Initial Investigation of Physically Tightly-Coupled Single-Chip MEMS IMU for Mutual Compensation of Two Differential Resonant Accelerometers and a Mode-Matched Donut-Mass Gyroscope

In this study, we report an initial study on mutual compensation between a differential resonant accelerometer (DRA) and a donut-mass gyroscope (DMG). High-precision inertial measurement units (IMUs) require compensation for temperature drift and multi-axis sensitivity in addition to the development of high-precision sensors. One effective means for achieving this is to integrate each sensor into a single chip. DRAs are suitable for IMUs because they can separate the main sensitivity acceleration and temperature drift components from the resonance frequencies of the two beams. We developed the first single-chip that integrates two DRAs with XY-axis sensitivity and a high-precision DMG capable of acquiring Z-axis angular velocity and conducted an initial evaluation using a microcontroller-based module. We demonstrated linear operation of the DMG by applying angular velocities of +1, 5, 10, and 50 deg/s, and found high agreement (
$\mathrm{R}^{2}=0.9826,\ 0.9965$
) with the frequencies of DMG and DRA corrected for multi-axis sensitivity of the DRA when ±1 G acceleration was applied in the X, Y, and Z-axes.