A new steering system which has variable gear ratio according to vehicle speed and steering wheel angle has been developed with the aim of ideal steering. As the steering gear ratio in existing vehicles is almost constant, the yaw rate gain increases with increasing vehicle speed. Moreover, for under-steer vehicle, the yaw rate gain tends to decrease with increasing lateral acceleration. With a view to making driver-vehicle response improvement, a steering system which the equivalent steering gear ratio increases with increasing vehicle speed and decreases with steering wheel angle has been created with simple mechanism. This paper presents the procedure for selecting variable gear ratio characteristic from hypothesis of ideal gear ratio which was derived from observation of driver's steering behavior to the compensation of the gear ratio for vehicle speed and steering wheel angle, and the estimation of the effects of the gear ratio by simulation. And this also introduces the construction in order to realize the selected gear ratio, the effects that were confirmed by vehicle test, and the results that were confirmed if the vehicle with VGS was easy to drive for many ordinary drivers.

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Intermodal transport centered on rail travel is one of the vital mechanisms to sustain mobility in the 21st century, from the viewpoint of global warming and dwindling energy supplies. At the same time, intermodality has inherited defects originated from interchanging nodes, where different modes of transport meet and therefore physical and psychological barriers exist. One of the reasons of these flaws comes from the old business model, which is being used in the public transport. In the CyberRail concept, the mass production system of the public transport will be re-engineered into a customized travel responding to each passenger's demand, as well as improving efficiency of the rail operators.

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This paper descrives elevator technologies, past and future, especially future trends using IT technologies. Key words in an IT Revolution Era would be Networking, Application of pictures and ASP(Application Service Provider).

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In the severe competition with other transit systems speed-up on railway has been carried out to shorten the journey time of trains. In case of conventional narrow gauge lines, the speed-up on curved tracks is effective since there are many small radius curves. On the other hand, wheel lateral forces acting towards the outer rail increase with the speed-up, and it causes the concern on the wear of rail side and wheel flange and still more that on the destruction of track. Therefore various kinds of steering truck have been developed for reducing the wheel lateral force, and many research works have been reported from the viewpoint of trade-off between curving performance and running stability. In the paper, some interesting matters on steering trucks are presented, which have been obtained in the simulation study by authors until now. They are related to the performance of a forced steering truck, an active steering one and a self-steering one and the effects of gauge widening on them, and future possibility of steering truck is discussed.

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First this paper reviews evolution of automotive safety technology since 1960's when the US government compiled the Federal Motor Vehicle Safety Standards and advocated worldwide research on automotive safety called Experimental Safety Vehicle Project. Then after discussing real world effectiveness of safety measures developed and problems remain unsolved along with risks emerging from the recent traffic environment, it is concluded that, in the 21st century instead of crash safety, preventive safety should be emphasized in order to cope with both traffic safety and global environmental protection.

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The Advanced Cruise-Assist Highway System (AHS) functions to improve the safety of road traffic by using road infrastructure sensors to detect various dangerous conditions that drivers and vehicle-side sensors cannot detect on their own, and using communications technology to provide that information to the drivers. Research and development for practical application of AHS has proceeded according to the Smart Cruise Systems Infrastructure Requirements (Primary), formulated in October 1999. These proving tests of the element technologies and systems that had been the subject of research and development have finally brought this program to the point of embarking on the process of practical application.

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In order to carry out manufacturing activities more safely, it is necessary to acquire the safety information at the manufacturing design stage. However, it is very difficult to acquire the safety information considering the industrial accident cases relevant to the assembling work on the factory. Therefore, in this paper, the authors develop the framework of safety information management system to assess the risk based on simulation. In this system, the industrial accident cases are represented as the information network model, and integrated with the virtual assembling simulation. This system can show a designer the work direction documents to reflect the safety information on assembling process, and also make the assembling design safer.

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This paper reviews major environmental problems caused by transport systems and proposes the measures to be taken towards more environmentally harmonized transport systems. Among various modes of transport, motor vehicles are most widespread, hence often causes considerable impacts on the environment. In addition to unsolved, traditional "pollution" problems, global environmental issues such as the climate change issue by CO_2 attract increasing attention. In order to comprehend environmental impacts of transport systems, Life-Cycle Assessment (LCA) is useful. Discussion towards "sustainable transport systems" which covers not only an environmental aspect but also economic, social and institutional aspects should be activated, reflecting long term perspective of rapidly changing our society.

