container handling operation.

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Outdoor elevator ropes are excited forcibly by wind forces. And for reducing the rope vibration, a vibration suppressor is used. Finite difference analyses of the rope vibration are performed, by considering the vibration suppressor and the tension distribution of the rope. Interaction load of vibration suppressor is demonstrated through the numerical calculation. For verification, experiments are performed. Calculated results are in good agreement with experimental ones.

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Some experimental and theoretical investigations were carried out to stabilize the dynamic motions of a vehicle with independent rotating wheels by control of steering on wheels. Scale model (about 1/8) of independently rotating 4 wheels truck with drive motors was made. The wheels steering angle was controlled by actuator using a microcomputer with the information of lateral displacement of the truck. Equations of motion were derived and simulation was performed. In the experiment, the responsibility of the actuator was improved by changing the presetting the actuator. As the results, stabilizing control at the 4 times running speed became possible. In the theory, motion equations in expanding the control algorithm of steering angle were derived. And, some simulations results were shown with the considerations of influence of control parameters.

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This paper deals with curve negotiation of a rail vehicle with independently rotating wheels (IRW). In order to reduce the wheel lateral force, addition of two kinds of steering mechanism, forced and active ones, are examined by numerical simulation. As a result, it is shown that the active steering has a potential to improve the curving performance of a vehicle with IRW in anycurve radius. The forced steering, however, increases the wheel lateral force in tight curves of radius less equal 100 m and it can make the critical speed lower greatly.

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It requires calculating the contact point between wheel and rail to analyze the behavior of railway vehicle. However the definitive method of a contact point suitable for practical use has not been established completely, because the forms of wheel and rail are complicated. This paper shows the concrete solving method for the contact point between the arbitrary form of wheel tread and of rail top, based on the theory of kinematics. Furthermore, the solving method for the contact information on the two-point contact that takes place under the particular combination of wheel and rail is also shown. This method is a useful for calculating the position of contact point.

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Two types bolsterless articulated trucks (2 air springs type and 4 air springs type) were developed for AC Train. This paper deal with outline of these articulated trucks and running tests. The experimental results show that good running safety of the articulated trucks was obtained and 4 air springs type was effective to wheel unloading on running a transition curve.

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Increased deceleration in high-speed and high-density train operation worsens riding comfort and frequently causes wheel skids. This requires introduction of control engeneering to upgrade control performance of the brake system on rolling stock. We are now studying a control method for mechanical brake that uses friction, a sort of nonlinear element as the basis of brake force. One of our targets is to develop a brake control device that can control deceleration or jerk and decelerating pattern to optimize riding comfort and prevents wheel skids. We are designing a deceleration feedback control system as a tracking control method. This paper introduces simulation and experimental results of this control system.

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