Development of a High-Sensitivity Optical Accelerometer for Low-Frequency Vibration Measurement

Area of Science:

• Mechanical Engineering
• Instrumentation
• Optics

Background:

• Low-frequency vibrations degrade micro/nano-measuring machine accuracy.
• Passive vibration control methods are insufficient for complete elimination.
• Accurate measurement is crucial for active vibration suppression.

Purpose of the Study:

• To design a low-cost, high-sensitivity optical accelerometer.
• To enable precise measurement of low-frequency, low-amplitude vibrations.
• To verify the accelerometer's efficacy in dynamic response measurement.

Main Methods:

• Design of an optical accelerometer with seismic mass, leaf spring, and four-quadrant photodetector (QPD).
• Utilizing an optical lever to amplify displacement detected by the QPD.
• Simulation of seismic structures for optimal low-frequency detection.
• Calibration using a custom vibration calibration system.

Main Results:

• Sensitivity achieved: 1.74 V/(m·s⁻²).
• Measurement range: 0.003–7.29 m·s⁻².
• Operating frequency range: 0.4–12 Hz.
• Measurement standard deviation < 7.9 × 10⁻⁴ m·s⁻².

Conclusions:

• The proposed optical accelerometer is effective for measuring low-frequency, low-amplitude dynamic responses.
• The design offers a viable solution for mitigating vibration effects in precision machinery.
• The device demonstrates high sensitivity and a wide operating range for vibration analysis.