aInstitut de recherche Robert-Sauvé en santé et en sécurité du travail, 505 boul. de Maisonneuve West, Montreal, Quebec, H3A 3C2, Canada.
Ind Health. 2010;48(5):715-24. doi: 10.2486/indhealth.mswbvi-17.
Subway operators have complained about discomfort caused by whole-body vibration. To address this problem, a suspension seat with extensive ergonomic features has been adapted to the confined space of the subway operator cab. The suspension was modified from an existing suspension in order to reduce the dominant frequency of the subway vertical vibration (2.4 Hz). The suspension seat has been extensively tested on a vertical hydraulic shaker. These tests have shown that the SEAT value was lower for a higher vibration level, for higher subject weight, and for the suspension adjusted at median height. The seat also produces a lower SEAT value when there was a predominance of the 6 Hz vibration component. The horizontal seat adjustments had no influence on the suspension SEAT value. Removing the suspension damper also decreases the SEAT value for all the tested configurations. The final version of the suspension seat prototype was validated during normal subway operation with 19 different operators having weight in the 5th, 50th and 95th percentile of the operator population. Accelerations were measured with triaxial accelerometers at the seat cushion, above the suspension and on the floor. In addition to the vibration measurements, each operator was asked about his perceived discomfort from vibration exposure. Globally, the suspension seat attenuated the vertical vibration (SEAT values from 0.86 to 0.99), but discomfort due to amplification of the 2.4 Hz component occurred when the suspension height was adjusted at the minimum, even when the global weighted acceleration was lower (SEAT value < 1). These results suggest that in order to reduce the discomfort caused by whole-body vibration, the transmissibility of the seat should also be considered, in particular when there is a dominant frequency in the vibration spectra.
地铁运营商抱怨全身振动引起的不适。为了解决这个问题，一种具有广泛人体工程学特征的悬挂座椅已被应用于地铁司机驾驶室的有限空间。悬挂系统是为了降低地铁垂直振动的主导频率（2.4Hz）而从现有悬挂系统中修改而来的。悬挂座椅已在垂直液压振动台上进行了广泛测试。这些测试表明，在较高的振动水平、较高的受试者体重和悬挂在中等高度调整的情况下，SEAT 值较低。当 6Hz 振动分量占主导地位时，座椅也会产生较低的 SEAT 值。水平座椅调节对悬挂 SEAT 值没有影响。对于所有测试的配置，去除悬挂阻尼器也会降低 SEAT 值。最终版本的悬挂座椅原型在正常地铁运行中得到了验证，共有 19 名不同体重的运营商（体重处于运营商群体的第 5、50 和 95 百分位）进行了测试。加速度使用三轴加速度计在座椅垫、悬挂上方和地板上进行测量。除了振动测量，每个操作员还被问到他对振动暴露的感知不适。总体而言，悬挂座椅降低了垂直振动（SEAT 值从 0.86 到 0.99），但当悬挂高度调整到最低时，即使总加权加速度较低（SEAT 值<1），2.4Hz 分量的放大也会导致不适。这些结果表明，为了减少全身振动引起的不适，还应考虑座椅的传递率，特别是在振动频谱中有主导频率时。
