A Fiber Bragg Grating based Accelerometer for Monitoring the Vibration of an Industrial Engine Prototype: A Preliminary Study

Monitoring the vibration of industrial engines is essential for running diagnostics that can detect faults and point out the feasibility of predictive maintenance. Therefore, this paper describes an optical accelerometer based on a fiber Bragg grating to monitor the vibration of the gearbox of an industrial engine prototype. Experimental tests were performed varying the motor’s rotation speed during normal operation. To validate the proposed system, two electronic accelerometers were attached to the motor’s gearbox and bearing. The natural frequency response of the optical accelerometer was simulated and good agreement with the experimental results was obtained (0.83% of error). The proposed sensor was able to correctly identify the operation speeds of 20, 25, 35, 40, 45 and 50 rps with a maximum error of 0.05%. The mean signal-to-noise ratio (SNR) of the optical accelerometer was 64.05% higher than the SNR of one of the electronic solutions. The experimental results show that the vibration signals have different characteristics when measured at the bearings and at the gearbox, indicating the feasibility of multi-signals analysis for fault detection.