Hoffmann E R, Mortimer R G
Department of Mechanical and Manufacturing Engineering, University of Melbourne, Parkville, Victoria, Australia.
Accid Anal Prev. 1996 Jul;28(4):415-21. doi: 10.1016/0001-4575(96)00005-x.
Data are presented on the ability of drivers to perceive and scale the relative velocity between their own and a lead vehicle. Experiments were carried out on four groups of subjects using Ekman's ratio-rating method. Only when the subtended angular velocity of the lead vehicle exceeded about 0.003 rad/s were the subjects able to scale the relative velocity. The threshold subtended angular velocity obtained in the experiments was very much affected by the ability of subjects to use the concept of a ratio-engineering students found this a simpler task than did subjects from the general population. The result of this was that the values used by engineering students were closer to the real values. The relative velocity was perceived non-linearly, with a Stevens' power law exponent of about 0.8. It was found that linear models gave as good a fit to the data. The implications of the results of the experiments are (i) traffic flow models that include human visual characteristics must consider the "dead zones" in response produced by thresholds of subtended angle change subtended angular velocity; (ii) it may be necessary to consider the non-linear relationship between perceived relative velocity and actual relative velocity; (iii) in overtaking, the driver will not be able to scale the speed of the oncoming vehicle as the subtended angular velocity will be below the threshold value at the time of making the decision to overtake.
本文给出了关于驾驶员感知和估算自身车辆与前车之间相对速度能力的数据。使用埃克曼比率评级法对四组受试者进行了实验。只有当前车的张角角速度超过约0.003弧度/秒时，受试者才能估算相对速度。实验中获得的阈值张角角速度受受试者运用比率概念能力的影响很大——工科学生发现这一任务比普通人群中的受试者更简单。结果是，工科学生使用的值更接近真实值。相对速度的感知是非线性的，史蒂文斯幂律指数约为0.8。研究发现线性模型对数据的拟合效果也很好。实验结果的影响在于：（i）包含人类视觉特征的交通流模型必须考虑由张角变化阈值（张角角速度）产生的响应中的“盲区”；（ii）可能有必要考虑感知到的相对速度与实际相对速度之间的非线性关系；（iii）在超车时，驾驶员无法估算迎面驶来车辆的速度，因为在做出超车决定时张角角速度将低于阈值。
