Research on a High-Sensitivity FBG Tilt Sensor With Vibration Suppression

To address the susceptibility of conventional fiber Bragg grating (FBG) tilt sensors to external vibrations and temperature interference, this paper proposes a high-sensitivity FBG tilt sensor with integrated vibration suppression. The sensor is based on a flexible hinge structure and employs a non-contact magnetic damping mechanism to enhance vibration resistance. Additionally, it achieves high sensitivity and temperature compensation through a self-differential compensation method. First, a theoretical model of the sensor is derived based on dynamic response equations. Then, static structural optimization is performed using finite element analysis (FEA) to determine the optimal structural parameters. A coupled magnetic-mechanical field simulation is also conducted to validate the feasibility of vibration suppression using the magnetic damping mechanism. Based on the optimized parameters, the sensor is fabricated and packaged, followed by comprehensive performance testing. Experimental results show that within a tilt range of ±5°, the sensor achieves a sensitivity of 248.4 pm/°, a linearity coefficient of 0.9993, and a repeatability error of less than 1.716%. The differential FBG configuration effectively eliminates temperature induced errors in tilt measurement. Furthermore, vibration tests confirm that the magnetic damping mechanism significantly reduces measurement errors caused by external random vibrations. In summary, the FBG tilt sensor proposed in this study achieves vibration suppression and temperature compensation while maintaining high tilt measurement sensitivity, thereby enhancing the environmental adaptability of the tilt sensor and broadening its application scenarios.