Feasibility of frequency-modulated wireless transmission for a multi-purpose MEMS-based accelerometer

Area of Science:

• Engineering
• Materials Science
• Sensor Technology

Background:

• Micro Electro-Mechanical System (MEMS) accelerometers are valuable for Structural Health Monitoring (SHM) of civil structures.
• Current MEMS accelerometers face limitations in sensitivity and accuracy at low frequencies, hindering their use in large structures.
• Conventional analog-to-digital conversion (ADC) for wireless transmission can attenuate critical low-frequency, low-amplitude signals.

Purpose of the Study:

• To develop an improved wireless MEMS accelerometer system for enhanced detection of low-frequency and low-amplitude dynamic responses.
• To overcome the sensitivity limitations of conventional MEMS accelerometers in Structural Health Monitoring applications.
• To present a prototype system utilizing voltage-to-frequency conversion for more effective signal transmission.

Main Methods:

• Developed a novel MEMS accelerometer system employing Voltage to Frequency (V/F) conversion instead of traditional Analog to Digital Conversion (ADC).
• Designed and constructed a prototype system comprising transmitter and receiver circuit boards.
• Integrated a MEMS accelerometer, V/F converter, and RF transmitter on the transmitter board; RF receiver and Frequency to Voltage (F/V) converter on the receiver board.

Main Results:

• The developed MEMS accelerometer system effectively converts sensor output voltage to a frequency-modulated signal for wireless transmission.
• Laboratory tests and experiments on a flow-loop pipeline demonstrated the system's efficacy in measuring low-frequency and low-amplitude dynamic responses.
• The V/F conversion method proved superior in preserving the integrity of subtle dynamic signals compared to conventional ADC.

Conclusions:

• The novel V/F-based wireless MEMS accelerometer system significantly enhances the capability for monitoring low-frequency and low-amplitude structural dynamics.
• This technology offers a promising solution for overcoming previous limitations in applying MEMS accelerometers to large-scale civil engineering structures.
• The prototype system validates the effectiveness of V/F conversion for accurate wireless sensing in Structural Health Monitoring.