2017 年 83 巻 852 号 p. 17-00006
This paper presents theoretical research on an optimum transition curve with smoothly changing curvature using a multiple clothoid curve for improving the occupant ride comfort of automobiles. At the connecting points between an inlet straight line and a circular arc, or between a circular arc and an outlet straight line, vehicles cannot run smoothly owing to the discontinuity of curvature. Especially, the vehicles equipped with a driving support device which assists driver's steering operation or performs steering operation instead of a driver will increase both unstable movement of vehicle and discomforts of occupant. Moreover, the discontinuity of curvature in the connecting points makes the control of advanced accuracy of apparatus difficult. In order to solve such problems, three dimensional vehicle occupant model which is 21 degrees of freedom is assembled, and the multiple clothoid curve is proposed as a new transition curve. The validity of the multiple clothoid curve is shown as compared with the case where it is interpolated by a single clothoid curve or by a non-interpolation. It was found that the influence of the multiple clothoid curve on vehicle movement and ride comfort is superior to those of the single clothoid curve or the non-interpolation. Some results are presented in the form of parametric plots.
