School of Physics and Optoelectronic Engineering, Xidian University, Xi'an 710071, China.
Shandong Institute of Space Electronic Technology, Yantai 264670, China.
Sensors (Basel). 2018 Jun 5;18(6):1834. doi: 10.3390/s18061834.
The Chinese space station is designed to carry out manned spaceflight, space science research, and so on. In serious applications, it is a common operation to inject gas into the hull, which can produce strain of the bulkhead. Accurate measurement of strain for the bulkhead is one of the key tasks in evaluating the health condition of the space station. This is the first work to perform strain detection for the Chinese space station bulkhead by using optical fiber Bragg grating. In the period of measurements, the resistance strain gauge is used as the strain standard. The measurement error of the fiber optical sensor in the circumferential direction is very small, being less than 4.52 με. However, the error in the axial direction is very large with the highest value of 28.93 με. Because the measurement error of bare fiber in the axial direction is very small, the transverse effect of the substrate of the fiber optical sensor likely plays a role. The comparison of the theoretical and experimental results of the transverse effect coefficients shows that they are fairly consistent, with values of 0.0271 and 0.0287, respectively. After the transverse effect is compensated, the strain deviation in the axial detection is smaller than 2.04 με. It is of great significance to carry out real-time health assessment for the bulkhead of the space station.
中国空间站旨在进行载人航天、空间科学研究等。在严重的应用中，向舱体注入气体是一种常见的操作，这会产生舱壁的应变。准确测量舱壁的应变是评估空间站健康状况的关键任务之一。这是首次使用光纤布拉格光栅对中国空间站舱壁进行应变检测。在测量期间，电阻应变计被用作应变标准。光纤传感器在周向方向的测量误差非常小，小于 4.52 με。然而，轴向方向的误差非常大，最大值为 28.93 με。由于光纤在轴向方向的测量误差非常小，光纤传感器基底的横向效应可能起作用。横向效应系数的理论和实验结果的比较表明，它们非常一致，分别为 0.0271 和 0.0287。横向效应补偿后，轴向检测的应变偏差小于 2.04 με。这对空间站舱壁的实时健康评估具有重要意义。
