单曲线弯道几何参数对小客车转向行为的影响

为了研究车辆在单曲线上行驶时的运动学行为和驾驶行为,在ADAMS软件环境下创建了小客车的动力学模型,进行了切弯和跟弯两种驾驶模式的单曲线行驶试验.根据仿真输出的转向盘角度变化,将转向过程划分为进弯、维持和出弯3个阶段,分别得到了车辆进弯和出弯时的转向长度和转向时间,以及这2个参量与弯道半径、转角和车辆轴距的关系.研究结果表明:当弯道转角不超过某个临界值时,转向盘转角、转向时间以及转向长度随着弯道转角的增大而增大,并且切弯时更显著;当弯道半径不超过550 m时,转向长度随弯道半径增大而增大;不同驾驶模式会导致转向长度出现显著差别,切弯时的稳定转向长度约为跟弯时的2倍;切弯模式的"稳定转向时间-弯道半径"曲线先升后降,呈抛物线形状,而采用跟弯模式时该曲线呈单调下降趋势, 2种模式的平均转向时间为3.75 s. 

Effect of Geometric Features of Simple Curves on Steering Behavior of Passenger Car

To study the kinematics characteristic and driver behaviors of vehicle driving on simple curves, a dynamic model of passenger car was built with ADAMS software to perform virtual driving tests on simple curves under the driving patterns of curve-cutting and curve-following. On the basis of the angle change of the steering wheel, a steering process was divided into three stages: entering the curve, maintaining the steering wheel, and exiting the curve. Parameters of steering behavior at the three stages were collected separately for the two driving patterns, such as steering distance and steering time when the vehicle entered or exited the simple curve, and the effects of deflection angle and vehicle wheelbase on vehicle steering behavior were analyzed. The result shows that: steering angle, steering distance, and steering time increase with the deflection angle when deflection angle is smaller than a critical value, especially for the curve-cutting pattern; steering distance of vehicle entering or departing a curve increases as the curve radius when the radius is shorter than 550 m; different driving patterns can lead to different steering distances, and the steering distance of the curve-cutting pattern is about twice as long as that of the curve-following pattern; for the curve-cutting pattern, the profile of steering time against curve radius increases first then decreases, namely, it takes on a parabolic shape, while the profile of the curve-following pattern falls in a monotone manner, and the average steering time of two patterns is approximately 3.75 s.