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This paper describes a brief view of amusement rides and jet coaster, in view of technical designing. The first section relates to a classification of amusement rides(incl. pictures), main design rules(governmental) and introducing an example on dynamic analysis. The second section describes general considerations on technical items of jet coaster, such as velocity calculation, accereration, relaxation curve, banking angle, wheels, suspension etc.

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I introduce topics related to the investigation of railway accidents and some examples of accidents which happened after the serious accident in Hibiya line of Teito Rapid Transit on March of 2000. In the first part I describe the countermeasures and activities after the Hibiya accident and the "Aircraft & Railway Accident Investigation Commission", that was organized officially from this October. In the main part I introduce several examples of railway accidents during this one-year, such as train head-on collisions in Keifuku Electric Railway, and try to consider the causes and backgrounds of the accidents from the point of view of safety engineering. Especially redundancy and fail-safe of brake system are considered.

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This paper describes why and how the concept of adaptive automation was invented, starting with static function allocation, followed by dynamic function allocation. Levels of automation concept is utilized in explaining what kind of cooperation may be possible between human and automation in information acquisition, information analysis, decision and action selection, and action implementation. Sharing and trading are distinguished explicitly to clarify the style of human-automation cooperation. Algorithms for implementing adaptive automation are categorized into three groups, and comparisons are made among them. Decision authority and trust-related issues are also discussed. Benefits and costs of adaptive automation are described for better understanding and for future research activities.

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The objective of the paper is to seek the significant factors which are anticipated to contribute for the enhancement of the aviation safety of 21^<st> century by reviewing the aircraft accident experiences of 20^<th> century. The paper consists of the following three parts: ○ Examination of statistics of world aviation accident and accident causes. ○ Effect of improvement of survivability factors in aircraft accident. ○ Comparative case studies on the effect of countermeasures after the fatal accident.

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The estimation of ride comfort characteristics of automobile by driving simulator with motion device is proposed in this paper. Making use of the driving simulator with multibody automobile model that has already been developed by the authors, the influence of the specifications of suspension on ride comfort characteristics can be investigated in detail. By the experiments with driving simulator, it was shown that developed driving simulator can realize the vibration of automobiles to the extents of the frequency of 3-Hertz, and that the vibration characteristics of driving simulator varies by changing the specifications of vehicle model.

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This paper discusses a material handling system which we call shortcut circulation type vehicle routing system (denoted SCVRS), and evaluates its performances by simulation. This paper also considers a vehicle scheduling problem for the SCVRS.

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Two-lane traffic model equivalent to extended Burgers cellular automaton (EBCA1) model is studied. The flow and configuration of vehicles on two lanes are investigated and three kinds of metastable local congested states are found on the density-flow diagram. (1) The first is the stable 8tate in time where vehicles advance by stop-and-go on their own lanes without lane change. (2) The second is that where they advance changing lanes periodically. (3) The third is that where they advance changing the lane, which induces fluctuation of the flow with extremely long period. The metastable flows may correspond to the synchronized states observed in the traffic flow on expressway.

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Several methods are proposed for investigating the complex traffic flow. However, the dynamics of vehicle and the driver's characteristic, which are important factor for the traffic flow analysis, are not considered enough so far. This paper describes a new concept for simulating complex traffic flow by multiple agents. The agents are considered as a kind of artificial life (A-Life) and they behave based on their own knowledge independently. Drivers, vehicles, roads and traffic environment, which are essentialelements in our simulation, are defined as the agents. The vehicle agent combined with a driver agent works based on driver's region of sight and their own charactereristics. The road agent communicates with the vehicle agent responding velocity, position of the vehicle. The effectiveness of our new method for modeling the traffic flow is shown by simulation study.

