双车道公路弯道半径及回旋线长度对转向行为的影响

为研究驾驶员在双车道公路回旋线路段转向行为的影响因素，采用驾驶模拟实验收集15 名驾驶员在72个不同半径、不同转向和不同回旋线长度的弯道上的方向盘转角信号。运用小波变换将方向盘转角信号的空间序列进行分解，研究自然转向行为和轨迹修正行为依半径和回旋线长度的变化规律。结果表明：车辆入弯时的自然转向行程和曲线半径、回旋线长度均显著相关，但与弯道转向无关；入弯时，驾驶员对路线半径变化率的敏感度随着曲线半径的增大而减小。对于轨迹修正行为，在半径一定的条件下方向盘的平均摆幅随回旋线长度的增加而减小，但方向盘回转速率会随着回旋线长度增加而增加；出弯时方向盘的平均摆幅和回转速率整体较入弯时高。当回旋线长度与自然转向行程接近时，方向盘平均摆幅和回转速率均处于较低水平，故以自然转向行程为理想回旋线长度是合理的。

Impact of Curve Radius and Spiral Length on Steering Behavior on Two-lane Highway

To identify the factors that are closely related to driver's steering behavior on the spiral segment of a twolane highway, this study performed driving simulation experiments and collected steering wheel angle data from 15 drivers on 72 curves with different curve radius, turning direction, and spiral length. The Wavelet transform was used to decompose the spatial sequence of steering wheel angle signal. Then a co-relation analysis was conducted to examine the variation of natural steering behavior and trajectory correction behavior under different curve radius and spiral length conditions. The results show that natural steering distance at entrance spiral is significantly affected by curve radius and spiral length, but the natural steering distance is not affected by the turning direction. At entrance spiral, drivers are less sensitive to the route radius change when the curve radius increases. For the trajectory correction behavior, the average swing amplitude of steering wheel decreases with longer spiral length when radius is fixed. However, the rotation rate of steering wheel for correction appear to increase with longer spiral length. The average swing amplitude and rotation rate of steering wheel for correction at exit spiral are higher than those at entrance spiral. When the length of spiral is close to the natural steering distance, the average swing amplitude of steering wheel and the rotation rate are both at low levels. Therefore, it is reasonable to take the natural steering distance as the ideal spiral length.