Near-Vertical Attitude Determination Based on Balance Correction

At the near-vertical position, the system error is a major factor lowering the attitude accuracy in the attitude determination system, and correction technology is often used to compensate all kinds of system errors. First, the absolute errors of the computed attitude angle including the measurement error and the correction error are analyzed, and the correction error caused by the correction matrix is emphatically derived and discussed. Then, a novel balance correction method with a non-unit correction matrix is proposed and verified theoretically. Finally, an inertial measurement unit (IMU) is tested for the near-vertical position and corrected with the conventional unit matrix and the proposed balance correction. The experimental results suggest that the balance correction under the near-vertical position can enhance the accuracies of the attitude angles over four times than those with the conventional correction.