Modeling and improvement of a low-frequency micro-accelerometer

Abstract

A sensitivity- and resolution-improving method for a low-frequency micro-vibration accelerometer is presented in this paper. A sensitivity model of the measurement system is derived and established. The key parameters that limit the sensitivity and the resolution of the accelerometer were identified through the sensitivity coefficient analysis method. The structural parameters and the signal process method were then optimized. Experimental results show that the sensitivity of the accelerometer has improved from 1.10 V/(m/s2) to 19.21 V/(m/s2), and the resolution has improved from 1.47 mm/s2 to 0.21 mm/s2. The lowest working frequency range has expanded from 1 Hz to 0.7 Hz. The presented method is effective and cheap and can be applied to other sensors.

Optical Accelerometers for Detecting Low-Frequency Micro-Vibrations

“…Therefore, Li et al designed an accelerometer with a fully symmetric leaf spring (as shown in Figure 4); it has a resolution of 0.3 mg and measurement uncertainty as low as 0.07 mg (K = 2) [22]. To improve the sensitivity of optical accelerometers, Cheng et al modeled an optical accelerometer by using sensitivity analysis and improved its sensing optical path to achieve a resolution as low as 4 µg [23].…”

“…The resonant frequency in the x and y directions of a cantile vered beam is not significantly greater than the resonant frequency in the z-direction, and vibrations in the x and y directions exert a greater effect on the output of the accelerometer Therefore, Li et al designed an accelerometer with a fully symmetric leaf spring (as shown in Figure 4); it has a resolution of 0.3 mg and measurement uncertainty as low as 0.07 mg (K = 2) [22]. To improve the sensitivity of optical accelerometers, Cheng et al modeled an opti cal accelerometer by using sensitivity analysis and improved its sensing optical path to achieve a resolution as low as 4 µg [23].…”

“…In summary, optical accelerometers based on optical path modulation are characterized by a simple structure and convenient signal processing; high sensitivity can be achieved by optimizing the mechanical [22] or optical sensing units [23]. However, the measurement accuracy of this type of optical accelerometer is directly related to the structure of the optical path and the performance of the photodetector.…”