An FBG Sensor Placement Method to Achieve Long Fatigue Life and High Measurement Accuracy in Deformation Sensing of Satellite Solar Panels

Sensing the deformation of the satellite solar panel is significant to the satellite health monitoring in the harsh space environment. The fiber Bragg grating (FBG) sensor with the advantages of small size, easy to connect in series, and high electromagnetic immunity is one of the ideal sensors. In this article, an FBG sensor placement method to achieve long fatigue life and high measurement accuracy is proposed. A finite-element analysis (FEA) model of the satellite solar panel is developed and the FEA results of the strain field, the stress field, and the displacement field are used in the proposed method. By virtue of the multiobjective simulated annealing (MOSA) algorithm, all optimal placements of FBG sensors on the Pareto front can be obtained. Point P1 (0.0319, 31.7744) and point P2 (0.0166, 18.4765) at the top and bottom of the Pareto front, respectively, have the optimal average number of fatigue cycles and the optimal measurement accuracy. Point P3 (0.0306, 20.8603) on the Pareto front has relatively excellent performance in both the fatigue life and the measurement accuracy. A deformation sensing experimental system with a satellite solar panel and nine FBG sensors was established. Eight FBG sensors are used to measure the strain, and one FBG sensor is used to compensate the temperature-induced error. The trend of experimental results coincides with the simulation results. Thus, the proposed method provides an effective approach to achieve high-reliable and high-accuracy FBG sensor's placement.