佩戴瞄准具头盔的人体振动响应和目标跟踪能力

目的研究振动条件下佩戴瞄准具头盔时,头和头盔的共振频率,共振频率点的正弦振动以及随机振动对头盔稳定性和目标跟踪能力的影响,为飞行头盔的设计和使用提供依据。方法选取被试6人,体检合格,佩戴适体的头盔。头盔上安装瞄准具或激光器。受试者坐在弹射座椅上,座椅刚性固定在振动台上。在振动台、座椅、头、头盔上分别固定安装加速度传感器。拉杆式线性位移传感器固定在面部,拉出端连接在头盔上。受试者的前面有一显示器,显示器上有一运动着的目标。先进行正弦扫描振动试验,频率范围2~110 Hz,确定头和头盔的共振频率。然后在共振频率点进行正弦振动试验,受试者观察瞄准显示信息或进行目标跟踪,测量头盔位移。最后进行随机振动试验。结果头和头盔的共振频率4.5 Hz左右。头盔位移在0.5~6.7 mm之间,振幅对头盔的位移有较大影响。振动对目标跟踪误差和有效跟踪时间有非常显著性影响。结论佩戴头盔后,人体头部仍为低频响应;振动对目标跟踪能力有显著性影响。

The Human-body Response and Target Tracking Performance with Sighting Helmet in Vibration Conditions

Objective To determine the resonance frequencies of head with sighting helmet in vibration con- ditions, and measure the displacement of helmet slippage from head, and investigate the target tracking perfor- mance, so as to provide basis for the design and use of helmet. Method 6 healthy volunteers who sit in e- jection seat. The helmet was mounted with sighting device or laser pointer. The seat was firmly mounted on the platform of vibration machine. Accelerometers were firmly mounted on the platform, seat, head and helmet. One end of a linear displacement transducer was firmly mounted on the face and the other end linked with helmet. There was a screen in the front of volunteer. In the screen there was a moving target. The sine scan vibration test was taken first to determine the resonance frequencies of head and helmet. The scan bandwidth was 2~110 Hz. Then, the sine vibration at the resonance frequency tests were taken to measure the displace- ment of helmet and the target tracking performance. Finally, the random vibration was tested. Result The res- onance frequency of head and helmet is about 4.5 Hz.The displacement of helmet is from 0.5mmto 6.7mm, apparently affected by the vibration amplitude. The tracking errors and time-on- target （TOT） are affected by vibrations significantly. Conclusion The low frequency resonance of head with helmet has been keeping. The tracking performance is affected by vibrations significantly.