Research on design technology of fiber optic fuel level sensor with novel structure

Traditional aircraft fuel level sensors, represented by capacitive fuel level sensors, have inherent shortcomings, making it difficult to meet the increasing aviation needs in terms of intrinsic safety and electromagnetic interference resistance. Therefore, this article studies the design technology of fiber optic fuel level sensors. By analyzing various optical fiber liquid level measurement methods, the fiber Bragg grating method that best meets practical needs is selected, and a novel and reasonable sensor structure design is achieved. Specifically, in order to improve the measurement accuracy, a lever-type sensitivity enhancing structure based on flexure hinge is studied in this paper. Combined with the metal diaphragm, it can generate higher axial strain on the fiber grating under a given liquid pressure. In order to ensure the practicality of the sensor, this paper analyzes the interference factors that may cause the measurement error in the actual fuel tank. Correspondingly, this paper proposes a design of fixed distance double measuring points to compensate the influence of posture, uses the reference fiber grating method to compensate the influence of temperature, and designs a reasonable assembly and sealing scheme. To verify the rationality of the design, the sensor test platform is built and the sensor function is tested comprehensively. The results show that the sensor has good precision and can achieve expected compensation effect.