Static Calibration of a New Three-Axis Fiber Bragg Grating-Based Optical Accelerometer

Area of Science:

• Engineering
• Materials Science
• Sensor Technology

Background:

• Optical sensors offer high sensitivity and electromagnetic immunity for structural health monitoring.
• Previous work introduced an interrogator-free Fiber Bragg Grating (FBG)-based accelerometer for autonomous applications.

Purpose of the Study:

• To present the characterization results of an improved autonomous optical accelerometer.
• To demonstrate enhanced precision and accuracy in structural monitoring applications.

Main Methods:

• Characterization of sensor axes orthogonality and electronic noise reduction.
• Development of a 12-parameter matrix calibration approach using the least-squares method.
• Implementation of a correction term table to enhance acceleration estimation accuracy.

Main Results:

• Achieved R² of 0.9999 in static characterization for X- and Y-axes.
• Demonstrated compensation for gain, offset, and cross-axis sensitivity.
• Reported zero mean error and a maximum standard deviation of 0.018 m/s² for acceleration components.
• Attained a maximum RMSE of 6.7 × 10⁻³ m/s² across tested positions.

Conclusions:

• The enhanced optical accelerometer provides high precision and accuracy for structural health monitoring.
• The developed calibration method effectively compensates for sensor imperfections.
• This autonomous device is suitable for detecting subtle structural changes and dynamic motions.