Design and test of a FBG acceleration sensor based on multi-stage flexible hinges

Area of Science:

• Engineering Technology
• Sensor Development
• Optical Sensing

Background:

• High-precision and high-sensitivity vibration acceleration sensors are crucial for engineering structural health monitoring, seismic activity detection, and geological exploration.
• Existing fiber Bragg grating (FBG) acceleration sensors often suffer from limitations in sensitivity and resistance to transverse interference.
• There is a continuous need for advanced sensor technologies to improve the accuracy and reliability of vibration measurements.

Purpose of the Study:

• To propose and develop a novel fiber Bragg grating (FBG) acceleration sensor with enhanced sensitivity and transverse interference resistance.
• To address the limitations of current FBG acceleration sensors for high-precision vibration measurement.
• To provide a new approach for vibration sensing in demanding engineering applications.

Main Methods:

• Design and theoretical modeling of an FBG acceleration sensor incorporating a mass block and a multi-stage flexible hinge.
• Optimization of the sensor's structural parameters through theoretical analysis.
• Fabrication of actual sensor prototypes and experimental performance testing.
• Analysis of sensor performance including natural frequency, frequency response, sensitivity, linearity, and transverse interference.

Main Results:

• The developed FBG acceleration sensor demonstrated a high natural frequency of 1400 Hz.
• A flat frequency response was observed in the range of 50-800 Hz.
• The sensor achieved a sensitivity of 18.4 pm/g with excellent linearity (R² = 0.9983).
• Transverse interference was effectively minimized, remaining below 3.2%.

Conclusions:

• The novel FBG acceleration sensor design significantly improves sensitivity and transverse interference immunity compared to existing sensors.
• The sensor's performance characteristics make it suitable for high-precision vibration measurement in various engineering fields.
• This research offers a promising new direction for the development of advanced vibration sensing technologies.