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In recent years several studies have reported the multiagent based simulatior(MAS) concerning to complex traffic flow and have proved its effectiveness. However, when MAS applies to a large scale simulation, the calculation size has became larger than processing ability of one computer. Therefore, the necessity becomes apparent the parallel and distributed processing on multi-processors. This study proposes a new parallel and distributed computing environment suitable for multiagent based large scale simulations by network-agent. The network-agent migrates or is propagated on the global computer network for dynamic construction of parallel and distributed computing environment and dynamic load balancing, depending on the situation. This system is independent of the platform and works on the various computers connected to the Internet such as ordinary PC and workstations not only exclusive parallel computer just like the PC-cluster.

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The elevator dynamic simulator has been developed to evaluate the emergent behavior. The model is derived with the multi-body system, especially the rope model is introduced by the separated mass-spring model. Estimation of the elevator emergent behavior is very difficult for a numerical analysis, because it contains the highly non-linear conditions. The proposed simulator can easily solve the buffer contact problem, rope slip and high mode rope vibration. The simulator shows reasonable results compared with the experiment. In this paper, the simulation model is explained in details, and several simulation results are shown related to the buffer strike behavior. And also an ideas for the elevator structural design is proposed with the structural optimization.

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This paper is concerned with the running stability of tractor-semitrailer combination at braking. Firstly, we construct nonlinear equations of motion for the articulated vehicles, which have 9 degrees of freedom. Secondly, simulation study is carried out to show the vehicle performance in realistic situation. Jack-knifing on the straight road section was recreated by the simulation in consideration of road gradient not only longitudinal direction but also lateral direction. By using the concept of load rate of each tire, we confirmed that the model shows the mechanism of the jack-knifing on straight road section, and the motion of limit performance conditions. Finally, the relationship between limit performance, road gradient condition, and vehicle parameters is shown. These results emphasize the importance of observation of the tire load rate. Especially, rear axle of tractor should be considered when we discuss the limit performance of jack-knifing.

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This paper deals with improving the ride comfort of heavy-duty tractor semi-trailer. It is constructed that a half truck model of 12 degrees freedom included driver human body-seat model. The influence is discussed which of the parameters of seat cushion and seat suspension on the ride comfort of truck. It is done that the simulation of road random response with seat semi-active suspension damping control. It shows that the ride comfort of tractor semi-trailer is improved with damping control seat semi-active suspension.

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This paper descirbes the stability performance of articulated-vehicles by considering the effect of fifth wheel's rigs wear which is king-pin and jaw of plates. This wear makes gap between king-pin and jaw. add up to be transfer lag of force. It has influence on vehicle stability. By an analysis of a driver-vehicle system with 4 DOF vehicle dynamic model and multi-body dynamics modeler, DADS, is used to build the dynamic model of articulated-vehicles by considering the effect of fifth wheel coupling. The target articulated-vehicle consists of tractor-frame, leaf-suspension, steering-system, axle, coupler, cabin, trailer-frame, axle, cargo, and running wheel. 84rigid bodies including sprung mass are used for the vehicle modelling.

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In this study, we constructed autonomous two wheeled vehicle (the Rider Robot) which use for evaluation of two wheeled vehicle dynamics. The Rider Robot consist electromechanical device and operate by the control algorithm without the need for a human rider. We consider the control algorithm was separated directory and standing control. The model of standing control was constructed for the model using the data based on maneuver of the rider using multiple regression analysis. And direction control was giving the purpose of dynamic roll angle, which from purpose turning radius that acquired the difference between image analysis and second order prediction model.

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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 stability of compact bicycle especially the effect of wheelbase and small tire on the stability has been examined experimentally.

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This paper aims to design guidance and control laws that are derived from a minimum fuel-consumption problem and has robustness against various disturbances such as dispersion of initial condition and thruster failure. The nonlinear robust control system is proposed to track the reference profiles, which are expressed by exponential functions. An adjustment law in the tracking controller is given in the form of the differential equations in tetms of the contoller's variable gains. Computer simulations are performed to verify the tracking accuracy, the robustness in a thrust failure mode, and the achievement of vertical/soft landing at a pre-assigned point on the lunar surface. The results of numerical simulation show the effectiveness of the proposed control law.

