多連クロソイド曲線を用いた曲率変化の滑らかな走行路緩和曲線の提案

（第２報：交差点旋回への適用）

抄録

This paper presents theoretical research on an optimum transition curve with a smoothly changing curvature using a multiple clothoid curve for improving the occupant ride comfort of automobiles when vehicles turn at an intersection. In the first report, three dimensional vehicle occupant model which was 21 degrees of freedom was developed, and the multiple clothoid curve was proposed as a new transition curve. In this paper, application of a newly-developed multiple clothoid curve for the vehicle turning at a traffic intersection is presented. The turning of vehicles at a traffic intersection consists of a series of movements from inlet to outlet in the combination of a straight line and an arc of circle. The curvature becomes discontinuous at the connecting point of a straight line and a circular arc or a circular arc and a circular arc in a traveling path. 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. Therefore, the smoothly changed curvature of a multiple clothoid curve is applied as a transition curve at a connecting point. With sorts of running tracks in a traffic intersection which consists of various combination of a straight line and a circular arc, the validity of application of a multiple clothoid curve as a transition curve at connecting points is examined. In order to solve these problems, the three dimensional vehicle occupant model is applied and the validity of the multiple clothoid curve is quantitatively demonstrated as compared with the case where connecting points are not interpolated. It was found that the effect of the multiple clothoid curve on the vehicle movement and a ride comfort is superior to those of the non-interpolation. Some results are presented in the form of parametric plots.