Sensitivity Analysis of MEMS Accelerometer for the Vibration Measurement of VTOL UAV

The Vertical Take-Off and Landing (VTOL) UAV has attracted great attention due to the long flight time and convenient take-off and landing. VTOLs are utilized in various military and civilian applications. The malfunctioning in the VTOL’s thrust due to the motor fault will result in wear and tear and significant loss to the property and human. The vibration-based signals provided by the high-rate inertial measurement unit are widely used to monitor the structural health of UAVs. In this study, a 3-axis MEMS capacitive accelerometer is proposed for low-level vibration detection of the VTOL UAV rotor. We designed and analyzed a highly sensitive three-axis capacitive accelerometer by using Finite Element Modeling (FEM). The FEM results were validated with the analytical results. The analysis results revealed that the designed accelerometer has a resonant frequency of 8515.8Hz and a sensitivity of 3.27nm/g. Additionally, the miniature-size accelerometer has a minimal impact of accelerometer weight on the net weight of a VTOL UAV. Moreover, the design accelerometer is mechanically safe, and its high sensitivity enables it to detect very low amplitude or vibration produced within VTOL UAVs.