脚部受振疲劳对驾驶人制动反应时间的影响
Influence of feet vibration fatigue on driver braking reaction time

为研究机动车驾驶人在振动环境中脚部振动疲劳对行车制动反应时间的影响，选择12名身心健康的受试志愿者进行试验。受试志愿者在性别、年龄、体重、职业等方面有一定的代表性，符合中国驾驶人的基本情况。首先在电磁振动台上安装空气座椅及制动踏板模拟真实的驾驶环境，利用［0,1］区间估量法对驾驶人脚部振动响应进行评价；然后利用VBOX数据采集系统，依次测量得到12名受试志愿者脚部承受标准激励（频率8 Hz，幅值6.45 m/s2）约2 min振动前后的制动反应时间。试验结果表明:12名受试志愿者坐姿的脚部振动疲劳降低工效界限对应的振动加速度均值为6.45 m/s2；经历2 min脚部振动疲劳后，受试志愿者制动反应时间平均延长0.33 s，且制动过程中出现滞速现象明显增多，主观感受脚部发麻，动作迟钝，表明脚部振动疲劳对驾驶人制动反应时间影响显著；基于国际标准ISO 2631中人体对于振动的反应与振动的能量关系和连续4 h驾驶条件，计算得到中国驾驶人坐姿脚部振动疲劳降低工效界限对应的垂直方向振动限值为0.59 m/s2，因此在确定中国驾驶人制动行为模型时应充分考虑脚部振动疲劳对其制动反应时间的影响。研究结论可为车辆驾驶室地板振动限值制定及车辆智能驾驶辅助系统研发提供参考。
In order to study the driver’s feet vibration fatigue effect on braking reaction time when the whole body exposed to vibration environment, 12 healthy trial volunteers served as the subjects. The volunteers had a certain representation in gender, age, weight, occupation, etc. They met the basic standards of domestic drivers. At first, an experiment was proceed through the ［0,1］ interval analogy evaluation method, using electromagnetic vibration exciter installed a real seat and a brake pedal to simulate the driving vibration environment. Secondly, the braking reaction time of every volunteer was experimented by the VBOX braking measurement system before and after volunteer’s foot suffered about two minutes vibration which is determined by the result of preliminary test (frequency 8 Hz, amplitude 6.45 m/s2). The results show that the corresponding average amplitude of vibrating acceleration to the efficiency boundary reduced for the feet vibration fatigue of 12 volunteers sitting is 6.45 m/s2, and the average braking feedback time of volunteers after 2 min tiredness of feet vibration for 2 minutes has been prolonged to 0.33 s. Moreover, the hysteresis speed for volunteers after the feet vibrating tiredness during braking has been increased tremendously. Volunteers felt numb and sluggish in their foot. It shows that the tiredness of feet has had an obvious impact on the time of braking for drivers. In addition, 0.59 m/s2 is calculated from the vibration limiting value of vertical direction orientation corresponding to the reduced efficiency boundary of feet vibrating tiredness for Chinese drivers under consecutive 4 h driving based on ISO 2631 the relationship between vibrating feedback and energy for body in this paper. Thus, the effects of feet vibrating tiredness on braking reaction time must be fully considered when the model of braking behavior setting for Chinese drivers are confirmed. The conclusion of this paper can provide a reference for the design of braking limiting value on the floor of vehicles and the