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With the rapidly increasing awareness on environmental issues, a competition of eco-friendly car development among vehicle manufacturers has become so intense. In fact, decent numbers of modern production vehicles which equipped with low fuel consumption means in various ways have been around in the world today. Since each vehicle manufacturer proposes brand-new vehicle systems one after another, vehicle types become significantly diversified and each one shows different characteristics indeed. On the other hand, these changes in requirements over vehicle performance bring corresponding changes in the development of tires suitable for a variety of the latest eco-vehicles. Recent tire requirements can be basically represented by compatibility between low Rolling Resistance (RR) and other performance while pursuit of RR reduction results in poor force and moment characteristics in general.

An experiment was conducted to seek the models of the human pilot controlling a vehicle with time-varying dynamics manually. In the experiment the human pilot controlled basic first-order linear time-varying controlled elements in a compensatory closed-loop fashion for step and random inputs. The analysis of the experimental data has found that for the step input case the human pilot can be modeled as a stationary proportional-plus-integral controller, whereas for the random input case a stationary model with constant coefficients cannot describe the pilot's control behavior sufficiently well. A nonstationary time series analysis suggests that the human pilot's control behavior for the random input case is also time-varying; adapting his characteristics to the changing controlled element dynamics in such a manner that the error and output spectral characteristics do not make appreciable changes with respect to time.

This paper describes the behavior of a driver side occupant restrained by airbag system on a passenger vehicle at a frontal barrier crash. In order to secure effective occupant protection at collisions, it is necessary to conduct close examination into the movement of steering system due to the rearward movement of dashboard as well as vehicle deformation characteristics, generally for vehicles whose crash space at engine compartment is small. The authors examine the influence of these two parameters on occupant injury indices using MADYMO 2D computer simulation program. As a result, it is found important to model the axial collapse and the rotation of steering system in the vertical plane caused by dashboard deformation, in order to achieve good correlations between experiment and simulation. It is demonstrated.

This paper describes the rotational behavior of the vehicle in the vertical plane at frontal collision against a flat barrier. The control of the rotational behavior is important because this often has a great influence on both passenger compartment integrity and occupant protection. The authors examine the cause of this rotational behavior of the vehicle using the numerical simulation of a full scale passenger car model with an explicit finite element method. As a result, it is found that the deformation process and the transmitted force of basic framework greatly affect to the rotational behavior. The simulation explains its difference between a typical FR (front engine &, front drive) vehicle and a FR (front engine & rear drive) vehicle. The mechanism during the rotational behavior is analyzed by means of the transmitted force to subsequent frame members. The typical comparison of the simulation and the vehicle test are also presented.

In order to secure effective occupant protection at vehicle collisions, it is necessary to conduct close examination into vehicle crash characteristics as well as interior parts, etc. This paper analyzes the behavior of a HYBRID III dummy restrained by three point seatbelt using MVMA2D computer simulation program at a 35 mph vehicle frontal barrier crash. As a result, it is found for good agreement between experiment and simulation that the exact input data of successive toeboard intrusion play an important role. As for the parametric study on vehicle crashworthiness, the authors propose the convenient method to represent the actual crash pulse by two simplified trapezoids. Then using these trapezoids, the parametric study clarifies the influence of vehicle deformation characteristics as well as the interior parts on dummy injury.