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This paper investigates the use of four-wheel-steering system for the control of vehicle, in the context of automatic lane-tracking. Four-wheel-steering system provides two independent control inputs which can much enhance handling and stability, thus it is expected that such system can also provide satisfactory lane-tracking performance. In this paper, the lane-tracking control system is designed on the basis of the four-wheel-steering automobile whose desired steering response is realized by the application of model matching control. Two representative desired steering responses are proposed in this paper. Finally, simulations in lane-tracking and theoretical analysis are conducted to investigate the effectiveness of the proposed control system.

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Current automotive technologies for automatic driving have encountered the problems of system reliability, human factors and responsibility of accident. A fully automatic driving system, however, can be realized relatively easily as long as it is operated in the exclusive area. This study is aiming at investigating the human factors, system reliability and methodology of system management by operating a fully automatic driving system in the campus. In this paper, experimental studies are carried out for developing such a fully automatic driving system. Two control algorithms for automatic driving in local area is proposed. One is control algorithm for tracking a trajectory with small radius of curvature, and the other is that for automatic parking. Experimental results clarified that a controlled vehicle can track a trajectory with curvature of more than 0.2, and can accurately park at a parking slot with reverse movement by the proposed control algorithms.

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An acoustic tube was developed and applied using the volume velocity measurement method for the prediction of constant exterior engine noise. Using accelerometers to measure engine surface vibration is a difficult task,especially for places like the exhaust manifold. The proposed method, an acoustic tube containing a microphone is set at a given distance from the engine and measurements are made in such a way that the whole engine surface is covered. Exterior engine noise at a certain distance from the vehicle was predicted by using the measured volume velocity valuse and propagation characteristics. The predicted results agreed well with previously experimented values.

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Some theoretical investigations are carried out to stabilize the dynamic motions of a vehicle with independent rotating wheels by control of steering on wheelset. The equations of motion are derived and root locus are analyzed. It is cleared that with control of steering, stabilization of vehicle is capable and the influence of the feedback coefficient on the characteristics of stabilization.

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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 root locus was analyzed. With both experiments and theoretical investigation, it was made clear that the stabilization of a truck with independently rotating wheels is feasible by this method.

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In the previous report, the effectiveness of an active suspension added with centering control was confirmed by numerical simulation and experiment. However, the examination did not consider the effects of the car body tilting which is necessary to negotiate curved tracks at high-speeds. Thus, this paper deals with the cooperation of centering and vibration controls under the actual conditions in a tilting vehicle. As a result, it is shown that the cooperative work of two controls is possible using accelerations observed on the floor of the car body with tilt mechanism.

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This paper presents running performance of the vehicles with the single axle truck. Recently, the use of the single axle truck is increasing for the new generation of rail vehicles. In this study theoretical analysis for dynamic stability and curving performance of the single axle truck were made. The asymmetric structure fore-and-aft was proposed to achieve the compatibility between stability and curving performance. Using equivalent stiffness model the condition to satisfy the perfect steering in which the attack angle of the wheelset is zero in curving is obtained. The optimal design for compatibility between stability and curving performance was shown. The numerical simulations and eigen value analysis with multibody dynamics software were made and the improved performance of the proposed vehicle was proved. Moreover, it was found that the single axle truck with air suspension has a superior performance at the transition curve.

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According to the marked decrease of the three-axle truck for locomotives, the need for diminution of the slack in gauge has been pointed out by rail maintenance division. About this problem, the curving performance under the presence of gauge widening has been investigated with the consideration of truck mechanism and wheel shape. In this study, the modification of wheel tread shape treated in the 3rd report is reconsidered by using an inclination diagram of wheel tread and rail head. Simulation results show that the tread shape obtained by above diagram can get further availability of gauge widening. Further, it is shown that the effectiveness of gauge widening can be obtained also in a vehicle assumed to negotiate very tight curves at low-speeds.

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To keep safety to running on curve, it's very important to reduce wheel load variations of rolling stock on the track cant run-off section. In this study, the cant run-off section is laid on straight track in the yard. On the section, the wheel load variations are measured with various conditions of air spring control system at low speed of the actual vehicle. The results of the test, maximum wheel load variation rate at low speed is decreased very much by improvement of the air spring characteristics, the leveling valve characteristics and differential pressure valve characteristics. Concerning the test results, we suggested better characteristics of the air-spring control system.

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