Quaternion-based Complementary Filter for Aiding in the Self-Alignment of the MEMS IMU

Herein, an effective self-alignment method for MEMS IMUs (MIMUs) on swing bases is proposed. The self-alignment of MIMUs is generally considered impossible, and other sensors are often necessary to provide initial heading information. In addition, the traditional north-seeking algorithm is no longer applicable for MIMUs on swing bases. This study proposes continuous rotation of the MIMU in the horizontal plane, which is referred to as carouseling to suppress the bias effect on the heading error, and then the use of quaternion-based complementary filtering and inertial space gravity-based alignment to achieve the self-alignment of the MIMU on the swing base. The of pitch, roll, and heading obtained using this approach were 0.006°, 0.004°, and 0.84°, respectively, verifying the effectiveness of this method.