Research on a non-contact magnetically coupled vibration sensor of fiber grating

Real-time monitoring of vibration status is essential to ensure the safe operation of major and precision mechanical equipment. However, vibration sensors based on traditional electromagnetic signal principles are often difficult to withstand harsh environments, and signal transmission can be unstable. In view of this, a non-contact magnetically coupled vibration sensor based on Fiber Bragg Grating (FBG) technology was developed. The sensor adopts a new design, combines the classic permanent magnet and diaphragm, and introduces a lever hinge structure, and proposes a sensing mechanism connected to the diaphragm and the lever hinge, and realizes the amplification effect of displacement through the lever action. The working principle of the sensor is described in detail, simulation analysis is carried out, and its performance is verified by experiments. After relevant experiments, it is obtained: (1) amplitude range: 1.0mm-2.2mm (2) sensitivity: −83pm/mm (3) linear fitting correlation coefficient: 0.97 (4) working frequency band: 0-3400Hz (5) resonant frequency: 3750Hz. Such sensors show great potential for fault detection and health monitoring in large-scale precision machinery.