Reed Matthew P, Ebert Sheila M, Jones Monica L H, Hallman Jason J
University of Michigan Transportation Research Institute, Ann Arbor, Michigan.
Toyota Motor Engineering & Manufacturing North America, Inc, Erlanger, Kentucky.
Traffic Inj Prev. 2020 Oct 12;21(sup1):S7-S12. doi: 10.1080/15389588.2020.1793971. Epub 2020 Jul 21.
Recent studies have suggested that a relationship exists between crash injury risk and occupant posture, particularly in postures different from those used with anthropomorphic test devices (ATDs) in crash testing. The objective of this study was to increase scientific understanding of typical front-seat passenger postures through a naturalistic study.
Video cameras were installed in the passenger cabins of the vehicles of 75 drivers. Reflective targets were attached to the seats and the seat position and seat back angle was moved through their available ranges during instrumentation. The video data, along with vehicle acceleration and location data, were downloaded after the vehicles were operated as usual by their owners for two weeks. Video frames were manually coded to identify characteristics of front-seat passenger posture and position. Seat position and seat back angle were estimated using the calibration data obtained during vehicle instrumentation.
Video frames from a total of 2733 trips were coded for 306 unique front-seat passengers. For these trips, a total of 13638 frames were coded; each frame represents about four minutes of travel time. The head was rotated left or right in 33% of frames, and the torso was rotated left or right about 10% of the time and pitched forward in almost 10% of frames. No seat position or seat back angle change was noted in 40 (53%) of vehicles and the distributions of seat position and seat back angle on arrival were essentially unchanged during travel. The seat was positioned full-rear on the seat track about 23% of the time and rearward of the mid-track position in 92% of frames. The mean seat back angle was 25.4 degrees (standard deviation 6.4 degrees); seat back angle was greater than 30 degrees in 15% of frames and greater than 35 degrees in less than 1% of frames.
This study is the first to report distributions of postures, seat positions, and seat back angles for front-seat passengers. Seat positions rearward of the middle of the seat adjustment range are common, but highly reclined postures are infrequent. Non-nominal torso and head postures also are nontrivial.
近期研究表明，碰撞伤害风险与驾乘人员姿势之间存在关联，尤其是与碰撞测试中使用的人体模型（ATD）姿势不同的姿势。本研究的目的是通过一项自然主义研究来增进对典型前排乘客姿势的科学理解。
在75名驾驶员的车辆客舱内安装了摄像机。在安装仪器期间，将反光目标附着在座椅上，并将座椅位置和座椅靠背角度在其可用范围内移动。在车主照常驾驶车辆两周后，下载视频数据以及车辆加速度和位置数据。对视频帧进行人工编码，以识别前排乘客姿势和位置的特征。使用车辆安装仪器期间获得的校准数据估计座椅位置和座椅靠背角度。
对总共2733次行程的视频帧进行了编码，涉及306名不同的前排乘客。对于这些行程，总共编码了13638帧；每帧代表大约4分钟的行驶时间。在33%的帧中，头部向左或向右转；在约10%的时间里，躯干向左或向右转，在近10%的帧中向前倾斜。在40辆（53%）车辆中未观察到座椅位置或座椅靠背角度变化，并且行驶过程中到达时座椅位置和座椅靠背角度的分布基本不变。座椅在座椅轨道上处于完全后部位置的时间约为23%，在92%的帧中位于轨道中间位置之后。座椅靠背平均角度为25.4度（标准差6.4度）；在15%的帧中座椅靠背角度大于30度，在不到1%的帧中大于35度。
本研究首次报告了前排乘客的姿势、座椅位置和座椅靠背角度的分布情况。座椅位置在座椅调节范围中间之后很常见，但高度倾斜的姿势很少见。非标准的躯干和头部姿势也很常见。
