Simultaneous Implementation of the High Reliability and Accuracy in a Fiber Bragg Grating Sensing System for Space Application

The complex space environment puts forward more stringent requirements for the reliability and accuracy of sensors and instrumentation. In this article, a dual light source multiplexing fiber Bragg grating (FBG) sensing system with high reliability and accuracy for space application is proposed. The proposed FBG sensing system has two independently driven light sources, which emit scanning laser light into the FBG sensors. The proposed system eliminates single-point failures (SPOF) compared with other system configurations. The five-year single channel reliability and the five-year all channels reliability are 0.9802 and 0.9349 respectively, which are the highest among the five systems. The reliability of the proposed system is improved by 14.1% compared with the common commercial FBG sensing system. Moreover, the experimental systems were established and two FBGs were tested six times on a constant temperature heating stage. The average coefficient of determination (COD)
$R^{2}$
of FBG1 and FBG2 are 0.9112 and 0.9058 in the proposed system, which are 4.9% and 8.4% higher than those in the common commercial FBG sensing system owing to higher wavelength resolution. Therefore, the proposed dual light sources multiplexing FBG sensing system will provide higher reliability and accuracy performance in space applications.