Analysis of Noise-Detection Characteristics of Electric Field Coupling in Quartz Flexible Accelerometer

Abstract

The internal electric field coupling noise of a quartz flexible accelerometer (QFA) restricts the improvement of the measurement accuracy of the accelerometer. In this paper, the internal electric field coupling mechanism of a QFA is studied, an electric field coupling detection noise model of the accelerometer is established, the distributed capacitance among the components of the QFA is simulated, the structure of the detection noise transfer system of different carrier modulation differential capacitance detection circuits is analyzed, and the influence of each transfer chain on the detection noise is discussed. The simulation results of electric field coupling detection noise show that the average value of detection noise can reach 41.7 μg, which is close to the effective resolution of the QFA, 50 μg. This confirms that electric field coupling detection noise is a non-negligible factor affecting the measurement accuracy of the accelerometer. A method of adding a high-pass filter to the front of the phase-shifting circuit is presented to suppress the noise of electric field coupling detection. This method attenuates the average value of the detected noise by about 78 dB, and reduces the average value of the detected noise to less than 0.1 μg, which provides a new approach and direction for effectively breaking through the performance of the QFA.

Study on the influence of pendulum convex plate on the partial value of quartz flexible accelerometer

“…The accelerometer exhibits issues such as poor long-term repeatability and complex operation during its use. Therefore, a significant amount of research has been conducted both domestically and internationally [2][3][4][5][6] , and the international mainstream quartz flexible accelerometer products include Honeywell's QA-3000-030 accelerometer and European Inna Labs' AI-Q-2030 accelerometer [7] . China started late in the development of quartz flexible accelerometers and lagged behind foreign countries in terms of structural design, materials, accuracy, range, and other aspects.…”

Study on driving noise of quartz flexible accelerometer torquer

“…When the QFA is working, electromagnetic coupling occurs between the torquer coil and the differential capacitance sensor, which results in bidirectional interference. Our previous studies have found that when the driving signal in the torque coil changes rapidly, electromagnetic radiation will be generated and coupled to the differential capacitor plate, which is transmitted to the differential capacitor detection circuit and affects the measurement accuracy of the QFA [25]. In fact, the high frequency voltage excitation signal in the differential capacitor detection circuit will also be transmitted to the torquer coil through electromagnetic radiation to form driving noise, but the related characteristics of driving noise are not clear.…”