This paper describes the construction of a driver model of a powered wheelchair operation for the understanding of the characteristics of the driver. The main targets of existing researches about driver models are the operation of the automobiles and motorcycles, not a low-speed vehicle such as powered wheelchairs. Therefore, we started by verifying the possibility of modeling the turning operation at a corner of a corridor. At first, we conducted an experiment on a daily powered wheelchair user by using his vehicle. High reproducibility of driving and the driving characteristics for the construction of a driver model were both confirmed from the result of the experiment. Next, experiments with driving simulators were conducted for the collection of quantitative driving data. The parameters of the proposed driver model were identified from experimental results. From the simulations with the proposed driver model and identified parameters, the characteristics of the proposed driver model were analyzed.

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The air spring of bolsterless bogie trucks, which have been widely employed in railway vehicles in recent years, undergoes a large distortion when the vehicles negotiate sharp curves in lines such as subway lines, and this can deteriorate the durability of air springs. Furthermore, bolsterless trucks tend to suffer from increased wheel lateral force around sharp curves with a radius of 100 m or less. In this paper we discuss the application of a link-type forced steering mechanism to bogie trucks with a bolster as a countermeasure against the above-mentioned situation. A numerical simulation is carried out using a MBS software, SIMPACK. As a result, under the condition of reduced longitudinal stiffness in the primary suspension, a bolster truck with the link-type steering mechanism exhibits the potential to suppress the wheel lateral force occurring around sharp curves. Also, the deterioration in running stability due to the application of the steering mechanism can be recovered by adding moderate lateral damping in the secondary suspension. In addition, the obtained wear index shows that the forced steering truck has decreased flange wear resulting from passing through sharp curves.

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Sensory evaluation of ride on a railway vehicle is performed based on international standards such as ISO2631. However, it is expected that this evaluation would be insufficient because of the development of technologies of a railway vehicle. The evaluation for view and sound from the viewpoint of ergonomic and psychological perspectives might be needed as well as traditional evaluations in the future. Authors focused on the relation between view and motion of the railway vehicle. The experiment in sensory evaluation of ride on a railway vehicle using a motion simulator was performed. In this paper, the way and results of the experiment and the environmental psychological analysis are described.

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This study was an attempt to obtain optimal landing approaches for helicopters to reduce ground noise impact. Simulations and real flight tests in our previous study confirmed that flights along pre-calculated optimal trajectories resulted in lower noise levels than flights along conventional approach paths. However, some experiments did not show the expected optimization effects because of unforeseen disturbances. This paper therefore improves the algorithms in order to realize practical real-time optimization, which can involve external disturbances. To validate the effect of the new method, various computer simulations were conducted under real flight experimental scenarios. The obtained optimal solutions were characterized by steep flight path angles, which can avoid the generation of loud noise, the avoidance of noise sensitive points, and short flight times. These are different from conventional landing approaches. The optimal trajectories resulted in noise reduction on the ground, which shows the effectiveness and potential of the proposed real-time trajectory optimization method.

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The application of carbody tilting technology is the most efficient way to raise train speed during curve negotiations. This paper mainly deals with the dynamic performance simulation of the tilting train. Through the establishment of the nonlinear mathematical model for the titling train electromechanical coupled system, the carbody tilting control law, bogie radial steering mechanism, and titling train curving performance are investigated. The effect of time delay caused by the sensing and control system on the tilting performance of the train is analyzed, and the compensation methods for the time delay effect are studied.

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This paper is concerned with the effects of the axle misalignment of a truck with independently rotating wheels (IRWs) on the wheel lateral force and flange wear. Since a truck with IRWs lacks self-steering ability, it is of concern that the wheel flange remains in contact with the rail owing to the effect of axle misalignment in parallelity, resulting in rapid wear of the flange upon continuous contact with the rail. Numerical simulations are carried out using an analytical vehicle model with axle misalignment. The obtained results are as follows. Even if misalignment is small, a vehicle with IRWs tends to run under the flange contact condition, and thus a continuous lateral force acts between the flange and rail. A vehicle with IRWs that has axle misalignment only in the lateral direction does not tend to run with continuous flange contact. In the range of misalignment in parallelity considered in this paper, the wheel lateral force increases with increasing misalignment, and the wheel lateral force acting on the IRWs increases more rapidly than that acting on the solid wheelset. The wheel lateral force generated by misalignment is equivalent to that generated during the negotiation of a curved track with a certain radius, which causes the attack angle to correspond to the angle of misalignment.

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